WorldWideScience

Sample records for emplacement

  1. Emplacement engineering

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Ernest E [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-01

    Emplacement Engineering can be defined as that portion of a nuclear explosive project that is concerned with the emplacement of the explosive. This definition would then include virtually everything except the design and fabrication of the explosive and the post-shot-effects program. For future commercial application, the post-shot-effects program will essentially disappear. This emplacement portion of a nuclear explosive project constitutes a large fraction of the total project cost, but it has largely been overshadowed by the explosive and explosive-effects portions. As we move into commercial applications. Emplacement Engineering must receive more attention from both industry and government. To place emplacement costs in their proper relationship with total projects costs, we have performed a study of commercial underground nuclear explosive applications such as gas stimulation. Although there are many intangibles in such a study, we have been able to at least obtain some feel for the relative fractional costs of the non-explosive costs compared with the explosive costs. This study involved estimating the cost elements for applications using a single explosive at 5,000 ft, 10,000 ft, and 15,000 ft. For each depth, the cost estimates were made for a range of emplacement hole and explosive diameters. Results of these estimates for explosive-related costs, hole-related costs, and total costs are shown for the three depths. Note that the explosive package outside diameter is assumed as 2 inches less than the hole (or casing) inside diameter for all cases. For the 5,000-ft application the explosive-related costs dominate, and of particular importance is the indicated diameter for minimum total cost which occurs at approximately a 17.5-in. hole (15.5-in. explosive). The hole-related costs are in 'the same range as the explosive-related costs for the 10,000-ft application. For this case, the minimum total cost occurs at approximately a 14-in. hole (12-in. explosive

  2. SUBSURFACE EMPLACEMENT TRANSPORTATION SYSTEM

    International Nuclear Information System (INIS)

    Wilson, T.; Novotny, R.

    1999-01-01

    The objective of this analysis is to identify issues and criteria that apply to the design of the Subsurface Emplacement Transportation System (SET). The SET consists of the track used by the waste package handling equipment, the conductors and related equipment used to supply electrical power to that equipment, and the instrumentation and controls used to monitor and operate those track and power supply systems. Major considerations of this analysis include: (1) Operational life of the SET; (2) Geometric constraints on the track layout; (3) Operating loads on the track; (4) Environmentally induced loads on the track; (5) Power supply (electrification) requirements; and (6) Instrumentation and control requirements. This analysis will provide the basis for development of the system description document (SDD) for the SET. This analysis also defines the interfaces that need to be considered in the design of the SET. These interfaces include, but are not limited to, the following: (1) Waste handling building; (2) Monitored Geologic Repository (MGR) surface site layout; (3) Waste Emplacement System (WES); (4) Waste Retrieval System (WRS); (5) Ground Control System (GCS); (6) Ex-Container System (XCS); (7) Subsurface Electrical Distribution System (SED); (8) MGR Operations Monitoring and Control System (OMC); (9) Subsurface Facility System (SFS); (10) Subsurface Fire Protection System (SFR); (11) Performance Confirmation Emplacement Drift Monitoring System (PCM); and (12) Backfill Emplacement System (BES)

  3. Solar energy emplacement developer

    Science.gov (United States)

    Mortensen, Michael; Sauls, Bob

    1991-01-01

    A preliminary design was developed for a Lunar Power System (LPS) composed of photovoltaic arrays and microwave reflectors fabricated from lunar materials. The LPS will collect solar energy on the surface of the Moon, transform it into microwave energy, and beam it back to Earth where it will be converted into usable energy. The Solar Energy Emplacement Developer (SEED) proposed will use a similar sort of solar energy collection and dispersement to power the systems that will construct the LPS.

  4. TRANSPORT AND EMPLACEMENT EQUIPMENT DESCRIPTIONS

    International Nuclear Information System (INIS)

    1997-01-01

    The objective and the scope of this document are to list and briefly describe the major mobile equipment necessary for waste package (WP) Transport and Emplacement in the proposed subsurface nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the equipment are explained and summarized in the individual subsections of this document. The Transport and Emplacement equipment described in this document consists of the following: (1) WP Transporter; (2) Reusable Rail Car; (3) Emplacement Gantry; (4) Gantry Carrier; and (5) Transport Locomotive

  5. Construction, emplacement, and retrievability (preclosure)

    International Nuclear Information System (INIS)

    McClain, W.

    1985-01-01

    Each of the three preclosure subgroups of the Construction, Emplacement, and Retrievability Working Group adopted a six-step approach to identify and assess current needs in geotechnical modeling and characterization. This approach may be summarized as follows: identify phenomena related to emplacement of high-level nuclear wastes, identify types of models which are required to calculate the phenomena, establish the input data needs for the models, assess the current availability of the models, assess the current status of documentation, verification, and validation of the models, and determine the adequacy of instrumentation and measurement techniques to (a) validate the models, where necessary, and (b) obtain input data for design. Systematic application of these six steps leads to the establishment of the research requirements for geotechnical modeling and characterization. A summary of modeling techniques which apply to the three subsequent sections on construction, emplacement, and retrievability is presented. Research needs, which apply to all preclosure activities, are summarized

  6. Elements of transport and emplacement system

    International Nuclear Information System (INIS)

    1981-02-01

    This report, undertaken to review proposals for transport, handling and emplacement of high-level radioactive wastes in an underground repository, appropriate to the U.K. context, falls under the headings: basic design concepts; waste block size and configuration; self-shielded or partially shielded blocks; concept of emplacement in long boreholes; concept of emplacement in short boreholes; concept of emplacement in tunnels; methods of emplacement; stages of disposal; repository access by adit, incline or shaft; handling techniques within repository; conventional and radiological safety; costs; areas for further research and development. (U.K.)

  7. Emplacement Gantry Gap Analysis Study

    International Nuclear Information System (INIS)

    Thornley, R.

    2005-01-01

    To date, the project has established important to safety (ITS) performance requirements for structures, systems, and components (SSCs) based on the identification and categorization of event sequences that may result in a radiological release. These performance requirements are defined within the ''Nuclear Safety Design Bases for License Application'' (NSDB) (BSC 2005 [DIRS 171512], Table A-11). Further, SSCs credited with performing safety functions are classified as ITS. In turn, assurance that these SSCs will perform as required is sought through the use of consensus codes and standards. This gap analysis is based on the design completed for license application only. Accordingly, identification of ITS SSCs beyond those defined within the NSDB are based on designs that may be subject to further development during detail design. Furthermore, several design alternatives may still be under consideration to satisfy certain safety functions, and final selection will not be determined until further design development has occurred. Therefore, for completeness, alternative designs currently under consideration will be discussed throughout this study. This gap analysis will evaluate each code and standard identified within the ''Emplacement Gantry ITS Standards Identification Study'' (BSC 2005 [DIRS 173586]) to ensure each ITS performance requirement is fully satisfied. When a performance requirement is not fully satisfied, a gap is highlighted. This study will identify requirements to supplement or augment the code or standard to meet performance requirements. Further, this gap analysis will identify nonstandard areas of the design that will be subject to a design development plan. Nonstandard components and nonstandard design configurations are defined as areas of the design that do not follow standard industry practices or codes and standards. Whereby, assurance that an SSC will perform as required may not be readily sought though the use of consensus standards. This

  8. Magma emplacement in 3D

    Science.gov (United States)

    Gorczyk, W.; Vogt, K.

    2017-12-01

    Magma intrusion is a major material transfer process in Earth's continental crust. Yet, the mechanical behavior of the intruding magma and its host are a matter of debate. In this study, we present a series of numerical thermo-mechanical experiments on mafic magma emplacement in 3D.In our model, we place the magmatic source region (40 km diameter) at the base of the mantle lithosphere and connect it to the crust by a 3 km wide channel, which may have evolved at early stages of magmatism during rapid ascent of hot magmatic fluids/melts. Our results demonstrate continental crustal response due to magma intrusion. We observe change in intrusion geometries between dikes, cone-sheets, sills, plutons, ponds, funnels, finger-shaped and stock-like intrusions as well as injection time. The rheology and temperature of the host-rock are the main controlling factors in the transition between these different modes of intrusion. Viscous deformation in the warm and deep crust favours host rock displacement and magma pools along the crust-mantle boundary forming deep-seated plutons or magma ponds in the lower to middle-crust. Brittle deformation in the cool and shallow crust induces cone-shaped fractures in the host rock and enables emplacement of finger- or stock-like intrusions at shallow or intermediate depth. A combination of viscous and brittle deformation forms funnel-shaped intrusions in the middle-crust. Low-density source magma results in T-shaped intrusions in cross-section with magma sheets at the surface.

  9. Ground Control for Emplacement Drifts for LA

    International Nuclear Information System (INIS)

    Y. Sun

    2004-01-01

    The purpose of this calculation is to analyze the stability of repository emplacement drifts during the preclosure period, and to provide a final ground support method for emplacement drifts for the License Application (LA). The scope of the work includes determination of input parameter values and loads, selection of appropriate process and methods for the calculation, application of selected methods, such as empirical or analytical, to the calculation, development and execution of numerical models, and evaluation of results. Results from this calculation are limited to use for design of the emplacement drifts and the final ground support system installed in these drifts. The design of non-emplacement openings and their ground support systems is covered in the ''Ground Control for Non-Emplacement Drifts for LA'' (BSC 2004c)

  10. Emplacement of Columbia River flood basalt

    Science.gov (United States)

    Reidel, Stephen P.

    1998-11-01

    Evidence is examined for the emplacement of the Umatilla, Wilbur Creek, and the Asotin Members of Columbia River Basalt Group. These flows erupted in the eastern part of the Columbia Plateau during the waning phases of volcanism. The Umatilla Member consists of two flows in the Lewiston basin area and southwestern Columbia Plateau. These flows mixed to form one flow in the central Columbia Plateau. The composition of the younger flow is preserved in the center and the composition of the older flow is at the top and bottom. There is a complete gradation between the two. Flows of the Wilbur Creek and Asotin Members erupted individually in the eastern Columbia Plateau and also mixed together in the central Columbia Plateau. Comparison of the emplacement patterns to intraflow structures and textures of the flows suggests that very little time elapsed between eruptions. In addition, the amount of crust that formed on the earlier flows prior to mixing also suggests rapid emplacement. Calculations of volumetric flow rates through constrictions in channels suggest emplacement times of weeks to months under fast laminar flow for all three members. A new model for the emplacement of Columbia River Basalt Group flows is proposed that suggests rapid eruption and emplacement for the main part of the flow and slower emplacement along the margins as the of the flow margin expands.

  11. Wire-rope emplacement of diagnostics systems

    International Nuclear Information System (INIS)

    Burden, W.L.

    1982-01-01

    The study reported here was initiated to determine if, with the Cable Downhole System (CDS) currently under development, there is an advantage to using continuous wire rope to lower the emplacement package to the bottom of the hole. A baseline design using two wire ropes as well as several alternatives are discussed in this report. It was concluded that the advantages of the wire-rope emplacement system do not justify the cost of converting to such a system, especially for LLNL's maximum emplacement package weights

  12. Waste package emplacement borehole option study

    International Nuclear Information System (INIS)

    Streeter, W.S.

    1992-03-01

    This study evaluates the cost and thermal effects of various waste package emplacement configurations that differ in emplacement orientation, number of containers per borehole, and standoff distance at the potential Yucca Mountain nuclear waste repository. In this study, eight additional alternatives to the vertical and horizontal orientation options presented in the Site Characterization Plan Conceptual Design Report are considered. Typical panel layout configurations based on thermal analysis of the waste and cost estimates for design and construction, operations, and closure and decommissioning were made for each emplacement option. For the thermal analysis average waste 10 years out of reactor and the SIM code were used to determine whether the various configurations temperatures would exceed the design criteria for temperature. This study does not make a recommendation for emplacement configuration, but does provide information for comparison of alternatives

  13. Effects of Fault Displacement on Emplacement Drifts

    International Nuclear Information System (INIS)

    Duan, F.

    2000-01-01

    The purpose of this analysis is to evaluate potential effects of fault displacement on emplacement drifts, including drip shields and waste packages emplaced in emplacement drifts. The output from this analysis not only provides data for the evaluation of long-term drift stability but also supports the Engineered Barrier System (EBS) process model report (PMR) and Disruptive Events Report currently under development. The primary scope of this analysis includes (1) examining fault displacement effects in terms of induced stresses and displacements in the rock mass surrounding an emplacement drift and (2 ) predicting fault displacement effects on the drip shield and waste package. The magnitude of the fault displacement analyzed in this analysis bounds the mean fault displacement corresponding to an annual frequency of exceedance of 10 -5 adopted for the preclosure period of the repository and also supports the postclosure performance assessment. This analysis is performed following the development plan prepared for analyzing effects of fault displacement on emplacement drifts (CRWMS M and O 2000). The analysis will begin with the identification and preparation of requirements, criteria, and inputs. A literature survey on accommodating fault displacements encountered in underground structures such as buried oil and gas pipelines will be conducted. For a given fault displacement, the least favorable scenario in term of the spatial relation of a fault to an emplacement drift is chosen, and the analysis is then performed analytically. Based on the analysis results, conclusions are made regarding the effects and consequences of fault displacement on emplacement drifts. Specifically, the analysis will discuss loads which can be induced by fault displacement on emplacement drifts, drip shield and/or waste packages during the time period of postclosure

  14. Ground Control for Emplacement Drifts for SR

    International Nuclear Information System (INIS)

    Y. Sun

    2000-01-01

    This analysis demonstrates that a satisfactory ground control system can be designed for the Yucca Mountain site, and provides the technical basis for the design of ground support systems to be used in repository emplacement and non-emplacement drifts. The repository ground support design was based on analytical methods using acquired computer codes, and focused on the final support systems. A literature review of case histories, including the lessons learned from the design and construction of the ESF, the studies on the seismic damages of underground openings, and the use of rock mass classification systems in the ground support design, was conducted (Sections 6.3.4 and 6.4). This review provided some basis for determining the inputs and methodologies used in this analysis. Stability of the supported and unsupported emplacement and non-emplacement drifts was evaluated in this analysis. The excavation effects (i.e., state of the stress change due to excavation), thermal effects (i.e., due to heat output from waste packages), and seismic effects (i.e., from potential earthquake events) were evaluated, and stress controlled modes of failure were examined for two in situ stress conditions (k 0 =0.3 and 1.0) using rock properties representing rock mass categories of 1 and 5. Variation of rock mass units such as the non-lithophysal (Tptpmn) and lithophysal (Tptpll) was considered in the analysis. The focus was on the non-lithophysal unit because this unit appears to be relatively weaker and has much smaller joint spacing. Therefore, the drift stability and ground support needs were considered to be controlled by the design for this rock unit. The ground support systems for both emplacement and non-emplacement drifts were incorporated into the models to assess their performance under in situ, thermal, and seismic loading conditions. Both continuum and discontinuum modeling approaches were employed in the analyses of the rock mass behavior and in the evaluation of the

  15. Automated emplacement and retrieval of hazardous waste

    International Nuclear Information System (INIS)

    Slocum, A.H.; Hou, W.M.

    1987-01-01

    The design of several dedicated machines to perform simple tasks often results in higher system reliability and efficiency than the design of a single, multifunctional machine. Similarly, a reliable system for emplacement and retrieval of nuclear waste can be realized if emplacement/retrieval operations are decomposed into a well-defined series of independent tasks. The basic methodology is to design a system that eliminates contact between the waste package and the vehicle in the event of machine failure. The disabled vehicle can then be withdrawn to a safe location, repaired, and set back to resume normal operation

  16. Longevity of Emplacement Drift Ground Support Materials

    International Nuclear Information System (INIS)

    D.H.Tang

    2001-01-01

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. REV 01 ICN 01 of this analysis is developed in accordance with AP-3.10Q, Analyses and Models, Revision 2, ICN 4, and prepared in accordance with the Technical Work Plan for Subsurface Design Section FY 01 Work Activities (CRWMS M and O 2001a). The objective of this analysis is to update the previous analysis (CRWMS M and O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M and O 2000b), the Monitored Geologic Repository Project Description Document, which is included in the Requirements and Criteria for Implementing a Repository Design that can be Operated Over a Range of Thermal Modes (BSC 2001), input information, and in environmental conditions, and to provide updated information on candidate ground support materials. Candidate materials for ground support are carbon steel and cement grout. Steel is mainly used for steel sets, lagging, channel, rock bolts, and wire mesh. Cement grout is only considered in the case of grouted rock bolts. Candidate materials for the emplacement drift invert are carbon steel and granular natural material. Materials are evaluated for the repository emplacement drift environment based on the updated thermal loading condition and waste package design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground support materials for use in emplacement drifts. (2) Review existing documents concerning the behavior of candidate ground support materials during the preclosure period. (3) Evaluate impacts of temperature and radiation effects on mechanical and thermal properties of steel. Assess corrosion potential of steel at emplacement drift environment. (4

  17. Emplacement of small and large buffer blocks

    International Nuclear Information System (INIS)

    Saari, H.; Nikula, M.; Suikki, M.

    2010-05-01

    The report describes emplacement of a buffer structure encircling a spent fuel canister to be deposited in a vertical hole. The report deals with installability of various size blocks and with an emplacement gear, as well as evaluates the achieved quality of emplacement and the time needed for installing the buffer. Two block assembly of unequal size were chosen for examination. A first option involved small blocks, the use of which resulted in a buffer structure consisting of small sector blocks 200 mm in height. A second option involved large blocks, resulting in a buffer structure which consists of eight blocks. In these tests, the material chosen for both block options was concrete instead of bentonite. The emplacement test was a three-phase process. A first phase included stacking a two meter high buffer structure with small blocks for ensuring the operation of test equipment and blocks. A second phase included installing buffer structures with both block options to a height matching that of a canister-encircling cylindrical component. A third phase included testing also the installability of blocks to be placed above the canister by using small blocks. In emplacement tests, special attention was paid to the installability of blocks as well as to the time required for emplacement. Lifters for both blocks worked well. Due to the mass to be lifted, the lifter for large blocks had a more heavy-duty frame structure (and other lifting gear). The employed lifters were suspended in the tests on a single steel wire rope. Stacking was managed with both block sizes at adequate precision and stacked-up towers were steady. The stacking of large blocks was considerably faster. Therefore it is probably that the overall handling of the large blocks will be more convenient at a final disposal site. From the standpoint of reliability in lifting, the small blocks were safer to install above the canister. In large blocks, there are strict shape-related requirements which are

  18. Cryovolcanic Emplacement of Domes on Europa

    Science.gov (United States)

    Quick, Lynnae C.; Glaze, Lori S.; Baloga, Stephen M.

    2016-01-01

    Here we explore the hypothesis that certain domes on Europa may have been produced by the extrusion of viscous cryolavas. A new mathematical method for the emplacement and relaxation of viscous lava domes is presented and applied to putative cryovolcanic domes on Europa. A similarity solution approach is applied to the governing equation for fluid flow in a cylindrical geometry, and dome relaxation is explored assuming a volume of cryolava has been rapidly emplaced onto the surface. Nonphysical sin- gularities inherent in previous models for dome relaxation have been eliminated, and cryolava cooling is represented by a time-variable viscosity. We find that at the onset of relaxation, bulk kinematic viscosities may lie in the range between 10(exp 3) and 10(exp 6) sq m/s, while the actual fluid lava viscosity may be much lower. Plausible relaxation times to form the domes, which are linked to bulk cryolava rheology, are found to range from 3.6 days to 7.5 years. We find that cooling of the cryolava, while dominated by conduction through an icy skin, should not prevent fluids from advancing and relaxing to form domes within the timescales considered. Determining the range of emplacement conditions for putative cryolava domes will shed light on Europa's resurfacing history. In addition, the rheologies and compositions of erupted cryolavas have implications for subsurface cryomagma ascent and local surface stress conditions on Europa.

  19. Longevity of Emplacement Drift Ground Support Materials

    International Nuclear Information System (INIS)

    Tang, D.

    2000-01-01

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for selection of materials for ground support that will function throughout the preclosure period. The Development Plan (DP) for this analysis is given in CRWMS M and O (Civilian Radioactive Waste Management System Management and Operating Contractor) (1999a). The candidate materials for ground support are steel (carbon steel, ductile cast iron, galvanized steel, and stainless steel, etc.) and cement. Steel will mainly be used for steel sets, lagging, channels, rock bolts, and wire mesh. Cement usage is only considered in the case of grouted rock bolts. The candidate materials for the invert structure are steel and crushed rock ballast. The materials shall be evaluated for the repository emplacement drift environment under a specific thermal loading condition based on the proposed License Application Design Selection (LADS) design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground control materials for use in emplacement drifts. (2) Review existing documents concerning behavior of candidate ground control materials during the preclosure period. The major criteria to be considered for steel are mechanical and thermal properties, and durability, of which corrosion is the most important concern. (3) Evaluate the available results and develop recommendations for material(s) to be used

  20. TBV 361 RESOLUTION ANALYSIS: EMPLACEMENT DRIFT ORIENTATION

    International Nuclear Information System (INIS)

    Lin, M.; Kicker, D.C.; Sellers, M.D.

    1999-01-01

    The purpose of this To Be Verified/To Be Determined (TBX) resolution analysis is to release ''To Be Verified'' (TBV)-361 related to the emplacement drift orientation. The system design criterion in ''Subsurface Facility System Description Document'' (CRWMS M andO 1998a, p.9) specifies that the emplacement drift orientation relative to the dominant joint orientations should be at least 30 degrees. The specific objectives for this analysis include the following: (1) Collect and evaluate key block data developed for the repository host horizon rock mass. (2) Assess the dominant joint orientations based on available fracture data. (3) Document the maximum block size as a function of drift orientation. (4) Assess the applicability of the drift orientation/joint orientation offset criterion in the ''Subsurface Facility System Description Document'' (CRWMS M andO 1998a, p.9). (5) Consider the effects of seepage on drift orientation. (6) Verify that the viability assessment (VA) drift orientation complies with the drift orientation/joint orientation offset criterion, or provide justifications and make recommendations for modifying the VA emplacement drift layout. In addition to providing direct support to the System Description Document (SDD), the release of TBV-361 will provide support to the Repository Subsurface Design Department. The results from this activity may also provide data and information needs to support the MGR Requirements Department, the MGR Safety Assurance Department, and the Performance Assessment Organization

  1. Performance implications of waste package emplacement orientation

    International Nuclear Information System (INIS)

    Wilder, D.G.

    1991-05-01

    Emplacement borehole orientation directly impacts many aspects of the Engineered Barrier System (EBS) and interactions with the near field environment. This paper considers the impacts of orientation on the hydrologic portion of the environment and its interactions with the EBS. The hydrologic environment is considered from a conceptual standpoint, the numerical analyses are left for subsequent work. As reported in this paper, several aspects of the hydrological environment are more favorable for long term performance of vertically oriented rather than horizontally oriented Waste Packages. 19 refs., 15 figs

  2. EMPLACEMENT GANTRY ITS STANDARDS IDENTIFICATION STUDY

    International Nuclear Information System (INIS)

    Voegele, M.

    2005-01-01

    To date, the project has established ITS performance requirements for SSCs based on identification and categorization of event sequences that may result in a radiological release. These performance requirements are defined within the NSDB. Further, SSCs credited with performing safe functions are classified as ITS. In turn, perform confirmation for these SSCs is sought through the use of consensus code and standards. The purpose of this study is to identify applicable codes and standards for the WP Emplacement Gantry ITS SSCs. Further, this study will form the basis for selection and the extent of applicability of each code and standard. This study is based on the design development completed for LA only. Accordingly, identification of ITS SSCs beyond those defined within the NSDB are based on designs that may be subject to further development during detail design. Furthermore, several design alternatives may still be under consideration to satisfy certain safety functions, and that final selection will not be determined until further design development has occurred. Therefore, for completeness, throughout this study alternative designs currently under considered will be discussed. Further, the results of this study will be subject to evaluation as part of a follow-on GAP analysis study. Based on the results of this study the GAP analysis will evaluate each code and standard to ensure each ITS performance requirement is fully satisfied. When a performance requirement is not fully satisfied a ''gap'' is highlighted. Thereafter, the study will identify supplemental requirements to augment the code or standard to meet performance requirements. Further, the GAP analysis will identify non-standard areas of the design that will be subject to a Development Plan. Non-standard components and non-standard design configurations are defined as areas of the design that do not follow standard industry practices or codes and standards. Whereby, performance confirmation cannot be

  3. EMPLACEMENT DRIFT ISOLATION DOOR CONTROL SYSTEM

    International Nuclear Information System (INIS)

    N.T. Raczka

    1998-01-01

    The purpose of this analysis is to review and refine key design concepts related to the control system presently under consideration for remotely operating the emplacement drift isolation doors at the potential subsurface nuclear waste repository at Yucca Mountain. This analysis will discuss the key design concepts of the control system that may be utilized for remotely monitoring, opening, and closing the emplacement drift isolation doors. The scope and primary objectives of this analysis are to: (1) Discuss the purpose and function of the isolation doors (Presented in Section 7.1). (2) Review the construction of the isolation door and other physical characteristics of the doors that the control system will interface with (Presented in Section 7.2). (3) Discuss monitoring and controlling the operation of the isolation doors with a digital control system (either a Programmable Logic Controller (PLC) system or a Distributed Control System (DCS)) (Presented in Section 7.3). (4) Discuss how all isolation doors can be monitored and controlled from a subsurface central control center (Presented in Section 7.4). This analysis will focus on the development of input/output (I/O) counts including the types of I/O, redundancy and fault tolerance considerations, and processor requirements for the isolation door control system. Attention will be placed on operability, maintainability, and reliability issues for the system operating in the subsurface environment with exposure to high temperatures and radiation

  4. Deep Borehole Emplacement Mode Hazard Analysis Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Sevougian, S. David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-08-07

    This letter report outlines a methodology and provides resource information for the Deep Borehole Emplacement Mode Hazard Analysis (DBEMHA). The main purpose is identify the accident hazards and accident event sequences associated with the two emplacement mode options (wireline or drillstring), to outline a methodology for computing accident probabilities and frequencies, and to point to available databases on the nature and frequency of accidents typically associated with standard borehole drilling and nuclear handling operations. Risk mitigation and prevention measures, which have been incorporated into the two emplacement designs (see Cochran and Hardin 2015), are also discussed. A key intent of this report is to provide background information to brief subject matter experts involved in the Emplacement Mode Design Study. [Note: Revision 0 of this report is concentrated more on the wireline emplacement mode. It is expected that Revision 1 will contain further development of the preliminary fault and event trees for the drill string emplacement mode.

  5. Concept of Operations for Waste Transport, Emplacement, and Retrieval

    International Nuclear Information System (INIS)

    Raczka, Norman T.

    2001-01-01

    The preparation of this technical report has two objectives. The first objective is to discuss the base case concepts of waste transport, emplacement, and retrieval operations and evaluate these operations relative to a lower-temperature repository design. Aspects of the operations involved in waste transport, emplacement and retrieval may be affected by the lower-temperature operating schemes. This report evaluates the effects the lower-temperature alternatives may have on the operational concepts involved in emplacing and retrieving waste. The second objective is to provide backup material for the design description, in a traceable and defensible format, for Section 2 of the Waste Emplacement/Retrieval System Description Document

  6. WP EMPLACEMENT CONTROL AND COMMUNICATION EQUIPMENT DESCRIPTIONS

    International Nuclear Information System (INIS)

    Raczka, N.T.

    1997-01-01

    The objective and scope of this document are to list and briefly describe the major control and communication equipment necessary for waste package emplacement at the proposed nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the required equipment are explained and summarized in the individual subsections of this document. This task was evaluated in accordance with QAP-2-0 and found not to be quality affecting. Therefore, this document was prepared in accordance with NAP-MG-012. The following control and communication equipment are addressed in this document: (1) Programmable Logic Controllers (PLC's); (2) Leaky Feeder Radio Frequency Communication Equipment; (3) Slotted Microwave guide Communication Equipment; (4) Vision Systems; (5) Radio Control Equipment; and (6) Enclosure Cooling Systems

  7. Additive Construction with Mobile Emplacement (ACME)

    Science.gov (United States)

    Vickers, John

    2015-01-01

    The Additive Construction with Mobile Emplacement (ACME) project is developing technology to build structures on planetary surfaces using in-situ resources. The project focuses on the construction of both 2D (landing pads, roads, and structure foundations) and 3D (habitats, garages, radiation shelters, and other structures) infrastructure needs for planetary surface missions. The ACME project seeks to raise the Technology Readiness Level (TRL) of two components needed for planetary surface habitation and exploration: 3D additive construction (e.g., contour crafting), and excavation and handling technologies (to effectively and continuously produce in-situ feedstock). Additionally, the ACME project supports the research and development of new materials for planetary surface construction, with the goal of reducing the amount of material to be launched from Earth.

  8. Ground Control for Non-Emplacement Drifts for LA

    International Nuclear Information System (INIS)

    Tang, D.

    2004-01-01

    The purpose of this calculation is to analyze the stability of repository non-emplacement drifts during the preclosure period, and to provide a final ground support method for non-emplacement drifts for the License Application (LA). This calculation will provide input for the development of LA documents. The scope of this calculation is limited to the non-emplacement drifts including access mains, ramps, exhaust mains, turnouts, intersections between access mains and turnouts, and intersections between exhaust mains and emplacement drifts, portals, TBM launch chambers, observation drift and test alcove in the performance confirmation (PC) facilities, etc. The calculation is limited to the non-emplacement drifts subjected to a combined loading of in-situ stress, seismic stress, and/or thermal stress. Other effects such as hydrological and chemical effects are not considered in this analysis

  9. Relating rock avalanche morphology to emplacement processes

    Science.gov (United States)

    Dufresne, Anja; Prager, Christoph; Bösmeier, Annette

    2015-04-01

    The morphology, structure and sedimentological characteristics of rock avalanche deposits reflect both internal emplacement processes and external influences, such as runout path characteristics. The latter is mainly predisposed by topography, substrate types, and hydrogeological conditions. Additionally, the geological setting at the source slope controls, e.g. the spatial distribution of accumulated lithologies and hence material property-related changes in morphology, or the maximum clast size and amount of fines of different lithological units. The Holocene Tschirgant rock avalanche (Tyrol, Austria) resulted from failure of an intensely deformed carbonate rock mass on the southeast face of a 2,370-m-high mountain ridge. The initially sliding rock mass rapidly fragmented as it moved towards the floor of the Inn River valley. Part of the 200-250 x 106 m3 (Patzelt 2012) rock avalanche debris collided with and moved around an opposing bedrock ridge and flowed into the Ötz valley, reaching up to 6.3 km from source. Where the Tschirgant rock avalanche spread freely it formed longitudinal ridges aligned along motion direction as well as smaller hummocks. Encountering high topography, it left runup ridges, fallback patterns (i.e. secondary collapse), and compressional morphology (successively elevated, transverse ridges). Further evidence for the mechanical landslide behaviour is given by large volumes of mobilized valley-fill sediments (polymict gravels and sands). These sediments indicate both shearing and compressional faulting within the rock avalanche mass (forming their own morphological units through, e.g. in situ bulldozing or as distinctly different hummocky terrain), but also indicate extension of the spreading landslide mass (i.e. intercalated/injected gravels encountered mainly in morphological depressions between hummocks). Further influences on its morphology are given by the different lithological units. E.g. the transition from massive dolomite

  10. Review of potential subsurface permeable barrier emplacement and monitoring technologies

    International Nuclear Information System (INIS)

    Riggsbee, W.H.; Treat, R.L.; Stansfield, H.J.; Schwarz, R.M.; Cantrell, K.J.; Phillips, S.J.

    1994-02-01

    This report focuses on subsurface permeable barrier technologies potentially applicable to existing waste disposal sites. This report describes candidate subsurface permeable barriers, methods for emplacing these barriers, and methods used to monitor the barrier performance. Two types of subsurface barrier systems are described: those that apply to contamination.in the unsaturated zone, and those that apply to groundwater and to mobile contamination near the groundwater table. These barriers may be emplaced either horizontally or vertically depending on waste and site characteristics. Materials for creating permeable subsurface barriers are emplaced using one of three basic methods: injection, in situ mechanical mixing, or excavation-insertion. Injection is the emplacement of dissolved reagents or colloidal suspensions into the soil at elevated pressures. In situ mechanical mixing is the physical blending of the soil and the barrier material underground. Excavation-insertion is the removal of a soil volume and adding barrier materials to the space created. Major vertical barrier emplacement technologies include trenching-backfilling; slurry trenching; and vertical drilling and injection, including boring (earth augering), cable tool drilling, rotary drilling, sonic drilling, jetting methods, injection-mixing in drilled holes, and deep soil mixing. Major horizontal barrier emplacement technologies include horizontal drilling, microtunneling, compaction boring, horizontal emplacement, longwall mining, hydraulic fracturing, and jetting methods

  11. Nornahraun lava morphology and mode of emplacement

    Science.gov (United States)

    Pedersen, Gro B. M.; Höskuldsson, Armann; Riishuus, Morten S.; Jónsdóttir, Ingibjörg; Gudmundsson, Magnús T.; Sigmundsson, Freysteinn; Óskarsson, Birgir V.; Drouin, Vincent; Gallagher, Catherine; Askew, Rob; Moreland, William M.; Dürig, Tobias; Dumont, Stephanie; Þórdarson, Þór

    2015-04-01

    The ongoing Nornahraun eruption is the largest effusive eruption in Iceland since the Laki eruption in 1783-84, with an estimated lava volume of ~1.15 km3 covering an area of ~83.4 km2 (as of 5 JAN 2015). The eruption provides an unprecedented opportunity to study i) lava morphologies and their emplacement styles, ii) the transition from from open to closed lava pathways and iii) lava pond formation. Tracking of the lava advancement and morphology has been performed by GPS and GoPro cameras installed in 4×4 vehicles as well as video footage. Complimentary observations have been provided from aircraft platforms and by satellite data. Of particular importance for lava morphology observations are 1-12 m/pixel airborne SAR images (x-band). The Nornahraun flow field comprises a continuum of morphologies from pāhoehoe to 'a'ā, which have varied tem-porally and spatially. At the onset of the eruption 31 AUG, lava flows advanced rapidly (400-800 m/hr) from the 1.5 km long fissure as large slabby pāhoehoe [1-3] sheet lobes, 100-500 m wide and 0.3-1 m thick at the flow fronts. By 1 SEPT, the flows began channeling towards the NE constrained by the older Holuhraun I lava field and the to-pography of flood plain itself. A central open channel developed, feeding a 1-2 km wide active 'a'ā frontal lobe that advanced 1-2 km/day. In addition to its own caterpillar motion, the frontal lobe advanced in a series of 30-50 m long breakouts, predominantly slabby and rubbly pāhoehoe [4,5]. These breakouts had initial velocities of 10-30 m/hr and reached their full length within tens of minutes and subsequently inflated over hours. With the continuous advancement of the 'a'ā flow front, the breakouts were incorporated into the 'a'ā flow fronts and seldom preserved. At the margins of the frontal lava lobe, the breakouts were more sporadic, but predominantly rubbly pāhoehoe and slabby pāhoehoe, as at the flow front. The lava flow advanced ENE into Jökulsá á Fjöllum on 7 SEPT

  12. Rootless tephra stratigraphy and emplacement processes

    Science.gov (United States)

    Hamilton, Christopher W.; Fitch, Erin P.; Fagents, Sarah A.; Thordarson, Thorvaldur

    2017-01-01

    Volcanic rootless cones are the products of thermohydraulic explosions involving rapid heat transfer from active lava (fuel) to external sources of water (coolant). Rootless eruptions are attributed to molten fuel-coolant interactions (MFCIs), but previous studies have not performed systematic investigations of rootless tephrostratigraphy and grain-size distributions to establish a baseline for evaluating relationships between environmental factors, MFCI efficiency, fragmentation, and patterns of tephra dispersal. This study examines a 13.55-m-thick vertical section through an archetypal rootless tephra sequence, which includes a rhythmic succession of 28 bed pairs. Each bed pair is interpreted to be the result of a discrete explosion cycle, with fine-grained basal material emplaced dominantly as tephra fall during an energetic opening phase, followed by the deposition of coarser-grained material mainly as ballistic ejecta during a weaker coda phase. Nine additional layers are interleaved throughout the stratigraphy and are interpreted to be dilute pyroclastic density current (PDC) deposits. Overall, the stratigraphy divides into four units: unit 1 contains the largest number of sediment-rich PDC deposits, units 2 and 3 are dominated by a rhythmic succession of bed pairs, and unit 4 includes welded layers. This pattern is consistent with a general decrease in MFCI efficiency due to the depletion of locally available coolant (i.e., groundwater or wet sediments). Changing conduit/vent geometries, mixing conditions, coolant and melt temperatures, and/or coolant impurities may also have affected MFCI efficiency, but the rhythmic nature of the bed pairs implies a periodic explosion process, which can be explained by temporary increases in the water-to-lava mass ratio during cycles of groundwater recharge.

  13. Improvements relating to apparatus for emplacing or replacing a gaiter

    International Nuclear Information System (INIS)

    Chilvers, D.; Morrison, D.M.

    1982-01-01

    The invention relates to apparatus for emplacing or replacing a gaiter of the type which may be used in sealing the hot side of an isolation enclosure which is associated with a master-slave manipulator. (author)

  14. Longevity of Emplacement Drift Ground Support Materials, Rev. 01

    International Nuclear Information System (INIS)

    David H. Tang

    2000-01-01

    The purpose of this analysis is to evaluate the factors affecting the longevity of emplacement drift ground support materials and to develop a basis for the selection of materials for ground support that will function throughout the preclosure period of a potential repository at Yucca Mountain. The Development Plan (DP) for this analysis is given in Longevity of Emplacement Drift Ground Support Materials (CRWMS M and O 1999a). The objective of this analysis is to update the previous analysis (CRWMS M and O 2000a) to account for related changes in the Ground Control System Description Document (CRWMS M and O 2000b), the Monitored Geologic Repository Project Description Document (CRWMS M and O 1999b), and in environmental conditions, and to provide updated information on candidate ground support materials. Candidate materials for ground support are carbon steel and cement grout. Steel is mainly used for steel sets, lagging, channel, rock bolts, and wire mesh. Cement grout is only considered in the case of grouted rock bolts. Candidate materials for the emplacement drift invert are carbon steel and crushed rock ballast. Materials are evaluated for the repository emplacement drift environment based on the updated thermal loading condition and waste package design. The analysis consists of the following tasks: (1) Identify factors affecting the longevity of ground support materials for use in emplacement drifts; (2) Review existing documents concerning the behavior of candidate ground support materials during the preclosure period; (3) Evaluate impacts of temperature and radiation effects on mechanical and thermal properties of steel. Assess corrosion potential of steel at emplacement drift environment; (4) Evaluate factors affecting longevity of cement grouts for fully grouted rock bolt system. Provide updated information on cement grout mix design for fully grouted rock bolt system; and (5) Evaluate longevity of materials for the emplacement drift invert

  15. Emplacement and stemming of nuclear explosives for Plowshare applications

    International Nuclear Information System (INIS)

    Cramer, J.L.

    1970-01-01

    This paper will discuss the various methods used for emplacement and design considerations that must be taken into account when the emplacement and stemming method is selected. The step-by-step field procedure will not be discussed in this paper. The task of emplacing and stemming the nuclear explosive is common to all Plowshare experiments today. All present-day applications of a nuclear explosive for Plowshare experiments require that the detonation take place some distance below the surface of the ground. This is normally done by lowering the explosive into an emplacement hole to a desired depth and then backfilling the hole with a suitable stemming material. At first glance it scenes like a very straightforward, simple task to perform. It would appear to be a task that could become a standard procedure for all experiments; however, this is not the case. In actuality, the emplacement and stemming of a nuclear explosive must almost be a custom design. It varies with the application of the experiment, i.e., cratering or underground engineering. It also varies with the condition of the hole, the available equipment to do the job, the actual purpose of the stemming, possible postshot reentry, hydrology, geology, and future production. A very important item that must always be considered is the protection of the firing and signal cables during the downhole and stemming operation. Each of these things must be considered; ignoring any one of them could jeopardize one of the objectives of the experiment or perhaps even the experiment itself. It should be emphasized that for a multiple-shot program such as would be used to develop a gas field where the geology, depths of burial etc. are the same, the emplacement and stemming operation would be standardized, as would all other parts of the program. However, for individual experiments in totally different areas, complete standardization of the emplacement and stemming is impossible

  16. Emplacement and stemming of nuclear explosives for Plowshare applications

    Energy Technology Data Exchange (ETDEWEB)

    Cramer, J L [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

    1970-05-15

    This paper will discuss the various methods used for emplacement and design considerations that must be taken into account when the emplacement and stemming method is selected. The step-by-step field procedure will not be discussed in this paper. The task of emplacing and stemming the nuclear explosive is common to all Plowshare experiments today. All present-day applications of a nuclear explosive for Plowshare experiments require that the detonation take place some distance below the surface of the ground. This is normally done by lowering the explosive into an emplacement hole to a desired depth and then backfilling the hole with a suitable stemming material. At first glance it scenes like a very straightforward, simple task to perform. It would appear to be a task that could become a standard procedure for all experiments; however, this is not the case. In actuality, the emplacement and stemming of a nuclear explosive must almost be a custom design. It varies with the application of the experiment, i.e., cratering or underground engineering. It also varies with the condition of the hole, the available equipment to do the job, the actual purpose of the stemming, possible postshot reentry, hydrology, geology, and future production. A very important item that must always be considered is the protection of the firing and signal cables during the downhole and stemming operation. Each of these things must be considered; ignoring any one of them could jeopardize one of the objectives of the experiment or perhaps even the experiment itself. It should be emphasized that for a multiple-shot program such as would be used to develop a gas field where the geology, depths of burial etc. are the same, the emplacement and stemming operation would be standardized, as would all other parts of the program. However, for individual experiments in totally different areas, complete standardization of the emplacement and stemming is impossible.

  17. Handling and Emplacement Options for Deep Borehole Disposal Conceptual Design.

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, John R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-07-01

    This report presents conceptual design information for a system to handle and emplace packages containing radioactive waste, in boreholes 16,400 ft deep or possibly deeper. Its intended use is for a design selection study that compares the costs and risks associated with two emplacement methods: drill-string and wireline emplacement. The deep borehole disposal (DBD) concept calls for siting a borehole (or array of boreholes) that penetrate crystalline basement rock to a depth below surface of about 16,400 ft (5 km). Waste packages would be emplaced in the lower 6,560 ft (2 km) of the borehole, with sealing of appropriate portions of the upper 9,840 ft (3 km). A deep borehole field test (DBFT) is planned to test and refine the DBD concept. The DBFT is a scientific and engineering experiment, conducted at full-scale, in-situ, without radioactive waste. Waste handling operations are conceptualized to begin with the onsite receipt of a purpose-built Type B shipping cask, that contains a waste package. Emplacement operations begin when the cask is upended over the borehole, locked to a receiving flange or collar. The scope of emplacement includes activities to lower waste packages to total depth, and to retrieve them back to the surface when necessary for any reason. This report describes three concepts for the handling and emplacement of the waste packages: 1) a concept proposed by Woodward-Clyde Consultants in 1983; 2) an updated version of the 1983 concept developed for the DBFT; and 3) a new concept in which individual waste packages would be lowered to depth using a wireline. The systems described here could be adapted to different waste forms, but for design of waste packaging, handling, and emplacement systems the reference waste forms are DOE-owned high- level waste including Cs/Sr capsules and bulk granular HLW from fuel processing. Handling and Emplacement Options for Deep Borehole Disposal Conceptual Design July 23, 2015 iv ACKNOWLEDGEMENTS This report has

  18. WIPP waste package testing on simulated DHLW: emplacement

    International Nuclear Information System (INIS)

    Molecke, M.A.

    1984-01-01

    Several series of simulated (nonradioactive) defense high-level waste (DHLW) package tests have been emplaced in the WIPP, a research and development facility authorized to demonstrate the safe disposal of defense-related wastes. The primary purpose of these 3-to-7 year duration tests is to evaluate the in situ materials performance of waste package barriers (canisters, overpacks, backfills, and nonradioactive DHLW glass waste form) for possible future application to a licensed waste repository in salt. This paper describes all test materials, instrumentation, and emplacement and testing techniques, and discusses progress of the various tests. These tests are intended to provide information on materials behavior (i.e., corrosion, metallurgical and geochemical alterations, waste form durability, surface interactions, etc.), as well as comparison between several waste package designs, fabrications details, and actual costs. These experiments involve 18 full-size simulated DHLW packages (approximately 3.0 m x 0.6 m diameter) emplaced in vertical boreholes in the salt drift floor. Six of the test packages contain internal electrical heaters (470 W/canister), and were emplace under approximately reference DHLW repository conditions. Twelve other simulated DHLW packages were emplaced under accelerated-aging or overtest conditions, including the artificial introduction of brine, and a thermal loading approximately three to four times higher than reference. Eight of these 12 test packages contain 1500 W/canister electrical heaters; the other four are filled with DHLW glass. 9 refs., 1 fig

  19. Permeability of granular beds emplaced in vertical drill holes

    International Nuclear Information System (INIS)

    Griffiths, S.K.; Morrison, F.A. Jr.

    1979-01-01

    To determine the permeabilities of granular materials emplaced in vertical drill holes used for underground nuclear tests, an experiment at the USDOE Nevada Test Site (NTS) was conducted. As the hole is being filled, falling material increases pressure above and within the granular beds beneath. When the filling operation starts or stops, a transient pressure response occurs within the beds; measurements of this response in beds of various compositions were made. The permeabilities after emplacement were found by matching analytical predictions of the response to these data. This information is useful in assuring the containment of nuclear tests conducted in such drill holes

  20. Effect of repository underground ventilation on emplacement drift temperature control

    International Nuclear Information System (INIS)

    Yang, H.; Sun, Y.; McKenzie, D.G.; Bhattacharyya, K.K.

    1996-01-01

    The repository advanced conceptual design (ACD) is being conducted by the Civilian Radioactive Waste Management System, Management ampersand Operating Contractor. Underground ventilation analyses during ACD have resulted in preliminary ventilation concepts and design methodologies. This paper discusses one of the recent evaluations -- effects of ventilation on emplacement drift temperature management

  1. Salt Repository Project waste emplacement mode decision paper: Revison 1

    International Nuclear Information System (INIS)

    1987-08-01

    This paper provides a recommendation as to the mode of waste emplacement to be used as the current basis for site characterization activity for the Deaf Smith County, Texas, high level nuclear waste repository site. It also presents a plan for implementing the recommendation so as to provide a high level of confidence in the project's success. Since evaluations of high-level waste disposal in geologic repositories began in the 1950s, most studies emplacement in salt formations employed the vertical orientation for emplacing waste packages in boreholes in the floor of the underground facility. This orientation was used in trials at Project Salt Vault in the 1960s. The Waste Isolation Pilot Plant (WIPP) has recently settled on a combination of vertical and horizontal modes for various waste types. This paper analyzes the information available and develops a project position upon which to base current site characterization activities. The position recommended is that the SRP should continue to use the vertical waste emplacement mode as the reference design and to carry the horizontal mode as a ''passive'' alternative. This position was developed based upon the conclusions of a decision analysis, risk assessment, and cost/schedule impact assessment. 52 refs., 6 figs., 1 tab

  2. Rooted in two Countries? Migrant Heritage, emplacement and the ‘Canon van Nederland’.

    NARCIS (Netherlands)

    van Faassen, M.; Hoekstra, F.G.

    2017-01-01

    Rooted in two Countries? Migrant Heritage, emplacement and the ‘Canon van Nederland’. In the cultural heritage sector theorizing emplacement is considered to be vital for identity: “people need to anchor there identity concretely to a location (emplacement)” (Grever&Van Boxtel, 2014). The question

  3. Operational considerations in drift emplacement of waste packages

    International Nuclear Information System (INIS)

    Benton, H.A.

    1993-01-01

    This paper discusses the operational considerations as well as the advantages and disadvantages of emplacing waste packages in drifts in a repository. The considerations apply particularly to the potential repository for spent nuclear fuel and high-level waste glass at Yucca Mountain, although most of the considerations and the advantages and disadvantages discussed in this paper do not necessarily represent the official views of the DOE or of the Management and Operations Contractor, since most of these considerations are still under active discussion and the final decisions will not be made for some time - perhaps years. This paper describes the issues, suggests some principles upon which decisions should be based, and states some of the most significant advantages and disadvantages of the emplacement modes, and the associated waste package types and thermal loadings

  4. Sediment mechanical response due to emplacement of a waste canister

    International Nuclear Information System (INIS)

    Karnes, C.H.; Dawson, P.R.; Silva, A.J.; Brown, W.T.

    1980-01-01

    Preliminary studies have been conducted to determine the interaction between a waste canister and seabed sediment during and after emplacement. Empirical and approximate methods for determining the depth reached by a freefall penetrator indicate that a boosted penetrator emplacement method may be necessary. Hole closure is necessary, but has not been verified because calculations and laboratory experiments show sensitivity to boundary conditions which control the degree of dynamic hole closure. Laboratory studies show that closure will take place by creep deformation but closure times in seabed environments are uncertain. For assumed thermomechanical properties of sediments, it is shown that a heat generating waste canister will probably not move a significant distancce during the heat generation period

  5. Wireless Sensor Networks for Detection of IED Emplacement

    Science.gov (United States)

    2009-06-01

    unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Abstract We are investigating the use of wireless nonimaging -sensor...networks for the difficult problem of detection of suspicious behavior related to IED emplacement. Hardware for surveillance by nonimaging -sensor networks...with people crossing a live sensor network. We conclude that nonimaging -sensor networks can detect a variety of suspicious behavior, but

  6. Thermally-assisted Magma Emplacement Explains Restless Calderas

    Science.gov (United States)

    Amoruso, A.; Crescentini, L.; D'Antonio, M.; Acocella, V.

    2017-12-01

    Many calderas show repeated unrest over centuries. Though probably induced by magma, this unique behaviour is not understood and its dynamics remains elusive. To better understand these restless calderas, we interpret deformation data and build thermal models of Campi Flegrei, Italy, which is the best-known, yet most dangerous calderas, lying to the west of Naples and restless since the 1950s at least.Our elaboration of the geodetic data indicates that the inflation and deflation of magmatic sources at the same location explain most deformation, at least since the build-up of the last 1538 AD eruption. However, such a repeated magma emplacement requires a persistently hot crust.Our thermal models show that the repeated emplacement was assisted by the thermal anomaly created by magma that was intruded at shallow depth 3 ka before the last eruption and, in turn, contributed to maintain the thermal anomaly itself. This may explain the persistence of the magmatic sources promoting the restless behaviour of the Campi Flegrei caldera; moreover, it explains the crystallization, re-melting and mixing among compositionally distinct magmas recorded in young volcanic rocks.Available information at other calderas highlights similarities to Campi Flegrei, in the pattern and cause of unrest. All monitored restless calderas have either geodetically (Yellowstone, Aira Iwo-Jima, Askja, Fernandina and, partly, Long Valley) or geophysically (Rabaul, Okmok) detected sill-like intrusions inducing repeated unrest. Some calderas (Yellowstone, Long Valley) also show stable deformation pattern, where inflation insists on and mimics the resurgence uplift. The common existence of sill-like sources, also responsible for stable deformation patterns, in restless calderas suggests close similarities to Campi Flegrei. This suggests a wider applicability of our model of thermally-assisted sill emplacement, to be tested by future studies to better understand not only the dynamics of restless

  7. Analogue experiments as benchmarks for models of lava flow emplacement

    Science.gov (United States)

    Garel, F.; Kaminski, E. C.; Tait, S.; Limare, A.

    2013-12-01

    During an effusive volcanic eruption, the crisis management is mainly based on the prediction of lava flow advance and its velocity. The spreading of a lava flow, seen as a gravity current, depends on its "effective rheology" and on the effusion rate. Fast-computing models have arisen in the past decade in order to predict in near real time lava flow path and rate of advance. This type of model, crucial to mitigate volcanic hazards and organize potential evacuation, has been mainly compared a posteriori to real cases of emplaced lava flows. The input parameters of such simulations applied to natural eruptions, especially effusion rate and topography, are often not known precisely, and are difficult to evaluate after the eruption. It is therefore not straightforward to identify the causes of discrepancies between model outputs and observed lava emplacement, whereas the comparison of models with controlled laboratory experiments appears easier. The challenge for numerical simulations of lava flow emplacement is to model the simultaneous advance and thermal structure of viscous lava flows. To provide original constraints later to be used in benchmark numerical simulations, we have performed lab-scale experiments investigating the cooling of isoviscous gravity currents. The simplest experimental set-up is as follows: silicone oil, whose viscosity, around 5 Pa.s, varies less than a factor of 2 in the temperature range studied, is injected from a point source onto a horizontal plate and spreads axisymmetrically. The oil is injected hot, and progressively cools down to ambient temperature away from the source. Once the flow is developed, it presents a stationary radial thermal structure whose characteristics depend on the input flow rate. In addition to the experimental observations, we have developed in Garel et al., JGR, 2012 a theoretical model confirming the relationship between supply rate, flow advance and stationary surface thermal structure. We also provide

  8. Thermally-assisted Magma Emplacement Explains Restless Calderas.

    Science.gov (United States)

    Amoruso, Antonella; Crescentini, Luca; D'Antonio, Massimo; Acocella, Valerio

    2017-08-11

    Many calderas show repeated unrest over centuries. Though probably induced by magma, this unique behaviour is not understood and its dynamics remains elusive. To better understand these restless calderas, we interpret deformation data and build thermal models of Campi Flegrei caldera, Italy. Campi Flegrei experienced at least 4 major unrest episodes in the last decades. Our results indicate that the inflation and deflation of magmatic sources at the same location explain most deformation, at least since the build-up of the last 1538 AD eruption. However, such a repeated magma emplacement requires a persistently hot crust. Our thermal models show that this repeated emplacement was assisted by the thermal anomaly created by magma that was intruded at shallow depth ~3 ka before the last eruption. This may explain the persistence of the magmatic sources promoting the restless behaviour of the Campi Flegrei caldera; moreover, it explains the crystallization, re-melting and mixing among compositionally distinct magmas recorded in young volcanic rocks. Our model of thermally-assisted unrest may have a wider applicability, possibly explaining also the dynamics of other restless calderas.

  9. Salt Repository emplacement mode evaluation and selection: Final report

    International Nuclear Information System (INIS)

    1988-03-01

    This document describes the decision analysis performed to evaluate and compare the emplacement mode for the Salt Repository. The study was commissioned to recommend one emplacement mode to the Salt Repository Project Office using multi-attribute decision analysis. The nature of the decision required analysis of uncertain outcomes and conflicting attributes and offers a high degree of objectivity for these types of decisions since the decision model is structured to allow only the facts to enter into the final decision. The analysis requires an explicit definition of the attributes used to evaluate the alternative (e.g., cost, safety, environmental impact), the definition of a utility function over the attributes which incorporated both risk attitudes and trade-offs between attributes, and the probability distribution over the outcomes that would result from the selection of one alternative over the other. The decision process is described and results are given. A simulation model was developed to evaluate the probability distributions over the attributes. This report documents logic, inputs and results of this model. Final ranking of alternatives is given. Extensive technical backup documentation is included in the appendices to provide the quantitative basis for this decision. 5 refs., 2 figs., 8 tabs

  10. CLASSIFICATION OF THE MGR WASTE EMPLACEMENT/RETRIEVAL SYSTEM

    International Nuclear Information System (INIS)

    J.A. Ziegler

    2000-01-01

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) waste emplacement/retrieved system structures, systems and components (SSCs) performed by the MGR Preclosure Safety and Systems Engineering Section. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 2000). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, Quality Assurance Requirements and Description (QARD) (DOE 2000). This QA classification incorporates the current MGR design and the results of the ''Design Basis Event Frequency and Dose Calculation for Site Recommendation'' (CRWMS M andO 2000a). The content and technical approach of this analysis is in accordance with the development plan ''QA Classification of MGR Structures, Systems, and Components'' (CRWMS M andO 1999b)

  11. Remote excavation using the telerobotic small emplacement excavator

    International Nuclear Information System (INIS)

    Thompson, D.H.; Burks, B.L.; Killough, S.M.

    1993-01-01

    Oak Ridge National Laboratory is developing remote excavation technologies for the Office of Technology Development, Robotics Technology Development Program. This work is being done to meet the need for remote excavation and removal of radioactive and contaminated buried waste at several DOE sites. System requirements are based on the need to uncover and remove waste from burial sites in a way that does not cause unnecessary personnel exposure or additional environmental contamination. Goals for the current project are to demonstrate dexterous control of a backhoe with force feedback and to implement robotic operations that will improve productivity. The Telerobotic Small Emplacement Excavator is a prototype system that incorporates the needed robotic and telerobotic capabilities on a commercially available platform. The ability to add remote dexterous teleoperation and robotic operating modes is intended to be adaptable to other commercially available excavator systems

  12. Novel Emplacement Device for a Very Deep Borehole Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Min Soo; Choi, Heui-joo; Lee, Jong Yul [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    There is a worldwide attempt of HLW disposal into a very deep borehole of around 3-5 km depth with the advancement of an underground excavation technology recently. As it goes into deeper underground, the rock becomes more uniform and flawless. And then the underground water circulation system at 3-5 km depth is almost disconnected with near groundwater circulation system. The canister integrity is less important in this very deep borehole disposal system unlike a general geologic disposal system at 500 m. In the deep borehole disposal procedures, one SNF (Spent Nuclear Fuel) assembly is stored in one disposal canister (D30-40cm, H4.7-5.0m), and approximately 10-40 disposal canisters are connected axially, which parade length can leach to around 200m in maximum. The connected canister parade is lowered through a very deep borehole (D40-50cm) by emplacement devices. Therefore the connections between canisters and canister to lowering joint are very important for the safe operation of it. The well-known connection method between canisters is Threaded Coupled Connection method, in which releasing of the connection is almost impossible after thread fastening in the borehole. The novel joint device suggested in this paper can accommodate a canister emplacement and retrieval in the borehole disposal process. The joint can be lowered by bound to a drilling pipe, or high tension cable along 3-5 km distance. This novel device can cope with an accidental event easily without any joint head change. When canisters are damaged or stuck on the borehole wall during their descending, the canisters in trouble can be retrieved simply by the control of a lifting speed.

  13. Granite ascent and emplacement during contractional deformation in convergent orogens

    Science.gov (United States)

    Brown, Michael; Solar, Gary S.

    1998-09-01

    Based on a case study in the Central Maine Belt of west-central Maine, U.S.A., it is proposed that crustal-scale shear zone systems provide an effective focussing mechanism for transfer of granite melt through the crust in convergent orogens. During contractional deformation, flow of melt in crustal materials at depths below the brittle-plastic transition is coupled with plastic deformation of these materials. The flow is driven by pressure gradients generated by buoyancy forces and tectonic stresses. Within the oblique-reverse Central Maine Belt shear zone system, stromatic migmatite and concordant to weakly discordant irregular granite sheets occur in zones of higher strain, which suggests percolative flow of melt to form the migmatite leucosomes and viscous flow of melt channelized in sheet-like bodies, possibly along fractures. Cyclic fluctuations of melt pressure may cause instantaneous changes in the effective permeability of the flow network if self-propagating melt-filled tensile and/or dilatant shear fractures are produced due to melt-enhanced embrittlement. Inhomogeneous migmatite and schlieric granite occur in zones of lower strain, which suggests migration of partially-molten material through these zones en masse by granular flow, and channelized flow of melt carrying entrained residue. Founded on the Central Maine Belt case study, we develop a model of melt extraction and ascent using the driving forces, stress conditions and crustal rheologies in convergent, especially transpressive orogens. Ascent of melt becomes inhibited with decreasing depth as the solidus is approached. For intermediate a(H 2O) muscovite-dehydration melting, the water-saturated solidus occurs between 400 and 200 MPa, near the brittle-plastic transition during high- T-low- P metamorphism, where the balance of forces favors (sub-) horizontal fracture propagation. Emplacement of melt may be accommodated by ductile flow and/or stoping of wall rock, and inflation may be accommodated

  14. Recurrent uranium relocations in distal turbidites emplaced in pelagic conditions

    International Nuclear Information System (INIS)

    Colley, S.; Thomson, J.

    1985-01-01

    The sediments of the Madeira Abyssal Plain, east of Great Meteor Seamount, are dominated by distal turbidite deposition. While the turbidites exhibit a wide compositional range, individual examples can be correlated over a wide area and are relatively homogeneous. Organic C oxidation, by bottom water oxygen, proceeds from the turbidite tops downwards after emplacement in pelagic conditions, and the progress of this oxidation front is marked by a sharp colour contrast in the sediments. In turbidites with Csub(org) > 0.5%, redistribution of authigenic U occurs to form a concentration peak (4 to 9 ppm U), just below the oxidation front or colour change. Several tens μg U/cm 2 may be mobilised, and in all examples studied > 60% of the remobilised U is relocated into the peak. Following burial by subsequent turbidites, such U concentration peaks are persistent as relict indicators of their extinct oxidation fronts for at least 2 x 10 5 years. In the case of thin turbidites where labile Csub(org) is almost exhausted, the U peaks may be located in underlying sedimentary units because of their relationship to the oxidation front. A redox mechanism for U peak formation is suggested from these data rather than a complexation with organic matter. (author)

  15. Emplacement hole drill evaluation and specification study. Volume I

    International Nuclear Information System (INIS)

    1977-01-01

    Results of a conceptual design program are presented for mine floor drilling in preparation for radioactive waste disposal. Two classes of drills can be used to drill emplacement holes in salt. Both are sufficiently rugged and reliable. Raise borers have a higher capital cost and require more modifications, but are more flexible in other applications and require less labor. The life cycle cost for the raise borers and for the auger rigs are about the same, while the life cycle costs of bucket drills are much higher. As long as the hole is 36 inches in diameter or less and 40 feet deep or less in salt, then the auger rig is recommended because of the lower capital cost and lower operating cost. This recommended system represents what is thought to be the best combination of available drill components assembled into a drill rig which will provide at least adequate performance. Furthermore, this drill system can be procured from at least three manufacturers. If the facility criteria change significantly, however, then the drill rig recommendations will have to be reassessed on the merits of the changes. The drill rig manufacturers can be quite flexible in combining components provided the buyer is willing to accept components with which the manufacturer has had experience. If this condition can be met, then most drill rig manufacturers will include the associated design cost as part of the drill cost. If special components are required, however, then the number of manufacturers willing to participate in a procurement may be severely reduced

  16. Conceptual designs of automated systems for underground emplacement and retrieval of nuclear waste

    International Nuclear Information System (INIS)

    Slocum, A.H.; Hou, W.M.; Park, K.; Hochmuth, C.; Thurston, D.C.

    1987-01-01

    Current designs of underground nuclear waste repositories have not adequately addressed the possibility of automated, unmanned emplacement and retrieval. This report will present design methodologies for development of an automated system for underground emplacement of nuclear waste. By scaling generic issues to different repositories, it is shown that a two vehicle automated waste emplacement/retrieval system can be designed to operate in a fail-safe mode. Evaluation of cost at this time is not possible. Significant gains in worker safety, however, can be realized by minimizing the possibility of human exposure

  17. Calculation of drift seepage for alternative emplacement designs

    International Nuclear Information System (INIS)

    Li, Guomin; Tsang, Chin-Fu; Birkholzer, Jens

    1999-01-01

    The calculations presented in this report are performed to obtain seepage rates into drift and boreholes for two alternative designs of drift and waste emplacement at Yucca Mountain. The two designs are defined according to the Scope of Work 14012021M1, activity 399621, drafted October 6, 1998, and further refined in a conference telephone call on October 13, 1998, between Mark Balady, Jim Blink, Rob Howard and Chin-Fu Tsang. The 2 designs considered are: (1) Design A--Horizontal boreholes 1.0 m in diameter on both sides of the drift, with each borehole 8 m long and inclined to the drift axis by 30 degrees. The pillar between boreholes, measured parallel to the drift axis, is 3.3 m. In the current calculations, a simplified model of an isolated horizontal borehole 8 m long will be simulated. The horizontal borehole will be located in a heterogeneous fracture continuum representing the repository layer. Three different realizations will be taken from the heterogeneous field, representing three different locations in the rock. Seepage for each realization is calculated as a function of the percolation flux. Design B--Vertical boreholes, 1.0 m in diameter and 8.0 m deep, drilled from the bottom of an excavated 8.0 m diameter drift. Again, the drift with the vertical borehole will be assumed to be located in a heterogeneous fracture continuum, representing the rock at the repository horizon. Two realizations are considered, and seepage is calculated for the 8-m drift with and without the vertical 1-m borehole at its bottom

  18. Parameters and criteria influencing the selection of waste emplacement configurations in mined geologic repositories

    International Nuclear Information System (INIS)

    Bechthold, W.; Closs, K.D.; Papp, R.

    1988-01-01

    Reference concepts for repositories in deep geological formations have been developed in several countries. For these concepts, emplacement configurations vary within a wide range that comprises drift emplacement of unshielded or self-shielded packages and horizontal or vertical borehole emplacement. This is caused by different parameters, criteria, and criteria weighting factors. Examples for parameters are the country's nuclear power program and waste management policy, its geological situation, and safety requirements, examples for criteria and repository area requirements, expenditures of mining and drilling, and efforts for emplacement and, if required, retrieval. Due to the variety of these factors and their ranking in different countries, requirements for a safe, dependable and cost-effective disposal of radioactive waste can be met in various ways

  19. Thermal/thermomechanical analyses for the room region with horizontal and vertial modes of emplacement

    International Nuclear Information System (INIS)

    1988-01-01

    Extensive thermal/thermomechanical analyses of the Site Characterization Plan-Conceptual Design at the Deaf Smith county Site, Texas, have been carried out for the room region with horizontal and vertical modes of emplacement. The main purpose of this study is to make a good comparison between these two modes of emplacement in this region. Homogeneous and nonhomogeneous strata under isothermal or transient temperature conditions cases were considered in the analyses. Furthermore, various pillar widths for the vertical mode emplacement were also taken into consideration. Only spent fuel (SF) waste was considered in this study. Finite element method was used throughout the analyses. The thermal responses were evaluated using SPECTROM-41 while the thermomechanical responses were calculated using SPECTROM-32. Thermal and thermomechanical comparisons between the two modes of emplacement for various cases were presented in this paper

  20. Mechanisms Of Saucer-Shaped Sill Emplacement: Insight From Experimental Modeling

    Science.gov (United States)

    Galland, O.; Planke, S.; Malthe-Sørenssen, A.; Polteau, S.; Svensen, H.; Podladchikov, Y. Y.

    2006-12-01

    It has been recently demonstrated that magma intrusions in sedimentary basins had a strong impact on petroleum systems. Most of these intrusions are sills, and especially saucer-shaped sills. These features can be observed in many sedimentary basins (i.e. the Karoo basin, South Africa; the Norwegian and North Sea; the Tunguska basin, Siberia; the Neuquén basin in Argentina). The occurrence of such features in so various settings suggests that their emplacement results from fundamental processes. However, the mechanisms that govern their formation remain poorly constrained. Experiments were conducted to simulate the emplacement of saucer-shaped magma intrusions in sedimentary basins. The model rock and magma were fine-grained silica flour and molten vegetable oil, respectively. This modeling technique allows simultaneous simulation of magma emplacement and brittle deformation at a basin scale. For our purpose, we performed our experiments without external deformation. During the experiments, the oil was injected horizontally at constant flow rate within the silica flour. Then the oil initially emplaced in a sill, whereas the surface of the model inflated into a smooth dome. Subsequently, the oil propagated upwards along inclined sheets, finally reaching the surface at the edge of the dome. The resulting geometries of the intrusions were saucer-shaped sills. Then the oil solidified, and the model was cut in serial cross-sections through which the structures of the intrusive body and of the overburden can be observed. In order to constraint the processes governing the emplacement of such features, we performed a parametric study based on a set of experiments in which we systematically varied parameters such as the depth of emplacement and the injection flow rate of the oil. Our results showed that saucer diameters are larger at deeper level of emplacement. Opposite trend was obtained with varying injection flow rates. Based on our results, we conducted a detailed

  1. Magnetic properties and emplacement of the Bishop tuff, California

    Science.gov (United States)

    Palmer, H.C.; MacDonald, W.D.; Gromme, C.S.; Ellwood, B.B.

    1996-01-01

    Anisotropy of magnetic susceptibility (AMS) and characteristic remanence were measured for 45 sites in the 0.76 Ma Bishop tuff, eastern California. Thirty-three sites were sampled in three stratigraphic sections, two in Owens gorge south of Long Valley caldera, and the third in the Adobe lobe north of Long Valley. The remaining 12 sites are widely distributed, but of limited stratigraphic extent. Weakly indurated, highly porous to dense, welded ash-flow tuffs were sampled. Saturation magnetization vs temperature experiments indicate two principal iron oxide phases: low Ti magnetites with 525-570 ??C Curie temperatures, and maghemite with 610??-640??C Curie temperatures. AF demagnetization spectra of isothermal remanent magnetizations are indicative of magnetite/maghemite predominantly in the multidomain to pseudo-single domain size ranges. Remeasurement of AMS after application of saturating direct fields indicates that randomly oriented single-domain grains are also present. The degree of anisotropy is only a few percent, typical of tuffs. The AMS ellipsoids are oblate with Kmin axes normal to subhorizontal foliation and Kmax axes regionally aligned with published source vents. For 12 of 16 locality means, Kmax axes plunge sourceward, confirming previous observations regarding flow sense. Topographic control on flow emplacement is indicated by the distribution of tuff deposits and by flow directions inferred from Kmax axes. Deposition east of the Benton range occurred by flow around the south end of the range and through two gaps (Benton notch and Chidago gap). Flow down Mammoth pass of the Sierra Nevada is also evident. At least some of the Adobe lobe in the northeast flowed around the west end of Glass mountain. Eastward flow directions in the upper Owens gorge and southeast directions in the lower Owens gorge are parallel to the present canyon, suggesting that the present drainage has been established along the pre-Bishop paleodrainage. Characteristic remanence

  2. An optimization procedure for borehole emplacement in fractured media

    International Nuclear Information System (INIS)

    Billaux, D.; Guerin, F.

    1998-01-01

    Specifying the position and orientation of the 'next borehole(s)' in a fractured medium, from prior incomplete knowledge of the fracture field and depending on the objectives assigned to this new borehole(s), is a crucial point in the iterative process of site characterization. The work described here explicitly includes site knowledge and specific objectives in a tractable procedure that checks possible borehole characteristics, and rates all trial boreholes according to their compliance with objectives. The procedure is based on the following ideas : Firstly, the optimization problem is strongly constrained, since feasible borehole head locations and borehole dips are generally limited. Secondly, a borehole is an 'access point' to the fracture network. Finally, when performing a flow or tracer test, the information obtained through the monitoring system will be best if this system detects the largest possible share of the flow induced by the test, and if it cuts the most 'interesting' flow paths. The optimization is carried out in four steps. 1) All possible borehole configurations are defined and stored. Typically, several hundred possible boreholes are created. Existing boreholes are also specified. 2) Stochastic fracture networks reproducing known site characteristics are generated. 3) A purely geometrical rating of all boreholes is used to select the 'geometrically best' boreholes or groups of boreholes. 4) Among the boreholes selected by the geometrical rating, the best one(s) is chosen by simulating the experiment for which it will be used and checking flowrates through possible boreholes. This method is applied to study the emplacement of a set of five monitoring boreholes prior to the sinking of a shaft for a planned underground laboratory in a granite massif in France (Vienne site). Twelve geometrical parameters are considered for each possible borehole. A detailed statistical study helps decide on the shape of a minimization function. This is then used

  3. Comparative Noise Performance of Portable Broadband Sensor Emplacements

    Science.gov (United States)

    Sweet, Justin; Arias-Dotson, Eliana; Beaudoin, Bruce; Anderson, Kent

    2015-04-01

    IRIS PASSCAL has supported portable broadband seismic experiments for close to 30 years. During that time we have seen a variety of sensor vaults deployed. The vaults deployed fall into two broad categories, a PASSCAL style vault and a Flexible Array style vault. The PASSCAL vault is constructed of materials available in-county and it is the Principle Investigator (PI) who establishes the actual field deployed design. These vaults generally are a large barrel placed in a ~1 m deep hole. A small pier, decoupled from the barrel, is fashioned in the bottom of the vault (either cement, paving stone or tile) for the sensor placement. The sensor is insulated and protected. Finally the vault is sealed and buried under ~30 cm of soil. The Flexible Array vault is provided to PIs by the EarthScope program, offering a uniform portable vault for these deployments. The vault consists of a 30 cm diameter by 0.75 cm tall piece of plastic sewage pipe buried with ~10 cm of pipe above grade. A rubber membrane covers the bottom and cement was poured into the bottom, coupling the pier to the pipe. The vault is sealed and buried under ~30 cm of soil. Cost, logistics, and the availability of materials in-country are usually the deciding factors for PIs when choosing a vault design and frequently trades are made given available resources. Recently a third type of portable broadband installation, direct burial, is being tested. In this case a sensor designed for shallow, direct burial is installed in a ~20 cm diameter by ~1 m deep posthole. Direct burial installation costs are limited to the time and effort required to dig the posthole and emplace the sensor. Our initial analyses suggest that direct burial sensors perform as well and at times better than sensor in vaults on both horizontal and vertical channels across a range of periods (<1 s to 100 s). Moving towards an instrument pool composed entirely of direct burial sensors (some with integrated digitizers) could yield higher

  4. Equipment for the emplacement of heat-producing waste in long horizontal boreholes

    International Nuclear Information System (INIS)

    Young, K.D.; Scully, L.W.; Fisk, A.; deBakker, P.; Friant, J.; Anderson, A.

    1983-01-01

    Emplacement of heat-producing waste in long horizontal holes may offer several technical and economic advantages over shallow vertical hole emplacement. Less of the host rock suffers damage as a result of drift construction; the heat from the waste can be isolated from the access drifts for long periods of time; and the amount of rock which must be excavated is much less than in traditional disposal scenarios. One of the major reasons that has been used to reject the long hole concept in the past and adhere to the shallow vertical hole concept is the equipment required to drill the holes and to emplace and retrieve the waste. Such equipment does not currently exist. It clearly is more difficult to drill a 600 to 1000 foot horizontal hole, possibly 3 to 4 feet in diameter, and place a canister of waste at the end of it than to drill a 30 foot vertical hole and lower the waste to the bottom. A liner, for emplacement hole stabilization, appears to be feasible by adapting existing technology for concrete slip forming or jacking in a steel liner. The conceptual design of the equipment to drill long horizontal holes, emplace waste and retrieve waste will be discussed. Various options in concept will be presented as well as their advantages and disadvantages. The operating scenario of the selected concept will be described as well as solutions to potential problems encountered

  5. Heat transfer effects in vertically emplaced high level nuclear waste container

    International Nuclear Information System (INIS)

    Moujaes, S.F.; Lei, Y.M.

    1994-01-01

    Modeling free convection heat transfer in a cylindrical annular enclosure is still an active area of research and an important problem to be addressed in the high level nuclear waste repository. For the vertically emplaced waste container, the air gap which is between the container shell and the rock borehole, have an important role of dissipating heat to surrounding rock. These waste containers are vertically emplaced in the borehole 300 meters just below ground, and in a horizontal grid of 30 x 8 meters apart. The borehole will be capped after the container emplacement. The expected initial heat generated is between 3-4.74 kW per container depending on the type of waste. The goal of this study is to use a computer simulation model to find the borehole wall, air-gap and the container outer wall temperature distributions. The borehole wall temperature history has been found in the previous study, and was estimated to reach a maximum temperature of about 218 degrees C after 18 years from the emplacement. The temperature history of the rock surface is then used for the air-gap simulation. The problem includes convection and radiation heat transfer in a vertical enclosure. This paper will present the results of the convection in the air-gap over one thousand years after the containers' emplacement. During this long simulation period it was also observed that a multi-cellular air flow pattern can be generated in the air gap

  6. Equipment for the emplacement of heat-producing waste in long horizontal boreholes

    International Nuclear Information System (INIS)

    Young, K.D.; Fisk, A.; Friant, J.; Scully, L.W.

    1983-01-01

    Emplacement of heat-producing waste in long horizontal holes may offer several technical and economic advantages over shallow vertical hole emplacement. Less of the host rock suffers damage as a resul of drift construction; the heat from the waste can be isolated from the access drifts for long periods of time; and the amount of rock which must be excavated is much less than in traditional disposal scenarios. One of the major reasons that has been used to reject the long hole concept in the past and adhere to the shallow vertical hole concept is the equipment required to drill the holes and to emplace and retrieve the waste. Such equipment does not currently exist. It clearly is more difficult to drill a 600 to 100 foot horizontal hole, possibly 3 to 4 feet in diameter, and place a canister of waste at the end of it than to drill a 30 foot vertical hole and lower the waste to the bottom. A liner, for emplacement hole stabilization, appears to be feasible by adapting existing technology for concrete slip forming or jacking in a steel liner. The conceptual design of the equipment to drill long horizontal holes, emplace waste and retrieve waste is discussed. Various options in concept are presented as well as their advantages and disadvantages. The operating scenario of the selected concept is described as well as solutions to potential problems encountered

  7. Emplacement and retrieval equipment design considerations for a repository in salt

    International Nuclear Information System (INIS)

    Nair, B.R.; Bahorich, R.J.

    1987-01-01

    The current design concept for the disposal of nuclear high level waste packages in a repository in salt is based on the emplacement of individual packages in vertical boreholes in the underground mine floor. A key requirement is that the waste packages be capable of being retrieved during the last 26 years of the 76-year repository operating period. The unique design considerations relating to the retrieval of waste packages emplaced in bedded salt are presented in this paper. The information is based on the experience developed during the design of vertical emplacement and retrieval equipment in support of the Sandia Defense High Level Waste experiments at the Waste Isolation Pilot Plant. Also included are the impact of retrievability on the design of the equipment, the special salt cutting technology that was developed for this application, and a description of the equipment

  8. Waste Handling and Emplacement Options for Disposal of Radioactive Waste in Deep Boreholes.

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, John R.; Hardin, Ernest

    2015-11-01

    Traditional methods cannot be used to handle and emplace radioactive wastes in boreholes up to 16,400 feet (5 km) deep for disposal. This paper describes three systems that can be used for handling and emplacing waste packages in deep borehole: (1) a 2011 reference design that is based on a previous study by Woodward–Clyde in 1983 in which waste packages are assembled into “strings” and lowered using drill pipe; (2) an updated version of the 2011 reference design; and (3) a new concept in which individual waste packages would be lowered to depth using a wireline. Emplacement on coiled tubing was also considered, but not developed in detail. The systems described here are currently designed for U.S. Department of Energy-owned high-level waste (HLW) including the Cesium- 137/Strontium-90 capsules from the Hanford Facility and bulk granular HLW from fuel processing in Idaho.

  9. Heat transfer effects in vertically emplaced high level nuclear waste container

    International Nuclear Information System (INIS)

    Moujaes, S.F.; Lei, Y.M.

    1994-01-01

    Modeling free convection heat transfer in an cylindrical annular enclosure is still an active area of research and an important problem to be addressed in the high level nuclear waste repository. For the vertically emplaced waste container, the air gap which is between the container shell and the rock borehole, have an important role of dissipating heat to surrounding rack. These waste containers are vertically emplaced in the borehole 300 meters below ground, and in a horizontal grid of 30 x 8 meters apart. The borehole will be capped after the container emplacement. The expected initial heat generated is between 3--4.74 kW per container depending on the type of waste. The goal of this study is to use a computer simulation model to find the borehole wall, air-gap and the container outer wall temperature distributions

  10. Waste Handling and Emplacement Options for Disposal of Radioactive Waste in Deep Boreholes

    International Nuclear Information System (INIS)

    Cochran, John R.; Hardin, Ernest

    2015-01-01

    Traditional methods cannot be used to handle and emplace radioactive wastes in boreholes up to 16,400 feet (5 km) deep for disposal. This paper describes three systems that can be used for handling and emplacing waste packages in deep borehole: (1) a 2011 reference design that is based on a previous study by Woodward-Clyde in 1983 in which waste packages are assembled into ''strings'' and lowered using drill pipe; (2) an updated version of the 2011 reference design; and (3) a new concept in which individual waste packages would be lowered to depth using a wireline. Emplacement on coiled tubing was also considered, but not developed in detail. The systems described here are currently designed for U.S. Department of Energy-owned high-level waste (HLW) including the Cesium- 137/Strontium-90 capsules from the Hanford Facility and bulk granular HLW from fuel processing in Idaho.

  11. Eruption and emplacement dynamics of a thick trachytic lava flow of the Sancy volcano (France)

    Science.gov (United States)

    Latutrie, Benjamin; Harris, Andrew; Médard, Etienne; Gurioli, Lucia

    2017-01-01

    A 70-m-thick, 2200-m-long (51 × 106 m3) trachytic lava flow unit underlies the Puy de Cliergue (Mt. Dore, France). Excellent exposure along a 400-m-long and 60- to 85-m-high section allows the flow interior to be accessed on two sides of a glacial valley that cuts through the unit. We completed an integrated morphological, structural, textural, and chemical analysis of the unit to gain insights into eruption and flow processes during emplacement of this thick silicic lava flow, so as to elucidate the chamber and flow dynamic processed that operate during the emplacement of such systems. The unit is characterized by an inverse chemical stratification, where there is primitive lava beneath the evolved lava. The interior is plug dominated with a thin basal shear zone overlying a thick basal breccia, with ramping affecting the entire flow thickness. To understand these characteristics, we propose an eruption model that first involves processes operating in the magma chamber whereby a primitive melt is injected into an evolved magma to create a mixed zone at the chamber base. The eruption triggered by this event first emplaced a trachytic dome, into which banded lava from the chamber base was injected. Subsequent endogenous dome growth led to flow down the shallow slope to the east on which the highly viscous (1012 Pa s) coulée was emplaced. The flow likely moved extremely slowly, being emplaced over a period of 4-10 years in a glacial manner, where a thick (>60-m) plug slid over a thin (5-m-thick) basal shear zone. Excellent exposure means that the Puy de Cliergue complex can be viewed as a case type location for understanding and defining the eruption and emplacement of thick, high-viscosity, silicic lava flow systems.

  12. Emplacement time of Salai Patai carbonatite, Malakand, Pakistan, from fission track dating of zircon and apatite

    International Nuclear Information System (INIS)

    Qureshi, A.A.; Khan, H.A.

    1991-01-01

    Based on fission track dating of zircon and apatite, the emplacement history of Salai Patai carbonatite has been traced. It has been estimated that the carbonatite was emplaced along the thrust plane associated with the Indian-Eurasian plate collision during the Oligocene period followed by some thermal/tectonic episode during Early Miocene. This negates the previous proposal that all carbonatites found in Pakistan are a part of a 200 km long alkaline province associated with the rifting of Peshawar Valley during Late Cretaceous or early tertiary. (author)

  13. High level radioactive waste repositories. Task 3. Review of underground handling and emplacement. 1. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    A review is presented of proposals for transport, handling and emplacement of high-level radioactive waste in an underground repository appropriate to the U.K. context, with particular reference to waste block size and configuration; self-shielded or partially-shielded block; stages of disposal; transport by road/rail to repository site; handling techniques within repository; emplacement in vertical holes or horizontal tunnels; repository access by adit, incline or shaft; conventional and radiological safety; costs; and major areas of uncertainty requiring research or development.

  14. EVALUATION OF RISKS AND WASTE CHARACTERIZATION REQUIREMENTS FOR THE TRANSURANIC WASTE EMPLACED IN WIPP DURING 1999

    International Nuclear Information System (INIS)

    Channell, J.K.; Walker, B.A.

    2000-01-01

    Specifically this report: 1. Compares requirements of the WAP that are pertinent from a technical viewpoint with the WIPP pre-Permit waste characterization program, 2. Presents the results of a risk analysis of the currently emplaced wastes. Expected and bounding risks from routine operations and possible accidents are evaluated; and 3. Provides conclusions and recommendations

  15. High-precision 40Ar/39AR age of the gas emplacement into the Songliao Basin

    NARCIS (Netherlands)

    Qiu, H.N.; Wu, H.Y.; Yun, Y.B.; Feng, Z.H.; Xu, Y.G.; Mei, L.F.; Wijbrans, J.R.

    2011-01-01

    The problem of determining an exact isotopic age of hydrocarbon emplacement is complex because minerals suitable for dating with common isotopic methods are often lacking in the sedimentary domain. However, the igneous quartz from the Cretaceous volcanic rocks that host the gas reservoir in the

  16. Strike-slip pull-apart process and emplacement of Xiangshan uranium-producing volcanic basin

    International Nuclear Information System (INIS)

    Qiu Aijin; Guo Lingzhi; Shu Liangshu

    2001-01-01

    Xiangshan volcanic basin is one of the famous uranium-producing volcanic basins in China. Emplacement mechanism of Xiangshan uranium-producing volcanic basin is discussed on the basis of the latest research achievements of deep geology in Xiangshan area and the theory of continental dynamics. The study shows that volcanic activity in Xiangshan volcanic basin may be divided into two cycles, and its emplacement is controlled by strike-ship pull-apart process originated from the deep regional faults. Volcanic apparatus in the first cycle was emplaced in EW-trending structure activated by clockwise strike-slipping of NE-trending deep fault, forming the EW-trending fissure-type volcanic effusion belt. Volcanic apparatus in the second cycle was emplaced at junction points of SN-trending pull-apart structure activated by sinistral strike-slipping of NE-trending deep faults and EW-trending basement faults causing the center-type volcanic magma effusion and extrusion. Moreover, the formation mechanism of large-rich uranium deposits is discussed as well

  17. From Embodiment to Emplacement: Re-Thinking Competing Bodies, Senses and Spatialities

    Science.gov (United States)

    Pink, Sarah

    2011-01-01

    In this article I discuss how a shift from theories of embodiment to one of emplacement can inform how we understand the performing body in competitive and pedagogical contexts. I argue that recent theoretical advances concerning the senses, human perception and place offer new analytical possibilities for understanding skilled performances and…

  18. Origin of elevated water levels encountered in Pahute Mesa emplacement boreholes: Preliminary investigations

    International Nuclear Information System (INIS)

    Brikowski, T.; Chapman, J.; Lyles, B.; Hokett, S.

    1993-11-01

    The presence of standing water well above the predicted water table in emplacement boreholes on Pahute Mesa has been a recurring phenomenon at the Nevada Test Site (NTS). If these levels represent naturally perched aquifers, they may indicate a radionuclide migration hazard. In any case, they can pose engineering problems in the performance of underground nuclear tests. The origin of these elevated waters is uncertain. Large volumes of water are introduced during emplacement drilling, providing ample source for artificially perched water, yet elevated water levels can remain constant for years, suggesting a natural origin instead. In an effort to address the issue of unexpected standing water in emplacement boreholes, three different sites were investigated in Area 19 on Pahute Mesa by Desert Research Institute (DRI) staff from 1990-93. These sites were U-19az, U-19ba, and U-19bh. As of this writing, U-19bh remains available for access; however, nuclear tests were conducted at the former two locations subsequent to this investigations. The experiments are discussed in chronological order. Taken together, the experiments indicate that standing water in Pahute Mesa emplacement holes originates from the drainage of small-volume naturally perched zones. In the final study, the fluids used during drilling of the bottom 100 m of emplacement borehole U-19bh were labeled with a chemical tracer. After hole completion, water level rose in the borehole, while tracer concentration decreased. In fact, total mass of tracer in the borehole remained constant, while water levels rose. After water levels stabilized in this hole, no change in tracer mass was observed over two years, indicating that no movement of water out of the borehole is taking place (as at U- 19ba). Continued labeling tests of standing water are recommended to confirm the conclusions made here, and to establish their validity throughout Pahute Mesa

  19. Buffered and unbuffered dike emplacement on Earth and Venus - Implications for magma reservoir size, depth, and rate of magma replenishment

    Science.gov (United States)

    Parfitt, E. A.; Head, J. W., III

    1993-01-01

    Models of the emplacement of lateral dikes from magma chambers under constant (buffered) driving pressure conditions and declining (unbuffered) driving pressure conditions indicate that the two pressure scenarios lead to distinctly different styles of dike emplacement. In the unbuffered case, the lengths and widths of laterally emplaced dikes will be severely limited and the dike lengths will be highly dependent on chamber size; this dependence suggests that average dike length can be used to infer the dimensions of the source magma reservoir. On Earth, the characteristics of many mafic-dike swarms suggest that they were emplaced in buffered conditions (e.g., the Mackenzie dike swarm in Canada and some dikes within the Scottish Tertiary). On Venus, the distinctive radial fractures and graben surrounding circular to oval features and edifices on many size scales and extending for hundreds to over a thousand km are candidates for dike emplacement in buffered conditions.

  20. From steep feeders to tabular plutons - Emplacement controls of syntectonic granitoid plutons in the Damara Belt, Namibia

    Science.gov (United States)

    Hall, Duncan; Kisters, Alexander

    2016-01-01

    Granitoid plutons in the deeply eroded south Central Zone of the Damara Belt in Namibia commonly show tabular geometries and pronounced stratigraphic controls on their emplacement. Subhorizontal, sheet-like pluton geometries record emplacement during regional subhorizontal shortening, but the intrusion of spatially and temporally closely-related granitoid plutons at different structural levels and in distinct structural settings suggests independent controls on their levels of emplacement. We describe and evaluate the controls on the loci of the dyke-to-sill transition that initiated the emplacement of three syntectonic (560-530 Ma) plutons in the basement-cover stratigraphy of the Erongo region. Intrusive relationships highlight the significance of (1) rigidity anisotropies associated with competent sedimentary packages or pre-existing subhorizontal granite sheets and (2) rheological anisotropies associated with the presence of thick ductile marble horizons. These mechanical anisotropies may lead to the initial deflection of steep feeder conduits as well as subsequent pluton assembly by the repeated underaccretion of later magma batches. The upward displacement of regional isotherms due to the heat advection associated with granite emplacement is likely to have a profound effect on the mechanical stratification of the upper crust and, consequently, on the level at which granitoid pluton emplacement is initiated. In this way, pluton emplacement at progressively shallower crustal depths may have resulted in the unusually high apparent geothermal gradients recorded in the upper crustal levels of the Damara Belt during its later evolution.

  1. Emplacement technology for the direct disposal of spent fuel into deep vertical boreholes

    International Nuclear Information System (INIS)

    Bollingerfehr, W.; Filbert, W.; Wehrmann, J.

    2008-01-01

    In the early sixties it was decided to investigate salt formations on its suitability to host heat generating radioactive waste in Germany. In the reference repository concept consequently the emplacement of vitrified waste canisters in deep vertical boreholes inside a salt mine was considered whereas spent fuel should be disposed of in self shielding casks (type POLLUX) in horizontal drifts. The POLLUX casks, 65 t heavy carbon steel casks, will be laid down on the floor of a horizontal drift in one of the disposal zones to be constructed in the salt dome at the 870 m level. The space between casks and drift walls will be backfilled with crushed salt. The transport, the handling und the emplacement of POLLUX casks were subject of successfully performed demonstration and in situ tests in the nineties and resulted in an adjustment of the atomic law. The borehole disposal concept comprises the emplacement of unshielded canisters with vitrified HLW in boreholes with a diameter of 60 cm and a depth of up to 300 m. In order to facilitate the fast encapsulation of the waste canister by the host rock (rock salt), no lining of the boreholes is planned. With regard to harmonize and optimize the emplacement technology for both categories of packages (vitrified waste and spent fuel) alternatives were developed. In this context the borehole emplacement technique for consolidated spent fuel as already foreseen for high-level reprocessing waste was reconsidered. This review resulted in the design of a new disposal package, a fuel rod canister (type 'BSK 3'), and an appropriate modified transport and emplacement technology. This concept (called BSK 3-concept) provides the following optimization possibilities: (i) A new steel canister of the same diameter (43 cm) as the standardized HLW canisters applied for high-level waste and compacted technological waste from reprocessing abroad can be filled with fuel rods of 3 PWR or 9 BWR fuel assemblies. (II) The standardized canister

  2. Shapes of Venusian 'pancake' domes imply episodic emplacement and silicic composition

    Science.gov (United States)

    Fink, Jonathan H.; Bridges, Nathan T.; Grimm, Robert E.

    1993-01-01

    The main evidence available for constraining the composition of the large circular 'pancake' domes on Venus is their gross morphology. Laboratory simulations using polyethylene glycol show that the height to diameter (aspect) ratios of domes of a given total volume depend critically on whether their extrusion was continuous or episodic, with more episodes leading to greater cooling and taller domes. Thus without observations of their emplacement, the compositions of Venusian domes cannot be uniquely constrained by their morphology. However, by considering a population of 51 Venusian domes to represent a sampling of many stages during the growth of domes with comparable histories, and by plotting aspect ratio versus total volume, we find that the shapes of the domes are most consistent with episodic emplacement. On Earth this mode of dome growth is found almost exclusively in lavas of dacite to rhyolite composition, strengthening earlier inferences about the presence of evolved magmas on Venus.

  3. STRUCTURAL CALCULATION OF AN EMPLACEMENT PALLET STATICALLY LOADED BY A WASTE PACKAGE

    International Nuclear Information System (INIS)

    S. Mastilovic

    2000-01-01

    The purpose of this calculation is to determine the structural response of the emplacement pallet (EP) subjected to static load from the mounted waste package (WP). The scope of this document is limited to reporting the calculation results in terms of stress intensity magnitudes. This calculation is associated with the waste emplacement systems design; calculations are performed by the Waste Package Design group. AP-3.12Q, Revision 0, ICN 0, Calculations, is used to perform the calculation and develop the document. The finite element solutions are performed by using the commercially available ANSYS Version (V) 5.4 finite element code. The results of these calculations are provided in terms of maximum stress intensity magnitudes

  4. Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

    1982-01-01

    The age of nuclear waste - the length of time between its removal from the reactor cores and its emplacement in a repository - is a significant factor in determining the thermal loading of a repository. The surface cooling period as well as the density and sequence of waste emplacement affects both the near-field repository structure and the far-field geologic environment. To investigate these issues, a comprehensive review was made of the available literature pertaining to thermal effects and thermal properties of mined geologic repositories. This included a careful evaluation of the effects of different surface cooling periods of the wastes, which is important for understanding the optimal thermal loading of a repository. The results led to a clearer understanding of the importance of surface cooling in evaluating the overall thermal effects of a radioactive waste repository. The principal findings from these investigations are summarized in this paper

  5. Uncertainty and sensitivity results for pre-waste-emplacement groundwater travel time

    International Nuclear Information System (INIS)

    Kaplan, P.G.

    1992-01-01

    In this paper uncertainty and sensitivity analyses for pre-waste-emplacement groundwater travel time conducted. Although preliminary, a numbed of interesting results were obtained. Uncertainty in the ground water travel time statistics, as measured by the coefficient of variation, increases and then decrease as the modeled system transitions from matrix-dominated to fracture-dominated flow. The uncertainty analysis also suggests that the median, as opposed to the mean, may be a better indicator of performance with respect to the regulatory criterion. The sensitivity analysis shows a strong correlation between an effective fracture property, fracture porosity, and failure to meet the regulatory pre-waste-emplacement groundwater travel time criterion of 1,000 years

  6. Far-field thermomechanical response of argillaceous rock to emplacement of a nuclear-waste repository

    International Nuclear Information System (INIS)

    McVey, D.F.; Thomas, R.K.; Lappin, A.R.

    1980-08-01

    Before heat-producing wastes can be emplaced safely in any argillaceous rock, it will be necessary to understand the far-field thermal and thermomechanical response of this rock to waste emplacement. This report presents the results of a first series of calculations aimed at estimating the far-field response of argillite to waste emplacement. Because the thermal and mechanical properties of argillite are affected by its content of expandable clay, its behavior is briefly compared and contrasted with that of a shale having the same matrix thermal properties, but containing no expandable clay. Under this assumption, modeled temperatures are the same for the two rock types at equivalent power densities and reflect the large dependence of in-situ temperatures on both initial power density and waste type. Thermomechanical calculations indicate that inclusion of contraction behavior of expandable clays in the assumed argillite thermal expansion behavior results, in some cases, in generation of a large zone in and near the repository that has undergone volumetric contraction but is surrounded by uniformly compressive stresses. Information available to date indicates that this contraction would likely result in locally increased fluid permeability and decreased in-situ thermal conductivity, but might well be advantageous as regards radionuclide retention, because of the increased surface area within the contracted zone. Assumption of continuous and positive expansion behavior for the shale eliminates the near-repository contraction and tensional zones, but results in near-surface tensional zones directly above the repository

  7. The role of the geothermal gradient in the emplacement and replenishment of ground ice on Mars

    Science.gov (United States)

    Clifford, Stephen M.

    1993-01-01

    Knowledge of the mechanisms by which ground ice is emplaced, removed, and potentially replenished, are critical to understanding the climatic and hydrologic behavior of water on Mars, as well as the morphologic evolution of its surface. Because of the strong temperature dependence of the saturated vapor pressure of H2O, the atmospheric emplacement or replenishment of ground ice is prohibited below the depth at which crustal temperatures begin to monotonically increase due to geothermal heating. In contrast, the emplacement and replenishment of ground ice from reservoirs of H2O residing deep within the crust can occur by at least three different thermally-driven processes, involving all three phases of water. In this regard, Clifford has discussed how the presence of a geothermal gradient as small as 15 K/km can give rise to a corresponding vapor pressure gradient sufficient to drive the vertical transport of 1 km of water from a reservoir of ground water at depth to the base of the cryosphere every 10(exp 6) - 10(exp 7) years. This abstract expands on this earlier treatment by considering the influence of thermal gradients on the transport of H2O at temperatures below the freezing point.

  8. Postclosure performance assessment of the SCP [Site Characterization Plan] conceptual design for horizontal emplacement: Revision 1

    International Nuclear Information System (INIS)

    1987-08-01

    This report is a preliminary postclosure performance assessment of the repository design specified in the Site Characterization Plan Conceptual Design Report (SCP-CDR) for horizontal emplacement of high-level nuclear waste. At the time that these analyses were done, horizontal emplacement was the preferred orientation for the waste packages but vertical emplacement is now the reference design. This assessment consists of (1) a review of the regulatory requirements and strategy to demonstrate compliance with these requirements, (2) an analysis of the performance of the total repository system, (3) an analysis of the thermomechanical behavior of the repository, (4) an analysis of brine mobility in the repository, (5) an analysis of the waste package performance, (6) an analysis of the performance of seals, and (7) comments on the sensitivity of the various performance measures to uncertainties in the data and models. These are preliminary analyses and, in most cases, involve bounding calculations of the repository behavior. They have several purposes including (1) assessing how well this conceptual design ''measures up'' against requirements, (2) gaining experience in implementing the performance assessment strategy and tools and thereby learning where improvements are needed, (3) helping to identify needed data, and (4) helping to indicate required design modifications. 26 refs., 40 figs., 20 tabs

  9. Mechanical degradation of Emplacement Drifts at Yucca Mountain - A Modeling Case Study. Part I: Nonlithophysal Rock

    International Nuclear Information System (INIS)

    M. Lin; D. Kicker; B. Damjanac; M. Board; M. Karakouzian

    2006-01-01

    This paper outlines rock mechanics investigations associated with mechanical degradation of planned emplacement drifts at Yucca Mountain, which is the designated site for the proposed U.S. high-level nuclear waste repository. The factors leading to drift degradation include stresses from the overburden, stresses induced by the heat released from the emplaced waste, stresses due to seismically related ground motions, and time-dependent strength degradation. The welded tuff emplacement horizon consists of two groups of rock with distinct engineering properties: nonlithophysal units and lithophysal units, based on the relative proportion of lithophysal cavities. The term 'lithophysal' refers to hollow, bubble like cavities in volcanic rock that are surrounded by a porous rim formed by fine-grained alkali feldspar, quartz, and other minerals. Lithophysae are typically a few centimeters to a few decimeters in diameter. Part I of the paper concentrates on the generally hard, strong, and fractured nonlithophysal rock. The degradation behavior of the tunnels in the nonlithophysal rock is controlled by the occurrence of keyblocks. A statistically equivalent fracture model was generated based on extensive underground fracture mapping data from the Exploratory Studies Facility at Yucca Mountain. Three-dimensional distinct block analyses, generated with the fracture patterns randomly selected from the fracture model, were developed with the consideration of in situ, thermal, and seismic loads. In this study, field data, laboratory data, and numerical analyses are well integrated to provide a solution for the unique problem of modeling drift degradation

  10. Subsurface geology of a potential waste emplacement site, Salt Valley Anticline, Grand County, Utah

    Science.gov (United States)

    Hite, R.J.

    1977-01-01

    The Salt Valley anticline, which is located about 32 km northeast of Moab, Utah, is perhaps one of the most favorable waste emplacement sites in the Paradox basin. The site, which includes about 7.8 km 2, is highly accessible and is adjacent to a railroad. The anticline is one of a series of northwest-trending salt anticlines lying along the northeast edge of the Paradox basin. These anticlines are cored by evaporites of the Paradox Member of the Hermosa Formation of Middle Pennsylvanian age. The central core of the Salt Valley anticline forms a ridgelike mass of evaporites that has an estimated amplitude of 3,600 m. The evaporite core consists of about 87 percent halite rock, which includes some potash deposits; the remainder is black shale, silty dolomite, and anhydrite. The latter three lithologies are referred to as 'marker beds.' Using geophysical logs from drill holes on the anticline, it is possible to demonstrate that the marker beds are complexly folded and faulted. Available data concerning the geothermal gradient and heatflow at the site indicate that heat from emplaced wastes should be rapidly dissipated. Potentially exploitable resources of potash and petroleum are present at Salt Valley. Development of these resources may conflict with use of the site for waste emplacement.

  11. Subsurface geology of a potential waste emplacement site, Salt Valley Anticline, Grand County, Utah

    International Nuclear Information System (INIS)

    Hite, R.J.

    1977-01-01

    The Salt Valley anticline, which is located about 32 km northeast of Moab, Utah, is perhaps one of the most favorable waste emplacement sites in the Paradox basin. The site, which includes about 7.8 km 2 , is highly accessible and is adjacent to a railroad. The anticline is one of a series of northwest-trending salt antilcines lying along the northeast edge of the Paradox basin. These anticlines are cored by evaporites of the Paradox Member of the Hermosa Formation of Middle Pennsylvanian age. The central core of the Salt Valley anticline forms a ridgelike mass of evaporites that has an estimated amplitude of 3,600 m. The evaporite core consists of about 87 percent halite rock, which includes some potash deposits; the remainder is black shale, silty dolomite, and anhydrite. The latter three lithologies are referred to as ''marker beds.'' Using geophysical logs from drill holes on the anticline, it is possible to demonstrate that the marker beds are complexly folded and faulted. Available data concerning the geothermal gradient and heatflow at the site indicate that heat from emplaced wastes should be rapidly dissipated. Potentially exploitable resources of potash and petroleum are present at Salt Valley. Development of these resources may conflict with use of the site for waste emplacement

  12. Logistics Modeling of Emplacement Rate and Duration of Operations for Generic Geologic Repository Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Kalinina, Elena Arkadievna; Hardin, Ernest

    2015-11-01

    This study identified potential geologic repository concepts for disposal of spent nuclear fuel (SNF) and (2) evaluated the achievable repository waste emplacement rate and the time required to complete the disposal for these concepts. Total repository capacity is assumed to be approximately 140,000 MT of spent fuel. The results of this study provide an important input for the rough-order-of-magnitude (ROM) disposal cost analysis. The disposal concepts cover three major categories of host geologic media: crystalline or hard rock, salt, and argillaceous rock. Four waste package sizes are considered: 4PWR/9BWR; 12PWR/21BWR; 21PWR/44BWR, and dual purpose canisters (DPCs). The DPC concepts assume that the existing canisters will be sealed into disposal overpacks for direct disposal. Each concept assumes one of the following emplacement power limits for either emplacement or repository closure: 1.7 kW; 2.2 kW; 5.5 kW; 10 kW; 11.5 kW, and 18 kW.

  13. Logistics Modeling of Emplacement Rate and Duration of Operations for Generic Geologic Repository Concepts

    International Nuclear Information System (INIS)

    Kalinina, Elena Arkadievna; Hardin, Ernest

    2015-01-01

    This study identified potential geologic repository concepts for disposal of spent nuclear fuel (SNF) and (2) evaluated the achievable repository waste emplacement rate and the time required to complete the disposal for these concepts. Total repository capacity is assumed to be approximately 140,000 MT of spent fuel. The results of this study provide an important input for the rough-order-of-magnitude (ROM) disposal cost analysis. The disposal concepts cover three major categories of host geologic media: crystalline or hard rock, salt, and argillaceous rock. Four waste package sizes are considered: 4PWR/9BWR; 12PWR/21BWR; 21PWR/44BWR, and dual purpose canisters (DPCs). The DPC concepts assume that the existing canisters will be sealed into disposal overpacks for direct disposal. Each concept assumes one of the following emplacement power limits for either emplacement or repository closure: 1.7 kW; 2.2 kW; 5.5 kW; 10 kW; 11.5 kW, and 18 kW.

  14. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository. Baseline concept criteria specifications and mechanical failure probabilities

    International Nuclear Information System (INIS)

    Hudson, E.E.; McCleery, J.E.

    1979-05-01

    One of the integral elements of the Nuclear Waste Management Program is the material handling task of retrieving Canisters containing spent unreprocessed fuel from their emplacement in a deep geologic salt bed Depository. A study of the retrieval concept data base predicated this report. In this report, alternative concepts for the tasks are illustrated and critiqued, a baseline concept in scenario form is derived and basic retrieval subsystem specifications are presented with cyclic failure probabilities predicted. The report is based on the following assumptions: (a) during retrieval, a temporary radiation seal is placed over each Canister emplacement; (b) a sleeve, surrounding the Canister, was initially installed during the original emplacement; (c) the emplacement room's physical and environmental conditions established in this report are maintained while the task is performed

  15. Thermal modeling of pluton emplacement and associated contact metamorphism:Parashi stock emplacement in the Serranía de Jarara (Alta Guajira, Colombia

    Directory of Open Access Journals (Sweden)

    Zuluaga C. Carlos A.

    2010-12-01

    Full Text Available

    In the northernmost portion of the Serrania de Jarara (Alta Guajira, Colombia, low - medium grade metamorphic rocks from the Etpana Metamorphic Suite were thermally affected by emplacement of a small calc-alkaline intrusion (Parashi Stock. Detailed petrographic analysis in collected rock samples across the NE and NW plutonic contacts show occurrences of textural and mineralogical changes in the country rock fabric that evidence contact metamorphism overprinting regional metamorphism of the Etpana Suite. These changes include growth of andalusite (chiastolite, calcic clinopyroxeneand amphibole porphyroblast crosscutting Sn+1 metamorphicfoliation. Hornblende-plagioclase barometry (ca. 3.1 kbar and cooling models for the stock show maximum time temperature evolution in the country rock at the interpreted depth of intrusion (ca. 11 km and help to evaluate the behavior of the country rock with the changing local geotherm.

  16. The full-scale Emplacement (FE) Experiment at the Mont Terri URL

    International Nuclear Information System (INIS)

    Mueller, H.R.; Weber, H.P.; Koehler, S.; Vogt, T.; Vietor, T.

    2012-01-01

    Document available in extended abstract form only. The Full-Scale Emplacement (FE) Experiment at the Mont Terri underground research laboratory (URL) is a full-scale heater test in a clay-rich formation. It simulates the construction, waste emplacement and backfilling of a spent fuel (SF) / vitrified high-level waste (HLW) repository tunnel as realistically as possible. The entire experiment implementation as well as the post-closure THM(C) evolution will be monitored using several hundred sensors. These are distributed in the host rock in the near- and far-field, the tunnel lining, the engineered barrier system and on the heaters. The aim of this experiment is to investigate HLW repository-induced thermo-hydro-mechanical (THM) coupled effects on the host rock and the validation of existing coupled THM models. A further aim is the verification of the technical feasibility of constructing a 50 m repository section at full scale with all relevant components using standard industrial equipment. Finally, the experiment will demonstrate the canister and buffer emplacement procedures for underground conditions based on the Swiss disposal concept. Experimental layout The FE experiment is based on the Swiss disposal concept for SF / HLW. The 50 m long test gallery, at the end of the former MB test tunnel in the Mont Terri URL, will be realised with a diameter of approx. 3 m. In the experiment gallery, 3 heaters with dimensions similar to those of waste canisters will be emplaced on top of abutments built of bentonite blocks. The remaining space will be backfilled with compacted bentonite pellets. The experiment will be sealed off towards the start niche with a concrete plug holding the buffer in place and reducing air and water fluxes. The first scoping calculations and design modelling for the 'far-field' instrumentation have been completed; these works have been carried out using CodeBRIGHT and the multiphase flow simulator TOUGH2. With an initial heat output of 1500 W

  17. Thermal simulation of drift emplacement. Geotechnical and geophysical investigations in and around backfilled galleries

    International Nuclear Information System (INIS)

    Schneefub, J.U.; Gommlich, G.E.

    1988-01-01

    The concept for the direct disposal of spent fuel in rock salt foresees the emplacement of large waste canisters on the floor of a disposal gallery. Subsequent to emplacement the drift is backfilled with salt grit. In a demonstration test six cylindrical containments are to be emplaced within distances of 3 m from each other in two parallel galleries of 14 m 2 , separated by a pillar of 10 m thickness. They will be heated up by a power output of approx. 1 kW/m to 200 degree C surface temperature by electrical heaters. The thermal and mechanical response of the salt rock and the backfilling to the artificial heating is to be investigated as follows: (1) measurement of the temperature field at the contained surface, in the backfill and in the rock salt; (2) deformation measurements of the salt rock around the heated drifts; (3) measurements of tunnel convergence in heated and unheated sections; (4) compaction measurements of the backfilling in heated and unheated areas; (5) measurement of rock stresses in areas very close to the galleries; and (6) pressure measurements in the backfilling, between backfilling and rock, and between backfilling and containers. The rock burst monitoring system of the Asse salt mine will be expanded to this special field of the mine to detect seismic events due to thermomechanical effects. Another seismoacoustic system will be installed to observe the compaction of the backfilling. This system must be calibrated for the relation between the density and velocities of seismic waves. It is planned to monitor the density by gamma-gamma log measurements. The changes in overall density during the entire experiment will be observed by gravimeter measurements of high precision

  18. Implementation of the full-scale emplacement (FE) experiment at the Mont Terri rock laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Müller, H.R.; Garitte, B.; Vogt, T.; and others

    2017-04-15

    Opalinus Clay is currently being assessed as the host rock for a deep geological repository for high-level and low- and intermediate-level radioactive wastes in Switzerland. Within this framework, the 'Full-Scale Emplacement' (FE) experiment was initiated at the Mont Terri rock laboratory close to the small town of St-Ursanne in Switzerland. The FE experiment simulates, as realistically as possible, the construction, waste emplacement, backfilling and early post-closure evolution of a spent fuel/vitrified high-level waste disposal tunnel according to the Swiss repository concept. The main aim of this multiple heater test is the investigation of repository-induced thermo-hydro-mechanical (THM) coupled effects on the host rock at this scale and the validation of existing coupled THM models. For this, several hundred sensors were installed in the rock, the tunnel lining, the bentonite buffer, the heaters and the plug. This paper is structured according to the implementation timeline of the FE experiment. It documents relevant details about the instrumentation, the tunnel construction, the production of the bentonite blocks and the highly compacted 'granulated bentonite mixture' (GBM), the development and construction of the prototype 'backfilling machine' (BFM) and its testing for horizontal GBM emplacement. Finally, the plug construction and the start of all 3 heaters (with a thermal output of 1350 Watt each) in February 2015 are briefly described. In this paper, measurement results representative of the different experimental steps are also presented. Tunnel construction aspects are discussed on the basis of tunnel wall displacements, permeability testing and relative humidity measurements around the tunnel. GBM densities achieved with the BFM in the different off-site mock-up tests and, finally, in the FE tunnel are presented. Finally, in situ thermal conductivity and temperature measurements recorded during the first heating months

  19. Emplacement of rock avalanche material across saturated sediments, Southern Alp, New Zealand

    Science.gov (United States)

    Dufresne, A.; Davies, T. R.; McSaveney, M. J.

    2012-04-01

    The spreading of material from slope failure events is not only influenced by the volume and nature of the source material and the local topography, but also by the materials encountered in the runout path. In this study, evidence of complex interactions between rock avalanche and sedimentary runout path material were investigated at the 45 x 106 m3 long-runout (L: 4.8 km) Round Top rock avalanche deposit, New Zealand. It was sourced within myolinitic schists of the active strike-slip Alpine Fault. The narrow and in-failure-direction elongate source scarp is deep-seated, indicating slope failure was triggered by strong seismic activity. The most striking morphological deposit features are longitudinal ridges aligned radially to source. Trenching and geophysical surveys show bulldozed and sheared substrate material at ridge termini and laterally displaced sedimentary strata. The substrate failed at a minimum depth of 3 m indicating a ploughing motion of the ridges into the saturated material below. Internal avalanche compression features suggest deceleration behind the bulldozed substrate obstacle. Contorted fabric in material ahead of the ridge document substrate disruption by the overriding avalanche material deposited as the next down-motion hummock. Comparison with rock avalanches of similar volume but different emplacement environments places Round Top between longer runout avalanches emplaced over e.g. playa lake sediments and those with shorter travel distances, whose runout was apparently retarded by topographic obstacles or that entrained high-friction debris. These empirical observations indicate the importance of runout path materials on tentative trends in rock avalanche emplacement dynamics and runout behaviour.

  20. Engineering for a disposal facility using the in-room emplacement method

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, P; Bilinsky, D M; Ates, Y; Read, R S; Crosthwaite, J L; Dixon, D A

    1996-06-01

    This report describes three nuclear fuel waste disposal vaults using the in-room emplacement method. First, a generic disposal vault design is provided which is suitable for a depth range of 500 m to 1000 m in highly stressed, sparsely fractured rock. The design process is described for all components of the system. The generic design is then applied to two different disposal vaults, one at a depth of 750 m in a low hydraulically conductive, sparsely fractured rock mass and another at a depth of 500 m in a higher conductivity, moderately fractured rock mass. In the in-room emplacement method, the disposal containers with used-fuel bundles are emplaced within the confines of the excavated rooms of a disposal vault. The discussion of the disposal-facility design process begins with a detailed description of a copper-shell, packed-particulate disposal container and the factors that influenced its design. The disposal-room generic design is presented including the detailed specifications, the scoping and numerical thermal and thermal mechanical analyses, the backfilling and sealing materials, and the operational processes. One room design is provided that meets all the requirements for a vault depth range of 500 to 1000 m. A disposal-vault layout and the factors that influenced its design are also presented, including materials handling, general logistics, and separation of radiological and nonradiological operations. Modifications to the used-fuel packaging plant for the filling and sealing of the copper-shell, packed-particulate disposal containers and a brief description of the common surface facilities needed by the disposal vault and the packaging plant are provided. The implementation of the disposal facility is outlined, describing the project stages and activities and itemizing a specific plan for each of the project stages: siting, construction, operation; decommissioning; and closure. (author). 72 refs., 15 tabs., 63 figs.

  1. Engineering for a disposal facility using the in-room emplacement method

    International Nuclear Information System (INIS)

    Baumgartner, P.; Bilinsky, D.M.; Ates, Y.; Read, R.S.; Crosthwaite, J.L.; Dixon, D.A.

    1996-06-01

    This report describes three nuclear fuel waste disposal vaults using the in-room emplacement method. First, a generic disposal vault design is provided which is suitable for a depth range of 500 m to 1000 m in highly stressed, sparsely fractured rock. The design process is described for all components of the system. The generic design is then applied to two different disposal vaults, one at a depth of 750 m in a low hydraulically conductive, sparsely fractured rock mass and another at a depth of 500 m in a higher conductivity, moderately fractured rock mass. In the in-room emplacement method, the disposal containers with used-fuel bundles are emplaced within the confines of the excavated rooms of a disposal vault. The discussion of the disposal-facility design process begins with a detailed description of a copper-shell, packed-particulate disposal container and the factors that influenced its design. The disposal-room generic design is presented including the detailed specifications, the scoping and numerical thermal and thermal mechanical analyses, the backfilling and sealing materials, and the operational processes. One room design is provided that meets all the requirements for a vault depth range of 500 to 1000 m. A disposal-vault layout and the factors that influenced its design are also presented, including materials handling, general logistics, and separation of radiological and nonradiological operations. Modifications to the used-fuel packaging plant for the filling and sealing of the copper-shell, packed-particulate disposal containers and a brief description of the common surface facilities needed by the disposal vault and the packaging plant are provided. The implementation of the disposal facility is outlined, describing the project stages and activities and itemizing a specific plan for each of the project stages: siting, construction, operation; decommissioning; and closure. (author)

  2. Characteristics and Significance of Magma Emplacement Horizons, Black Sturgeon Sill, Nipigon, Ontario

    Science.gov (United States)

    Zieg, M. J.; Hone, S. V.

    2017-12-01

    Spatial scales strongly control the timescales of processes in igneous intrusions, particularly through the thermal evolution of the magma, which in turn governs the evolution of crystallinity, viscosity, and other important physical and chemical properties of the system. In this study, we have collected a highly detailed data set comprising geochemical (bulk rock composition), textural (size and alignment of plagioclase crystals), and mineralogical (modal abundance) profiles through the central portion of the 250 m thick Black Sturgeon diabase sill. In this data, we have identified characteristic signals in texture (soft and somewhat diffuse chills), composition (reversals in differentiation trends), and mineralogy (olivine accumulations), all coinciding and recurring at roughly 10 meter intervals. Based on these signatures, we are able to map out multiple zones representing discrete pulses of magma that were emplaced sequentially as the intrusion was inflated. Simple thermal calculations suggest that each 10 meters of new crystallization would require repose times on the order of 10-100 years. To build up 250 meters of magma at this rate would only require approximately 250-2500 years, significantly less than the thermal lifetime of the entire sill. The soft chills we observe in the Black Sturgeon sill are therefore consistent with a system that remained warm throughout the emplacement process. Successive pulses were injected into partially crystalline mush, rather than pure liquid (which would result in hybridization) or solid (which would produce sharp hard chills). Episodic emplacement is by now widely recognized as a fundamental process in the formation of large felsic magma chambers; our results suggest that this also may be an important consideration in understanding the evolution of smaller mafic intrusions.

  3. Lower Crstal Reflectity bands and Magma Emplacement in Norweigian sea, NE Atlantic

    Science.gov (United States)

    Rai, A.; Breivik, A. J.; Mjelde, R.

    2013-12-01

    In this study we present the OBS data collected along seismic profiles in the norweigian sea. The traveltime modelling of the OBS data provides first-hand information about seismic structure of the subsurface. However, waveform modelling is used to further constrain the fine scale structure, velocity constrast and velocity gradients. By forward modelling and inversion of the seismic waveforms, we show that the multiple bands of reflectivity could be due to multiple episodes of magma emplacements that might have frozen in the form of sills. These mafic intrusions probably intruded into the ductile lower crust during the main rifting phase of Europe and Greenland.

  4. A review of the ascent and emplacement of granitoid bodies into the crust

    Directory of Open Access Journals (Sweden)

    Katarína Bónová

    2005-03-01

    Full Text Available This paper relates to basic information (i.e. mechanical aspects of ascent, indicators faciliting the discriminability of various ascent styles about the models of ascent and emplacement of granitoid bodies, since the purely mechanical aspect of intrusion of magmas is a fascinating subject and it has generated a considerable controversy over many years. Individual models are demonstrated by world-known occurrences and examples from Western Carpathian’s region. The conditions of magma migration are demonstrated as well.

  5. A feasibility study of the disposal of radioactive waste in deep ocean sediments by drilled emplacement

    International Nuclear Information System (INIS)

    Bury, M.R.C.

    1983-08-01

    This report describes the second phase of a study of the feasibility of disposal and isolation of high level radioactive waste in holes drilled deep into the sediments of the ocean. In this phase, work has concentrated on establishing the state of the art of the various operations and developing the design, in particular the drilling operation, the loading of flasks containing waste canisters from supply vessels onto the platform, the handling of radioactive waste on board, and its emplacement into predrilled holes. In addition, an outline design of the offshore platform has been prepared. (author)

  6. The Summer 1997 Eruption at Pillan Patera on Io: Implications for Ultrabasic Lava Flow Emplacement

    Science.gov (United States)

    Williams, David A.; Davies, Ashley G.; Keszthelyi, Laszlo P.; Greeley, Ronald

    2001-01-01

    Galileo data and numerical modeling were used to investigate the summer 1977 eruption at Pillan Patera on Io. This event, now defined as "Pillanian" eruption style, included a high-temperature (greater than 1600 C), possible ultrabasic , 140-km-high plume eruption that deposited dark, orthopyroxene-rich pyroclastic material over greater than 125,000 sq km, followed by emplacement of dark flow-like material over greater than 3100 sq km to the north of the caldera. We estimate that the high-temperature, energetic episode of this eruption had a duration of 52 - 167 days between May and September 1997, with peak eruption temperatures around June 28, 1997. Galileo 20 m/pixel images of part of the Pillan flow field show a wide-spread, rough, pitted surface that is unlike any flow surface we have seen before. We suggest that this surface may have resulted from: 1. A fractured lava crust formed during rapid, low-viscosity lava surging, perhaps including turbulent flow emplacement. 2. Disruption of the lava flow by explosive interaction with a volatile-rich substrate. or 3. A combination of 1 and 2 with or without accumulation of pyroclastic material on the surface. Well-developed flow lobes are observed, suggesting that this is a relatively distant part of the flow field.Shadow measurements at flow margins indicate a thickness of-8 - 10 m. We have modeled the emplacement of putative ultrabasic flow from the summer 1997 Pillan eruption using constraints from new Galileo data. Results suggest that either laminar sheet flows or turbulent channelized flows could have traveled 50 - 150 km on a flat, unobstructed surface, which is consistent with the estimated length of the Pillan flow field (approx. 60 km). Our modeling suggests low thermal erosion rates (less than 4.1 m/d), and that the formation of deep (greater than 20 m) erosion channels was unlikely, especially distal to the source. We calculate a volumetric flow rate of approx. 2 - 7 x 10(exp 3)cu m/s, which is greater

  7. Architecture and emplacement of flood basalt flow fields: case studies from the Columbia River Basalt Group, NW USA

    Science.gov (United States)

    Vye-Brown, C.; Self, S.; Barry, T. L.

    2013-03-01

    The physical features and morphologies of collections of lava bodies emplaced during single eruptions (known as flow fields) can be used to understand flood basalt emplacement mechanisms. Characteristics and internal features of lava lobes and whole flow field morphologies result from the forward propagation, radial spread, and cooling of individual lobes and are used as a tool to understand the architecture of extensive flood basalt lavas. The features of three flood basalt flow fields from the Columbia River Basalt Group are presented, including the Palouse Falls flow field, a small (8,890 km2, ˜190 km3) unit by common flood basalt proportions, and visualized in three dimensions. The architecture of the Palouse Falls flow field is compared to the complex Ginkgo and more extensive Sand Hollow flow fields to investigate the degree to which simple emplacement models represent the style, as well as the spatial and temporal developments, of flow fields. Evidence from each flow field supports emplacement by inflation as the predominant mechanism producing thick lobes. Inflation enables existing lobes to transmit lava to form new lobes, thus extending the advance and spread of lava flow fields. Minimum emplacement timescales calculated for each flow field are 19.3 years for Palouse Falls, 8.3 years for Ginkgo, and 16.9 years for Sand Hollow. Simple flow fields can be traced from vent to distal areas and an emplacement sequence visualized, but those with multiple-layered lobes present a degree of complexity that make lava pathways and emplacement sequences more difficult to identify.

  8. Lithofacies of deep marine basalts emplaced on a Jurassic backarc apron, Baja California (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Busby-Spera, C.J.

    1987-09-01

    Basalts of the mid-Jurassic Gran Canon Formation, Cedros Island, Mexico, were emplaced on a volcaniclastic apron in a deep marine backarc basin. Elongate pillows and lava tubes, as well as paleocurrent data from the volcaniclastic apron, indicate a southward regional paleoslope away from the island arc source. Basalts emplaced on relatively proximal parts of the apron are nearly entirely pillowed and have thick flow units with mega-pillows. Basalts on distal parts of the apron (about 15 to 20 km down paleo-current) are dominated by pillow fragment breccias (flow foot rubble), and individual lava flows are generally thin, with small pillows, suggesting that the distal ends of lava flows, erupted upslope, are represented. These distal flow fronts, however, are interstratified with features that typically form close to a vent, including thick massive to mega-pillowed lavas and lava tubes up to 8 m in diameter. It is inferred that a fissure (or system of fissures) extended from the arc into the backarc basin, erupting basalt lavas onto both proximal and distal parts of the volcaniclastic apron. Such intraplate volcanism may be common on the hot frontal arc side of backarc basins. 26 references.

  9. Hazard and consequence analysis for waste emplacement at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Gerstner, D.M.; Clayton, S.G.; Farrell, R.F.; McCormick, J.A.; Ortiz, C.; Standiford, D.L.

    1996-01-01

    The Carlsbad Area Office established and analyzed the safety bases for the design and operations as documented in the WIPP Safety Analysis Report (SAR). Additional independent efforts are currently underway to assess the hazards associated with the long-term (10,000 year) isolation period as required by 40 CFR 191. The structure of the WIPP SAR is unique due to the hazards involved, and the agreement between the State of New Mexico and the DOE regarding SAR content and format. However, the hazards and accident analysis philosophy as contained in DOE-STD-3009-94 was followed as closely as possible, while adhering to state agreements. Hazards associated with WIPP waste receipt, emplacement, and disposal operations were systematically identified using a modified Hazard and Operability Study (HAZOP) technique. The WIPP HAZOP assessed the potential internal, external, and natural phenomena events that can cause the identified hazards to develop into accidents. The hazard assessment identified deviations from the intended design and operation of the waste handling system, analyzed potential accident consequences to the public and workers, estimated likelihood of occurrence, and evaluated associated preventative and mitigative features. It was concluded from the assessment that the proposed WIPP waste emplacement operations and design are sufficient to ensure safety of the public, workers, and environment, over the 35 year disposal phase

  10. Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses

    International Nuclear Information System (INIS)

    Glowka, D.A.

    1990-09-01

    This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs

  11. Geochronological Constraints on the Exhumation and Emplacement of Subcontinental Lithospheric Mantle Peridotites in the Westernmost Mediterranean

    Science.gov (United States)

    Garrido, Carlos J.; Hidas, Károly; Marchesi, Claudio; Varas-Reus, María Isabel; Booth-Rea, Guillermo

    2017-04-01

    Exhumation of subcontinental mantle peridotite in the Western Mediterranean has been attributed to different tectonic processes including pure extension, transpression, or alternating contractive and extensional processes related with continental subduction followed by extension, before final their contractive intracrustal emplacement. Any model trying to explain the exhumation and emplacement of subcontinental lithospheric mantle peridotites in the westernmost Mediterranean should take into account the available geochronological constraints, as well as the petrological and geochemical processes that lead to internal tectono-magmatic zoning so characteristic of the Betic and Rif orogenic peridotites. Different studies have suggested a Hercynian, Cenozoic-Mesozoic or an Alpine age for the late tectono-magmatic evolution and intra-crustal emplacement of Betic-Rif peridotites. The pervasive presence of Mesozoic U-Pb zircon ages in Ronda UHP and HP garnet pyroxenites does not support a Hercynian age for the intracrustal emplacement of the peridotite. A hyper-extended margin setting for is in good agreement with the Jurassic extensional event that pervasively affected ALKAPECA terrains (i.e. the Alboran, Kabylides, Peloritani, and Calabria domains) in the western Mediterranean due to the opening of the Piemonte-Ligurian Ocean. However, a Jurassic age and a passive margin tectonic setting do not account, among other observations, for the late Miocene thermochronological ages recorded in zircons rims (U-Pb) and garnets (Lu-Hf) in garnet pyroxenites from the Betic-Rif peridotites, the pervasive Miocene resetting of U-Pb zircon and monazite ages in the overlying Jubrique crustal section, the supra-subduction radiogenic signature of late pyroxenite intrusive dikes in the Ronda peridotite, and the arc tholeiitic affinity of late mantle-derived, gabbroic dykes intruding in the Ronda and Ojen plagioclase lherzolites. These data are more consistent with a supra

  12. Study on a transportation and emplacement system of pre-assembled EBS module for HLW geological disposal

    International Nuclear Information System (INIS)

    Awano, Toshihiko; Kanno, Takeshi; Katsumata, Syunsuke; Kosuge, Kazuhiro

    2009-01-01

    HLW disposal is one of the largest issue to utilize Nuclear power safely. In the past study, the concept, which buffer materials and Overpacked waste were transported into underground respectively, have shown. The concept of pre-assembled engineered barrier has advantage to simplify the logistics and emplacement procedure, however there are difficulties to support heavy weight of pre-assembled package by equipment under the condition of little clearance between tunnel and package. In this study, Combination of air bearing and two degree-of-freedom wheels were suggested for transportation, and air jack was suggested for unloading and emplacement system. Also, whole system for transportation and emplacement procedure was designed, and Scale model test was examined to evaluate the feasibility of these concept and functions. (author)

  13. The Influence of Topography on the Emplacement Dynamics of Martian Lava flows

    Science.gov (United States)

    Tremblay, J.; Fitch, E. P.; Fagents, S. A.

    2017-12-01

    Lava flows on the Martian surface exhibit a diverse array of complex morphologies. Previous emplacement models, based on terrestrial flows, do not fully account for these observed complex morphologies. We assert that the topography encountered by the flow can exert substantial control over the thermal, rheological, and morphological evolution of the flow, and that these effects can be better incorporated into flow models to predict Martian flow morphologies. Our development of an updated model can be used to account for these topographical effects and better constrain flow parameters. The model predicts that a slope break or flow meander induces eddy currents within the flow, resulting in the disruption of the flow surface crust. The exposure of the flow core results in accelerated cooling of the flow and a resultant increase in viscosity, leading to slowing of the flow. A constant source lava flux and a stagnated flow channel would then result in observable morphological changes, such as overflowing of channel levees. We have identified five morphological types of Martian flows, representing a range of effusion rates, eruption durations and topographic settings, which are suitable for application of our model. To characterize flow morphology, we used imaging and topographic data sets to collect data on flow dimensions. For eight large (50 to hundreds of km long) channelized flows in the Tharsis region, we used the MOLA 128 ppd DEM and/or individual MOLA shot points to derive flow cross-sectional thickness profiles, from which we calculated the cross-sectional area of the flow margins adjacent to the main channel. We found that the largest flow margin cross sectional areas (excluding the channel) occur in association with a channel bend, typically near the bend apex. Analysis of high-resolution images indicates that these widened flow margins are the result of repeated overflows of the channel levees and emplacement of short flow lobes adjacent to the main flow. In

  14. Structural Analysis of Silicic Lavas Reveals the Importance of Endogenous Flow During Emplacement

    Science.gov (United States)

    Andrews, G. D.; Martens, A.; Isom, S.; Maxwell, A.; Brown, S. R.

    2017-12-01

    Recent observations of silicic lava flows in Chile strongly suggest sustained, endogeneous flow beneath an insulating carapace, where the flow advances through breakouts at the flow margin. New mapping of vertical exposures around the margin of Obsidian Dome, California, has identified discreet lobe structures in cross-section, suggesting that flow-front breakouts occured there during emplacement. The flow lobes are identified through structural measurements of flow-banding orientation and the stretching directions of vesicles. Newly acquired lidar of the Inyo Domes, including Obsidian Dome, is being analyzed to better understand the patterns of folding on the upper surface of the lavas, and to test for fold vergence patterns that may distinguish between endogenous and exogenous flow.

  15. Technical operations procedure for assembly and emplacement of the soil temperature test--test assembly

    International Nuclear Information System (INIS)

    Weber, A.P.

    1978-01-01

    A description is given of the plan for assembly, instrumentation, emplacement, and operational checkout of the soil temperature test assembly and dry well liner. The activities described cover all operations necessary to accomplish the receiving inspection, instrumentation and pre-construction handling of the dry well liner, plus all operations performed with the test article. Actual details of construction work are not covered by this procedure. Each part and/or section of this procedure is a separate function to be accomplished as required by the nature of the operation. The organization of the procedure is not intended to imply a special operational sequence or schedular requirement. Specific procedure operational sections include: receiving inspection; liner assembly operations; construction operations (by others); prepare shield plug; test article assembly and installation; and operational checkout

  16. Pre-Alleghenian (Pennsylvanian-Permian) hydrocarbon emplacement along Ordovician Knox unconformity, eastern Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, F.M.; Kesler, S.E.

    1989-03-01

    Cores taken during exploration for Mississippi Valley-type lead and zinc ores in the Mascot-Jefferson City zinc district of eastern Tennessee commonly contain hydrocarbon residues in carbonate rocks of the Knox Group immediately below the Lower Ordovician Knox unconformity. The location and number of these residue-bearing strata reveal information about the Paleozoic history of hydrocarbon emplacement in the region. Contour maps, generated from nearly 800 holes covering more than 20 km/sup 2/, indicate that zones with elevated organic content in the uppermost 30 m of the Lower Ordovician Mascot Dolomite show a strong spatial correlation with Middle Ordovician paleotopographic highs. These same zones show no spatial association with present-day structural highs, which were formed during Pennsylvanian-Permian Alleghenian tectonism. This suggests that the physical entrapment of hydrocarbons migrating through the upper permeable units of the Mascot must have occurred prior to the principal tectonism of the Alleghenian orogeny. 7 figures, 1 table.

  17. Magnetotelluric Investigations of the Yellowstone Caldera: Understanding the Emplacement of Crustal Magma Bodies

    Science.gov (United States)

    Gurrola, R. M.; Neal, B. A.; Bennington, N. L.; Cronin, R.; Fry, B.; Hart, L.; Imamura, N.; Kelbert, A.; Bowles-martinez, E.; Miller, D. J.; Scholz, K. J.; Schultz, A.

    2017-12-01

    Wideband magnetotellurics (MT) presents an ideal method for imaging conductive shallow magma bodies associated with contemporary Yellowstone-Snake River Plain (YSRP) magmatism. Particularly, how do these magma bodies accumulate in the mid to upper crust underlying the Yellowstone Caldera, and furthermore, what role do hydrothermal fluids play in their ascent? During the summer 2017 field season, two field teams from Oregon State University and the University of Wisconsin-Madison installed forty-four wideband MT stations within and around the caldera, and using data slated for joint 3-D inversion with existing seismic data, two 2-D vertical conductivity sections of the crust and upper mantle were constructed. These models, in turn, provide preliminary insight into the emplacement of crustal magma bodies and hydrothermal processes in the YSRP region.

  18. Landsat investigations of the northern Paradox basin, Utah and Colorado: implications for radioactive waste emplacement

    Science.gov (United States)

    Friedman, Jules D.; Simpson, Shirley L.

    1978-01-01

    The first stages of a remote-sensing project on the Paradox basin, part of the USGS (U.S. Geological Survey) radioactive waste-emplacement program, consisted of a review and selection of the best available satellite scanner images to use in geomorphologic and tectonic investigations of the region. High-quality Landsat images in several spectral bands (E-2260-17124 and E-5165-17030), taken under low sun angle October 9 and 10, 1975, were processed via computer for planimetric rectification, histogram analysis, linear transformation of radiance values, and edge enhancement. A lineament map of the northern Paradox basin was subsequently compiled at 1:400,000 using the enhanced Landsat base. Numerous previously unmapped northeast-trending lineaments between the Green River and Yellowcat dome; confirmatory detail on the structural control of major segments of the Colorado, Gunnison, and Dolores Rivers; and new evidence for late Phanerozoic reactivation of Precambrian basement structures are among the new contributions to the tectonics of the region. Lineament trends appear to be compatible with the postulated Colorado lineament zone, with geophysical potential-field anomalies, and with a northeast-trending basement fault pattern. Combined Landsat, geologic, and geophysical field evidence for this interpretation includes the sinuousity of the composite Salt Valley anticline, the transection of the Moab-Spanish Valley anticline on its southeastern end by northeast-striking faults, and possible transection (?) of the Moab diapir. Similarly, northeast-trending lineaments in Cottonwood Canyon and elsewhere are interpreted as manifestations of structures associated with northeasterly trends in the magnetic and gravity fields of the La Sal Mountains region. Other long northwesterly lineaments near the western termination of the Ryan Creek fault zone. may be associated with the fault zone separating the Uncompahgre horst uplift from the Paradox basin. Implications of the

  19. Analysis of thermal-hydrologic-mechanical behavior near an emplacement drift at Yucca Mountain

    International Nuclear Information System (INIS)

    Rutqvist, Jonny; Tsang, Chin-Fu

    2002-01-01

    A coupled thermal, hydrologic and mechanical (THM) analysis is conducted to evaluate the impact of coupled THM processes on the performance of a potential nuclear waste repository at Yucca Mountain, Nevada. The analysis considers changes in rock mass porosity, permeability, and capillary pressure caused by rock deformations during drift excavation, as well as those caused by thermo-mechanically induced rock deformations after emplacement of the heat-generating waste. The analysis consists of a detailed calibration of coupled hydraulic-mechanical rock mass properties against field experiments, followed by a prediction of the coupled thermal, hydrologic, and mechanical behavior around a potential repository drift. For the particular problem studied and parameters used, the analysis indicates that the stress-induced permeability changes will be within one order of magnitude and that these permeability changes do not significantly impact the overall flow pattern around the repository drift

  20. Biographical Narratives of Encounter: The Significance of Mobility and Emplacement in Shaping Attitudes towards Difference

    Science.gov (United States)

    Sadgrove, Joanna

    2014-01-01

    This paper is located within work in urban studies about the significance of contact with difference as a means for reducing prejudice and achieving social change. Recent approaches, influenced by theories of affect, have emphasised non-conscious everyday negotiations of difference in the city. In this paper it is argued that such approaches lose sight of the significance of the subject: of the reflective judgements of ‘others’ made by individuals; of our ability to make decisions around the control of our feelings and identifications; and of the significance of personal pasts and collective histories in shaping the ways we perceive and react to encounters. Rather, this paper uses a biographical approach focusing on interviewees’ narratives of encounter. Through its attention to processes of mobility and emplacement, it contributes to debates about when contact with difference matters by highlighting the importance of everyday social normativities in the production of moral dispositions. PMID:26300566

  1. Waste package transfer, emplacement and retrievability in the French deep geological repository

    Energy Technology Data Exchange (ETDEWEB)

    Roulet, Alain; Delort, Daniel; Herve, Jean Francois; Bosgiraud, Jean Michel; Guenin, Jean Jacques [Technical Department ANDRA (France)

    2009-06-15

    Safe, reliable and reversible handling of waste is a significant issue related to the design and safety assessment of deep geological repository in France. The first step taken was to study various waste handling solutions. ANDRA also decided to fabricate and demonstrate industrial scale handling equipment for HLW (since 2003) and for ILW-LL wastes (since 2008). We will review the main equipment developed for the transfer process in the repository, for both types of waste, and underline the benefits of developing industrial demonstrators within the framework of international cooperation agreements. Waste retrieval capability will be simultaneously examined. Two types of waste have to be handled underground in Andra's repository. The HLW disposal package for vitrified waste is a 2 ton carbon steel cylindrical canister with a diameter of 600 mm. The weight of ILW-LL concrete disposal packages range from a minimum of 6 tonnes to over 20 tonnes, and their volume from approximately 5 to 10 m3. The underground transfer to the disposal drift requires moving the disposal package within a shielded transfer cask placed on a trailer. Transfer cask design has evolved since 2005, due to optimisation studies and as a result of industrial feedback from SKB. For HLW handling equipment two design options have been studied. In the first solution (Andra's Dossier 2005), the waste package are emplaced, one at a time, in the disposal drift by a pushing robot. Successive steps in design and proto-typing have lead to improve the design of the equipment and to gain confidence. Recently a fully integrated process has been successfully demonstrated, at full scale, (in a 100 m long mock up drift) as part of the EC funded ESDRED Project. This demonstrator is now on display in Andra's Technology Centre at Saudron, near the Bure Underground Laboratory. The second disposal option which has been investigated is based on a concept of utilising an external apparatus to push a row of

  2. The offshore disposal of radioactive waste by drilled emplacement: A feasibility study

    International Nuclear Information System (INIS)

    Bury, M.R.C.

    1985-01-01

    This book is a report, based on a study by Taylor Woodrow Construction Limited, on the overall feasibility of the disposal of high-level radioactive waste in boreholes drilled deep into the ocean bed. The work comprises an engineering appraisal of the disposal process with a view to establishing technical and operational feasibility and providing overall cost information to enable an economic assessment to be made. Contents: Summary report; Reference criteria; Drilling operation; Transfer of radioactive waste, personnel and other supplies; Handling of radioactive waste on board; Lowering strings of canisters; Emplacement and backfilling of canisters; Preliminary design of marine platform; Retrieval of flasks or canisters lost or misplaced; Variations to the features of the lowering system; Logistics of the operation; Construction cost estimate; Operational costs; Appendix

  3. Geomorphology of crater and basin deposits - Emplacement of the Fra Mauro formation

    Science.gov (United States)

    Morrison, R. H.; Oberbeck, V. R.

    1975-01-01

    Characteristics of continuous deposits near lunar craters larger than about 1 km wide are considered, and it is concluded that (1) concentric dunes, radial ridges, and braided lineations result from deposition of the collision products of ejecta from adjacent pairs of similarly oriented secondary-crater chains and are, therefore, concentrations of secondary-crater ejecta; (2) intracrater ridges are produced within preexisting craters surrounding a fresh primary crater by ricocheting and focusing of secondary-crater ejecta from the preexisting craters' walls; and (3) secondary cratering has produced many of the structures of the continuous deposits of relatively small lunar craters and is the dominant process for emplacement of most of the radial facies of the continuous deposits of large lunar craters and basins. The percentages of Imbrium ejecta in deposits and the nature of Imbrium sculpturing are investigated.

  4. Homeless Blogs as Travelogues. Travel as a Struggle for Recognition and Emplacement

    Directory of Open Access Journals (Sweden)

    Halina Gąsiorowska

    2017-07-01

    Full Text Available Applying Clifford’s broad concept of travel, I discuss American homeless blogs as autobiographical travel writing serving the struggle for recognition of the street people. The analysed travelogues are hitchhiker Ruth Rader’s Ruthie in the Sky blog and self-made woman Brianna Karp’s Girl’s Guide to Homelessness – a memoir published on the basis of the blog bearing the same title. In the travelogues I analyse the characteristic features of a personal travel writing: travel of the self, advice for future travelers, geographic information and portrayal of society in which the travel is undertaken. I claim that homeless bloggers recounting their stories of otherness and displacement in the US contribute to (reconstructing American cultural identity their personal Self, just like many other American travelers before. Additionally, homeless blogging about homelessness is shown as the process of emplacement (Casey – the bloggers’ attempt of making themselves at home in the world.

  5. Additive Construction with Mobile Emplacement (ACME) / Automated Construction of Expeditionary Structures (ACES) Materials Delivery System (MDS)

    Science.gov (United States)

    Mueller, R. P.; Townsend, I. I.; Tamasy, G. J.; Evers, C. J.; Sibille, L. J.; Edmunson, J. E.; Fiske, M. R.; Fikes, J. C.; Case, M.

    2018-01-01

    The purpose of the Automated Construction of Expeditionary Structures, Phase 3 (ACES 3) project is to incorporate the Liquid Goods Delivery System (LGDS) into the Dry Goods Delivery System (DGDS) structure to create an integrated and automated Materials Delivery System (MDS) for 3D printing structures with ordinary Portland cement (OPC) concrete. ACES 3 is a prototype for 3-D printing barracks for soldiers in forward bases, here on Earth. The LGDS supports ACES 3 by storing liquid materials, mixing recipe batches of liquid materials, and working with the Dry Goods Feed System (DGFS) previously developed for ACES 2, combining the materials that are eventually extruded out of the print nozzle. Automated Construction of Expeditionary Structures, Phase 3 (ACES 3) is a project led by the US Army Corps of Engineers (USACE) and supported by NASA. The equivalent 3D printing system for construction in space is designated Additive Construction with Mobile Emplacement (ACME) by NASA.

  6. Field test demonstration of emplacement feasibility of precompacted clay buffer materials in a granitic medium

    International Nuclear Information System (INIS)

    Jorda, M.; Lajudie, A.; Gatabin, C.; Atabek, R.

    1992-01-01

    Field test demonstration of emplacement feasibility of precompacted clay buffer materials in a granitic medium has been successfully carried out in February 1990 at the mining centre of FANAY. SILORD site was selected allowing the drilling through the 'Raise Boring' technique of pits of 30 m depth minimum between two pre-existent galleries. Two pits of 37 m depth were drilled and characterized in detail: mean diameter and vertical deviation measurements, valuation of the surface condition (rugosity) and cracking. The pit which was the most regular was selected for the feasibility test it-self. In parallel, manufacturing and handling techniques for the engineered barrier were improved. The bricks were made from a powdered mixture of clay and 10% sand and formed the barrier which was installed in the pit using iron baskets. The technique used was compacting by uniaxial pressing at 64 MPa. Twenty eight baskets containing the engineered barrier were fabricated at LIBOS (refractory manufactory of CTE Group) and taken to FANAY-SILORD. A maximal diameter of 96.03 cm was determined for the basket passing through (basket height = 1.335 m) and verified by the lowering of basket gauges in the pit. The baskets were stacked up in the pit, without any difficulty, with a mean radial gap of 1.6 cm (for a pit mean diameter of 99.3 cm). Three simulated COGEMA waste containers were then satisfactorily installed. The real volume to be sealed, including residual voids, was estimated at 21.47 m 3 . The engineered barrier weight after emplacement came to 36280 kg leading to a dry density in service, i.e. after the engineered barrier swelling, of 1.69. 30 figs

  7. Emplacement of zero-valent metal for remediation of deep contaminant plumes

    International Nuclear Information System (INIS)

    Hubble, D.W.; Gillham, R.W.; Cherry, J.A.

    1997-01-01

    Some groundwater plumes containing chlorinated solvent contaminants are found to be so deep that current in situ remediation technologies cannot be economically applied. Also, source zones are often found to be too deep for removal or inaccessible due to surface features. Plumes emanating from these sources require containment or treatment. Containment technologies are available for shallow sites (< 15 m) and are being developed for greater depths. However, it is important to advance the science of reactive treatment - both for cut off of plumes and to contain and treat source zones. Zero-valent metal technology has been used for remediation of solvent plumes at sites in Canada, the UK and at several industrial and military sites in the USA. To date, all of the plumes treated with zero-valent metal (granular iron) have been at depths less than 15 m. This paper gives preliminary results of research into methods to emplace granular iron at depths in the range of 15 to 60 m. The study included review of available and emerging methods of installing barrier or reactive material and the selection, preliminary design and costing of several methods. The design of a treatment system for a 122 m wide PCE plume that, immediately down gradient from its source, extends from a depth of 24 to 37 m below the ground surface is used as a demonstration site. Both Permeable Reactive Wall and Funnel-and-Gate trademark systems were considered. The emplacement methods selected for preliminary design and costing were slurry wall, driven/vibrated beam, deep soil mixing and hydrofracturing injection. For each of these methods, the iron must be slurried for ease of pumping and placement using biodegradable polymer viscosifiers that leave the iron reactive

  8. The Sonju Lake layered intrusion, northeast Minnesota: Internal structure and emplacement history inferred from magnetic fabrics

    Science.gov (United States)

    Maes, S.M.; Tikoff, B.; Ferre, E.C.; Brown, P.E.; Miller, J.D.

    2007-01-01

    The Sonju Lake intrusion (SLI), in northeastern Minnesota, is a layered mafic complex of Keweenawan age (1096.1 ?? 0.8 Ma) related to the Midcontinent rift. The cumulate paragenesis of the intrusion is recognized as broadly similar to the Skaergaard intrusion, a classic example of closed-system differentiation of a tholeiitic mafic magma. The SLI represents nearly closed-system differentiation through bottom-up fractional crystallization. Geochemical studies have identified the presence of a stratabound, 50-100 m thick zone anomalously enriched in Au + PGE. Similar to the PGE reefs of the Skaergaard intrusion, this PGE-enriched zone is hosted within oxide gabbro cumulates, about two-third of the way up from the base of the intrusion. We present a petrofabric study using the anisotropy of magnetic susceptibility (AMS) to investigate the emplacement and flow patterns within the Sonju Lake intrusion. Petrographic and electron microprobe studies, combined with AMS and hysteresis measurements indicate the primary source of the magnetic signal is pseudo-single domain (PSD) magnetite or titanomagnetite. Low field AMS was measured at 32 sites within the Sonju Lake intrusion, which provided information about primary igneous fabrics. The magnetic fabrics in the layered series of the Sonju Lake intrusion are consistent with sub-horizontal to inclined emplacement of the intrusion and show evidence that the cumulate layers were deposited in a dynamic environment. Well-aligned magnetic lineations, consistently plunging shallowly toward the southwest, indicate the source of the magma is a vertical sill-like feeder, presumably located beneath the Finland granite. The Finland granite acted as a density trap for the Sonju Lake magmas, forcing lateral flow of magma to the northeast. The strongly oblate magnetic shape fabrics indicate the shallowly dipping planar fabrics were enhanced by compaction of the crystal mush. ?? 2007 Elsevier B.V. All rights reserved.

  9. Transitions in Lava Emplacement Recorded in the Deccan Traps Sequence (India)

    Science.gov (United States)

    Vanderkluysen, L.; Self, S.; Jay, A. E.; Sheth, H. C.; Clarke, A. B.

    2015-12-01

    Transitions in the style of lava flow emplacement are recognized in the stratigraphic sequence of several mafic large igneous provinces (LIPs), including the Etendeka (Namibia), the Faeroe Islands (North Atlantic LIP), the Ethiopian Traps, and the Deccan Traps (India). These transitions, from units dominated by meter-sized pāhoehoe toes and lobes to those dominated by inflated sheet lobes tens to hundreds of meters in width and meters to tens of meters in height, seems to be a fundamental feature of LIP emplacement. In the Deccan, this volcanological transition is thought to coincide with deeper changes to the volcano-magmatic system expressed, notably, in the trace element and isotopic signature of erupted flows. We investigated this transition in the Deccan Traps by logging eight sequences along the Western Ghats, an escarpment in western India where the Deccan province is thickest and best exposed. The Deccan province, which once covered ~1 million km2 of west-central India, is subdivided in eleven chemo-stratigraphic formations in the type sections of the Western Ghats. Where the lower Deccan formations are exposed, we found that as much as 65% of the exposed thickness (below the Khandala Formation) is made up of sheet lobes, from 40% in the Bhimashankar Formation to 75% in the Thakurvadi Formation. Near the bottom of the sequence, 25% of the Neral Formation is composed of sheet lobes ≥15 m in thickness. On this basis, the traditional view that inflated sheet lobes are an exclusive feature of the upper part of the stratigraphy must be challenged. Several mechanisms have been proposed to explain the development of compound flows and inflated sheet lobes, involving one or more of the following factors: underlying slope, varying effusion rate, and source geometry. Analogue experiments are currently under way to test the relative influence of each of these factors in the development of different lava flow morphologies in LIPs.

  10. Emplacement and Deformation of Mesozoic Gabbros of the High Atlas (Morocco): Paleomagnetism and Magnetic Fabrics

    Science.gov (United States)

    Calvín, P.; Ruiz-Martínez, V. C.; Villalaín, J. J.; Casas-Sainz, A. M.; Moussaid, B.

    2017-12-01

    A paleomagnetic and magnetic fabric study is performed in Upper Jurassic gabbros of the central High Atlas (Morocco). These gabbros were emplaced in the core of preexisting structures developed during the extensional stage and linked to basement faults. These structures were reactivated as anticlines during the Cenozoic compressional inversion. Gabbros from 19 out of the 33 sampled sites show a stable characteristic magnetization, carried by magnetite, which has been interpreted as a primary component. This component shows an important dispersion due to postemplacement tectonic movements. The absence of paleoposition markers in these igneous rocks precludes direct restorations. A novel approach analyzing the orientation of the primary magnetization is used here to restore the magmatic bodies and to understand the deformational history recorded by these rocks. Paleomagnetic vectors are distributed along small circles with horizontal axes, indicating horizontal axis rotations of the gabbro bodies. These rotations are higher when the ratio between shales and gabbros in the core of the anticlines increases. Due to the uncertainties inherent to this work (the igneous bodies recording strong rotations), interpretations must be qualitative. The magnetic fabric is carried by ferromagnetic (s.s.) minerals mimicking the magmatic fabric. Anisotropy of magnetic susceptibility (AMS) axes, using the rotation routine inferred from paleomagnetic results, result in more tightly clustered magnetic lineations, which also become horizontal and are considered in terms of magma flow trend during its emplacement: NW-SE (parallel to the general extensional direction) in the western sector and NE-SW (parallel to the main faults) in the easternmost structures.

  11. Determination of emplacement mechanism of Zafarghand granitoid Pluton (Southeast of Ardestan by using anisotropy of magnetic susceptibility method (AMS

    Directory of Open Access Journals (Sweden)

    Mahmoud Sadeghian

    2017-03-01

    Full Text Available Zafarghand granitoid pluton with compositional range from gabbro to granite and early to middle Miocene age cropped out about 35 km of SE Ardestan. This pluton intrudedthe Eocene volcanic and volcanosedimentary rocks of the Urumieh - Dokhtar structuralzone. In this research, for the first time, the emplacement mechanism of Zafarghandgranitoidic pluton method has been investigated using of anisotropy of magneticsusceptibility (AMS. Based on field observations, as well as petrography andinterpretations of magnetic parameters, Zafarghand pluton divided into 5 domains (1A,1B, 2, 3, 4 and 5. Domain 1, in turn, is divided into 1A and 1B. Domains 2 and 4 arelithologically, gabbro to quartzdiorite and have been emplaced first. They have playedas feeder zones. Domains 1A, 1B, 3, and 5 are dominantly granodioritic to graniticcomposition and have been emplaced as a big and low dip magmatic flow (or possibly as a sill. The occurrence of gabbro to quartzdiorite as well as grandiorite, granite andtonalite in the margin borders of the body, are all indication of magma mixing. It isshould be noted that during emplacement of the pluton studied, fractionalcrystallization, magma mixing and crustal contamination contributed to its generationand the evolution as well.

  12. Lack of inhibiting effect of oil emplacement on quartz cementation: Evidence from Cambrian reservoir sandstones, Paleozoic Baltic Basin

    DEFF Research Database (Denmark)

    Molenaar, Nicolaas; Cyziene, Jolanta; Sliaupa, Saulius

    2008-01-01

    Currently, the question of whether or not the presence of oil in sandstone inhibits quartz cementation and preserves porosity is still debated. Data from a number of Cambrian sandstone oil fields and dry fields have been studied to determine the effects of oil emplacement on quartz cementation. T...

  13. Hanford 100-N Area In Situ Apatite and Phosphate Emplacement by Groundwater and Jet Injection: Geochemical and Physical Core Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Szecsody, James E.; Vermeul, Vincent R.; Fruchter, Jonathan S.; Williams, Mark D.; Rockhold, Mark L.; Qafoku, Nikolla; Phillips, Jerry L.

    2010-07-01

    The purpose of this study is to evaluate emplacement of phosphate into subsurface sediments in the Hanford Site 100-N Area by two different technologies: groundwater injection of a Ca-citrate-PO4 solution and water-jet injection of sodium phosphate and/or fish-bone apatite. In situ emplacement of phosphate and apatite adsorbs, then incorporates Sr-90 into the apatite structure by substitution for calcium. Overall, both technologies (groundwater injection of Ca-citrate-PO4) and water-jet injection of sodium phosphate/fish-bone apatite) delivered sufficient phosphate to subsur¬face sediments in the 100-N Area. Over years to decades, additional Sr-90 will incorporate into the apatite precipitate. Therefore, high pressure water jetting is a viable technology to emplace phosphate or apatite in shallow subsurface sediments difficult to emplace by Ca-citrate-PO4 groundwater injections, but further analysis is needed to quantify the relevant areal extent of phosphate deposition (in the 5- to 15-ft distance from injection points) and cause of the high deposition in finer grained sediments.

  14. Granitic magma emplacement and deformation during early-orogenic syn-convergent transtension: The Stare Sedlo complex, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Tomek, Filip; Žák, J.; Chadima, Martin

    2015-01-01

    Roč. 87, JUL (2015), s. 50-66 ISSN 0264-3707 Institutional support: RVO:67985831 Keywords : anisotropy of magnetic susceptibility (AMS) * Bohemian Massif * pluton emplacement * granite * transtension * Variscan orogeny Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.926, year: 2015

  15. Characteristics and mode of emplacement of gneiss domes and plutonic domes in central-eastern Pyrenees

    Science.gov (United States)

    Soula, Jean-Claude

    Gneiss domes and plutonic granitoid domes make up almost 50% of the pre-Hercynian terrains in the Central and Eastern Pyrenees. From a structural study of the shape and internal structure of the domes and of their relationships with the enclosing rocks, it can be shown that both types of domes were emplaced diapirically during the major regional deformation phase and the peak of regional metamorphism. The study also shows that the internal structure, the overall shape and general behaviour relative to the host rocks are similar for plutonic domes and for gneiss domes. This appears to be in good agreement with H. Ramberg's (1967, Gravity Deformation and the Earth's Crust. Academic Press, London; 1970, Model studies in relation to intrusion of plutonic bodies. In: Mechanisms of Igneous Intrusion (edited by Newall, G. & Rast, N.) Geol. J. Spec. Issue2, 261-286.) model studies showing that dome or mushroom-like structures, similar to those observed, develop when there is a small viscosity ratio between the rising body and its enclosing medium. This implies a high crystal content for the granitoid magma. This crystal content has been estimated by (i) calculating the viscosity and density in natural conditions from petrological data for the magma considered as a suspension, using the model and program of J. P. Carron et al. (1978 Bull Soc. géol. Fr.20, 739-744.); (ii) using the recent results of experimental deformation of partially melted granites of I. van der Molen & M. S. Paterson (1979, Contr. Miner. Petrol.70, 299-318.) and (ii) comparing the preceding results with the data obtained by deformation experiments on rocks similar to those enclosing the domes. The minimum crystal content for the development of a dome-like structure has been, thus, estimated to about 70%, i.e. a value very close to that estimated by van der Molen & Paterson (1979) to be the critical value separating the granular framework flow from suspension-like behaviour. The effect of small

  16. Explosive eruptive history of Pantelleria, Italy: Repeated caldera collapse and ignimbrite emplacement at a peralkaline volcano

    Science.gov (United States)

    Jordan, Nina J.; Rotolo, Silvio G.; Williams, Rebecca; Speranza, Fabio; McIntosh, William C.; Branney, Michael J.; Scaillet, Stéphane

    2018-01-01

    A new, pre-Green Tuff (46 ka) volcanic stratigraphy is presented for the peralkaline Pantelleria Volcano, Italy. New 40Ar/39Ar and paleomagnetic data are combined with detailed field studies to develop a comprehensive stratigraphic reconstruction of the island. We find that the pre-46 ka succession is characterised by eight silica-rich peralkaline (trachyte to pantellerite) ignimbrites, many of which blanketed the entire island. The ignimbrites are typically welded to rheomorphic, and are commonly associated with lithic breccias and/or pumice deposits. They record sustained radial pyroclastic density currents fed by low pyroclastic fountains. The onset of ignimbrite emplacement is typically preceded (more rarely followed) by pumice fallout with limited dispersal, and some eruptions lack any associated pumice fall deposit, suggesting the absence of tall eruption columns. Particular attention is given to the correlation of well-developed lithic breccias in the ignimbrites, interpreted as probable tracers of caldera collapses. They record as many as five caldera collapse events, in contrast to the two events reported to date. Inter-ignimbrite periods are characterised by explosive and effusive eruptions with limited dispersal, such as small pumice cones, as well as pedogenesis. These periods have similar characteristics as the current post-Green Tuff activity on the island, and, while not imminent, it is reasonable to postulate the occurrence of another ignimbrite-forming eruption sometime in the future.

  17. Alteration, age, and emplacement of the Tangihua Complex ophiolite, New Zealand

    International Nuclear Information System (INIS)

    Nicholson, K.N.; Black, P.M.; Picard, C.; Cooper, P.; Hall, C.M.; Itaya, T.

    2007-01-01

    The Tangihua Complex, New Zealand, represents an upper sequence of Late Cretaceous oceanic crustal material: massive basalt flows, pillow lavas, and dolerites. Three phases of alteration are preserved within the complex, each characterised by zeolite precipitation, which correlate to stratigraphic position. The mylonitised sole contains greenschist assemblages (c. 325 degrees C) grading upwards into the initial phase of alteration (250-300 degrees C), and is characterised by actinolite, epidote, albite, and Na-rich zeolites. This phase is cut by lower temperature veins of chlorite-smectite and Ca-rich zeolites. The final alteration phase ( + and Ca 2+ rich minerals, including apophyllite and calcite. Disruption of Ar/Ar spectra around 50 Ma correlate with rifting in the Loyalty Basin and initiation of obduction along the Loyalty-Three Kings Ridge system. We suggest that these events resulted in initial dismemberment, alteration, and movement of the ophiolite, whereas Ar/Ar plateaux at 25-35 Ma correspond to ophiolite emplacement and the last phases of alteration. (author). 49 refs., 5 figs., 3 tabs

  18. Emplacement of Xenolith Nodules in the Kaupulehu Lava Flow, Hualalai Volcano, Hawaii

    Science.gov (United States)

    Guest, J. E.; Spudis, P. D.; Greeley, R.; Taylor, G. J.; Baloga, S. M.

    1995-01-01

    The basaltic Kaupulehu 1800-1801 lava flow of Hualalai Volcano, Hawaii contains abundant ultramafic xenoliths. Many of these xenoliths occur as bedded layers of semi-rounded nodules, each thinly coated with a veneer (typically 1 mm thick) of lava. The nodule beds are analogous to cobble deposits of fluvial sedimentary systems. Although several mechanisms have been proposed for the formation of the nodule beds, it was found that, at more than one locality, the nodule beds are overbank levee deposits. The geological occurrence of the nodules, certain diagnostic aspects of the flow morphology and consideration of the inferred emplacement process indicate that the Kaupulehu flow had an exceptionally low viscosity on eruption and that the flow of the lava stream was extremely rapid, with flow velocities of at least 10 m/s (more than 40 km/h. This flow is the youngest on Hualalai Volcano and future eruptions of a similar type would pose considerable hazard to life as well as property.

  19. Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

    1982-08-01

    The thermal effects associated with the emplacement of aged radioactive wastes in a geologic repository were studied, with emphasis on the following subjects: the waste characteristics, repository structure, and rock properties controlling the thermally induced effects; the current knowledge of the thermal, thermomechanical, and thermohydrologic impacts, determined mainly on the basis of previous studies that assume 10-year-old wastes; the thermal criteria used to determine the repository waste loading densities; and the technical advantages and disadvantages of surface cooling of the wastes prior to disposal as a means of mitigating the thermal impacts. The waste loading densities determined by repository designs for 10-year-old wastes are extended to older wastes using the near-field thermomechanical criteria based on room stability considerations. Also discussed are the effects of long surface cooling periods determined on the basis of far-field thermomechanical and thermohydrologic considerations. The extension of the surface cooling period from 10 years to longer periods can lower the near-field thermal impact but have only modest long-term effects for spent fuel. More significant long-term effects can be achieved by surface cooling of reprocessed high-level waste.

  20. Design of the human computer interface on the telerobotic small emplacement excavator

    International Nuclear Information System (INIS)

    Thompson, D.H.; Killough, S.M.; Burks, B.L.; Draper, J.V.

    1995-01-01

    The small emplacement excavator (SEE) is a ruggedized military vehicle with backhoe and front loader used by the U.S. Army for explosive ordinance disposal (EOD) and general utility excavation activities. This project resulted from a joint need in the U.S. Department of Energy (DOE) for a remote controlled excavator for buried waste operations and the U.S. Department of Defense for remote EOD operations. To evaluate the feasibility of removing personnel from the SEE vehicle during high-risk excavation tasks, a development and demonstration project was initiated. Development of a telerobotic SEE (TSEE) was performed by the Oak Ridge National Laboratory in a project funded jointly by the U.S. Army and the DOE. The TSEE features teleoperated driving, a telerobotic backhoe with four degrees of freedom, and a teleoperated front loader with two degrees of freedom on the bucket. Remote capabilities include driving (forward, reverse, brake, steering), power takeoff shifting to enable digging modes, deploying stabilizers, excavation, and computer system booting

  1. Thermal impact of waste emplacement and surface cooling associated with geologic disposal of nuclear waste

    International Nuclear Information System (INIS)

    Wang, J.S.Y.; Mangold, D.C.; Spencer, R.K.; Tsang, C.F.

    1982-08-01

    The thermal effects associated with the emplacement of aged radioactive wastes in a geologic repository were studied, with emphasis on the following subjects: the waste characteristics, repository structure, and rock properties controlling the thermally induced effects; the current knowledge of the thermal, thermomechanical, and thermohydrologic impacts, determined mainly on the basis of previous studies that assume 10-year-old wastes; the thermal criteria used to determine the repository waste loading densities; and the technical advantages and disadvantages of surface cooling of the wastes prior to disposal as a means of mitigating the thermal impacts. The waste loading densities determined by repository designs for 10-year-old wastes are extended to older wastes using the near-field thermomechanical criteria based on room stability considerations. Also discussed are the effects of long surface cooling periods determined on the basis of far-field thermomechanical and thermohydrologic considerations. The extension of the surface cooling period from 10 years to longer periods can lower the near-field thermal impact but have only modest long-term effects for spent fuel. More significant long-term effects can be achieved by surface cooling of reprocessed high-level waste

  2. Emplacement feasibility of a multi-tier, expanded capacity repository at Yucca Mountain, Nevada USA

    International Nuclear Information System (INIS)

    Apted, Michael; Kessler, John; Fairhurst, Charles

    2008-01-01

    A geological repository at Yucca Mountain has been proposed for the disposal of spent fuel from the US commercial reactors and other radioactive waste. A legislative capacity of 70,000 MTHM has been set by the Nuclear Waste Policy Act of 1982, including 63,000 MTHM of commercial spent nuclear fuel (CSNF), the projected amount of CSNF that will be produced by about 2014. Policy issues remain as to how to handle waste that is generated beyond 2014 from a growing nuclear industry in the US. The Electric Power Research Institute (EPRI) is independently evaluating the technical, rather than legislative, limit of CSNF that could be safely disposed at Yucca Mountain. Geological, thermal management, safety and cost factors have been recently evaluated by EPRI (2006; 2007) for grouped emplacement drifts and/or a multi-tier repository. EPRI's evaluation of emplacement feasibility for a multi-tier concept is described here. Expanded capacity concepts as envisioned for Yucca Mountain (EPRI, 2006; 2007) assume excavation of one or two additional levels of drifts parallel to or above and/or below the original drift excavations. For the latter multi-tier concept each 'tier' or 'level' would essentially replicate the original layer with a 30-m separation between tiers. This arrangement essentially doubles or triples the capacity of the repository for a two- or three-tier design, respectively. The main issues that affect the feasibility of expanded capacity design are; (i) ventilation requirements; (ii) radiation hazards; (iii) thermal and thermo-mechanical constraints. (i)Ventilation: The repository design involves waste packages mounted in close proximity to each other in 600-m long drifts that remain open and actively ventilated for at least 50-100 years. Analyses,conservatively assuming that all three repository levels operate simultaneously, indicate no technological obstacles in meeting ventilation requirements for sustained simultaneous operation ba sed on current industrial

  3. Conodont geothermometry in pyroclastic kimberlite: constraints on emplacement temperatures and cooling histories

    Science.gov (United States)

    Pell, Jennifer; Russell, James K.; Zhang, Shunxin

    2018-03-01

    Kimberlite pipes from Chidliak, Baffin Island, Nunavut, Canada host surface-derived Paleozoic carbonate xenoliths containing conodonts. Conodonts are phosphatic marine microfossils that experience progressive, cumulative and irreversible colour changes upon heating that are experimentally calibrated as a conodont colour alteration index (CAI). CAI values permit us to estimate the temperatures to which conodont-bearing rocks have been heated. Conodonts have been recovered from 118 samples from 89 carbonate xenoliths collected from 12 of the pipes and CAI values within individual carbonate xenoliths show four types of CAI distributions: (1) CAI values that are uniform throughout the xenolith; (2) lower CAIs in core of a xenolith than the rim; (3) CAIs that increase from one side of the xenolith to the other; and, (4) in one xenolith, higher CAIs in the xenolith core than at the rim. We have used thermal models for post-emplacement conductive cooling of kimberlite pipes and synchronous heating of conodont-bearing xenoliths to establish the temperature-time history of individual xenoliths within the kimberlite bodies. Model results suggest that the time-spans for xenoliths to reach the peak temperatures recorded by CAIs varies from hours for the smallest xenoliths to 2 or 3 years for the largest xenoliths. The thermal modelling shows the first three CAI patterns to be consistent with in situ conductive heating of the xenoliths coupled to the cooling host kimberlite. The fourth pattern remains an anomaly.

  4. Quarter-scale modeling of room convergence effects on CH [contact-handled] TRU drum waste emplacements using WIPP [Waste Isolation Pilot Plant] reference design geometries

    International Nuclear Information System (INIS)

    VandeKraats, J.

    1987-11-01

    This study investigates the effect of horizontal room convergence on CH waste packages emplaced in the WIPP Reference Design geometry (rooms 13 feet high by 33 feet wide, with minus 3/8 inch screened backfill emplaced over and around the waste packages) as a function of time. Based on two tests, predictions were made with regard to full-scale 6-packs emplaced in the Reference Design geometry. These are that load will be transmitted completely through the stack within the first five years after waste emplacement and all drums in all 6-packs will be affected; that virtually all drums will show some deformation eight years after emplacement; that some drums may breach before the eighth year after emplacement has elapsed; and that based on criteria developed during testing, it is predicted that 1% of the drums emplaced will be breached after 8 years and, after 15 years, approximately 12% of the drums are predicted to be breached. 8 refs., 41 figs., 3 tabs

  5. Geology and tectonic magmatic of emplacement of a longitudinal dyke swarm of Nico Perez(Minas) URUGUAY

    International Nuclear Information System (INIS)

    Gonzalez, P.; Poire, D.; Canalicchio, J.; Garcia Repetto, F.

    2004-01-01

    The Mina Verdun Group (Precambrian) was deposited prior to the subvolcanic emplacement of a longitudinal dyke swarm of basaltic to andesitic composition (Minas Subvolcanic Swarm of the Mina Verdun quarry - Nico Perez Terrane, Minas, Uruguay). The swarm and its country rocks predated a tectono-metamorphic event that produced fragileductile shear zones associated with very low- to low-grade dislocation metamorphism. We interpreted a K-Ar whole rock datum of 485,2 ± 12,5 Ma (andesitic dyke) as a minimum cooling age in relation with late- to post-swarm emplacement deuteric alteration stage. Another K-Ar whole rock datum of 108,5 ± 2,9 Ma on a basaltic dyke was assumed here as a degasification stage, while its geological meaning is still matter of debate. The Minas Subvolcanic Dyke Swarm was intruded at high crustal levels, suggesting that the Minas region was affected by a period of extensional tectonics [es

  6. Preliminary uncertainty analysis of pre-waste-emplacement groundwater travel times for a proposed repository in basalt

    International Nuclear Information System (INIS)

    Clifton, P.M.; Arnett, R.C.

    1984-01-01

    Preliminary uncertainty analyses of pre-waste-emplacement groundwater travel times are presented for a potential high-level nuclear waste repository in the deep basalts beneath the Hanford Site, Washington State. The uncertainty analyses are carried out by means of a Monte Carlo technique, which requires the uncertain inputs to be described as either random variables or spatial stochastic processes. Pre-waste-emplacement groundwater travel times are modeled in a continuous, flat-lying basalt flow top that is assumed to overlie the repository horizon. Two-dimensional, steady state groundwater flow is assumed, and transmissivity, effective thickness, and regional hydraulic gradient are considered as uncertain inputs. Groundwater travel time distributions corresponding to three groundwater models are presented and compared. Limitations of these preliminary simulation results are discussed in detail

  7. Operational procedures for receiving, packaging, emplacing, and retrieving high-level and transuranic waste in a geologic repository in TUFF

    International Nuclear Information System (INIS)

    Dennis, A.W.; Mulkin, R.

    1984-01-01

    The Nevada Nuclear Waste Storage Investigations Project, directed by the Nevada Operations Office of the Department of Energy, is currently developing conceptual designs for a commercial nuclear waste repository. In this paper, the preliminary repository operating plans are identified and the proposed repository waste inventory is discussed. The receipt rates for truck and rail car shipments of waste are determined as are the required repository waste emplacement rates

  8. Emplacement dynamics of phonolite magma into maar-diatreme structures - Correlation of field, thermal modeling and AMS analogue modeling data

    Czech Academy of Sciences Publication Activity Database

    Závada, Prokop; Dědeček, Petr; Mach, K.; Lexa, O.; Potužák, M.

    2011-01-01

    Roč. 201, č. 1-4 (2011), s. 210-226 ISSN 0377-0273 R&D Projects: GA MŠk ME09011; GA AV ČR KJB301110703 Institutional research plan: CEZ:AV0Z30120515 Keywords : phonolite * maar-diatreme * magma emplacement dynamics * thermal modeling * AMS analogue modeling * cavitation Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.978, year: 2011

  9. Magnetic fabrics in characterization of magma emplacement and tectonic evolution of the Moyar Shear Zone, South India

    Directory of Open Access Journals (Sweden)

    P. Pratheesh

    2013-01-01

    Full Text Available The Moyar Shear Zone (MSZ of the South Indian granulite terrain hosts a prominent syenite pluton (∼560 Ma and associated NW-SE to NE-SW trending mafic dyke swarm (∼65 Ma and 95 Ma. Preliminary magnetic fabric studies in the mafic dykes, using Anisotropy of Magnetic Susceptibly (AMS studies at low-field, indicate successive emplacement and variable magma flow direction. Magnetic lineation and foliation in these dykes are identical to the mesoscopic fabrics in MSZ mylonites, indicating shear zone guided emplacement. Spatial distribution of magnetic lineation in the dykes suggests a common conduit from which the source magma has been migrated. The magnetic foliation trajectories have a sigmoidal shape to the north of the pluton and curve into the MSZ suggesting dextral sense of shear. Identical fabric conditions for magnetic fabrics in the syenite pluton and measured field fabrics in mylonite indicate syntectonic emplacement along the Proterozoic crustal scale dextral shear zone with repeated reactivation history.

  10. Evaluation of the post-emplacement environment of high level radioactive waste packages at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Glassley, W.

    1989-01-01

    Evaluation of the post-emplacement environment around high-level radioactive waste containers is required by federal regulations. The information derived from this evaluation will be used to determine the service performance of the waste containers, the chemical and hydrological conditions that may influence radionuclide release and transport if containers are breached, and retrievability of the waste containers prior to closure of the repository. Laboratory studies, numerical simulations, and field experiments and tests are used to provide data necessary for this evaluation. Results obtained to date demonstrate that the post-emplacement environment in the welded tuff at Yucca Mountain, Nevada maintains relatively benign chemical features (i.e., near neutral pH, low concentrations of dissolved species) for most scenarios. The hydrological environment appears to be one of low flow volume and rates for the expected condition of an unsaturated medium. Emplacement borehole stability will be a function of fracture density and orientation, which may be influenced by microcrack development. Field studies and numerical simulations are in progress that will extend the results of laboratory studies to long time periods. The extent to which chemical, hydrological and mechanical processes can be adequately coupled through numerical simulations remains a matter of concern

  11. Granitoid emplacement during syn-convergent transtension: An example from the Huamenlou pluton in North Qinling, central China

    Directory of Open Access Journals (Sweden)

    Yang Li

    2018-01-01

    Full Text Available The Huamenlou pluton, is an elongated granite intrusion with high aspect ratio, emplaced within the southern margin of the North Qinling (central China. Here we investigate this pluton through multiple techniques including the fabric study, microstructural observation and zircon geochronology. Our zircon U–Pb data confirm that the granite crystallized at ca. 462 Ma which is consistent with the ages of other linear plutons in North Qinling. Microstructural observations of the Huamenlou granites illustrate that the pluton has undergone superimposed deformation during its emplacement, from magmatic to high-temperature solid state conditions. The internal fabric obtained by anisotropy of magnetic susceptibility (AMS and shape preferred orientation (SPO show similar results. The fabrics are relatively concordant and generally vary from NE–SW to NEE–SWW which are roughly oblique to the trend of the pluton elongation and the regional structures. Meanwhile, scalar parameters reflect two completely different strain regimes for the pluton and its host rocks, i.e., the fabrics within host rocks are mainly oblate while the central part of the intrusion displays mainly prolate fabrics. It is inferred that the structural pattern recorded in this pluton was caused by local dextral transtension in consequence of oblique convergence between the South and North China Blocks. We propose that the local transtension in convergence setting probably evolved from vertical extrusion tectonics that provided room for the magma emplacement and imparted prolate fabrics in the Huamenlou pluton.

  12. Paleomagnetism in the Determination of the Emplacement Temperature of Cerro Colorado Tuff Cone, El Pinacate Volcanic Field, Sonora, Mexico.

    Science.gov (United States)

    Rodriguez Trejo, A.; Alva-Valdivia, L. M.; Vidal Solano, J. R.; Garcia Amador, B.; Gonzalez-Rangel, J. A.

    2014-12-01

    Cerro Colorado Maar is located at the World Heritage Site, biosphere reserve El Pinacate and Gran Desierto del Altar, at the NNW region of Sonora, Mexico (in El Pinacate Volcanic Field). It is a tuff cone, about 1 km diameter, result of several phreatomagmatic episodes during the late Quaternary. We report paleomagnetic and rock magnetic properties from fusiform volcanic bombs obtained from the borders of Cerro Colorado. This study is based in the thermoremanent magnetization TRM normally acquired by volcanic rocks, which can be used to estimate the emplacement temperature range. We performed the experiments on 20 lithic fragments (10 cm to 20 cm approximately), taking 6-8 paleomagnetic cores from each. Rock magnetic experiments (magnetic susceptibility vs. temperature (k-T), hysteresis curves and FORC analysis, shows that the main magnetic mineral carriers of magnetization are titanomagnetite and titanohematite in different levels of intergrowth. The k-T curves suggest in many cases, only one magnetic phase, but also in other cases a second magnetic phase. Thermal demagnetization was used to demagnetize the specimens in detailed short steps and make a well-defined emplacement temperature determination ranges. We found that temperature emplacement determination range for these two magnetic phases is between 350-450 °C, and 550-580 °C, respectively. These results are consistent with those expected in an eruption of Surtsey type, showing a distinct volcanic activity compared to the other craters from El Pinacate volcanic field.

  13. Transpressional granite-emplacement model: Structural and magnetic study of the Pan-African Bandja granitic pluton (West Cameroon)

    Science.gov (United States)

    Sandjo, A. F. Yakeu; Njanko, T.; Njonfang, E.; Errami, E.; Rochette, P.; Fozing, E.

    2016-02-01

    The Pan-African NE-SW elongated Bandja granitic pluton, located at the western part of the Pan-African belt in Cameroon, is a K-feldspar megacryst granite. It is emplaced in banded gneiss and its NW border underwent mylonitization. The magmatic foliation shows NE-SW and NNE-SSW strike directions with moderate to strong dip respectively in its northern and central parts. This mostly, ferromagnetic granite displays magnetic fabrics carried by magnetite and characterized by (i) magnetic foliation with best poles at 295/34, 283/33 and 35/59 respectively in its northern, central and southern parts and (ii) a subhorizontal magnetic lineation with best line at 37/8, 191/9 and 267/22 respectively in the northern, central and southern parts. Magnetic lineation shows an `S' shape trend that allows to (1) consider the complete emplacement and deformation of the pluton during the Pan-African D 2 and D 3 events which occurred in the Pan-African belt in Cameroon and (2) reorganize Pan-African ages from Nguiessi Tchakam et al. (1997) compared with those of the other granitic plutons in the belt as: 686 ±17 Ma (Rb/Sr) for D 1 age of metamorphism recorded in gneiss; and the period between 604-557 Ma for D 2-D 3 emplacement and deformation age of the granitic pluton in a dextral ENE-WSW shear movement.

  14. Tracking lava flow emplacement on the east rift zone of Kilauea, Hawai’i with synthetic aperture radar (SAR) coherence

    Science.gov (United States)

    Dietterich, Hannah R.; Poland, Michael P.; Schmidt, David; Cashman, Katharine V.; Sherrod, David R.; Espinosa, Arkin Tapia

    2012-01-01

    Lava flow mapping is both an essential component of volcano monitoring and a valuable tool for investigating lava flow behavior. Although maps are traditionally created through field surveys, remote sensing allows an extraordinary view of active lava flows while avoiding the difficulties of mapping on location. Synthetic aperture radar (SAR) imagery, in particular, can detect changes in a flow field by comparing two images collected at different times with SAR coherence. New lava flows radically alter the scattering properties of the surface, making the radar signal decorrelated in SAR coherence images. We describe a new technique, SAR Coherence Mapping (SCM), to map lava flows automatically from coherence images independent of look angle or satellite path. We use this approach to map lava flow emplacement during the Pu‘u ‘Ō‘ō-Kupaianaha eruption at Kīlauea, Hawai‘i. The resulting flow maps correspond well with field mapping and better resolve the internal structure of surface flows, as well as the locations of active flow paths. However, the SCM technique is only moderately successful at mapping flows that enter vegetation, which is also often decorrelated between successive SAR images. Along with measurements of planform morphology, we are able to show that the length of time a flow stays decorrelated after initial emplacement is linearly related to the flow thickness. Finally, we use interferograms obtained after flow surfaces become correlated to show that persistent decorrelation is caused by post-emplacement flow subsidence.

  15. Observations of obsidian lava flow emplacement at Puyehue-Cordón Caulle, Chile

    Science.gov (United States)

    Tuffen, H.; Castro, J. M.; Schipper, C. I.; James, M. R.

    2012-04-01

    The dynamics of obsidian lava flow emplacement remain poorly understood as active obsidian lavas are seldom seen. In contrast with well-documented basaltic lavas, we lack observational data on obsidian flow advance and temporal evolution. The ongoing silicic eruption at Puyehue-Cordón Caulle volcanic complex (PCCVC), southern Chile provides an unprecedented opportunity to witness and study obsidian lava on the move. The eruption, which started explosively on June 4th 2011, has since June 20 generated an active obsidian flow field that remains active at the time of writing (January 2012), with an area of ~6 km2, and estimated volume of ~0.18 km3. We report on observations, imaging and sampling of the north-western lava flow field on January 4th and 10th 2012, when vent activity was characterised by near-continuous ash venting and Vulcanian explosions (Schipper et al, this session) and was simultaneously feeding the advancing obsidian flow (Castro et al, this session). On January 4th the north-western lava flow front was characterised by two dominant facies: predominant rubbly lava approximately 30-40 m thick and mantled by unstable talus aprons, and smoother, thinner lobes of more continuous lava ~50 m in length that extended roughly perpendicular to the overall flow direction, forming lobes that protrude from the flow margin, and lacked talus aprons. The latter lava facies closely resembled squeeze-up structures in basaltic lava flows[1] and appeared to originate from and overlie the talus apron of the rubbly lava. Its upper surface consisted of smooth, gently folded lava domains cut by crevasse-like tension gashes. During ~2 hours of observation the squeeze-up lava lobe was the most frequent location of small-volume rockfalls, which occurred at ~1-10 minute intervals from the flow front and indicated a locus of lava advance. On January 10th the squeeze-up lava lobes had evolved significantly, with disruption and breakage of smooth continuous lava surfaces to form

  16. Eruption and emplacement timescales of ignimbrite super-eruptions from thermo-kinetics of glass shards

    Directory of Open Access Journals (Sweden)

    Yan eLavallée

    2015-02-01

    Full Text Available Super-eruptions generating hundreds of cubic kilometres of pyroclastic density currents are commonly recorded by thick, welded and lava-like ignimbrites. Despite the huge environmental impact inferred for this type of eruption, little is yet known about the timescales of deposition and post-depositional flow. Without these timescales, the critical question of the duration of any environmental impact, and the ensuing gravity of its effects for the Earth system, eludes us. The eruption and welding of ignimbrites requires three transects of the glass transition. Magma needs to: 1 fragment during ascent, 2 liquefy and relax during deposition, agglutination and welding (sintering, and 3 quench by cooling into the glassy state. Here we show that welding is a rapid, syn-depositional process and that the welded ignimbrite sheet may flow for up to a few hours before passing through the glass transition a final time. Geospeedometry reveals that the basal vitrophyre of the Grey’s Landing ignimbrite underwent the glass transition at a rate of ~0.1 °C.min^-1 at 870 °C; that is, 30-180 °C below pre-eruptive geothermometric estimates. Application of a 1-D cooling model constrains the timescale of deposition, agglutination, and welding of the basal vitrophyre to less than 1 hour, and possibly even tens of minutes. Thermo-mechanical iteration of the sintering process indicates an optimal temperature solution for the emplacement of the vitrophyres at 966 °C. The vitrophyres reveal a Newtonian rheology up to 46 MPa, which suggests that the ash particles annealed entirely during welding and that viscous energy dissipation is unlikely from loading conditions alone, unless shear stresses imposed by the overlying ash flow were excessively high and sustained over long distances. The findings underline the value of the term 'lava-like' flow to describe the end rheology of Snake River-type ignimbrites, fully consistent with the typical lithofacies observed.

  17. Processes accompanying of mantle plume emplacement into continental lithosphere: Evidence from NW Arabian plate, Western Syria

    Science.gov (United States)

    Sharkov, E. V.

    2015-12-01

    Lower crustal xenoliths occurred in the Middle Cretaceous lamprophyre diatremes in Jabel Ansaria (Western Syria) (Sharkov et al., 1992). They are represented mainly garnet granulites and eclogite-like rocks, which underwent by deformations and retrograde metamorphism, and younger fresh pegmatoid garnet-kaersutite-clinopyroxene (Al-Ti augite) rocks; mantle peridotites are absent in these populations. According to mineralogical geothermobarometers, forming of garnet-granulite suite rocks occurred under pressure 13.5-15.4 kbar (depths 45-54 kn) and temperature 965-1115oC. At the same time, among populations of mantle xenoliths in the Late Cenozoic platobasalts of the region, quite the contrary, lower crustal xenoliths are absent, however, predominated spinel lherzolites (fragments of upper cooled rim of a plume head), derived from the close depths (30-40 km: Sharkov, Bogatikov, 2015). From this follows that ancient continental crust was existed here even in the Middle Cretaceous, but in the Late Cenozoic was removed by extended mantle plume head; at that upper sialic crust was not involved in geomechanic processes, because Precambrian metamorphic rocks survived as a basement for Cambrian to Cenozoic sedimentary cover of Arabian platform. In other words, though cardinal rebuilding of deep-seated structure of the region occurred in the Late Cenozoic but it did not affect on the upper shell of the ancient lithosphere. Because composition of mantle xenolithis in basalts is practically similar worldwide, we suggest that deep-seated processes are analogous also. As emplacement of the mantle plume heads accompanied by powerful basaltic magmatism, very likely that range of lower (mafic) continental crust existence is very convenient for extension of plume heads and their adiabatic melting. If such level, because of whatever reasons, was not reached, melting was limited but appeared excess of volatile matters which led to forming of lamprophyre or even kimberlite.

  18. Vertical movement in mare basins: relation to mare emplacement, basin tectonics, and lunar thermal history

    International Nuclear Information System (INIS)

    Solomon, S.C.

    1979-01-01

    The spatial and temporal relationships of linear rilles and mare ridges in the Serenitatis basin region of the moon are explained by a combination of lithospheric flexure in response to basin loading by basalt fill and a time-dependent global stress due to the thermal evolution of the lunar interior. The pertinent tectonic observations are the radial distance of basin concentric rilles or graben from the mare center; the location and orientation of mare ridges, interpreted as compressive features; and the restriction of graben formation to times older than 3.6 +- 0.2 b.y. ago, while ridge formation continued after emplacement of the youngest mare basalt unit (approx.3 b.y. ago). The locations of the graben are consistent with the geometry of the mare basalt load expected from the dimensions of multiring basins for values of the thickness of the elastic lithosphere beneath Serenitatis in the range 25--50 km at 3.6--3.8 b.y. ago. The locations and orientations of mare ridges are consistent with the load inferred from surface mapping and subsurface radar reflections for values of the elastic lithosphere thickness near 100 km at 3.0--3.4 b.y. ago. The thickening of the lithosphere beneath a major basin during the evolution of mare volcanism is thus clearly evident in the tectonics. The cessation of rille formation and the prolonged period of ridge formation are attributed to a change in the global horizontal thermal stress from extension to compression as the moon shifted from net expansion to overall cooling and contraction. Severe limits as placed on the range of possible lunar thermal histories. The zone of horizontal extensional stresses peripheral to mare loads favors the edge of mare basins as the preferred sites for mare basalt magma eruption in the later stages of mare fill, although subsidence may lead to accumulation of such young lavas in basin centers

  19. Structural control on basaltic dike and sill emplacement, Paiute Ridge mafic intrusion complex, southern Nevada

    International Nuclear Information System (INIS)

    Carter Krogh, K.E.; Valentine, G.A.

    1996-08-01

    Late Miocene basaltic sills and dikes in the Paiute Ridge area of southern nevada show evidence that their emplacement was structurally controlled. Basaltic dikes in this area formed by dilating pre-existing vertical to steeply E-dipping normal faults. Magma propagation along these faults must have required less energy than the creation of a self-propagated fracture at dike tips and the magma pressure must have been greater than the compressive stress perpendicular to the fault surface. N- to NE-trending en echelon dikes formed locally and are not obviously attached to the three main dikes in the area. The en echelon segments are probably pieces of deeper dikes, which are segmented perhaps as a result of a documented rotation of the regional stresses. Alternatively, changes in orientation of principal stresses in the vicinity of each en echelon dike could have resulted from local loads associated with paleotopographic highs or nearby structures. Sills locally branched off some dikes within 300 m of the paleosurface. These subhorizontal bodies occur consistently in the hanging wall block of the dike-injected faults, and intrude Tertiary tuffs near the Paleozoic-Tertiary contact. The authors suggest that the change in stresses near the earth's surface, the material strength of the tuff and paleozoic rocks, and the Paleozoic bedding dip direction probably controlled the location of sill formation and direction of sill propagation. The two largest sills deflected the overlying tuffs to form lopoliths, indicating that the magma pressure exceeded vertical stresses at that location and that the shallow level and large size of the sills allowed interaction with the free (earth's) surface. 32 refs., 4 figs., 1 tab

  20. Emplacement and erosive effects of the south Kasei Valles lava on Mars

    Science.gov (United States)

    Dundas, Colin M.; Keszthelyi, Laszlo P.

    2014-01-01

    Although it has generally been accepted that the Martian outflow channels were carved by floods of water, observations of large channels on Venus and Mercury demonstrate that lava flows can cause substantial erosion. Recent observations of large lava flows within outflow channels on Mars have revived discussion of the hypothesis that the Martian channels are also produced by lava. An excellent example is found in south Kasei Valles (SKV), where the most recent major event was emplacement of a large lava flow. Calculations using high-resolution Digital Terrain Models (DTMs) demonstrate that this flow was locally turbulent, similar to a previously described flood lava flow in Athabasca Valles. The modeled peak local flux of approximately 106 m3 s−1 was approximately an order of magnitude lower than that in Athabasca, which may be due to distance from the vent. Fluxes close to 107 m3 s−1 are estimated in some reaches but these values are probably records of local surges caused by a dam-breach event within the flow. The SKV lava was locally erosive and likely caused significant (kilometer-scale) headwall retreat at several cataracts with tens to hundreds of meters of relief. However, in other places the net effect of the flow was unambiguously aggradational, and these are more representative of most of the flow. The larger outflow channels have lengths of thousands of kilometers and incision of a kilometer or more. Therefore, lava flows comparable to the SKV flow did not carve the major Martian outflow channels, although the SKV flow was among the largest and highest-flux lava flows known in the Solar System.

  1. The Chimborazo sector collapse and debris avalanche: Deposit characteristics as evidence of emplacement mechanisms

    Science.gov (United States)

    Bernard, Benjamin; van Wyk de Vries, Benjamin; Barba, Diego; Leyrit, Hervé; Robin, Claude; Alcaraz, Samantha; Samaniego, Pablo

    2008-09-01

    Chimborazo is a Late Pleistocene to Holocene stratovolcano located at the southwest end of the main Ecuadorian volcanic arc. It experienced a large sector collapse and debris avalanche (DA) of the initial edifice (CH-I). This left a 4 km wide scar, removing 8.0 ± 0.5 km 3 of the edifice. The debris avalanche deposit (DAD) is abundantly exposed throughout the Riobamba Basin to the Río Chambo, more than 35 km southeast of the volcano. The DAD averages a thickness of 40 m, covers about 280 km 2, and has a volume of > 11 km 3. Two main DAD facies are recognized: block and mixed facies. The block facies is derived predominantly from edifice lava and forms > 80 vol.% of the DAD, with a probable volume increase of 15-25 vol.%. The mixed facies was essentially created by mixing brecciated edifice rock with substratum and is found mainly in distal and marginal areas. The DAD has clear surface ridges and hummocks, and internal structures such as jigsaw cracks, injections, and shear-zone features are widespread. Structures such as stretched blocks along the base contact indicate high basal shear. Substratum incorporation is directly observed at the base and is inferred from the presence of substratum-derived material in the DAD body. Based on the facies and structural interpretation, we propose an emplacement model of a lava-rich avalanche strongly cataclased before and/or during failure initiation. The flow mobilises and incorporates significant substrata (10-14 vol.%) while developing a fine lubricating basal layer. The substrata-dominated mixed facies is transported to the DAD interior and top in dykes invading previously-formed fractures.

  2. Fluid flow and reactive transport around potential nuclear waste emplacement tunnels at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Spycher, N.F.; Sonnenthal, E.L.; Apps, J.A.

    2002-01-01

    The evolution of fluid chemistry and mineral alteration around a potential waste emplacement tunnel (drift) is evaluated using numerical modeling. The model considers the flow of water, gas, and heat, plus reactions between minerals, CO 2 gas, and aqueous species, and porosity permeability-capillary pressure coupling for a dual permeability (fractures and matrix) medium. Two possible operating temperature modes are investigated: a ''high-temperature'' case with temperatures exceeding the boiling point of water for several hundred years, and a ''loW--temperature'' case with temperatures remaining below boiling for the entire life of the repository. In both cases, possible seepage waters are characterized by dilute to moderate salinities and mildly alkaline pH values. These trends in fluid composition and mineral alteration are controlled by various coupled mechanisms. For example, upon heating and boiling, CO 2 exsolution from pore waters raises pH and causes calcite precipitation. In condensation zones, this CO 2 redissolves, resulting in a decrease in pH that causes calcite dissolution and enhances feldspar alteration to clays. Heat also enhances dissolution of wallrock minerals leading to elevated silica concentrations. Amorphous silica precipitates through evaporative concentration caused by boiling in the high-temperature case, but does not precipitate in the loW--temperature case. Some alteration of feldspars to clays and zeolites is predicted in the high-temperature case. In both cases, calcite precipitates when percolating waters are heated near the drift. The predicted porosity decrease around drifts in the high-temperature case (several percent of the fracture volume) is larger by at least one order of magnitude than in the low temperature case. Although there are important differences between the two investigated temperature modes in the predicted evolution of fluid compositions and mineral alteration around drifts, these differences are small relative to

  3. Generation and emplacement of fine-grained ejecta in planetary impacts

    Science.gov (United States)

    Ghent, R.R.; Gupta, V.; Campbell, B.A.; Ferguson, S.A.; Brown, J.C.W.; Fergason, R.L.; Carter, L.M.

    2010-01-01

    We report here on a survey of distal fine-grained ejecta deposits on the Moon, Mars, and Venus. On all three planets, fine-grained ejecta form circular haloes that extend beyond the continuous ejecta and other types of distal deposits such as run-out lobes or ramparts. Using Earth-based radar images, we find that lunar fine-grained ejecta haloes represent meters-thick deposits with abrupt margins, and are depleted in rocks 1cm in diameter. Martian haloes show low nighttime thermal IR temperatures and thermal inertia, indicating the presence of fine particles estimated to range from ???10??m to 10mm. Using the large sample sizes afforded by global datasets for Venus and Mars, and a complete nearside radar map for the Moon, we establish statistically robust scaling relationships between crater radius R and fine-grained ejecta run-out r for all three planets. On the Moon, ???R-0.18 for craters 5-640km in diameter. For Venus, radar-dark haloes are larger than those on the Moon, but scale as ???R-0.49, consistent with ejecta entrainment in Venus' dense atmosphere. On Mars, fine-ejecta haloes are larger than lunar haloes for a given crater size, indicating entrainment of ejecta by the atmosphere or vaporized subsurface volatiles, but scale as R-0.13, similar to the ballistic lunar scaling. Ejecta suspension in vortices generated by passage of the ejecta curtain is predicted to result in ejecta run-out that scales with crater size as R1/2, and the wind speeds so generated may be insufficient to transport particles at the larger end of the calculated range. The observed scaling and morphology of the low-temperature haloes leads us rather to favor winds generated by early-stage vapor plume expansion as the emplacement mechanism for low-temperature halo materials. ?? 2010 Elsevier Inc.

  4. Using restored cross sections to evaluate magma emplacement, White Horse Mountains, Eastern Nevada, U.S.A.

    Science.gov (United States)

    Marko, Wayne T.; Yoshinobu, Aaron S.

    2011-03-01

    New field observations and cross section restoration from the Jurassic White Horse pluton-host rock system, Goshute Range, eastern Nevada, USA, indicate a sequential variation of host rock rheology attending magma emplacement. The pluton intruded weakly to nondeformed Devonian-Mississippian limestone, argillite and quartzite at shallow crustal levels (ca. 7 km). The contact aureole is well exposed along the southern, eastern and northern margin of the intrusive body and is less than 1 km wide. Rocks outside of the aureole are sub-horizontal and do not contain a penetrative fabric or are gently folded (interlimb angles > 120°) about sub-vertical axial planes. Within the contact aureole, continuous and discontinuous spaced, axial planar foliations and harmonic to disharmonic, tight to isoclinal folds wrap around the eastern margin of the pluton. Folds verge toward and away from the pluton and rim anticlines, synclines, and monoclines with wavelength in excess of 250 m are preserved along the pluton margin. The spatial proximity of these ductile structures to the pluton and the apparent increase in intensity of structure development approaching the pluton is compatible with contraction within the aureole attending pluton emplacement. However, all of the above structures are truncated by the intrusive contact at various scales. Granodioritic dikes ranging in thickness from 1 m up to ˜ 10 m emanate from the intrusion and cut host rock structure at high angles and turn to propagate towards one another, parallel to the pluton margin and host rock anisotropy. Such features are interpreted to reflect the last stages of diking and brittle deformation that modified the pluton contact after emplacement-related folding of the carbonate rocks, but before final solidification of the pluton. Eight serial geologic cross sections were constructed and evaluated to place geometric constraints on the shape and growth of the White Horse intrusion. Based on line-length restoration of

  5. Subduction initiation, recycling of Alboran lower crust, and intracrustal emplacement of subcontinental lithospheric mantle in the Westernmost Mediterranean

    Science.gov (United States)

    Varas-Reus, María Isabel; Garrido, Carlos J.; Bosch, Delphine; Marchesi, Claudio; Hidas, Károly; Booth-Rea, Guillermo; Acosta-Vigil, Antonio

    2015-04-01

    Unraveling the tectonic settings and processes involved in the annihilation of subcontinental mantle lithosphere is of paramount importance for our understanding of the endurance of continents through Earth history. Unlike ophiolites -- their oceanic mantle lithosphere counterparts -- the mechanisms of emplacement of the subcontinental mantle lithosphere in orogens is still poorly known. The emplacement of subcontinental lithospheric mantle peridotites is often attributed to extension in rifted passive margins or continental backarc basins, accretionary processes in subduction zones, or some combination of these processes. One of the most prominent features of the westernmost Mediterranean Alpine orogenic arcs is the presence of the largest outcrops worldwide of diamond facies, subcontinental mantle peridotite massifs; unveiling the mechanisms of emplacement of these massifs may provide important clues on processes involved in the destruction of continents. The western Mediterranean underwent a complex Alpine evolution of subduction initiation, slab fragmentation, and rollback within a context of slow convergence of Africa and Europe In the westernmost Mediterranean, the alpine orogeny ends in the Gibraltar tight arc, which is bounded by the Betic, Rif and Tell belts that surround the Alboran and Algero-Balearic basins. The internal units of these belts are mostly constituted of an allochthonous lithospheric domain that collided and overthrusted Mesozoic and Tertiary sedimentary rocks of the Mesozoic-Paleogene, South Iberian and Maghrebian rifted continental paleomargins. Subcontinental lithospheric peridotite massifs are intercalated between polymetamorphic internal units of the Betic (Ronda, Ojen and Carratraca massifs), Rif (Beni Bousera), and Tell belts. In the Betic chain, the internal zones of the allochthonous Alboran domain include, from bottom to top, polymetamorphic rock of the Alpujarride and Malaguide complexes. The Ronda peridotite massif -- the

  6. Statistical analysis of the sustained lava dome emplacement and destruction processes at Popocatépetl volcano, Central México

    Science.gov (United States)

    Mendoza-Rosas, Ana Teresa; Gómez-Vázquez, Ángel; De la Cruz-Reyna, Servando

    2017-06-01

    Popocatépetl volcano reawakened in 1994 after nearly 70 years of quiescence. Between 1996 and 2015, a succession of at least 38 lava domes have been irregularly emplaced and destroyed, with each dome reaching particular volumes at specific emplacement rates. The complexity of this sequence is analyzed using statistical methods in an attempt to gain insight into the physics and dynamics of the lava dome emplacement and destruction process and to objectively assess the hazards related to that volcano. The time series of emplacements, dome residences, lava effusion lulls, and emplaced dome volumes and thicknesses are modeled using the simple exponential and Weibull distributions, the compound non-homogeneous generalized Pareto-Poisson process (NHPPP), and the mixture of exponentials distribution (MOED). The statistical analysis reveals that the sequence of dome emplacements is a non-stationary, self-regulating process most likely controlled by the balance between buoyancy-driven magma ascent and volatile exsolution crystallization. This balance has supported the sustained effusive activity for decades and may persist for an undetermined amount of time. However, the eruptive history of Popocatépetl includes major Plinian phases that may have resulted from a breach in that balance. Certain criteria to recognize such breaching conditions are inferred from this statistical analysis.

  7. Electrokinetically Emplaced Amendments for Enhanced Bioremediation of Chlorinated Solvents in Clay: a Pilot Field Test

    Science.gov (United States)

    O'Carroll, D. M.; Inglis, A.; Head, N.; Chowdhury, A. I.; Garcia, A. N.; Reynolds, D. A.; Hogberg, D.; Edwards, E.; Lomheim, L.; Austrins, L. M.; Hayman, J.; Auger, M.; Sidebottom, A.; Eimers, J.; Gerhard, J.

    2017-12-01

    Bioremediation is an increasingly popular treatment technology for contaminated sites due to the proven success of biostimulation and bioaugmentation. However, bioremediation, along with other in-situ remediation technologies, faces limitations due to challenges with amendment delivery in low permeability media. Studies have suggested that electrokinetics (EK) can enhance the delivery of amendments in low permeability soils, such as clay. A pilot field trial was conducted to evaluate the potential for electrokinetics to support anaerobic dechlorination in clay by improving the transport of lactate and microorganisms. The study was performed on a former chlorinated solvent production facility in Ontario, Canada. Five transect cells were set up within the contaminated clay test area. Different amendments were injected in three of these cells to test various remediation strategies under the influence of EK. The other two cells were used as controls, one with EK applied and the other with no EK. This study focuses on the cell that applied electrokinetics for lactate emplacement followed by bioremediation (EK-Bio). This cell had an initial single injection of KB-1 bioaugmentation culture (SiREM, Canada) followed by injection of sodium lactate as a biostimulant while direct current was applied for 45 days between two electrodes 3 m apart. EK can enhance lactate migration by electromigration, while microorganisms have the potential to be influenced by electroosmosis of the bulk fluid or by electrophoresis of the charged bacteria themselves. All monitoring well locations in the EK-Bio cell exhibited evidence of successful lactate delivery corresponding to an increase in dissolved organic carbon. Reduction in chlorinated volatile organic compound (cVOC) concentrations, in particular 1,2-dichloroethane (1,2-DCA), were evident in monitoring locations coinciding with significant lactate breakthrough. Further investigation into the influence of EK-Bio on the abundance and

  8. Understanding the mechanical coupling between magma emplacement and the resulting deformation: the example of saucer-shaped sills

    Science.gov (United States)

    Galland, O.; Neumann, E. R.; Planke, S.

    2009-12-01

    The mechanical coupling between magma intrusions and the surrounding rocks plays a major role in the emplacement of volcanic plumbing systems. The deformation associated with magma emplacement has been widely studied, such as caldera inflation/deflation, volcano deformation during dike intrusion, and doming above laccoliths. However, the feedback processes, i.e. the effect of deformation resulting from intruding magma on the propagation of the intrusion itself, have rarely been studied. Saucer-shaped sills are adequate geological objects to understand such processes. Indeed, observation show that saucer-shaped sills are often associated with dome-like structures affecting the overlying sediments. In addition, there is a clear geometrical relation between the sills and the domes: the dome diameters are almost identical to those of saucers, and the tips of the inclined sheets of saucers are superimposed on the edges of the domes. In this presentation, we report on experimental investigations of the emplacement mechanisms of saucer-shaped sills and associated deformation. The model materials were (1) cohesive fine-grained silica flour, representing brittle crust, and (2) molten low-viscosity oil, representing magma. A weak layer located at the top of the injection inlet simulates strata. The main variable parameter is injection depth. During experiments, the surface of the model is digitalized through a structured light technique based on the moiré projection principle. Such a tool provides topographic maps of the surface of the model and allows a periodic (every 1.5 s) monitoring of the model topography. When the model magma starts intruding, a symmetrical dome rises above the inlet. Subsequently, the dome inflates and widens, and then evolves to a plateau-like feature, with nearly flat upper surface and steep sides. At the end of the experiments, the intruding liquid erupts at the edge of the plateau. The intrusions formed in the experiments are saucer-shaped sills

  9. Constraining Controls on the Emplacement of Long Lava Flows on Earth and Mars Through Modeling in ArcGIS

    Science.gov (United States)

    Golder, K.; Burr, D. M.; Tran, L.

    2017-12-01

    Regional volcanic processes shaped many planetary surfaces in the Solar System, often through the emplacement of long, voluminous lava flows. Terrestrial examples of this type of lava flow have been used as analogues for extensive martian flows, including those within the circum-Cerberus outflow channels. This analogy is based on similarities in morphology, extent, and inferred eruptive style between terrestrial and martian flows, which raises the question of how these lava flows appear comparable in size and morphology on different planets. The parameters that influence the areal extent of silicate lavas during emplacement may be categorized as either inherent or external to the lava. The inherent parameters include the lava yield strength, density, composition, water content, crystallinity, exsolved gas content, pressure, and temperature. Each inherent parameter affects the overall viscosity of the lava, and for this work can be considered a subset of the viscosity parameter. External parameters include the effusion rate, total erupted volume, regional slope, and gravity. To investigate which parameter(s) may control(s) the development of long lava flows on Mars, we are applying a computational numerical-modelling to reproduce the observed lava flow morphologies. Using a matrix of boundary conditions in the model enables us to investigate the possible range of emplacement conditions that can yield the observed morphologies. We have constructed the basic model framework in Model Builder within ArcMap, including all governing equations and parameters that we seek to test, and initial implementation and calibration has been performed. The base model is currently capable of generating a lava flow that propagates along a pathway governed by the local topography. At AGU, the results of model calibration using the Eldgá and Laki lava flows in Iceland will be presented, along with the application of the model to lava flows within the Cerberus plains on Mars. We then

  10. Emplaced writing figuring as a manifestation of an ecocentric mindset in the narrative art of Petra Müller

    Directory of Open Access Journals (Sweden)

    Susan Meyer

    2014-06-01

    Full Text Available The human-earth connection is a sustained theme in Petra Müller’s oeuvre. The article focuses on this connection as reflected in her narrative art, specifically in accounts that have an autobiographical proclivity. The aim of this article is to outline the nature-centred disposition of Müller’s narrative art in a more definite sense. This is achieved by paying attention to the manner in which the author (the ‘I’ in accounts where the narrator can be identified as the author herself becomes part of the natural environment – whether on a sensory, an emotive, or an intellectual level – where she finds herself and the way she responds to it. At the core of the investigation are the ways in which this reactive engagement is manifested in Müller’s prose work by the implied author and the technique ofemplaced writing. Emplaced writing, a concept created by Linda Russo, was integrated by Susan Smith with Lawrence Buell’s concept of emplacement. This term refers to the technique allowing an active awareness of self and the place physically occupied by the author, as well as how that body fits into this place, to find expression. A broader perspective and greater appreciation of Müller’s work are drawn from the insight into how her close coexistence with the earth is reflected in her narrative art by means of the technique of emplaced writing which is explored in this article as it gives voice to a strong ecocentric disposition.

  11. Design management and stress analysis of a circular rock tunnel and emplacement holes for storage of spent nuclear fuel

    International Nuclear Information System (INIS)

    Kandalaft-Ladkany, N.; Wyman, R.V.

    1992-01-01

    This paper discusses a critical path method (CPM) diagram and logic net which are used for the design cycle of the rock tunnel system for a high level nuclear waste repository. In the analysis the design tunnel is subjected to pre-existing temperature and overburden loads at time of construction. high thermal stresses develop later due to the long term influx of heat from the canisters stored in vertical emplacement holes. Results indicate that thermal stresses reach a critical level for the rock in the vicinity of the canisters which could lead to local collapse of the rock and damage to the canisters

  12. Pre-waste-emplacement ground-water travel time sensitivity and uncertainty analyses for Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Kaplan, P.G.

    1993-01-01

    Yucca Mountain, Nevada is a potential site for a high-level radioactive-waste repository. Uncertainty and sensitivity analyses were performed to estimate critical factors in the performance of the site with respect to a criterion in terms of pre-waste-emplacement ground-water travel time. The degree of failure in the analytical model to meet the criterion is sensitive to the estimate of fracture porosity in the upper welded unit of the problem domain. Fracture porosity is derived from a number of more fundamental measurements including fracture frequency, fracture orientation, and the moisture-retention characteristic inferred for the fracture domain

  13. Engineered barrier emplacement experiment in Opalinus clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J. L.; Alonso, E.; Alheid, H. J.; Blumbling, P.

    2005-01-01

    exclusively devoted to the GBM: fabrication, emplacement equipments, and hydraulic, mechanical and geophysical (seismic) characterization in conventional laboratory. Chapter 4 refers to the excavation of the experimental drift, and to the geophysical (seismic, electric) and hydrogeological characterization of the near field of the clay rock. Chapter 5 is devoted to the installation of the different in situ test components, systems and instruments. The experimental in situ test results and interpretation is presented in Chapter 6, while their modelling and interpretation is presented in Chapter 7. Chapter 8 includes an assessment of the experiment results and overall conclusions, in relation to the declared project objectives. Chapter 9 consists of a list of references. Although a large number of bibliographic references have been used in this project, each included in the corresponding specific reports, the only references included herein are the specific reports detailing the various tasks performed to date, plus a few other reports considered to be essential. (Author)

  14. Engineered barrier emplacement experiment in opalinus clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J. L.; Alonso, E.; Alheid, H. J.; Blumbling, P.

    2005-01-01

    exclusively devoted to the GBM: fabrication, emplacement equipments, and hydraulic, mechanical and geophysical (seismic) characterization in conventional laboratory. Chapter 4 refers to the excavation of the experimental drift, and to the geophysical (seismic, electric) and hydrogeological characterization of the near field of the clay rock. Chapter 5 is devoted to the installation of the different in situ test components, systems and instruments. The experimental in situ test results and interpretation is presented in Chapter 6, while their modelling and interpretation is presented in Chapter 7. Chapter 8 includes an assessment of the experiment results and overall conclusions, in relation to the declared project objectives. Chapter 9 consists of a list of references. Although a large number of bibliographic references have been used in this project, each included in the corresponding specific reports, the only references included herein are the specific reports detailing the various tasks performed to date, plus a few other reports considered to be essential. (Author)

  15. Feasibility studies of air placed techniques as emplacement means of different backfilling materials in underground radioactive waste disposal

    International Nuclear Information System (INIS)

    Atabek, R.; Conche, P.; Lajudie, A.; Revertegat, E.

    1992-01-01

    Air placed techniques are likely to be used as emplacement means of different backfilling materials in underground waste repositories. A literature survey of the air placed techniques and equipments leads to the choice of the dry process taking into account the emplacement constraints (distance: 300 m, flow: 10 m 3 /h) and the large variety of materials to be placed. Tests performed in the case of cement-based materials (with and without addition of silica fumes), for different types of cement and as a function of the incidence of the jet, show that it is possible to put in place mortars of good quality. However heterogeneity in the material composition is found when the jet is stopped. This problem may be partly solved by a better automation of the process. Complementary tests, carried out with the preselected clay of Fourges Cahaignes, clearly demonstrate the ability of the air placed technique to put in place pure clay: a dry density of 1.50kg/m 3 is reached in the case of coarse material and for a final water content of 30% (in weight). Feasibility tests performed on clay-sand mixtures are not conclusive due to an unappropriate granulometry distribution of the sand. 11 figs., 9 tabs

  16. The controlling role of positive structures over the metallogenesis and emplacement of inter layer oxidation sandstone type uranium deposits

    International Nuclear Information System (INIS)

    Gu Kangheng; Chen Zuyi

    2010-01-01

    The positive structures in this paper mean the geological structures related to the occurrence of U-metallogenic zones or U-deposit such as anticlines, uplifts and uplifted fault-blocks. Occurrence features of interlayer oxidation sandstone type deposit at the southern margin of Yili basin and southwestern margin of Turpan-Hami basin, the northeastern margin of Jiudong basin illustrate that the sandstone-hosted uranium deposits, the U-mineralized sections and the uranium occurrences are always selectively emplaced on/in positive structures. The reasons for this lie in the formation mechanism of sandstone-hosted U-deposits. The positive structures raised the elevation of ore-hosting sandstone horizon and make it close to ground surface or exposed at the ground surface, which result in the infiltration of uranium and oxygen bearing groundwater from recharge area into host sandstone horizon, and the interlayer oxidation of host sandstone, as well as the dissolution and the migration of uranium in host sandstone, and the reduction mineralization at the oxidation-reduction interface. Sufficient attention should be paid to the controlling role of positive structures over the metallogenesis and emplacement of sandstone-hosted uranium deposits. They could act as an important criterion for recognizing and prognosticating potential uranium mineralized areas in uranium metallogenic zones or uranium-productive sedimentary basins. (authors)

  17. Effects of the deviation characteristics of nuclear waste emplacement boreholes on borehole liner stresses; Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    Glowka, D.A.

    1990-09-01

    This report investigates the effects of borehole deviation on the useability of lined boreholes for the disposal of high-level nuclear waste at the proposed Yucca Mountain Repository in Nevada. Items that lead to constraints on borehole deviation include excessive stresses that could cause liner failure and possible binding of a waste container inside the liner during waste emplacement and retrieval operations. Liner stress models are developed for two general borehole configurations, one for boreholes drilled with a steerable bit and one for boreholes drilled with a non-steerable bit. Procedures are developed for calculating liner stresses that arise both during insertion of the liner into a borehole and during the thermal expansion process that follows waste emplacement. The effects of borehole curvature on the ability of the waste container to pass freely inside the liner without binding are also examined. Based on the results, specifications on borehole deviation allowances are developed for specific vertical and horizontal borehole configurations of current interest. 11 refs., 22 figs., 4 tabs.

  18. Low Amplitude of Geomagnetic Secular Variations Recorded in Traps of the Southern Siberian Platform: Very Fast Emplacement or Regional Remagnetization?

    Science.gov (United States)

    Veselovskiy, R. V.; Latyshev, A. V.; Pavlov, V. E.

    2011-12-01

    We have studied the lowest part of the Permo-Triassic Siberian trap sequence which is located in the middle course of the Angara river (Southern Siberia). This sequenced is composed by 200m thick volcanoclastic rocks (tuffs with bombs of different composition) and includes numerous mafic subvolcanic bodies (dykes and sills). Altogether more than 20 sites representing tuffs, bombs, dykes and sills stretched along the valley of the Angara river over the distance more than 30 km have been sampled and studied. Obtained site mean paleomagnetic directions are tightly grouped, showing very lower scatter. Taking into account that amplitude of geomagnetic secular variation at the P-T boundary was about of same order as in Late Cenozoic (Pavlov et al., 2011) this lower scatter can be either a sequence of very fast traps emplacement which could have disastrous environmental impact or a result of subsequent regional remagnetization. The only geological event in the region which seems to be capable to cause this remagnetization is emplacement of Early Triassic sills in nearby areas. In such the case we should expect that mean paleomagnetic directions from these sills will be very close to these ones obtained from site presented in this report. We present results of paleomagnetic studies of these sills and make a choice in favor of one of discussed options. This work was supported by grants NSF EAR 0807585 ("The Siberian Traps and end-Permian extinction") and RFBR 09-05-01180, 10-05-00557.

  19. Contrasting magmatic structures between small plutons and batholiths emplaced at shallow crustal level (Sierras de Córdoba, Argentina)

    Science.gov (United States)

    Pinotti, Lucio P.; D'Eramo, Fernando J.; Weinberg, Roberto F.; Demartis, Manuel; Tubía, José María; Coniglio, Jorge E.; Radice, Stefania; Maffini, M. Natalia; Aragón, Eugenio

    2016-11-01

    Processes like injection, magma flow and differentiation and influence of the regional strain field are here described and contrasted to shed light on their role in the formation of small plutons and large batholiths their magmatic structures. The final geometric and compositional arrangement of magma bodies are a complex record of their construction and internal flow history. Magma injection, flow and differentiation, as well as regional stresses, all control the internal nature of magma bodies. Large magma bodies emplaced at shallow crustal levels result from the intrusion of multiple magma batches that interact in a variety of ways, depending on internal and external dynamics, and where the early magmatic, growth-related structures are commonly overprinted by subsequent history. In contrast, small plutons emplaced in the brittle-ductile transition more likely preserve growth-related structures, having a relatively simple cooling history and limited internal magma flow. Outcrop-scale magmatic structures in both cases record a rich set of complementary information that can help elucidate their evolution. Large and small granitic bodies of the Sierra Pampeanas preserve excellent exposures of magmatic structures that formed as magmas stepped through different rheological states during pluton growth and solidification. These structures reveal not only the flow pattern inside magma chambers, but also the rheological evolution of magmas in response to temperature evolution.

  20. Geochemical significance of neoproterozoic rasimalai alkali syenite emplaced along Dharmapuri shear zone in the Northern part of Tamil Nadu

    International Nuclear Information System (INIS)

    Thangavel, S.; Balasubramani, S.; Nagaraju, M.; Bhattacharya, D.; Zakaulla, Syed; Rai, A.K.

    2015-01-01

    The Rasimalai alkali syenite complex is emplaced within Peninsular Gneissic complex and spatially associated with NE-SW trending major Dharmapuri shear zone (DSZ) in the northern part of Tamil Nadu. It is surrounded by epidote hornblend egneiss, which is the fenetised product of Charnockite and occurs about 20 km NE of Alangayam in Vellore district. It is mainly comprised of medium to coarse grained grey syenite (albite and orthoclase) and medium to micro grained pink syenite (orthoclase, microcline and perthite) at places porphyritic in nature with hornblende, riebeckitc, aegirine and acmite as accessory minerals. Grey syenite is non radioactive and uranium mineralisation is associated with pink syenite (syngenetic and disseminated type) and quartz-barite veins (hydrothermal type). Hydrothermal activity is manifested in the form of pyrite, chalcopyrite, galena, barite, calcite and calcian-strontianite which occur in the form of disseminations, stringers, lumps, aggregates, veinlets and veins. Presence of high silica (63.14-75.43%) with high field strength elements (U, Th, Nb and Pb) and large ion lithophile elements (Rb, Sr, K, Ba) possibly indicates that Rasimalai alkali syenite is the product of crustal communication and partial melting of protracted emplacement of parental alkali basaltic magma

  1. Engineering studies: high-level radioactive waste repositories task 3 - review of underground handling and emplacement. 1. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    1981-02-01

    The report reviews proposals for transport, handling and emplacement of high-level radioactive waste in an underground repository with particular reference to: waste block size and configuration; self-shielded or partially-shielded block; stages of disposal; transport by road/rail to repository site; handling techniques within repository; emplacement in vertical holes or horizontal tunnels; repository access by adit, incline or shaft; conventional and radiological safety; costs; and major areas of uncertainty requiring research or development. In carrying out this programme due attention was given to work already carried out both in the U.K. and overseas and where appropriate comparisons with this work have been made to substantiate and explain the observations made in this report. The examination and use of this previous work however has been confined to those proposals which were considered capable of meeting the basic design criterion for a U.K. based repository, that the maximum temperature achieved by the host rock should not exceed 100/sup 0/C.

  2. Pluton emplacement in a releasing bend in a transpressive regime: the arrozal granite in the Paraíba do Sul shear belt, Rio de Janeiro.

    Science.gov (United States)

    Nummer, Alexis R; Machado, Rômulo; Dehler, Nolan M

    2007-06-01

    The Arrozal Granite, situated in the southwestern region of the State of Rio de Janeiro, has a granitic to granodioritic composition. It contains a strong mylonitic foliation along its border, passing gradually to a well-developed magmatic foliation towards its center. Structural analysis indicates that the Arrozal Granite was emplaced along the Além-Paraíba Shear Zone in a dextral transpressive tectonic regime. A regional shift of the trend along this shear zone from NE-SW to E-W, observed in the area, is interpreted to be casually related to the creation of space for the emplacement of the granite. Our data indicate that releasing bends may have played an important role for space generation during the emplacement of the Arrozal Granite and other plutons.

  3. Anisotropy of magnetic susceptibility of silicic rocks from quarries in the vicinity of São Marcos, Rio Grande do Sul, South Brazil: Implications for emplacement mechanisms

    Science.gov (United States)

    Cañón-Tapia, Edgardo; Raposo, M. Irene B.

    2018-04-01

    The Paraná-Etendeka Large Igneous Province includes acid volcanic rocks that can be found throughout its extension. Several aspects concerning those rocks remain controversial, including their mechanism of emplacement and location of their eruptive sources. Opening of several quarries of dimension stone near the city of Sao Marcos, Rio Grande do Sul, Brazil, offers a unique opportunity to study in detail the acid products. Here, we present the results of a study of the anisotropy of magnetic susceptibility (AMS) completed in some rocks that had been interpreted as the roots of volcanic conduits. Our results, and reexamination of the textural features of the rocks, lead to a reinterpretation that suggests that these rocks were emplaced subaerially, and involved assimilation and remelting of clastic components of previous products. Due to the inferred conditions of emplacement, it is unlikely that the eruptive vents are located far from the area of study, therefore ruling out the long-travelled nature of these products.

  4. State of the art for fabricating and emplacing concrete containers into large horizontal disposal caverns in the french geological repository - 59267

    International Nuclear Information System (INIS)

    Bosgiraud, Jean-Michel; Guariso, Maurice; Pineau, Francois

    2012-01-01

    The research and development work presented in this paper was initialized by Andra in 2007. The work necessary for manufacturing and testing a full scale demonstrator is presently implemented. The case story is twofold. The first part is related to the initial development of a high performance concrete formulation used for fabricating concrete storage containers (containing Intermediate Level and Long Lived Waste primary canisters) to be stacked and emplaced into 400-m long concrete lined horizontal disposal vaults (also called cavern), excavated in the Callovo-Oxfordian clay host formation at a 550 to 600-m depth, with an inside diameter of approximately 8-m. The fabrication of the concrete boxes is illustrated. The second part presents the outcome at the end of the detailed design phase, for a system which is now being manufactured (for further test and assembly), for the emplacement of the concrete containers inside the vault. The application was engineered for remote emplacing a pile of 2 concrete containers (the containers are preliminarily stacked in a pile of 2, inside a hot cell, thanks to a ground travelling gantry crane). The emplacement process is justified and the related emplacement synoptic is illustrated. The test campaign is scheduled in 2011-2012. The successful completion of the technical trials is mandatory to confirm the mechanical feasibility of remotely emplacing concrete containers into large horizontal disposal caverns over long distances. The later display of the machinery at work in Andra's showroom will be instrumental for the confidence building process involving the various stakeholders concerned by the public enquiry period (mid-2013) preceding the deep geological repository license application (2014-2015). (authors)

  5. Emplacement, petrological and magnetic susceptibility characteristics of diverse magmatic epidote-bearing granitoid rocks in Brazil, Argentina and Chile

    Science.gov (United States)

    Sial, A. N.; Toselli, A. J.; Saavedra, J.; Parada, M. A.; Ferreira, V. P.

    1999-03-01

    Magmatic epidote (mEp)-bearing granitoids from five Neoproterozoic tectonostratigraphic terranes in Northeastern (NE) Brazil, Early Palaeozoic calc-alkalic granitoids in Northwestern (NW) Argentina and from three batholiths in Chile have been studied. The elongated shape of some of these plutons suggests that magmas filled fractures and that dyking was probably the major mechanism of emplacement. Textures reveal that, in many cases, epidote underwent partial dissolution by host magma and, in these cases, may have survived dissolution by relatively rapid upward transport by the host magma. In plutons where such a mechanism is not evident, unevenly distributed epidote at outcrop scale is armoured by biotite or near-solidus K-feldspar aggregates, which probably grew much faster than epidote dissolution, preventing complete resorption of epidote by the melt. Al-in-hornblende barometry indicates that, in most cases, amphibole crystallized at P≥5 kbar. Kyanite-bearing thermal aureoles surrounding plutons that intruded low-grade metamorphic rocks in NE Brazil support pluton emplacement at intermediate to high pressure. mEp show overall chemical variation from 20 to 30 mol% (mole percent) pistacite (Ps) and can be grouped into two compositional ranges: Ps 20-24 and Ps 27-30. The highest Ps contents are in epidotes of plutons in which hornblende solidified under Pcorrosion of individual epidote crystals included in plagioclase in high-K calc-alkalic granitoids in NE Brazil, emplaced at 5-7 kbar pressure, yielded estimates of magma transport rate from 70 to 350 m year -1. Most of these plutons lack Fe-Ti oxide minerals and Fe +3 is mostly associated with the epidote structure. Consequently, magnetic susceptibility (MS) in the Neoproterozoic granitoids in NE Brazil, as well as Early Palaeozoic plutons in Argentina and Late Palaeozoic plutons in Chile, is usually low (3.0×10 -3 SI, typical of magnetite-series granitoids crystallized under higher oxygen fugacity. In NE

  6. Control of Precambrian basement deformation zones on emplacement of the Laramide Boulder batholith and Butte mining district, Montana, United States

    Science.gov (United States)

    Berger, Byron R.; Hildenbrand, Thomas G.; O'Neill, J. Michael

    2011-01-01

    What are the roles of deep Precambrian basement deformation zones in the localization of subsequent shallow-crustal deformation zones and magmas? The Paleoproterozoic Great Falls tectonic zone and its included Boulder batholith (Montana, United States) provide an opportunity to examine the importance of inherited deformation fabrics in batholith emplacement and the localization of magmatic-hydrothermal mineral deposits. Northeast-trending deformation fabrics predominate in the Great Falls tectonic zone, which formed during the suturing of Paleoproterozoic and Archean cratonic masses approximately 1,800 mega-annum (Ma). Subsequent Mesoproterozoic to Neoproterozoic deformation fabrics trend northwest. Following Paleozoic through Early Cretaceous sedimentation, a Late Cretaceous fold-and-thrust belt with associated strike-slip faulting developed across the region, wherein some Proterozoic faults localized thrust faulting, while others were reactivated as strike-slip faults. The 81- to 76-Ma Boulder batholith was emplaced along the reactivated central Paleoproterozoic suture in the Great Falls tectonic zone. Early-stage Boulder batholith plutons were emplaced concurrent with east-directed thrust faulting and localized primarily by northwest-trending strike-slip and related faults. The late-stage Butte Quartz Monzonite pluton was localized in a northeast-trending pull-apart structure that formed behind the active thrust front and is axially symmetric across the underlying northeast-striking Paleoproterozoic fault zone, interpreted as a crustal suture. The modeling of potential-field geophysical data indicates that pull-apart?stage magmas fed into the structure through two funnel-shaped zones beneath the batholith. Renewed magmatic activity in the southern feeder from 66 to 64 Ma led to the formation of two small porphyry-style copper-molybdenum deposits and ensuing world-class polymetallic copper- and silver-bearing veins in the Butte mining district. Vein orientations

  7. Triassic tholeiitic dolerites («ophites» of the El Grado diapir (Pyrenees, Huesca, Spain: emplacement and composition

    Directory of Open Access Journals (Sweden)

    Lago San José, M.

    2000-04-01

    Full Text Available Mesozoic dolerites in the south Pyrenean sector of El Grado (Huesca, Spain preserve emplacement structures (fluidity structures at the top and load structures at the base developed during their intrusion into unconsolidated marly-evaporitic Triassic sediments (Keuper facies. By analogy with other dolerites in the south Pyrenean domain, their emplacement age is equivalent to the uppermost Keuper facies terms, but prior to the final Triassic-early Liassic carbonated sediments. Radiometric ages (187-197±7 Ma show that the emplacement occurred during the lower Liassic. The petralogical differentiation from the chilled margin facies to the central facies, and also to the late pegmatitoids, is consistent with that obtained from major elements, trace elements and REE. Their tholeiitic affinity, as defined by their geochemical composition, is equivalent to that of similar racks in the Pyrenean domain. However, the rocks analyzed here, which are located at the external sector of this domain, display a greater petralogical and geochemical differentiation as compared to similar rocks in the central sectors of the Pyrenean domain.Las doleritas mesozoicas del sector surpirenaico de El Grado (Huesca conservan estructuras de emplazamiento (con desarrollo del movimiento de lava fluida al techo y de carga en su base desarrolladas al instruir en los sedimentos margo-evaporíticos en facies Keuper, todavía inconsolidados. Por similitud con otras doleritas del dominio surpirenaico, la edad del emplazamiento es equivalente a la de los términos superiores de la facies Keuper y previa a la sedimentación carbonatada del Trías terminal-Lías inferior. Las determinaciones de edades radiométricas (187-197±7 Ma indican que el emplazamiento debió tener lugar durante el Lías inferior. La diferenciación petralógica, desde la facies del borde enfriado a la central y, también, al posterior diferenciado pegmatoide concuerda con la obtenida con elementos mayores

  8. Distribución óptima de carga en emplazamientos de generadores; Optimal charging distribution in emplacements of generators

    Directory of Open Access Journals (Sweden)

    Sergio de la Fé Dotres

    2014-04-01

    Full Text Available Incorporados al Sistema Eletroenergético Nacional funcionan emplazamientos de generación distribuida que representan más del 40 por ciento de la capacidad generadora instalada. Estos grupo utilizan fuel oil o diesel como combustibles por lo que lograr su explotación eficiente constituye una necesidad económica de primer orden. Se propone un instrumento computacional para lograr la mayor eficiencia en el uso del combustible mediante la distribución económica de las cargas y se desarrolla un método de optimización basado en el criterio del costo incremental del combustible para determinar el costo total de la generación del emplazamiento. Empleando un algoritmo genético simple se minimiza la función del costo mediante la asignación de las potencias a generar por cada máquina. Se comprueba la aplicabilidad del método mediante su aplicación a un emplazamiento específico. Por su rapidez y calidad de los resultados el instrumento computacional se recomienda para su explotación en emplazamientos y el despacho.  The emplacements of distributed generation that represent over the 40 percent of the generating installed capability work to the electric national system incorporated. These group Fuel Oil or diesel utilize like fuels for that achieving his efficient exploitation constitutes a need cheap to run first-rate. Distribution cheap to run of loads proposes a computational instrument to achieve the bigger efficiency in the use of intervening fuel itself and a method of optimization based in the opinion of the incremental cost of fuel to determine the total cost of the generation of the emplacement develops. Using a genetic algorithm the assignment of potencies minimizes the show of the intervening cost itself to generate for each machine. His application finds to a specific summons the applicability of the intervening method. For his rapidity and quality of results the computational instrument is recommended to exploitation in

  9. Emplacement controls for the basaltic-andesitic radial dikes of Summer Coon volcano and implications for flank vents at stratovolcanoes

    Science.gov (United States)

    Harp, A. G.; Valentine, G. A.

    2018-02-01

    Mafic flank eruptions are common events that pose a serious hazard to the communities and infrastructure often encroaching on the slopes of stratovolcanoes. Flank vent locations are dictated by the propagation path of their feeder dikes. The dikes are commonly thought to propagate either laterally from the central conduit or vertically from a deeper source. However, these interpretations are often based on indirect measurements, such as surface deformation and seismicity at active systems, and several studies at eroded volcanoes indicate the propagation paths may be more complex. We investigated the Oligocene age Summer Coon volcano (Colorado, USA), where erosion has exposed over 700 basaltic-andesitic radial dikes, to constrain the propagation directions, geometries, and spatial distributions of mafic dikes within a stratovolcano. The mean fabric angle of aligned plagioclase crystals was measured in oriented samples from the margins of 77 dikes. Of the 41 dikes with statistically significant flow fabrics, 85% had fabric angles that were inclined—plunging both inward and outward relative to the center of the volcano. After comparing fabric angles to those reported in other studies, we infer that, while most of the dikes with outward-plunging fabrics descended toward the flanks from a source within the edifice and near its axis, dikes with inward-plunging fabrics ascended through the edifice and toward the flanks from a deeper source. A possible control for the inclination of ascending dikes was the ratio between magma overpressure and the normal stress in the host rock. While higher ratios led to high-angle propagation, lower ratios resulted in inclined emplacement. Dikes crop out in higher frequencies within a zone surrounding the volcano axis at 2500 m radial distance from the center and may be the result of ascending dikes, emplaced at similar propagation angles, intersecting the current level of exposure at common distances from the volcano axis. The process

  10. Monte-Carlo based comparison of the personal dose for emplacement scenarios of spent nuclear fuel casks in generic deep geological repositories

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, Hector Sauri; Becker, Franz; Metz, Volker [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Pang, Bo [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Shenzhen Univ. (China). College of Physics and Energy

    2017-06-15

    In the operational phase of a deep geological disposal facility for high-level nuclear waste, the radiation field in the vicinity of a waste cask is influenced by the backscattered radiation of the surrounding walls of the emplacement drift. For a comparison of disposal of spent nuclear fuel in various host rocks, it is of interest to investigate the influence of the surrounding materials on the radiation field and the personal radiation exposure. In this generic study individual dosimetry of personnel involved in emplacement of casks with spent nuclear fuel in drifts in rock salt and in a clay formation was modelled.

  11. Thermal simulation of drift emplacement (TSS): In-situ instrumentation and numerical modeling of stress measurement methods

    International Nuclear Information System (INIS)

    Heusermann, S.

    1988-01-01

    In the course of the planned demonstration test Thermal Simulation of Drift Emplacement (TSS) BGR is carrying out in-situ-measurements of rock stresses, rock deformability and permeability of salt rock and backfill material. The following techniques developed and proved by BGR during the last years are planned to be used in the TSS project: overcoring technique, dilatometer technique, hard inclusion technique, slot-cutting techniques, large-flatjack technique, compensation tests in laboratory, vacuum tests, injection tests, and tracer tests. The purpose of measurements is to determine: the initial stress state; stress gradients around test drifts; stress change caused by mining activities, by creep and stress relaxation and by temperature; the in-situ load-deformation behavior of rock salt; the permeability of rock salt around test drifts; the compaction behavior of backfill material; and the load-deformation behavior of rock salt and borehole grout in laboratory tests

  12. Conceptual design of retrieval systems for emplaced transuranic waste containers in a salt bed depository. Final report

    International Nuclear Information System (INIS)

    Fogleman, S.F.

    1980-04-01

    The US Department of Energy and the Nuclear Regulatory Commission have jurisdiction over the nuclear waste management program. Design studies were previously made of proposed repository site configurations for the receiving, processing, and storage of nuclear wastes. However, these studies did not provide operational designs that were suitable for highly reliable TRU retrieval in the deep geologic salt environment for the required 60-year period. The purpose of this report is to develop a conceptual design of a baseline retrieval system for emplaced transuranic waste containers in a salt bed depository. The conceptual design is to serve as a working model for the analysis of the performance available from the current state-of-the-art equipment and systems. Suggested regulations would be based upon the results of the performance analyses

  13. Development and demonstration of prototype transportation equipment for emplacing HL vitrified waste canisters into small diameter bored horizontal disposal cells

    International Nuclear Information System (INIS)

    Seidler, Wolf K.; Bosgiraud, Jean-Michel; Londe, Louis

    2008-01-01

    Over a period of 4 and years the National Radioactive Waste Management Agency (Andra), working with a variety of Contractors mostly specializing in nuclear orientated mechanical applications, successfully designed, fabricated and demonstrated 2 very different prototype high level waste transport systems. The first system, based on air cushion technology, was developed primarily for very heavy loads (17 to 45 tonnes). The results of this work are described in a separate presentation (Paper 21) at this Conference. The second system, developed by Andra within the framework of the ESDRED Project, generally referred to as the 'Pushing Robot System' for vitrified waste canisters, is the subject of this paper. The 'Pushing Robot System' is a part of the French national disposal concept that is described in Andra's 'Dossier 2005'. The latter is a public document that can be viewed on Andra's web site (www.andra.fr). The 'Pushing Robot System' system is designed for the deep geological disposal (in clay formations) of 'C' type vitrified waste canisters. In its entirety the system provides for the transport, emplacement and, if necessary, the retrieval of those canisters. Nothing in the design of the Andra emplacement equipment would preclude its utilization in horizontal openings in other types of geological settings. Over a period of some 8 years Andra has developed the 'Pushing Robot System' in 3 phases. Initially there was only the 'Conceptual Design' (Phase 1) which was incorporated in the Dossier 2005. This was followed by Phase 2 i.e. the design and fabrication of a simplified full scale prototype system henceforth referred to a P1, which includes a Pushing Robot, a Dummy Canister and a Test Bench. P1 details were also incorporated in the Dossier 2005. Finally, during Phase 3, a second more comprehensive full scale prototype system P2 has been designed and is being assembled and tested this month. This system includes a Transport Shuttle, a Transfer Shielding Cask, a

  14. The origin of elevated water levels in emplacement boreholes, Pahute Mesa, Nevada Test Site: A numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, G.G.; Brikowski, T.H.

    1993-12-01

    The origin of elevated water levels in emplacement boreholes at Pahute Mesa, Nevada Test Site, is uncertain. If the water is from naturally perched aquifers, then presumed ``above water table`` weapons tests may directly impact the groundwater quality. The purpose of this study is to determine the probable source of the elevated water in boreholes by comparing modeled seepage of infiltrated drilling fluids, and the seepage from a simulated naturally perched aquifer with the observed water level history. In the model, large volumes of water are infiltrated, yet return flow of fluids back into the hole stops within three days after the end of drilling and is insufficient to produce observed standing water. Return flow is limited for two reasons: (1) the volume of the saturated rock next to the borehole is small; (2) pressure head gradient direct unsaturated flow away from the borehole. Simulation of seepage from a naturally perched aquifer readily reproduces the observed water levels.

  15. Emplacement model of obsidian-rhyolite magma deduced from complete internal section of the Akaishiyama lava, Shirataki, northern Hokkaido, Japan

    Science.gov (United States)

    Wada, K.; Sano, K.

    2016-12-01

    Simultaneously explosive and effusive eruptions of silicic magmas has shed light on the vesiculation and outgassing history of ascending magmas in the conduit and emplacement model of obsidian-rhyolite lavas (Castro et al., 2014; Shipper et al, 2013). As well as the knowledge of newly erupted products such as 2008-2009 Chaitén and 2011-2012 Cordón Caule eruptions, field and micro-textural evidences of well-exposed internal structure of obsidian-rhyolite lava leads to reveal eruption processes of silicic magmas. The Shirataki monogenetic volcano field, 2.2 million year age, northern Hokkaido, Japan, contains many outcrops of obsidian and vesiculated rhyolite zones (SiO2=76.7-77.4 wt.%). Among their outcrops, Akaishiyama lava shows good exposures of internal sections from the top to the bottom along the Kyukasawa valley with thickness of about 190 meters, showing the symmetrical structure comprising a upper clastic zone (UCZ; 5m thick), an upper dense obsidian zone (UDO; 15m), an upper banded obsidian zone (UBO; 70-80m), a central rhyolite zone (CR; 65m), a lower banded obsidian zone (LBO; 15m), a lower dense obsidian zone (LDO; 20m), and a lower clastic zone (LCZ; 3m). The upper banded obsidian zone is characterized by existence of spherulite concentration layers with tuffisite veins and rhyolite enclaves. Spherulites consisting of albite, cristobalaite and obsidian glass, are clustered in the dense obsidian. Tuffisite veins show brecciated obsidians in tuffaceous matrix, showing an outgassing path during the emplacement of obsidian lava. Perpendicular dip of spherulite parallel rows indicates the banded zone itself was the domain of vent area. From the observation of these occurrences in the internal section and rock texture, we show the qualitative formation model of Shirataki obsidian-rhyolite lava.

  16. Zircon U-Pb geochronology and emplacement history of intrusive rocks in the Ardestan section, central Iran

    Energy Technology Data Exchange (ETDEWEB)

    Sarjoughian, F.; Kananian, A.

    2017-11-01

    The Urumieh-Dokhtar Magmatic Arc (UDMA) is part of the Alpine–Himalayan orogenic belt and interpreted to be a subduction-related Andean-type magmatic arc. Along this belt, Eocene volcanics and some gabbroic to granitic bodies crop out. The main rock types of the studied intrusion are granite, granodiorite, and diorite. They have geochemical features typical of magnesian, calc-alkaline, metaluminous to slightly peraluminous granites and I-type intrusive rock that have a strong enrichment in Large-Ion Lithophile (LIL) elements (e.g. Rb, Ba, Sr), and a depletion in High Field Strength (HFS) elements (e.g. Nb, Ti, P), typical of subduction-related magmas. Zircon U-Pb dating was applied to determine the emplacement ages of the different intrusions in the Ardestan area. Among them the Kuh-e Dom diorite is 53.9±0.4Ma old; the Kuh-e Dom granodiorite is 51.10±0.4Ma old; the Mehrabad granodiorite is 36.8±0.5Ma old, the Nasrand granodiorite is 36.5±0.5Ma old, the Zafarghand granodiorite is 24.6±1.0Ma old, and the Feshark granodiorite is 20.5±0.8Ma old. These results delineate more accurately the magmatic evolution related to the Neotethyan subduction from the Lower Eocene to Lower Miocene, and the subsequent Zagros orogeny that resulted from the Arabia-Eurasia collision. The emplacement of these intrusive rocks inside the UDMA, which has a close relationship with the collisional orogeny, is transitional from a subduction-related setting to post-collisional setting in the Ardestan area.

  17. Emplacement of Holocene silicic lava flows and domes at Newberry, South Sister, and Medicine Lake volcanoes, California and Oregon

    Science.gov (United States)

    Fink, Jonathan H.; Anderson, Steven W.

    2017-07-19

    This field guide for the International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly 2017 focuses on Holocene glassy silicic lava flows and domes on three volcanoes in the Cascade Range in Oregon and California: Newberry, South Sister, and Medicine Lake volcanoes. Although obsidian-rich lava flows have been of interest to geologists, archaeologists, pumice miners, and rock hounds for more than a century, many of their emplacement characteristics had not been scientifically observed until two very recent eruptions in Chile. Even with the new observations, several eruptive processes discussed in this field trip guide can only be inferred from their final products. This makes for lively debates at outcrops, just as there have been in the literature for the past 30 years.Of the three volcanoes discussed in this field guide, one (South Sister) lies along the main axis defined by major peaks of the Cascade Range, whereas the other two lie in extensional tectonic settings east of the axis. These two tectonic environments influence volcano morphology and the magmatic and volcanic processes that form silicic lava flows and domes. The geomorphic and textural features of glass-rich extrusions provide many clues about their emplacement and the magma bodies that fed them.The scope of this field guide does not include a full geologic history or comprehensive explanation of hazards associated with a particular volcano or volcanic field. The geochemistry, petrology, tectonics, and eruption history of Newberry, South Sister, and Medicine Lake volcanic centers have been extensively studied and are discussed on other field excursions. Instead, we seek to explore the structural, textural, and geochemical evolution of well-preserved individual lava flows—the goal is to understand the geologic processes, rather than the development, of a specific volcano.

  18. Zircon U-Pb geochronology and emplacement history of intrusive rocks in the Ardestan section, central Iran

    International Nuclear Information System (INIS)

    Sarjoughian, F.; Kananian, A.

    2017-01-01

    The Urumieh-Dokhtar Magmatic Arc (UDMA) is part of the Alpine–Himalayan orogenic belt and interpreted to be a subduction-related Andean-type magmatic arc. Along this belt, Eocene volcanics and some gabbroic to granitic bodies crop out. The main rock types of the studied intrusion are granite, granodiorite, and diorite. They have geochemical features typical of magnesian, calc-alkaline, metaluminous to slightly peraluminous granites and I-type intrusive rock that have a strong enrichment in Large-Ion Lithophile (LIL) elements (e.g. Rb, Ba, Sr), and a depletion in High Field Strength (HFS) elements (e.g. Nb, Ti, P), typical of subduction-related magmas. Zircon U-Pb dating was applied to determine the emplacement ages of the different intrusions in the Ardestan area. Among them the Kuh-e Dom diorite is 53.9±0.4Ma old; the Kuh-e Dom granodiorite is 51.10±0.4Ma old; the Mehrabad granodiorite is 36.8±0.5Ma old, the Nasrand granodiorite is 36.5±0.5Ma old, the Zafarghand granodiorite is 24.6±1.0Ma old, and the Feshark granodiorite is 20.5±0.8Ma old. These results delineate more accurately the magmatic evolution related to the Neotethyan subduction from the Lower Eocene to Lower Miocene, and the subsequent Zagros orogeny that resulted from the Arabia-Eurasia collision. The emplacement of these intrusive rocks inside the UDMA, which has a close relationship with the collisional orogeny, is transitional from a subduction-related setting to post-collisional setting in the Ardestan area.

  19. Conceptual designs for waste packages for horizontal or vertical emplacement in a repository in salt for reference in the site characterization plan

    International Nuclear Information System (INIS)

    1987-06-01

    This report includes the options of horizontal and vertical emplacement, the addition of a phased repository, an additional waste form (intact spent fuel), revised geotechnical data appropriate for the Deaf Smith County site, new corrosion data for the container, and new repository design data. The waste package consists of waste form and canister within a thick-walled, low-carbon steel container surrounded by packing. The container is a hollow cylinder with a flat head welded to each end. The design concepts for the waste container or vertical and horizontal emplacement are identical. This report discusses the results of analyses of aspects of the reference waste package concept needing changes because of new data and information believed applicable to the Deaf Smith County site. Included are waste package conceptual designs or (1) the reference defense high-level waste form from the Savannah River Plant; (2) intact spent fuel with our pressurized-water-reactor or nine boiling-water-reactor assemblies per package for emplacement during Phase 1 of repository operation; and (3) spent fuel which has been disassembled and consolidated into a segmented cylindrical canister with rods from either 12 pressurized-water-reactor or 30 boiling-water-reactor assemblies per package for emplacement during Phase 2. 30 refs., 61 figs., 30 tabs

  20. Erratum: Correction to: Emplacement controls for the basaltic-andesitic radial dikes of Summer Coon volcano and implications for flank vents at stratovolcanoes

    Science.gov (United States)

    Harp, A. G.; Valentine, G. A.

    2018-06-01

    In the article "Emplacement controls for the basaltic-andesitic radial dikes of Summer Coon volcano and implications for flank vents at stratovolcanoes", the vertical axis for Fig. 8 a was incorrectly labeled (i.e., the value for dikes per km2).

  1. Radioactive waste isolation in salt: Peer review of the Fluor Technology, Inc., report and position paper concerning waste emplacement mode and its effect on repository conceptual design

    International Nuclear Information System (INIS)

    Hambley, D.F.; Russell, J.E.; Whitfield, R.G.

    1987-02-01

    Recommendations for revising the Fluor Technology, Inc., draft position paper entitled Evaluation of Waste Emplacement Mode and the final report entitled Waste Package/Repository Impact Study include: reevaluate the relative rankings for the various emplacement modes; delete the following want objectives: maximize ability to locate the package horizon because sufficient flexibility exists to locate rooms in the relatively clean San Andres Unit 4 Salt and maximize far-field geologic integrity during retrieval because by definition the far field will be unaffected by thermal and stress perturbations caused by remining; give greater emphasis to want objectives regarding cost and use of present technology; delete the following statements from pages 1-1 and 1-2 of the draft position paper: ''No thought or study was given to the impacts of this configuration [vertical emplacement] on repository construction or short and long-term performance of the site'' and ''Subsequent salt repository designs adopted the vertical emplacement configuration as the accepted method without further evaluation.''; delete App. E and lines 8-17 of page 1-4 of the draft position paper because they are inappropriate; adopt a formal decision-analysis procedure for the 17 identified emplacement modes; revise App. F of the impact study to more accurately reflect current technology; consider designing the underground layout to take advantage of stress-relief techniques; consider eliminating reference to fuel assemblies <10 yr ''out-of-reactor''; model the temperature distribution, assuming that the repository is constructed in an infinitely large salt body; state that the results of creep analyses must be considered tentative until they can be validated by in situ measurements; and reevaluate the peak radial stresses on the waste package so that the calculated stress conditions more closely approximate expected in situ conditions

  2. Effects of irregular basement structure on the geometry and emplacement of frontal thrusts and duplexes in the Quebec Appalachians: Interpretations from well and seismic reflection data

    Science.gov (United States)

    Konstantinovskaya, E.; Malo, M.; Badina, F.

    2014-12-01

    Irregular basement geometry may affect thrust propagation in foreland fold-thrust belts creating a perturbation in structural continuity of hydrocarbon fields. Here we investigate how the irregular pattern of normal faults, along with the presence of uplifts and transverse faults in the Grenvillian basement has influenced the geometry and emplacement of frontal thrusts and duplexes in the parautochthonous domain of the southern Quebec Appalachians during the middle-late Ordovician Taconian orogeny. Integration of data from surface geology, wells, and 2D and 3D seismic reflection surveys into a regional-scale structural model is used to reconstruct the 3D geometry and emplacement history of one- and two-horse duplexes in the Joly-Saint-Flavien gas storage area. The normal hinterland to foreland sequence of thrusting in this area is complicated by the differential emplacement of tectonic slices along strike of the orogenic front, starting in the SW and developing subsequently to the NE within each structural level. The shortening related to duplex emplacement decreases laterally over the distance of 20 km from - 49% in the SW (Joly area) to - 31% in the NE (Saint-Flavien area). Duplex emplacement resulted from the differential forward propagation, deflexion and vertical-axis rotation of the roof thrust (Logan's Line), which, in turn, has been induced by the presence of frontal uplift and transverse faults in the basement. The structural-lithological analysis of tectonic slices and restoration of their initial location allows us to consider the lower slice of the Joly duplex as a structural trap comparable to the fractured reservoir in lower Ordovician dolomites of the Saint-Flavien duplex.

  3. New insights into the timing, triggers and emplacement processes of prodigious submarine landslides in the Nordic Seas

    Science.gov (United States)

    Talling, Peter; Pope, Ed; Hunt, James; Allin, Joshua; Cartigny, Matthieu; Long, David; Mozzato, Alessandro; Stanford, Jennifer; Tappin, David; Watts, Camilla

    2015-04-01

    Submarine landslides can generate tsunamis with the potential to cause severe damage. This is illustrated by the huge (> 3,000 cubic km) Storegga landslide offshore Norway that occurred 8,200 years ago, and which produced a tsunami that ran up surrounding coastlines for up to 20m. Here we report on a 1 month research cruise on the RV Pelagia in July 2014 to the Nordic Seas, which collected 88 sediment cores totalling more than 500m, together with over 7,000 square km of swath bathymetry. The overall aim of this research expedition was to better understand the tsunami risk from large submarine landslides in the Nordic Seas. This includes a better understanding of the timing and frequency of submarine landslides, factors that potentially trigger or precondition slope failure, and the manner in which landslides are emplaced. Much of the expedition was then devoted to understanding the age and emplacement mechanism of the ~900 cubic km Traenadjupet landslide, located to the north of the Storegga Slide. This included sampling and mapping of the main Traenadjupet Slide, four lobes froming the distal Traenadjupet Slide deposit. A newly discovered debris flow deposit with large blocks was found to continue from the most westerly of these lobes, and it was mapped to its termination. If the previously established age of ~4ka for the Traenadjupet Slide is correct, then it does not appear to produced a major tsunami (unlike the Storegga Slide). Indeed, the morphology of the Traenadjupet Slide suggests much slower emplacement than the Storegga Slide, which would be consistent with such a lack of major tsunami. Turbidites in cores from the deep-water Lofoten Basin will help to understand the frequency and character of faster moving slope failures around the basin margin. Cores were collected from the Lofoten Contourite Drift located next to the Traenadjupet Slide, and these contouritic sediment may provide a paleoceanographic record that can be compared to slide timing, in order

  4. Morphodynamics of Travertine Dam/Waterfall Growth due to the Interaction of Biological Activity, Water Flow and Limestone Emplacement

    Science.gov (United States)

    Izumi, N.; Parker, G.

    2012-12-01

    Plitvice Lakes in Croatia are characterized by a step-like train of lakes and waterfalls. The waterfalls are located at the crests of naturally-emplaced dams. The top of each dam grows upward at the rate of a few millimeters per year. It is thought that the upward growth of these dams is caused by the interaction of water flow and biological activity, resulting in the precipitation of dissolved limestone. Dam evolution is initiated by the growth of mosses that favor swift, shallow water. Bacteria that inhabit the roots of the moss excrete solid limestone (travertine) from the water. The limestone fossilizes the moss, and then more moss grows on top of the travertine deposit. In this way, the natural dam can grow over to 10 m high, impounding the water behind it to form a lake. We propose a simple model to explain the formation of natural limestone dams by the interaction between water flow and biologically-mediated travertine deposition. We assume for simplicity that light is the only factor determining the growth of moss, which is then colonized by travertine-emplacing bacteria. We also assume that the water is saturated with dissolved limestone, so that the process is not limited by limestone availability. Photosynthesis, and thus the growth rate of moss are crudely approximated as decreasing linearly with depth. We employ the shallow water equations to describe water flow over the dam. In order to obtain a profile of permanent form for a dam migrating upward and downstream at constant speed, we solve the problem in a moving coordinate system. When water flows over the dam, it is accelerated in the streamwise direction, and the water surface forms a backwater curve. The flow regime changes from Froude-subcritical to Froude-supercritical at a point slightly downstream of the crest of the dam. Farther downstream, the flow attains a threshold velocity beyond which moss is detached. This threshold point defines the downstream end of the active part of the dam. The

  5. Thrusting and back-thrusting as post-emplacement kinematics of the Almora klippe: Insights from Low-temperature thermochronology

    Science.gov (United States)

    Patel, R. C.; Singh, Paramjeet; Lal, Nand

    2015-06-01

    Crystalline klippen over the Lesser Himalayan Sequence (LHS) in the Kumaon and Garhwal regions of NW-Himalaya, are the representative of southern portion of the Main Central Thrust (MCT) hanging wall. These were tectonically transported over the juxtaposed thrust sheets (Berinag, Tons and Ramgarh) of the LHS zone along the MCT. These klippen comprise of NW-SE trending synformal folded thrust sheet bounded by thrusts in the south and north. In the present study, the exhumation histories of two well-known klippen namely Almora and Baijnath, and the Ramgarh thrust sheet, in the Kumaon and Garhwal regions vis-a-vis Himalayan orogeny have been investigated using Apatite Fission Track (AFT) ages. Along a ~ 60 km long orogen perpendicular transect across the Almora klippe and the Ramgarh thrust sheet, 16 AFT cooling ages from the Almora klippe and 2 from the Ramgarh thrust sheet have been found to range from 3.7 ± 0.8 to 13.2 ± 2.7 Ma, and 6.3 ± 0.8 to 7.2 ± 1.0 Ma respectively. From LHS meta-sedimentary rocks only a single AFT age of 3.6 ± 0.8 Ma could be obtained. Three AFT ages from the Baijnath klippe range between 4.7 ± 0.5 and 6.6 ± 0.8 Ma. AFT ages and exhumation rates of different klippen show a dynamic coupling between tectonic and erosion processes in the Kumaon and Garhwal regions of NW-Himalaya. However, the tectonic processes play a dominant role in controlling the exhumation. Thrusting and back thrusting within the Almora klippe and Ramgarh thrust sheet are the post-emplacement kinematics that controlled the exhumation of the Almora klippe. Combining these results with the already published AFT ages from the crystalline klippen and the Higher Himalayan Crystalline (HHC), the kinematics of emplacement of the klippen over the LHS and exhumation pattern across the MCT in the Kumaon and Garhwal regions of NW-Himalaya have been investigated.

  6. Emplacement Dynamics and Timescale of a Holocene Flow from the Cima Volcanic Field (CA): Insights from Rheology and Morphology

    Science.gov (United States)

    Soldati, A.; Beem, J. R.; Gomez, F.; Huntley, J. W.; Robertson, T.; Whittington, A. G.

    2017-12-01

    We present a rheological and morphological study of a Holocene lava flow emitted by a monogenetic cinder cone in the Cima Volcanic Field, eastern California. By combining field observations and experimental results, we reconstructed the few weeks-long emplacement timeline of the Cima flow. Sample textural analyses revealed that the near-vent portion of the flow is significantly more crystalline (fxtal=0.95±0.04) than the main flow body (fxtal=0.66±0.11), which reveals a multi-stage emplacement history. Airborne photogrammetry data were used to generate a digital elevation model, which allowed us to estimate the flow volume. The rheology of Cima lavas was determined experimentally by concentric cylinder viscometry between 1550 °C and 1160 °C, including the first subliquidus rheology measurements for a continental intraplate trachybasaltic lava. The experimentally determined effective viscosity increases from 54 Pa·s to 1,361 Pa·s during cooling from the liquidus ( 1230 ˚C) to 1160 ˚C, where crystal fraction is 0.11. Flow curves fitted to measurements at different strain rates indicate a Herschel-Bulkley rheological behavior, combining shear-thinning with a yield strength negligible at the higher measured temperatures but increasing up to 357±41 Pa at 1160˚C. The lava viscosity over this range is still lower than most basaltic melts, due to the high alkali content of Cima lavas ( 6 wt% Na2O+K2O). We determined that the morphological pahoehoe to `a'ā transition of this trachybasalt occurs at a temperature of 1160±10 ˚C, similar to that observed for Hawaiian tholeiitic lavas, but at higher apparent viscosity values. Monogenetic volcanism in the Western United States is typically characterized by low effusion rates and eruption on sub-horizontal desert plains. Under these low strain-rate conditions, the pahoehoe to `a'ā transition is likely to occur abruptly upon minimal cooling, i.e. very close to the vent, but lava tubes may transport fluid lava to flow

  7. Geochronological and mineralogical constraints on depth of emplacement and ascencion rates of epidote-bearing magmas from northeastern Brazil

    Science.gov (United States)

    Sial, Alcides N.; Vasconcelos, Paulo M.; Ferreira, Valderez P.; Pessoa, Ricardo R.; Brasilino, Roberta G.; Morais Neto, João M.

    2008-10-01

    Calc-alkalic to high-K calc-alkalic granitoid plutons in the Borborema province, northeastern Brazil, have been studied to constrain depth of emplacement by mineralogical and geological methods and to estimate upward magma transport rate based on partial dissolution of magmatic epidote. Laser-probe incremental heating 40Ar/ 39Ar dating of biotite and hornblende single crystals from the Neoproterozoic Tavares and Brejinho high-K calc-alkalic magmatic epidote (mEp)-bearing plutons reveals age differences of around 60 M.y. between these two minerals in each of these two intrusions. These data suggest solidification at relatively great depth followed by prolonged cooling interval between the closure temperatures of biotite and hornblende. Al-in-hornblende barometry indicates that hornblende in several mEp-bearing plutons in the Transversal Domain of the Borborema province solidified at 5 to 7 kbar, whereas in the Seridó and Macururé terranes, solidification pressures range from 3 to 4 kbar. Partial dissolution of epidote indicates very rapid upward transport. Partial corrosion occurred during 15-35 years (Cachoerinha-Salgueiro terrane), 10-30 years (Alto Pajeú), 15 years (Seridó), and 10 years (Macururé) corresponding to upward transport rates of 450-1300, 650-1050, 1200, and 1800 m/year respectively in these four terranes. Rapid upward magma migration in most cases was probably facilitated by diking simultaneous with regional shearing.

  8. Mont Terri Project - Engineered barrier emplacement experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J.; Alonso, E.; Alheid, H.-J.; Bluemling, P.

    2007-01-01

    The Engineered Barrier (EB) experiment was a full-scale test for the demonstration, in a horizontal drift, of an emplacement technics of the clay barrier, using a granular bentonite material in the upper part of this barrier and bentonite blocks at the bottom. The test has been carried out in a 6 m long section of a niche excavated in Opalinus Clay of the Mont Terri underground laboratory. A steel dummy canister, with the same dimensions and weight as the real reference canisters, was placed on top of a bed of highly compacted bentonite blocks (in turn lying on a concrete bed), and the rest of the clay barrier volume was backfilled with a Granular Bentonite Material (GBM), made of very highly compacted pellets of different sizes. Hydro-mechanical instrumentation and an artificial hydration system (to accelerate the saturation of the clay barrier) were installed, and the test section sealed with a concrete plug. The evolution of the hydro-mechanical parameters along the hydration, both in the barrier and in the clayey rock formation, has been monitored during about 1.5 years, and modelled using the CODE-BRIGHT code. The EB experiment has proved that fully automated production of a Granular Bentonite Material (GBM) is possible and large quantities can be produced in due time in the required quality. Only minor modifications of existing production lines in industry for other applications were necessary to achieve this result. In the EB test section, a dry density of 1.36 g/cm 3 of the emplaced GBM has been obtained. With this value it is estimated that the hydraulic conductivity of this material is lower than 5 x 10 -12 m/s and the swelling pressure is about 1.3 MPa. Even though the EB test section conditions are now not considered as representative of a true demonstration, it is deemed that the model emplacement testing results (dry density of about 1.40 g/cm 3 ) serve well to demonstrate the achievable densities expected in the real world setting. The artificial

  9. Preliminary assessment of the thermal effects of an annular air space surrounding an emplaced nuclear waste canister

    International Nuclear Information System (INIS)

    Davis, B.W.

    1979-01-01

    Modeling results have previously shown that the presence of a large air space (e.g., a repository room) within a nuclear waste repository is expected to cause a waste canister's temperature to remain cooler than it would otherwise be. Results presented herein show that an annular air space surrounding the waste canisters can have similar cooling effects under certain prescribable conditions; for a 16 ft x 1 ft diameter canister containing 650 PWR rods which initially generate a total of 4.61 kw, analysis will show that annular air spaces greater than 11 in will permit the canister surface to attain peak temperatures lower than that which would result from a zero-gap/perfect thermal contact. It was determined that the peak radial temperature gradient in the salt varies in proportion to the inverse of the drill hole radius. Thermal radiation is shown to be the dominant mode of heat transfer across an annular air space during the first two years after emplacement. Finally, a methodology is presented which will allow investigators to easily model radiation and convection heat transfer through air spaces by treating the space as a conduction element that possesses non-linear temperature dependent conductivity

  10. Mont Terri Project - Engineered barrier emplacement experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories

    Energy Technology Data Exchange (ETDEWEB)

    Mayor, J. C. [Empresa Nacional de Residuos Radioactivos SA (ENRESA), Madrid (Spain); Garcia-Sineriz, J. [Asociacion para la Investigacion y Desarollo Industrial de los Recursos Naturales (AITEMIN), Madrid (Spain); Alonso, E. [Centre Internacional de Metodos Numerics en Ingenyeria (CIMNE), Barcelona (Spain); Alheid, H.-J. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Bluemling, P. [National Cooperative for the Disposal of Radioactive Waste (Nagra), Wettingen (Switzerland)

    2007-07-01

    The Engineered Barrier (EB) experiment was a full-scale test for the demonstration, in a horizontal drift, of an emplacement technics of the clay barrier, using a granular bentonite material in the upper part of this barrier and bentonite blocks at the bottom. The test has been carried out in a 6 m long section of a niche excavated in Opalinus Clay of the Mont Terri underground laboratory. A steel dummy canister, with the same dimensions and weight as the real reference canisters, was placed on top of a bed of highly compacted bentonite blocks (in turn lying on a concrete bed), and the rest of the clay barrier volume was backfilled with a Granular Bentonite Material (GBM), made of very highly compacted pellets of different sizes. Hydro-mechanical instrumentation and an artificial hydration system (to accelerate the saturation of the clay barrier) were installed, and the test section sealed with a concrete plug. The evolution of the hydro-mechanical parameters along the hydration, both in the barrier and in the clayey rock formation, has been monitored during about 1.5 years, and modelled using the CODE-BRIGHT code. The EB experiment has proved that fully automated production of a Granular Bentonite Material (GBM) is possible and large quantities can be produced in due time in the required quality. Only minor modifications of existing production lines in industry for other applications were necessary to achieve this result. In the EB test section, a dry density of 1.36 g/cm{sup 3} of the emplaced GBM has been obtained. With this value it is estimated that the hydraulic conductivity of this material is lower than 5 x 10{sup -12} m/s and the swelling pressure is about 1.3 MPa. Even though the EB test section conditions are now not considered as representative of a true demonstration, it is deemed that the model emplacement testing results (dry density of about 1.40 g/cm{sup 3}) serve well to demonstrate the achievable densities expected in the real world setting. The

  11. Deformation mechanisms accommodating the emplacement of an igneous sill-complex in the Irish sector of the Rockall Basin, offshore NW Ireland

    Science.gov (United States)

    Magee, Craig; Jackson, Christopher; Schofield, Nick

    2013-04-01

    Magma intrusion within the subsurface is heavily influenced by the pre-existing architecture of the upper crust and, depending on the emplacement mechanisms, may modify basin structure and fluid flow pathways. Seismic reflection data reveal that intrusive networks predominantly consist of interconnected, saucer-shaped sills that are often associated with dome-shaped 'forced' folds generated by intrusion-induced uplift. Previous studies of intrusion-related forced folds have primarily focused on isolated sills or laccoliths and have shown that the fold amplitude is less than the intrusion thickness, suggesting that additional space-making mechanisms (e.g. grain comminution, fluidization) accompanied emplacement. Furthermore, forced folding is often considered as an instantaneous process over geological time. However, fold growth and the interplay between accompanying ductile and brittle deformation styles remains poorly understood. Here, we use 3D seismic reflection data from the eastern margin of the Irish Rockall Basin, NE Atlantic, to quantitatively study eighty-two igneous intrusions (i.e. saucer-shaped sills and inclined sheets) in order to constrain the emplacement history of a Palaeocene-to-Middle Eocene sill-complex. Emplacement occurred across a Cretaceous clastic-to-marl dominated succession at palaeodepths of limbs. The saucer-shaped sills are characterized by radial magma flow patterns, emanating from the inner sill, distinguished by mapping the long axes of magma lobes and fingers. These magma flow indictors also provide a proxy for intrusion style; i.e. where sills intrude the Lower Cretaceous sandstones, magma propagation was facilitated by brittle fracturing while non-brittle processes (e.g. fluidization) accompanied shallow-level intrusions into the Upper Cretaceous marls. Directly overlying the sill-complex, within the Palaeocene-Mid-Eocene succession, are a series of 22 forced folds that are interpreted to have formed via intrusion-induced uplift

  12. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, vertical emplacement mode: Volume 1

    International Nuclear Information System (INIS)

    1987-12-01

    This Conceptual Design Report describes the conceptual design of a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. Waste receipt, processing, packing, and other surface facility operations are described. Operations in the shafts underground are described, including waste hoisting, transfer, and vertical emplacement. This report specifically addresses the vertical emplacement mode, the reference design for the repository. Waste retrieval capability is described. The report includes a description of the layout of the surface, shafts, and underground. Major equipment items are identified. The report includes plans for decommissioning and sealing of the facility. The report discusses how the repository will satisfy performance objectives. Chapters are included on basis for design, design analyses, and data requirements for completion of future design efforts. 105 figs., 52 tabs

  13. Retrieval system for emplaced spent unreprocessed fuel (SURF) in salt bed depository: accident event analysis and mechanical failure probabilities. Final report

    International Nuclear Information System (INIS)

    Bhaskaran, G.; McCleery, J.E.

    1979-10-01

    This report provides support in developing an accident prediction event tree diagram, with an analysis of the baseline design concept for the retrieval of emplaced spent unreprocessed fuel (SURF) contained in a degraded Canister. The report contains an evaluation check list, accident logic diagrams, accident event tables, fault trees/event trees and discussions of failure probabilities for the following subsystems as potential contributors to a failure: (a) Canister extraction, including the core and ram units; (b) Canister transfer at the hoist area; and (c) Canister hoisting. This report is the second volume of a series. It continues and expands upon the report Retrieval System for Emplaced Spent Unreprocessed Fuel (SURF) in Salt Bed Depository: Baseline Concept Criteria Specifications and Mechanical Failure Probabilities. This report draws upon the baseline conceptual specifications contained in the first report

  14. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, vertical emplacement mode: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1987-12-01

    This Conceptual Design Report describes the conceptual design of a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. Waste receipt, processing, packing, and other surface facility operations are described. Operations in the shafts underground are described, including waste hoisting, transfer, and vertical emplacement. This report specifically addresses the vertical emplacement mode, the reference design for the repository. Waste retrieval capability is described. The report includes a description of the layout of the surface, shafts, and underground. Major equipment items are identified. The report includes plans for decommissioning and sealing of the facility. The report discusses how the repository will satisfy performance objectives. Chapters are included on basis for design, design analyses, and data requirements for completion of future design efforts. 105 figs., 52 tabs.

  15. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, horizontal emplacment mode: Volume 1

    International Nuclear Information System (INIS)

    1987-12-01

    This Conceptual Design Report describes the conceptual design of a high-level nuclear waste repository in salt at a proposed site in Deaf Smith County, Texas. Waste receipt, processing, packaging, and other surface facility operations are described. Operations in the shafts and underground are described, including waste hoisting, transfer, and horizontal emplacement. This report specifically addresses the horizontal emplacement mode, the passive alternate design for the repository. Waste retrieval capability is described. The report includes a description of the layout of the surface, shafts, and underground. Major equipment items are identified. The report includes plans for decommissioning and sealing of the facility. The report discusses how the repository will satisfy performance objectives. Chapters are included on basis for design, design analyses, and data requirements for completion of future design efforts. 105 figs., 52 tabs

  16. The Jeffers Brook diorite-granodiorite pluton: style of emplacement and role of volatiles at various crustal levels in Avalonian appinites, Canadian Appalachians

    Science.gov (United States)

    Pe-Piper, Georgia; Piper, David J. W.

    2018-04-01

    Small appinite plutons ca. 610 Ma outcrop in the peri-Gondwanan Avalon terrane of northern Nova Scotia, with different structural levels exposed. Field mapping shows that the Jeffers Brook pluton is a laccolith emplaced along an upper crustal thrust zone, likely in a dilational jog in a regional dextral strike-slip system. The oldest rocks are probably mafic sills, which heated the area facilitating emplacement of intermediate magmas. Cross-cutting relationships show that both mafic and intermediate magmas were supplied throughout the history of pluton emplacement. The modal composition, mineral chemistry, and bulk chemistry of gabbro, diorite, tonalite, granodiorite, and granite have been studied in the main plutonic phases, dykes, and sills, and mafic microgranular enclaves. As with the type appinites in the Scottish Caledonides, the pluton shows evidence of high water content: the dominance of hornblende, locally within pegmatitic texture; vesicles and irregular felsic patches in enclaves; and late aplite dykes. Analyzed mafic microgranular enclaves are geochemically similar to larger diorite bodies in the pluton. Tonalite-granodiorite is distinct from the diorite in trace-element geochemistry and radiogenic isotopes. Elsewhere to the east, similar rocks of the same age form vertically sheeted complexes in major shear zones; hornblende chemistry shows that they were emplaced at a deeper upper crustal level. This implies that little of the observed geochemical variability in the Jeffers Brook pluton was developed within the pluton. The general requirements to form appinites are proposed to be small magma volumes of subduction-related magmas that reach the upper crust because of continual heating by mafic magmas moving through strike-slip fault pathways and trapping of aqueous fluids rather than venting through volcanic activity.

  17. Geologic-geochemical characteristics of Guidong granitic massif and recognition of geo-tectonic environment at the time of its emplacement

    Energy Technology Data Exchange (ETDEWEB)

    Jianhong, Li; Shanyuan, Wei; Mingyue, Feng [Beijing Research Inst. of Uranium Geology, Beijing (China); Liang, Liang [East China Inst. of Technology, Fuzhou (China)

    2004-11-01

    Based on the study of geologic characteristics, such as mineralogic assemblage, structural and textural features of granite of Guidong granitic massif, and by using petrochemical, trace-element and isotopic data, and some petrochemical, trace-element and isotopic diagrams widely applied to the identification of geo-tectonic environments, authors recognize that Guidong granitic massif was emplaced in post-orogenic collision environment. (authors)

  18. Conditions for the test emplacement of intermediate-level radioactive wastes in chamber 8a of the 511 m level of the Asse Salt Mine

    International Nuclear Information System (INIS)

    1984-01-01

    The Gesellschaft fuer Strahlen- und Umweltforschung mbH (GSF) emplaces intermediate-level radioactive wastes which accumulate in an activity involving the use of radioactive materials that is licensed or reported in the Federal Republic of Germany or which are stored on an interim basis by the appropriate licensing or inspection agencies in chamber 8a of the 511 m level of the Asse Salt Mine in Remlingen near Wolfenbuettel in conjunction with an engineering test program. The type and form of the intermediate-level wastes must conform to certain conditions so that there are no hazards to personnel and the repository during transfer and subsequent storage. It is therefore necessary for the radioactive wastes to be treated and packaged before delivery in such a way that they satisfy the conditions presented in this document. The GSF shall inform the companies and organizations delivering wastes about its experiences with emplacement operations. The Conditions for the Test Emplacement of Intermediate-Level Radioactive Wastes in Chamber 8a of the 511 m Level of the Asse Salt Mine must be adapted to conform to the latest state of science and the art. The GSF must therefore reserve the right to modify the conditions, allowing for an appropriate transition period

  19. ERG [Engineering Review Group] and GRG [Geologic Review Group] review of the horizontal versus vertical modes of waste emplacement at the Deaf Smith County site, Texas

    International Nuclear Information System (INIS)

    Chytrowski, B.R.

    1988-01-01

    The Engineering Review Group (ERG) and Geologic Review Group (GRG) were established by the Office of Nuclear Waste Isolation (ONWI) to help evaluate specific issues in the US Department of Energy's nuclear waste repository program. The December 1985 meeting and the February 1986 meeting dealt with the evaluation of the Fluor Technology, Inc., architect-engineer recommendation of the horizontal mode of waste package emplacement for the Site Characterization Plan Conceptual Design Report (SCP-CDR). The ONWI recommendation regarding horizontal and vertical modes of waste package emplacement and associated studies was reviewed. This report documents the ERG and GRG's comments and recommendations on this subject and ONWI responses to the specific points raised by these groups. The ERG and GRG joint review groups concurred with ONWI recommendations that additional studies are required in order to reach a decision on the method of emplacement to be used. In the opinion of these groups, both methods can be implemented; however, should the decision be reached today the vertical mode would be preferred

  20. Radiometric, magnetic, and gravity study of the Quixadá batholith, central Ceará domain (NE Brazil): evidence for Pan-African/Brasiliano extension-controlled emplacement

    Science.gov (United States)

    Lopes de Castro, David; Mariano Gomes Castelo Branco, Raimundo; Martins, Guttenberg; Araújo de Castro, Neivaldo

    2002-10-01

    A geophysical survey was conducted in the central Ceará domain of the Borborema Province (NE Brazil). The aim of this investigation was to find geophysical evidence for the emplacement of the Quixadá batholith, which is a granitic body probably situated in the local extensional site in the oblique collisional regime of the Pan-African/Brasiliano collage. Remote sensing and airborne geophysical data provided information on the regional deformation that affected the intrusion and surrounding country rocks. In addition, a gravity study was used to determine the three-dimensional geometry and constrain the emplacement model of the Quixadá granite at depth. The trajectories of structural and magnetic lineaments suggest that the regional deformation is strongly influenced by dextral transcurrent movements of the major shear zones. The batholith, which shows an unusual positive gravity anomaly and a low U counts, displays a subhorizontal floor with several gently dipping areas, which are interpreted as magma feeder channels. The 2300 m thick root zones are roughly aligned with NE-SW-trending shear zones. Finally, the internal architecture of the pluton suggests that the Quixadá batholith was emplaced in a dilational shear zone tip area at the north end of Quixeramobim shear zone.

  1. Tracking lava flow emplacement on the east rift zone of Kīlauea, Hawai‘i, with synthetic aperture radar coherence

    Science.gov (United States)

    Dietterich, Hannah R.; Poland, Michael P.; Schmidt, David A.; Cashman, Katharine V.; Sherrod, David R.; Espinosa, Arkin Tapia

    2012-05-01

    Lava flow mapping is both an essential component of volcano monitoring and a valuable tool for investigating lava flow behavior. Although maps are traditionally created through field surveys, remote sensing allows an extraordinary view of active lava flows while avoiding the difficulties of mapping on location. Synthetic aperture radar (SAR) imagery, in particular, can detect changes in a flow field by comparing two images collected at different times with SAR coherence. New lava flows radically alter the scattering properties of the surface, making the radar signal decorrelated in SAR coherence images. We describe a new technique, SAR Coherence Mapping (SCM), to map lava flows automatically from coherence images independent of look angle or satellite path. We use this approach to map lava flow emplacement during the Pu`u `Ō`ō-Kupaianaha eruption at Kīlauea, Hawai`i. The resulting flow maps correspond well with field mapping and better resolve the internal structure of surface flows, as well as the locations of active flow paths. However, the SCM technique is only moderately successful at mapping flows that enter vegetation, which is also often decorrelated between successive SAR images. Along with measurements of planform morphology, we are able to show that the length of time a flow stays decorrelated after initial emplacement is linearly related to the flow thickness. Finally, we use interferograms obtained after flow surfaces become correlated to show that persistent decorrelation is caused by post-emplacement flow subsidence.

  2. The relative effectiveness of empirical and physical models for simulating the dense undercurrent of pyroclastic flows under different emplacement conditions

    Science.gov (United States)

    Ogburn, Sarah E.; Calder, Eliza S

    2017-01-01

    High concentration pyroclastic density currents (PDCs) are hot avalanches of volcanic rock and gas and are among the most destructive volcanic hazards due to their speed and mobility. Mitigating the risk associated with these flows depends upon accurate forecasting of possible impacted areas, often using empirical or physical models. TITAN2D, VolcFlow, LAHARZ, and ΔH/L or energy cone models each employ different rheologies or empirical relationships and therefore differ in appropriateness of application for different types of mass flows and topographic environments. This work seeks to test different statistically- and physically-based models against a range of PDCs of different volumes, emplaced under different conditions, over different topography in order to test the relative effectiveness, operational aspects, and ultimately, the utility of each model for use in hazard assessments. The purpose of this work is not to rank models, but rather to understand the extent to which the different modeling approaches can replicate reality in certain conditions, and to explore the dynamics of PDCs themselves. In this work, these models are used to recreate the inundation areas of the dense-basal undercurrent of all 13 mapped, land-confined, Soufrière Hills Volcano dome-collapse PDCs emplaced from 1996 to 2010 to test the relative effectiveness of different computational models. Best-fit model results and their input parameters are compared with results using observation- and deposit-derived input parameters. Additional comparison is made between best-fit model results and those using empirically-derived input parameters from the FlowDat global database, which represent “forward” modeling simulations as would be completed for hazard assessment purposes. Results indicate that TITAN2D is able to reproduce inundated areas well using flux sources, although velocities are often unrealistically high. VolcFlow is also able to replicate flow runout well, but does not capture

  3. Emplacement mechanisms of contrasting debris avalanches at Volcán Mombacho (Nicaragua), provided by structural and facies analysis

    Science.gov (United States)

    Shea, Thomas; van Wyk de Vries, Benjamin; Pilato, Martín

    2008-07-01

    We study the lithology, structure, and emplacement of two debris-avalanche deposits (DADs) with contrasting origins and materials from the Quaternary-Holocene Mombacho Volcano, Nicaragua. A clear comparison is possible because both DADs were emplaced onto similar nearly flat (3° slope) topography with no apparent barrier to transport. This lack of confinement allows us to study, in nature, the perfect case scenario of a freely spreading avalanche. In addition, there is good evidence that no substratum was incorporated in the events during flow, so facies changes are related only to internal dynamics. Mombacho shows evidence of at least three large flank collapses, producing the two well-preserved debris avalanches of this study; one on its northern flank, “Las Isletas,” directed northeast, and the other on its southern flank, “El Crater,” directed south. Other south-eastern features indicate that the debris-avalanche corresponding to the third collapse (La Danta) occurred before Las Isletas and El Crater events. The materials involved in each event were similar, except in their alteration state and in the amount of substrata initially included in the collapse. While “El Crater” avalanche shows no signs of substratum involvement and has characteristics of a hydrothermal weakening-related collapse, the “Las Isletas” avalanche involves significant substratum and was generated by gravity spreading-related failure. The latter avalanche may have interacted with Lake Nicaragua during transport, in which case its run-out could have been modified. Through a detailed morphological and structural description of the Mombacho avalanches, we provide two contrasting examples of non-eruptive volcanic flank collapse. We show that, remarkably, even with two distinct collapse mechanisms, the debris avalanches developed the same gross stratigraphy of a coarse layer above a fine layer. This fine layer provided a low friction basal slide layer. Whereas DAD layering and

  4. Dyke emplacement in a Quaternary active volcano: the exposed swarm of Monte Somma-Vesuvio (Naples, Italy)

    Science.gov (United States)

    Marinoni, L. B.

    2003-04-01

    the caldera. Moreover, the cumulative minimum extension (in direction N25°) corresponds to 75% of the maximum extension (in direction N90°). This value is similar to that computed for Etna (78%), where the influence of self-induced stresses on dyke emplacement is well-assessed. This may suggest that self-induced stresses constrained the emplacement of the MS sheet swarm. Therefore, interplay of the regional stress field from the basement, with the self-induced radial stress field may be envisaged for MS. The stratigraphic study along the caldera wall of MS, shows a long history of edifice instability that, together with structural data and with the apparent asymmetry of the volcano, provides clues to the possibility of past flank failures directed towards W-SW.

  5. Monitoring Inflation and Emplacement During the 2014-2015 Kilauea Lava Flow With an Unmanned Aerial Vehicle

    Science.gov (United States)

    Perroy, R. L.; Turner, N.; Hon, K. A.; Rasgado, V.

    2015-12-01

    Unmanned aerial vehicles (UAVs) provide a powerful new tool for collecting high resolution on-demand spatial data over volcanic eruptions and other active geomorphic processes. These data can be used to improve hazard forecasts and emergency response efforts, and also allow users to economically and safely observe and quantify lava flow inflation and emplacement on spatially and temporally useful scales. We used a small fixed-wing UAV with a modified point-and-shoot camera to repeatedly map the active front of the 2014-2015 Kīlauea lava flow over a one-month period in late 2014, at times with a two-hour repeat interval. An additional subsequent flight was added in July, 2015. We used the imagery from these flights to generate a time-series of 5-cm resolution RGB and near-infrared orthoimagery mosaics and associated digital surface models using structure from motion. Survey-grade positional control was provided by ground control points with differential GPS. Two topographic transects were repeatedly surveyed across the flow surface, contemporaneously with UAV flights, to independently confirm topographic changes observed in the UAV-derived surface models. Vertical errors were generally 10 cm. Inside our 50 hectare study site, the flow advanced at a rate of 0.47 hectares/day during the first three weeks of observations before abruptly stalling out 4 m. New outbreak areas, both on the existing flow surface and along the flow margins, were readily mapped across the study area. We detected sinuous growing inflation ridges within the flow surface that correlated with subsequent outbreaks of new lava, suggesting that repeat UAV flights can provide a means of better predicting pahoehoe lava flow behavior over flat or uneven topography. Our results show that UAVs can generate accurate and digital surface models quickly and inexpensively over rapidly changing active pahoehoe lava flows.

  6. The Wall-Rock Record of Incremental Emplacement in the Little Cottonwood-Alta Magmatic and Hydrothermal System, Wasatch Mountains, Utah, U.S.A.

    Science.gov (United States)

    Stearns, M.; Callis, S.; Beno, C.; Bowman, J. R.; Bartley, J. M.

    2017-12-01

    Contact aureoles record the cumulative effects on wall rocks of magma emplacement. Like the plutons they surround, contact aureoles have long been regarded to form geologically instantaneously. Protracted incremental emplacement of plutons must be reconciled with the wall-rock record of heat and mass transfer. Fundamental questions include how heat and material move from intrusions into their aureoles and how long that process takes. The Little Cottonwood stock is surrounded by a 2 km-wide contact aureole that contains prograde AFM mineral assemblages in the pelitic layers of the Proterozoic Big Cottonwood Formation. The Alta stock is surrounded by a well characterized 1 km-wide contact aureole containing both prograde AFM and CMS mineral assemblages in Ophir Shale and Mississippian dolostones, respectively. Understanding the petrogenesis of these aureoles requires the timing of magmatism and wall-rock metamorphism to be independently determined. Preliminary petrochronology (U/Th-Pb dates and trace element concentrations collected by LASS-ICP-MS) from the inner aureoles of both intrusions establishes a protracted history of monazite (re)crystallization from 35-25 Ma in the Little Cottonwood aureole and 35 Ma in the Alta aureole. Little Cottonwood aureole monazites are characterized by a positive age correlation with heavy rare earth elements (HREE) and a negative correlation with Eu/Eu*. Alta aureole monazites have a similar range of the HREE concentrations and Eu/Eu* variation. Zircon growth interpreted to record emplacement-level magmatic crystallization of the western Little Cottonwood stock ranges from 33-28 Ma near the contact. Multi-grain U-Pb zircon TIMS dates from the Alta stock range from 35-33 Ma and are interpreted to suggest the full range of emplacement-level magmatism in the Alta stock. Additionally, in situ U-Pb titanite dates from the Alta stock record intermittent high temperature hydrothermal activity in the stock margin from 35-24 Ma. These new

  7. Emplacement dynamics and lava field evolution of the flood basalt eruption at Holuhraun, Iceland: Observations from field and remote sensing data

    Science.gov (United States)

    Pedersen, Gro; Höskuldsson, Armann; Riishuus, Morten S.; Jónsdóttir, Ingibjörg; Thórdarson, Thorvaldur; Dürig, Tobias; Gudmundsson, Magnus T.; Durmont, Stephanie

    2016-04-01

    The Holuhraun eruption (Aug 2014- Feb 2015) is the largest effusive eruption in Iceland since the Laki eruption in 1783-84, with an estimated lava volume of ~1.6 km3 covering an area of ~83 km2. The eruption provides an unprecedented opportunity to study i) lava morphologies and their emplacement styles, ii) Morphological transitions iii) the transition from open to closed lava pathways and iv) the implication of lava pond formation. This study is based on three different categories of data; field data, airborne data and satellite data. The field data include tracking of the lava advancement by Global Positioning System (GPS) measurements and georeferenced GoPro cameras allowing classification of the lava margin morphology. Furthermore, video footage on-site documented lava emplacement. Complimentary observations have been provided from aircraft platforms and by satellite data. Of particular importance for lava morphology observations are 1-12 m/pixel airborne Synthetic Aperture Radar (SAR) images (x-band), as well as SAR data from TerraSAR-X and COSMO-SkyMed satellites. The Holuhraun lava field comprises a continuum of morphologies from pāhoehoe to 'a'ā, which have varied temporally and spatially. Shelly pāhoehoe lava was the first morphology to be observed (08-29). Spatially, this lava type was not widely distributed, but was emplaced throughout the eruption close to the vent area and the lava channels. Slabby pāhoehoe lava was initially observed the 08-31 and was observed throughout most of the eruption during the high-lava-flux phase of new lava lobe emplacement. 'A'ā lavas were the dominating morphology the first three months of the eruption and was first observed 09-01 like Rubbly pāhoehoe lava. Finally, Spiny pāhoehoe lava was first observed the 09-05 as a few marginal outbreaks along the fairly inactive parts of the 'a'ā lava lobe. However, throughout the eruption this morphology became more important and from mid-November/beginning of December the

  8. Diverse P-T paths for the Cycladic ultramafic rock associations: Constraints on their origin, emplacement and exhumation

    International Nuclear Information System (INIS)

    Katzir, Y; Garfunkel, Z; Avigad, D; Matthews, A

    2008-01-01

    Within the Alpine orogen of the Cyclades ultramafic rocks occur in diverse tectonic positions, are associated with a variety of rock sequences and are regionally metamorphosed at variable conditions. Here this diversity is interpreted in terms of variable mechanisms for incorporation of mantle rocks into orogenic belts and used to better constrain spatial heterogeneity of P-T burial and exhumation paths in the Cyclades. The Cycladic Blueschist Unit (CBU) was metamorphosed first at high pressure conditions in the Eocene (M1) and variably overprinted during exhumation in the Early Miocene (M2). On the islands of Syros and Evia the CBU includes relatively thin HP-LT ophiolitic melange intervals hosted by meta-sedimentary sequences. Meta-serpentinites are associated with eclogitized metagabbro and metabasites on Syros, but with epidote blueschists on Evia. Given the wide and comparable geochemical heterogeneity in the Syros and Evian melanges, the Syros metabasites record higher M1 temperatures (450-500 deg. C) relative to their Evian counterparts (400-430 deg. C). The M2 overprint is manifested in Syros by greenschist facies assemblages (∼450 deg. C), whereas pumpellyite-actinolite assemblage (∼350 deg. C) overgrew blueschists in Evia. Within the M2 migmatized leucogneiss core of the Naxos dome (∼700 0 C) meta-peridotite lenses are the sole preservers of pre-M2 history. The Naxos meta-peridotites possess relict mantle assemblage, fertile spinel lherzolite chemical composition and mantle-like oxygen isotope ratios. Thus unlike ophiolite-associated ultramafics in the Cyclades that were serpentinized prior to metamorphism, the Naxos metaperidotites were directly emplaced from the subcontinental mantle into an underthrust continent during collision and HP metamorphism. Ultramafic assemblages constrain M1 temperatures on Naxos to 550-650 0 C. It follows that going southeastwards from Evia through Syros to Naxos progressively deeper levels of the subducted plate are

  9. Emplacement processes of tuffaceous sandstones at IODP Site C0011B, Nankai Trough, derived from modal analysis

    Science.gov (United States)

    Schindlbeck, J. C.; Kutterolf, S.; Freundt, A.

    2011-12-01

    massive density-graded structure, and characteristic glass composition of each sandstone bed as well as as their occurrence ~ 350 km from mainland Japan, the most likely source region, support emplacement by huge turbidity currents directly derived from major explosive volcanic eruptions, probably involving massive entrance of pyroclastic flows into the ocean. Reference: Ridolfi F, Renzulli A, Puerini M (2009) Stability and chemical equilibrium of amphibole in calc-alkaline magmas: an overview, new thermobarometric formulations and application to subduction-related volcanoes. Contrib Mineral Petrol, DOI 10.1007/s00410-009-0465-7

  10. Mont Terri Project - Heater experiment, engineered barriers emplacement and ventilations tests. No 1 - Swiss Geological Survey, Bern, 2007

    International Nuclear Information System (INIS)

    Bossart, P.; Nussbaum, C.

    2007-01-01

    The international Mont Terri project started in January 1996. Research is carried out in the Mont Terri rock laboratory, an underground facility near the security gallery of the Mont Terri motorway tunnel (vicinity of St-Ursanne, Canton of Jura, Switzerland). The aim of the project is the geological, hydrogeological, geochemical and geotechnical characterisation of a clay formation, specifically of the Opalinus Clay. Twelve Partners from European countries and Japan participate in the project. These are ANDRA, BGR, CRIEPI, ENRESA, GRS, HSK, IRSN, JAEA, NAGRA, OBAYASHI, SCK.CEN and swisstopo. Since 2006, swisstopo acts as operator of the rock laboratory and is responsible for the implementation of the research programme decided by the partners. The three following reports are milestones in the research history of the Mont Terri project. It was the first time that an in-situ heating test with about 20 observation boreholes over a time span of several years was carried out in a clay formation. The engineered barrier emplacement experiment has been extended due to very encouraging measurement results and is still going on. The ventilation test was and is a challenge, especially in the very narrow microtunnel. All three projects were financially supported by the European Commission and the Swiss State Secretariat for Education and Research. The three important scientific and technical reports, which are presented in the following, have been provided by a number of scientists, engineers and technicians from the Partners, but also from national research organisations and private contractors. Many fruitful meetings where held, at the rock laboratory and at other facilities, not to forget the weeks and months of installation and testing work carried out by the technicians and engineers. The corresponding names and organisations are listed in detail in the reports. Special thanks are going to the co-ordinators of the three projects for their motivation of the team during

  11. Basaltic lava flows covering active aeolian dunes in the Paraná Basin in southern Brazil: Features and emplacement aspects

    Science.gov (United States)

    Waichel, Breno L.; Scherer, Claiton M. S.; Frank, Heinrich T.

    2008-03-01

    Burial of active aeolian dunes by lava flows can preserve the morphology of the dunes and generate diverse features related to interaction between unconsolidated sediments and lavas. In the study area, located in southern Brazil, burial of aeolian deposits by Cretaceous basaltic lava flows completely preserved dunes, and generate sand-deformation features, sand diapirs and peperite-like breccia. The preserved dunes are crescentic and linear at the main contact with basalts, and smaller crescentic where interlayered with lavas. The various feature types formed on sediment surfaces by the advance of the flows reflect the emplacement style of the lavas which are compound pahoehoe type. Four feature types can be recognized: (a) type 1 features are related to the advance of sheet flows in dune-interdune areas with slopes > 5°, (b) type 2 is formed where the lava flows advance in lobes and climb the stoss slope of crescentic dunes (slopes 8-12°), (c) type 3 is generated by toes that descend the face of linear dunes (slopes 17-23°) and (d) type 4 occurs when lava lobes descend the stoss slope of crescentic dunes (slopes 10-15°). The direction of the flows, the disposition and morphology of the dunes and the ground slope are the main factors controlling formation of the features. The injection of unconsolidated sand in lava lobes forms diapirs and peperite-like breccias. Sand diapirs occur at the basal portion of lobes where the lava was more solidified. Peperite-like breccias occur in the inner portion where lava was more plastic, favoring the mingling of the components. The generation of both features is related to a mechanical process: the weight of the lava causes the injection of sand into the lava and the warming of the air in the pores of the sand facilitates this process. The lava-sediment interaction features presented here are consistent with previous reports of basalt lavas with unconsolidated arid sediments, and additional new sand-deformation features

  12. Postorogenic emplacement of the Santa Marta Batholith, northwestern flank of the Sierra Nevada de Santa Marta (SNSM).

    Science.gov (United States)

    Sanchez Sierra, Johan Miguel Sebastian; Kammer, Andreas

    2017-04-01

    The Santa Marta Batholith (BSM) belongs to a Paleogene intrusive suite of the Santa Marta massif, an exhumed triangular block at the southern Caribbean margin. Its Paleogene age precludes its association to an active margin, although its emplacement was controlled by the flexure of the down-bent Southamerican plate. Its internal structure is outlined by a mafic border facies and a felsic core, both having a petrologic affinity to a TTG-suite. According to existing age data, the BSM consolidated sequentially from SW to NE, with a first pulse having crystallized at 56 Ma in the southern domain and a final pulse in the northern domain at 52-50 Ma. Pressures varied between 5-7 kb, corresponding to depths of 14-19 km. This study combines structural, thermochronological and geochemical data with an analysis of Anisotropy and Magnetic Susceptibility (AMS) and paleomagnetism. The SNSM had a clockwise rotation of 30 ° and the ASM results help distinguish between two fault-bounded structural domains. The southern domain is characterized by a magnetic foliation concordant to the contact of the host rock that dips toward the hinterland. The northern domain, in contrast, displays a N-S trending magnetic foliation that is oblique to the regional structural northeastern trend. This divergence is supported by the orientation of mineral lineations, enclaves and dikes. In spite of its arc signature, anomalies like enrichment in Ti, depletion of Nb-Ta and Zr-Hf, as well as flat REE patterns can be associated to the accumulation of crystallized mafic minerals from less-fractionated magmas. These data evidence mingling. Asymmetric internal organization, as indicated by a hinterland-dipping roof pendent, the structural setting at the margin of a thickened continental margin and its geochemical signature favor a scenario of a magma generation at a mid-crustal level and its consequent extrusion along a channel, that connected to the crustal bend of the continental plate that was

  13. Emplacement dynamics and timescale of a Holocene flow from the Cima Volcanic Field (CA): Insights from rheology and morphology

    Science.gov (United States)

    Soldati, Arianna; Beem, Jordon; Gomez, Francisco; Huntley, John Warren; Robertson, Timothy; Whittington, Alan

    2017-11-01

    We present a rheological and morphological study of a Holocene lava flow emitted by a monogenetic cinder cone in the Cima Volcanic Field, eastern California. Our field observations focused on surface morphology, which transitions from smooth core extrusions near the vent to jagged 'a'ā blocks over the majority of the flow, and on channel and levée dimensions. We collected airborne photogrammetry data and used it to generate a digital elevation model. From this, the total flow volume was estimated and surface roughness was quantified in terms of standard deviation of the real surface (5 cm resolution) from the software-generated 1 m-average plane. Sample textural analyses revealed that the near-vent portion of the flow is significantly more crystalline (ϕxtal = 0.95 ± 0.04) than the main flow body (ϕxtal = 0.66 ± 0.11). The rheology of Cima lavas was determined experimentally by concentric cylinder viscometry between 1550 °C and 1160 °C, including the first subliquidus rheology measurements for a continental intraplate trachybasaltic lava. The experimentally determined effective viscosity increases from 54 Pa·s to 1361 Pa·s during cooling from the liquidus ( 1230 °C) to 1160 °C, where crystal fraction is 0.11. The lava viscosity over this range is still lower than most basaltic melts, due to the high alkali content of Cima lavas ( 6 wt% Na2O + K2O). Monte Carlo simulations were used to account for and propagate experimental uncertainties, and to determine which rheological model (Bingham, power law, or Herschel-Bulkley) provides the best-fit of the obtained rheological data. Results suggest that Bingham and Herschel-Bulkley models are statistically indistinguishable from each other, and that both fit the data better than a power law model. By combining field observations and experimental results, we reconstructed the eruption temperature and few days-long emplacement history of the Cima flow.

  14. Geological setting, emplacement mechanism and igneous evolution of the Atchiza mafic-ultramafic layered suite in north-west Mozambique

    Science.gov (United States)

    Ibraimo, Daniel Luis; Larsen, Rune B.

    2015-11-01

    system of the continental rift environment. The intrusion resulted from the emplacement of mafic magma in space created by extensional forces. Space was created through a connecting fault generated as a result of overall extensional, torsion and slab displacement in a rift system. The geometry of the body is tectonically controlled, and it agrees with the tectonic framework of the Zambezi Belt during the Rodinia breakup in the early Neoproterozoic.

  15. The Swedish Concept for Disposal of Spent Nuclear Fuel: Differences Between Vertical and Horizontal Waste Canister Emplacement

    International Nuclear Information System (INIS)

    Bennett, D.G.; Hicks, T.W.

    2005-10-01

    The Swedish Nuclear Power Inspectorate (SKI) is preparing for the review of licence applications related to the disposal of spent nuclear fuel. The Swedish Nuclear Fuel and Waste Management Company (SKB) refers to its proposals for the disposal of spent nuclear fuel as the KBS-3 concept. In the KBS-3 concept, SKB plans that, after 30 to 40 years of interim storage, spent fuel will be disposed of at a depth of about 500 m in crystalline bedrock, surrounded by a system of engineered barriers. The principle barrier to radionuclide release is a cylindrical copper canister. Within the copper canister, the spent fuel is supported by a cast iron insert. Outside the copper canister is a layer of bentonite clay, known as the buffer, which is designed to provide mechanical protection for the canisters and to limit the access of groundwater and corrosive substances to their surfaces. The bentonite buffer is also designed to sorb radionuclides released from the canisters, and to filter any colloids that may form within the waste. SKB is expected to base its forthcoming licence applications on a repository design in which the waste canisters are emplaced in vertical boreholes (KBS-3V). However, SKB has also indicated that it might be possible and, in some respects, beneficial to dispose of the waste canisters in horizontal tunnels (KBS-3H). There are many similarities between the KBS-3V and KBS-3H designs. There are, however, uncertainties associated with both of the designs and, when compared, both possess relative advantages and disadvantages. SKB has identified many of the key factors that will determine the evolution of a KBS-3H repository and has plans for research and development work in many of the areas where the differences between the KBS-3V and KBS-3H designs mean that they could be significant in terms of repository performance. With respect to the KBS-3H design, key technical issues are associated with: 1. The accuracy of deposition drift construction. 2. Water

  16. Growth of plutons by incremental emplacement of sheets in crystal-rich host: Evidence from Miocene intrusions of the Colorado River region, Nevada, USA

    Science.gov (United States)

    Miller, C.F.; Furbish, D.J.; Walker, B.A.; Claiborne, L.L.; Koteas, G.C.; Bleick, H.A.; Miller, J.S.

    2011-01-01

    Growing evidence supports the notion that plutons are constructed incrementally, commonly over long periods of time, yet field evidence for the multiple injections that seem to be required is commonly sparse or absent. Timescales of up to several million years, among other arguments, indicate that the dominant volume does not remain largely molten, yet if growing plutons are constructed from rapidly solidifying increments it is unlikely that intrusive contacts would escape notice. A model wherein magma increments are emplaced into melt-bearing but crystal-rich host, rather than either solid or crystal-poor material, provides a plausible explanation for this apparent conundrum. A partially solidified intrusion undoubtedly comprises zones with contrasting melt fraction and therefore strength. Depending on whether these zones behave elastically or ductilely in response to dike emplacement, intruding magma may spread to form sheets by either of two mechanisms. If the melt-bearing host is elastic on the relevant timescale, magma spreads rather than continuing to propagate upward, where it encounters a zone of higher rigidity (higher crystal fraction). Similarly, if the dike at first ascends through rigid, melt-poor material and then encounters a zone that is weak enough (poor enough in crystals) to respond ductilely, the ascending material will also spread because the dike tip ceases to propagate as in rigid material. We propose that ascending magma is thus in essence trapped, by either mechanism, within relatively crystal-poor zones. Contacts will commonly be obscure from the start because the contrast between intruding material (crystal-poorer magma) and host (crystal-richer material) is subtle, and they may be obscured even further by subsequent destabilization of the crystal-melt framework. Field evidence and zircon zoning stratigraphy in plutons of the Colorado River region of southern Nevada support the hypothesis that emplacement of magma replenishments into a

  17. Pluton emplacement in a releasing bend in a transpressive regime: the arrozal granite in the Paraíba do Sul shear belt, Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Alexis R. Nummer

    2007-06-01

    Full Text Available The Arrozal Granite, situated in the southwestern region of the State of Rio de Janeiro, has a granitic to granodioritic composition. It contains a strong mylonitic foliation along its border, passing gradually to a well-developed magmatic foliation towards its center. Structural analysis indicates that the Arrozal Granite was emplaced along the Além-Paraíba Shear Zone in a dextral transpressive tectonic regime. A regional shift of the trend along this shear zone from NE-SW to E-W, observed in the area, is interpreted to be casually related to the creation of space for the emplacement of the granite. Our data indicate that releasing bends may have played an important role for space generation during the emplacement of the Arrozal Granite and other plutons.O Granito Arrozal ocorre na porção sudoeste do Estado do Rio de Janeiro e associa-se à Zona de Cisalhamento de Além-Paraíba. Possui composição granítica a granodiorítica eexibe predomínio de estruturas magmáticas na parte central, e estruturas de alto strain (miloníticas nas bordas. Os dados estruturais sugerem colocação em segmentos extensionais(releasing bends associados a uma tectônica transcorrentedestral, sob regime transpressivo. A forte mudança do trend estrutural desta zona de cisalhamento na região, passando de NE-SW para próximo de E-W, criou condições para geração de espaços que favoreceram a colocação do Granito Arrozal, além de outros granitos associados à referida zona.

  18. Multiple Emplacement and Exhumation History of the Late Mesozoic Dayunshan-Mufushan Batholith in Southeast China and Its Tectonic Significance: 1. Structural Analysis and Geochronological Constraints

    Science.gov (United States)

    Ji, Wenbin; Faure, Michel; Lin, Wei; Chen, Yan; Chu, Yang; Xue, Zhenhua

    2018-01-01

    The South China Block (SCB) experienced a polyphase reworking by the Phanerozoic tectonothermal events. To better understand its Late Mesozoic tectonics, an integrated multidisciplinary investigation has been conducted on the Dayunshan-Mufushan composite batholith in the north-central SCB. This batholith consists of two major intrusions that recorded distinct emplacement features. According to our structural analysis, two deformation events in relation to batholith emplacement and subsequent exhumation are identified. The early one (D1) was observed mostly at the southern border of the batholith, characterized by a top-to-the-SW ductile shearing in the early-stage intrusion and along its contact zone. This deformation, chiefly associated with the pluton emplacement at ca. 150 Ma, was probably assisted by farfield compression from the northern Yangtze foreland belt. The second but main event (D2) involved two phases: (1) ductile shearing (D2a) prominently expressed along the Dayunshan detachment fault at the western border of the batholith where the syntectonic late-stage intrusion and minor metasedimentary basement in the footwall suffered mylonitization with top-to-the-NW kinematics; and (2) subsequent brittle faulting (D2b) further exhumed the entire batholith that behaved as rift shoulder with half-graben basins developed on its both sides. Geochronological constraints show that the crustal ductile extension occurred during 132-95 Ma. Such a Cretaceous NW-SE extensional tectonic regime, as indicated by the D2 event, has been recognized in a vast area of East Asia. This tectonism was responsible not only for the destruction of the North China craton but also for the formation of the so-called "southeast China basin and range tectonics."

  19. Emplacement of pillow lavas from the ~ 2.8 Ga Chitradurga Greenstone Belt, South India: A physical volcanological, morphometric and geochemical perspective

    Science.gov (United States)

    Duraiswami, Raymond A.; Inamdar, Mustaqueem M.; Shaikh, Tahira N.

    2013-08-01

    The physical volcanology and morphometric analyses of pillowed lava flows from the Chitradurga basin of Chitradurga Greenstone Belt, South India have been undertaken. In the Chitradurga hills individual pillowed flows alternate with massive submarine sheet flows. The pillows from such flows are separated by chert and occur as spheroidal, elongated or reniform units that are devoid of vesicles, vesicle bands or pipe vesicles. The Mardihalli flow is exposed as a small elongated mound in the basin and consists of a massive core that is draped by pillows along the flow crest and flanks. The pillows from Mardihalli occur as spheroidal to elongate units with smooth, spalled or wrinkled surfaces with vesicular interiors. Repeated budding of larger pillows have produced a series of interconnected pillow units indicating fluid lava that was emplaced on steeply dipping flanks. Based on the morphological features the pillowed flows from the Chitradurga basin were emplaced at low effusion rates (≤ 5 m3/s). Pillows in these flows formed from low viscosity lavas that underwent negligible to moderate inflation due to rapid chilling. Sporadic occurrences of pillow breccias, hyaloclastite and chert breccias in the pillowed flow fields indicate disruption of pillows due to lava surges and slumping. It is envisaged that the Chitradurga basin witnessed distinct episodes of submarine tholeiite eruptions that produced pillowed lavas that variably interacted with sea water to produce geochemistries. The field and stratigraphic relationships of the volcanics and associated clastic sediments suggest that the pillow lavas were emplaced in a shallow marine marginal inter/back arc basin.

  20. Textural analysis of particles from El Zaguán debris avalanche deposit, Nevado de Toluca volcano, Mexico: Evidence of flow behavior during emplacement

    Science.gov (United States)

    Caballero, Lizeth; Capra, Lucia

    2011-02-01

    El Zaguán deposit originated at 28,000 yrs. B.P. from the flank collapse of Nevado de Toluca, a dacitic stratovolcano of the Transmexican Volcanic Belt. Scanning Electron Microprobe analyses (SEM) were performed on some particles from this deposit to observe microtextures produced during transport and emplacement of the debris avalanche flow. Particles from 2ϕ (250 μm), 0ϕ (1 mm) and - 2ϕ (4 mm) granulometric classes were randomly selected at different outcrops, and their surface textures were described. The observed textures are divided in two groups, Basal and Upper textures, each one indicating different clast interactions. Basal textures are observed predominantly in the lower part of the deposit and consist of parallel ridges, parallel grooves, scratches and lips. Upper textures are mainly present in the upper part of the deposit and consisted of fractures, percussion marks, and broken or grinded crystals. These characteristics, coupled with field observations such as the presence of clastic dikes and deformed lacustrine mega-blocks, indicate that the basal part of the debris avalanche was moving in a partially liquefied state. By contrast, the particles in the upper part were able to move freely, interacting by collision. These microscopic textures are in agreement with previously described emplacement behaviors in debris avalanches of volcanic origin, suggesting a stratified flow dominated by different transport and depositional mechanisms depending upon flow depth and possible fluid content at their base.

  1. Sem Analysis of particles from the 28, 000 B.P El Zaguan debris avalanche deposit, Nevado de Toluca volcano, Central Mexico: evidences of flow behavior during emplacement

    Science.gov (United States)

    Caballero, L.; Capra, L.

    2008-12-01

    The Zaguan deposit originated at 28, 000 yr. B.P from the flank collapse of the Nevado de Toluca volcano, a dacitic stratovolcano of the Transmexican Volcanic Belt. A Scanning Electron Microprobe analysis (SEM) was made to some clasts of this deposit to observe microtextures produced during transport and emplacement of the debris avalanche flow. Particles from 2, 0 and -2 Φ granulometric classes were randomly selected and their surface textures were described. The textures observed were divided in two groups, collision and shear structures indicating different clast interaction. Shear textures were observed predominantly on the basal part of the deposit and consisted of parallel ridges, parallel grooves, scratches and lips. Collision textures were mainly present in the upper part of the deposit and consisted of fractures, percussion marks, and broken or grinded crystals. These characteristics, coupled with field observation, like the presence of clast dikes and deformed lacustrine megaclasts, indicate that the basal part of the debris avalanche was moving in a partially liquefied state, were particles were not able to move freely because of the confinement exerted by the upper part of the flow, so shear stresses dominated. On the contrary, the particles in the upper part were able to move freely so the principal mechanism of interaction between particles was collision. These microscopic textures are in agreement with previously described behavior of emplacement of debris avalanches of volcanic origin, that suggest a stratified flow dominated by different transport and depositional mechanism depending on flow depth and possible fluid content at their base.

  2. Palaeomagnetism of the Cappadocian Volcanic Succession, Central Turkey: Major ignimbrite emplacement during two short (Miocene) episodes and Neogene tectonics of the Anatolian collage

    Science.gov (United States)

    Piper, J. D. A.; Koçbulut, F.; Gürsoy, H.; Tatar, O.; Viereck, L.; Lepetit, P.; Roberts, A. P.; Akpınar, Z.

    2013-07-01

    The Central Anatolian Volcanic Province in Cappadocia includes 13 high volume calc-alkaline ignimbrite sheets emplaced by plinian eruptions within a succession (the Ürgüp Formation) after ~ 10 Ma recording the last phase of Neotethyan subduction and accompanying emplacement of the Tauride orogen in southern Turkey. To evaluate magnetostratigraphy in the context of recent revisions of the chronostratigraphy we have extended palaeomagnetic investigation to 32 new sites yielding significant ChRM directions. Integrated rock magnetic and palaeomagnetic investigations identify magnetic remanence residing predominantly in Ti-poor titanomagnetites although secondary processes within the ignimbrite sheets, notably post-emplacement oxidation, have locally produced hematisation expressed by composite IRM spectra and variable reduction in intensity of magnetisation. The ignimbrite sheets possess weak anisotropies of magnetic susceptibility (AMS, mostly < 5%) describing tensors with axial distributions close to bedding and minimum axes predominantly perpendicular to this plane; collectively directions show weak imbrication correlating with palaeoflow during emplacement predominantly towards the north and east away from the Erdas Dağ, an inferred topographic palaeohigh at the southern margin of the basin. The precise control provided by magnetostratigraphy and radiometric age dating now shows that the bulk of Cappadocian ignimbrite magmatism was concentrated into two short episodes. An older Cardak Centre (Kavak Group and Zelve ignimbrites) produced in excess of 200 km3 of pyroclastic deposits during polarity chron C4r.1n between 9.31 and 9.43 Ma. Subsequent activity from the Acıgöl Centre further to the south west (Cemilköy, Gelveri, Gördeles, and Kızılkaya) produced in excess of 620 km3 of pyroclastic deposits during polarity chrons between 5.3 and 7.1 Ma. The younger İncesu ignimbrite was sourced in the Sultansazlığı pull-apart basin to the east during the Gauss

  3. Lava flow field emplacement studies of Manua Ulu (Kilauea Volcano, Hawai'i, United States) and Venus, using field and remote sensing analyses

    Science.gov (United States)

    Byrnes, Jeffrey Myer

    2002-04-01

    This work examines lava emplacement processes by characterizing surface units using field and remote sensing analyses in order to understand the development of lava flow fields. Specific study areas are the 1969--1974 Mauna Ulu compound flow field, (Kilauea Volcano, Hawai'i, USA), and five lava flow fields on Venus: Turgmam Fluctus, Zipaltonal Fluctus, the Tuli Mons/Uilata Fluctus flow complex, the Var Mons flow field, and Mylitta Fluctus. Lava surface units have been examined in the field and with visible-, thermal-, and radar-wavelength remote sensing datasets for Mauna Ulu, and with radar data for the Venusian study areas. For the Mauna Ulu flow field, visible characteristics are related to color, glass abundance, and dm- to m-scale surface irregularities, which reflect the lava flow regime, cooling, and modification due to processes such as coalescence and inflation. Thermal characteristics are primarily affected by the abundance of glass and small-scale roughness elements (such as vesicles), and reflect the history of cooling, vesiculation and degassing, and crystallization of the lava. Radar characteristics are primarily affected by unit topography and fracturing, which are related to flow inflation, remobilization, and collapse, and reflect the local supply of lava during and after unit emplacement. Mauna Ulu surface units are correlated with pre-eruption topography, lack a simple relationship to the main feeder lava tubes, and are distributed with respect to their position within compound flow lobes and with distance from the vent. The Venusian lava flow fields appear to have developed through emplacement of numerous, thin, simple and compound flows, presumably over extended periods of time, and show a wider range of radar roughness than is observed at Mauna Ulu. A potential correlation is suggested between flow rheology and surface roughness. Distributary flow morphologies may result from tube-fed flows, and flow inflation is consistent with observed

  4. Emplacement and deformation of the Cerro Durazno Pluton delineates stages of the lower Paleozoic tectono-magmatic evolution in NW-Argentina

    Science.gov (United States)

    Hongn, F.; Riller, U.

    2003-04-01

    Regional-scale transpression and transtension are considered to be important in the lower Paleozoic tectono-magmatic evolution of metamorphic and granitoid basement rocks of the southern central Andes. In order to test whether such kinematic changes affected Paleozoic basement rocks on the local scale, i.e. in the Eastern Cordillera of NW-Argentina, we performed a detailed field-based structural analysis of the 456 Ma granitoid Cerro Durazno pluton (CDP). The results of our analysis point to the following stages in the geodynamic evolution of this area: (1) Metamorphism and deformation of Neoproterozoic-Paleozoic basement rocks occurred at high T and low to medium P prior to emplacement of the CDP. This lead to the formation of schists and migmatites characterized by pervasive planar and linear mineral shape fabrics and the growth of andalusite, cordierite and fibrolite. (2) Magmatic foliation in the CDP is defined by the shape-preferred orientation of euhedral feldspar phenocrysts and microgranitoid enclaves. These fabrics are concordant to the NE-SW striking intrusive contact with migmatitic host rocks. The lack of submagmatic or high-T solid-state fabrics in the CDP may indicate that cooling and solidification of granitoid magma was not accompanied by regional deformation. Alternatively, emplacement of granitoid magma may have been facilitated by the creation of open space at mid-crustal level induced by regional deformation. (3) Ductile deformation under greenschist metamorphic conditions overprinted magmatic fabrics of the CDP. This is evident by NW-SE striking metamorphic foliation surfaces transecting magmatic shape fabrics at high angles. During this deformation, the pluton was thrust on a SW-dipping shear zone toward the NE over low-grade metamorphic host rocks which lead to a condensation of metamorphic isograds in the host rocks. Ages of strained pegmatitic dikes indicate that this deformation occurred at about 430 Ma. In summary, the difference in age

  5. Investigating Magmatic Processes in the Lower Levels of Mantle-derived Magmatic Systems: The Age & Emplacement of the Kunene Anorthosite Complex (SW Angola)

    Science.gov (United States)

    Hayes, B.; Bybee, G. M.; Owen-Smith, T.; Lehmann, J.; Brower, A. M.; Ashwal, L. D.; Hill, C. M.

    2017-12-01

    Our understanding of mantle-derived magmatic systems has shifted from a notion of upper crustal, melt-dominated magma chambers that feed short-lived volcanic eruptions, to a view of more long-lived trans-crustal, mush-dominated systems. Proterozoic massif-type anorthosite systems are voluminous, plagioclase-dominated plutonic suites with ubiquitous intermediate compositions (An 50 ± 10) that represent mantle-derived magmas initially ponded at Moho depths and crystallized polybarically until emplacement at mid-crustal levels. Thus, these systems provide unique insight into magma storage and processing in the lower reaches of the magma mush column, where such interpretation has previously relied on cumulate xenoliths in lavas, geophysical data and experimental/numerical modeling. We present new CA-ID-TIMS ages and a series of detailed field observations from the largest Proterozoic anorthosite massif on Earth, the Kunene Anorthosite Complex (KAC) of SW Angola. Field structures indicate that (i) the bulk of the material was emplaced in the form of crystal mushes, as both plutons and sheet-like intrusions; (ii) prolonged magmatism led to cumulate disaggregation (block structure development) and remobilization, producing considerable textural heterogeneity; (iii) crystal-rich magmatic flow induced localized recrystallization and the development of protoclastic (mortar) textures; and (iv) late residual melts were able to migrate locally prior to complete solidification. Dating of pegmatitic pods entrained from cumulate zones at the base of the crust (1500 ± 13 Ma) and their host anorthosites (1375-1438 Ma) reveals time periods in the range of 60-120 Myr between the earliest products of the system and the final mushes emplaced at higher crustal levels. Therefore, the KAC represents a complex, mushy magmatic system that developed over a long period of time. Not only do these observations help in refining our understanding of Proterozoic anorthosite petrogenesis, they

  6. U-Pb geochronology documents out-of-sequence emplacement of ultramafic layers in the Bushveld Igneous Complex of South Africa.

    Science.gov (United States)

    Mungall, James E; Kamo, Sandra L; McQuade, Stewart

    2016-11-14

    Layered intrusions represent part of the plumbing systems that deliver vast quantities of magma through the Earth's crust during the formation of large igneous provinces, which disrupt global ecosystems and host most of the Earth's endowment of Pt, Ni and Cr deposits. The Rustenburg Layered Suite of the enormous Bushveld Igneous Complex of South Africa has been presumed to have formed by deposition of crystals at the floor of a subterranean sea of magma several km deep and hundreds of km wide called a magma chamber. Here we show, using U-Pb isotopic dating of zircon and baddeleyite, that individual chromitite layers of the Rustenburg Layered Suite formed within a stack of discrete sheet-like intrusions emplaced and solidified as separate bodies beneath older layers. Our U-Pb ages and modelling necessitate reassessment of the genesis of layered intrusions and their ore deposits, and challenge even the venerable concept of the magma chamber itself.

  7. I. Some results from a field investigation of thermo-mechanical loading of a rock mass when heaters are emplaced in the rock

    International Nuclear Information System (INIS)

    Hood, M.

    1979-01-01

    Results are presented of a field experiment to monitor the response of a rock mass to thermomechanical loading from electrically heated canisters emplaced in the rock at a depth of 340 m. Measurements made to date of temperature, displacement, and stress fields indicate that heat is transferred through the rock mainly by conduction; discontinuities within the rock mass have a minimal effect on the heat flow. Displacements within the rock from thermal expansion are shown to be much less than those predicted by linear thermoelastic theory. A plausible, though not complete, reason for these reduced displacements is the absorption of the initial rock expansions into discontinuities within the rock mass. Difficulties have been experienced in obtaining reliable stress measurement data using borehole deformation gauges to monitor changes in rock stress. Some data have been obtained and are being analyzed. Rock decrepitation in the heater boreholes is discussed

  8. Comparison of measured and calculated radiation doses in granite around emplacement holes in the spent-fuel test: Climax, Nevada Test Site

    International Nuclear Information System (INIS)

    van Konynenburg, R.A.

    1982-01-01

    Lawrence Livermore National Laboratory (LLNL) has emplaced eleven spent nuclear-reactor fuel assemblies in the Climax granite at the Nevada Test Site as part of the DOE Nevada Nuclear-Waste Storage Investigations. One of our objectives is to study radiation effects on the rock. The neutron and gamma-ray doses to the rock have been determined by MORSE-L Monte Carlo calculations and measurements using optical absorption and thermoluminescence dosimeters and metal foils. We compare the results to date. Generally, good agreement is found in the spatial and time dependence of the doses, but some of the absolute dose results appear to differ by more than the expected uncertainties. Although the agreement is judged to be adequate for radiation effects studies, suggestions for improving the precision of the calculations and measurements are made

  9. Geology of the Curimatau medium region (Paraiba State, Brazil) and the emplacement of the Dona Ines granite associated to the Brasiliano transcurrent shear zones

    International Nuclear Information System (INIS)

    Borges, Sergio Vieira Freire

    1996-01-01

    In an area of about 700 Km 2 located in the northeast of Paraiba State and having as main point the town of Dona Ines, a geologic/structural mapping, a gravimetric survey and radiometric dating using the Rb/Sr method in whole rock and Sm.Nd model ages were undertaken in order to study and to understand the geology of this portion of terrain, the emplacement of the Dona Ines granitoids and its relationship with the enclosing rocks and the deformation acting at the time of the intrusion. The age of the pluton of Dona Ines was determined by the Rb/Sr whole rock method as 560 ± 20 Ma (end of Brasiliano Cycle in the region). Sm.Nd model ages in granitoids of Araras, Belem and Dona Ines have revealed paleoproterozoic ages for their crustal sources, as indicated by the negative ε nd of this rock

  10. Multistage magma emplacement and progressive strain accumulation in the shallow-level Krkonoše-Jizera plutonic complex, Bohemian Massif

    Science.gov (United States)

    Žák, Jiří; Verner, Kryštof; Sláma, Jiří; Kachlík, Václav; Chlupáčová, Marta

    2013-09-01

    relationships combined with new U-Pb zircon geochronology suggest that the shallow-level Krkonoše-Jizera plutonic complex, northern Bohemian Massif, was assembled successively from bottom to top, starting with emplacement of the separately evolved S-type Tanvald granite (317.3 ± 2.1 Ma), followed by at least two voluminous batches of the I-type porphyritic Liberec (319.5 ± 2.3 Ma) and Jizera (320.1 ± 3.0 Ma and 319.3 ± 3.7 Ma) granites. The intrusive sequence was completed by uppermost, minor intrusions of the equigranular Harrachov (315.0 ± 2.7 Ma) and Krkonoše granites. The I-type granites exhibit an unusually complex pattern of superposed feldspar phenocryst and magnetic fabrics as revealed from the anisotropy of magnetic susceptibility (AMS). The outer Liberec granite preserves margin-parallel foliations and lineations, interpreted to record emplacement-related strain captured by cooling from the pluton floor and walls. In contrast, the inner Jizera, Harrachov, and Krkonoše granites were overprinted by synmagmatic strain resulting from dextral movements along regional strike-slip faults cutting the opposite ends of the plutonic complex. Late-stage felsic dikes in the Liberec and Jizera granites reorient from horizontal to vertical (lineation-perpendicular) attitude in response to changing the least principal stress direction, whereas mafic schlieren do not do so, representing only randomly oriented small-scale thermal-mechanical instabilities in the phenocryst framework. In general, this case example challenges the common approach of inferring pluton-wide magma flow from interpolated foliation, lineation, and schlieren patterns. More likely, magmatic fabrics in large plutons record complex temporal succession of superposed strains resulting from diverse processes at multiple scales.

  11. The morphology and evolution of the Stromboli 2002-2003 lava flow field--An example of a basaltic flow field emplaced on a steep slope

    Science.gov (United States)

    Lodato, Luigi; Harris, A.; Spampinato, L.; Calvari, Sonia; Dehn, J.; Patrick, M.

    2007-01-01

    The use of a hand-held thermal camera during the 2002–2003 Stromboli effusive eruption proved essential in tracking the development of flow field structures and in measuring related eruption parameters, such as the number of active vents and flow lengths. The steep underlying slope on which the flow field was emplaced resulted in a characteristic flow field morphology. This comprised a proximal shield, where flow stacking and inflation caused piling up of lava on the relatively flat ground of the vent zone, that fed a medial–distal lava flow field. This zone was characterized by the formation of lava tubes and tumuli forming a complex network of tumuli and flows linked by tubes. Most of the flow field was emplaced on extremely steep slopes and this had two effects. It caused flows to slide, as well as flow, and flow fronts to fail frequently, persistent flow front crumbling resulted in the production of an extensive debris field. Channel-fed flows were also characterized by development of excavated debris levees in this zone (Calvari et al. 2005). Collapse of lava flow fronts and inflation of the upper proximal lava shield made volume calculation very difficult. Comparison of the final field volume with that expecta by integrating the lava effusion rates through time suggests a loss of ~70% erupted lava by flow front crumbling and accumulation as debris flows below sea level. Derived relationships between effusion rate, flow length, and number of active vents showed systematic and correlated variations with time where spreading of volume between numerous flows caused an otherwise good correlation between effusion rate, flow length to break down. Observations collected during this eruption are useful in helping to understand lava flow processes on steep slopes, as well as in interpreting old lava–debris sequences found in other steep-sided volcanoes subject to effusive activity.

  12. Generation and emplacement of shear-related highly mobile crustal melts: the synkinematic leucogranites from the Variscan Tormes Dome, Western Spain

    Science.gov (United States)

    López-Moro, Francisco Javier; López-Plaza, Miguel; Romer, Rolf L.

    2012-07-01

    The Tormes dome consists of S-type granites that intruded into Ordovician augen gneisses and Neoproterozoic-Lower Cambrian metapelites/metagreywackes at different extents of migmatization. S-type granites are mainly equigranular two-mica granites, occurring as: (1) enclave-laden subvertical feeder dykes, (2) small external sill-like bodies with size and shape relations indicative for self-similar pluton growth, and (3) as large pluton bodies, emplaced at higher levels than the external ones. These magmas were highly mobile as it is inferred from the high contents of fluxing components, the disintegration and alignment of pelitic xenoliths in feeder dykes and at the bottom of some sill-like bodies. Field relations relate this 311 Ma magmatism (U-Pb monazite) to the regional shearing of the D3 Variscan event. Partial melting modeling and the relatively high estimated liquidus temperatures indicate biotite-dehydration partial melting (800-840°C and 400-650 MPa) rather than water-fluxed melting, implying that there was no partial melting triggered by externally derived fluids in the shear zones. Instead, the subvertical shear zones favored extraction of melts that formed during the regional migmatization event around 320 Ma. Nd isotope variation among the granites might reflect disequilibrium partial melting or different protoliths. Mass-balance and trace element partial melting modeling strongly suggest two kinds of fertile crustal protoliths: augen gneisses and metapelites. Slight compositional variation among the leucogranites does not reflect different extent of protolith melting but is related to a small amount of fractional crystallization (bodies. The lower extent of fractional crystallization and the higher-pressure emplacement conditions of the sill-like bodies support a more restricted movement through the crust than for batholitic leucogranites.

  13. Lunar floor-fractured craters: Modes of dike and sill emplacement and implications of gas production and intrusion cooling on surface morphology and structure

    Science.gov (United States)

    Wilson, Lionel; Head, James W.

    2018-05-01

    Lunar floor-fractured craters (FFCs) represent the surface manifestation of a class of shallow crustal intrusions in which magma-filled cracks (dikes) rising to the surface from great depth encounter contrasts in host rock lithology (breccia lens, rigid solidified melt sheet) and intrude laterally to form a sill, laccolith or bysmalith, thereby uplifting and deforming the crater floor. Recent developments in the knowledge of lunar crustal thickness and density structure have enabled important revisions to models of the generation, ascent and eruption of magma, and new knowledge about the presence and behavior of magmatic volatiles has provided additional perspectives on shallow intrusion processes in FFCs. We use these new data to assess the processes that occur during dike and sill emplacement with particular emphasis on tracking the fate and migration of volatiles and their relation to candidate venting processes. FFCs result when dikes are capable of intruding close to the surface, but fail to erupt because of the substructure of their host impact craters, and instead intrude laterally after encountering a boundary where an increase in ductility (base of breccia lens) or rigidity (base of solidified melt sheet) occurs. Magma in dikes approaching the lunar surface experiences increasingly lower overburden pressures: this enhances CO gas formation and brings the magma into the realm of the low pressure release of H2O and sulfur compounds, both factors adding volatiles to those already collected in the rising low-pressure part of the dike tip. High magma rise velocity is driven by the positive buoyancy of the magma in the part of the dike remaining in the mantle. The dike tip overshoots the interface and the consequent excess pressure at the interface drives the horizontal flow of magma to form the intrusion and raise the crater floor. If sill intrusion were controlled by the physical properties at the base of the melt sheet, dikes would be required to approach to

  14. The Park Volcanics Group : field relations of an igneous suite emplaced in the Triassic-Jurassic Murihiku Terrane, South Island, New Zealand

    International Nuclear Information System (INIS)

    Coombs, D.S.; Cook, N.D.J.; Campbell, J.D.

    1992-01-01

    Park Volcanics Group is proposed for igneous rocks, either shallow intrusive or extrusive, emplaced in the Murihiku Terrane during Triassic-Jurassic times. The term replaces Park Intrusives of Mutch, some members of which are shown to be extrusive rather than intrusive. Formation status within the group is given to Gowan Andesite and Pinney Volcanics (new names) in western Southland, Glenham Porphyry in eastern Southland, and Barnicoat Andesite (new) in the Richmond area, Nelson. Gowan Andesite is a porphyritic feldspar two-pyroxene andesite with a glassy or microcrystalline groundmass. A suite of low-grade metavolcanic rocks which forms the main mass of Malakoff Hill and which has formerly been included in the 'Park Intrusives' is here excluded and ascribed to the Takitimu Group; representative chemical data are given. Glenham Porphyry is typically a porphyritic feldspar two-pyroxene andesite texturally similar to the Gowan Andesite but with significant geochemical differences. Two volumetrically minor members are recognised, Habukinini Trachydacite and Kenilworth Rhyolite. In the north of its outcrop area, Glenham Porphyry is emplaced on or into Late Triassic terrestrial beds; in the middle it overlies Kaihikuan (Middle Triassic) and is overlain by Otapirian (latest Triassic) marine beds; and in the southeast it is directly overlain by Ururoan (late Early to early Middle Jurassic) conglomerates and marine sandstones. Pinney Volcanics are restricted to a very few, probably one, massive conglomeratic horizon in the Oretian Stage. The commonest rock type is a two-pyroxene trachydacite, modified by very-low-grade burial metamorphism. Auto-brecciation is characteristic and rock types change over short distances. Hornblende-rich variants occur as well as more felsic varieties including rhyolite ignimbrite. These may have been erupted onto a bouldery floodplain or shallow-marine surface, but alternatively may have been mass-emplaced by debris avalanche resulting from

  15. Formation of D- and I-shaped geochemical profiles in saucer-shaped sills due to post- emplacement magma flow induced by thermal stresses

    Science.gov (United States)

    Aarnes, I.; Podladchikov, Y. Y.; Neumann, E.

    2007-12-01

    There are still unresolved problems in the processes of emplacement and crystallization of saucer shaped sill intrusions. We use geochemistry and numerical modelling in order to constrain identify processes in mafic sill intrusions. Profiles sampled through through a saucer-shaped sill complex in the Karoo igneous province, South Africa show a variety of geochemical variations. Some variations are observed repeatedly, i.e. the D- and I-shaped profiles. D-shaped profiles are recognized by having the least evolved composition in the center (high Mg#) with more evolved composition at the upper and lower margins (low Mg#), resulting in a D-shaped Mg# profile. I- shaped profiles are recognized by having no variation in the Mg# through the profile. The formation mechanism of D-shaped profiles is enigmatic, as classical fractional crystallization theory predicts C-shapes to occur. The least evolved composition will be at the margins where crystallization initiates, and with continued cooling and crystallization the center will be progressively more evolved. Hence, we need another formation mechanism. The most common explanation for D-shaped profiles is a movement of early formed phenocrysts towards the center due to flow segregation. However, petrographical evidences from a D-shaped profile in this study show no phenocryst assemblage in the center, and the modal composition is homogeneous through the profile. We propose that differentiation is caused by a melt flow from the central parts of the sill towards the margins driven by underpressure anomalies at the margins. The underpressures develop because of strong cooling gradients at the margins, assuming no volume change due to a rigid crystal network. The less compatible elements associated with the melt phase will be transported into the margins by advection, resulting in a more evolved total system composition from a higher total melt percentage. The central parts will progressively be depleted in the less compatible

  16. S-type granite generation and emplacement during a regional switch from extensional to contractional deformation (Central Iberian Zone, Iberian autochthonous domain, Variscan Orogeny)

    Science.gov (United States)

    Pereira, M. F.; Díez Fernández, R.; Gama, C.; Hofmann, M.; Gärtner, A.; Linnemann, U.

    2018-01-01

    Zircon grains extracted from S-type granites of the Mêda-Escalhão-Penedono Massif (Central Iberian Zone, Variscan Orogen) constrain the timing of emplacement and provide information about potential magma sources. Simple and composite zircon grains from three samples of S-type granite were analyzed by LA-ICP-MS. New U-Pb data indicate that granites crystallized in the Bashkirian (318.7 ± 4.8 Ma) overlapping the proposed age range of ca. 321-317 Ma of the nearby S-type granitic rocks of the Carrazeda de Anciães, Lamego and Ucanha-Vilar massifs. The timing of emplacement of such S-type granites seems to coincide with the waning stages of activity of a D2 extensional shear zone (i.e. Pinhel shear zone) developed in metamorphic conditions that reached partial melting and anatexis (ca. 321-317 Ma). Dykes of two-mica granites (resembling diatexite migmatite) are concordant and discordant to the compositional layering and S2 (main) foliation of the high-grade metamorphic rocks of the Pinhel shear zone. Much of the planar fabric in these dykes was formed during magmatic crystallization and subsequent solid-state deformation. Field relationships suggest contemporaneity between the ca. 319-317 Ma old magmatism of the study area and the switch from late D2 extensional deformation to early D3 contractional deformation. Inherited zircon cores are well preserved in these late D2-early D3 S-type granite plutons. U-Pb ages of inherited zircon cores range from ca. 2576 to ca. 421 Ma. The spectra of inherited cores overlap closely the range of detrital and magmatic zircon grains displayed by the Ediacaran to Silurian metasedimentary and metaigneous rocks of the Iberian autochthonous and parautochthonous domains. This is evidence of a genetic relationship between S-type granites and the host metamorphic rocks. There is no substantial evidence for the addition of mantle-derived material in the genesis of these late D2-early D3 S-type granitic rocks. The ɛNd arrays of heterogeneous

  17. Correlating Distal, Medial and Proximal Ejecta Transport/Emplacement From Oblique Cosmic Impact On North American Continental Ice Sheet At MIS20 ( 786 ka) Via Suborbital Analysis (SA).

    Science.gov (United States)

    Harris, T. H. S.; Davais, M. E.

    2017-12-01

    Several elements of the 786 ka Australasian (AA) tektite imprint bear close scrutinyin order to locate the parent impact site or structure. The unique Carolina bays unit geologic formation is indicated as a large "medial" ejecta blanket from a large cosmic impact during a period containing 786 ka. Coincidence? Kg-scale sub-spherical hollow splash form AA tektites implies prolonged atmospheric blow out-scale momentum current with a core of sub-parallel or divergent flow volume having essentially zero turbulence. This would allow for plasma entrainment and heating of target mass at prolonged low dynamic pressure during outflow, where adiabatic expansion could deliver both semi-solid Muong Nong-type and inviscid melts above the atmosphere for gentle release upon rarefaction in vacuum. Within a large atmospheric blow-out scale momentum current, target mass becomes entrained at the speed of adiabatic outflow. 10+ km/s ejecta entrainment yields inter-hemispheric emplacement from launch per governing suborbital mechanics, without question. Oblique impact into a thick ice sheet explains reduced excavation volume and shearing disruption in the form of hypersonic steam plasma scouring. Adiabatic expansion would be immediately available to accelerate and further heat proto-tektite target mass. With shock no longer the sole transport engine, kg-scale splash forms and tektite speeds above the post-shock vaporization velocity of quartz are explained by expansion of shocked ice, in agreement with the observed imprint. The 6 Carolina bay shapes or "Davias Archetypes" are reproducible using conic perturbation in Suborbital Analysis, conforming to a formative mechanism of suborbital transport and ballistic emplacement: "Suborbital Obstruction Shadowing" needs only 3 parts in 10,000 of VEL variation around a circular EL-AZ-VEL launch cone, before considering re-entry effects. Transport energy of the Carolina bay sand, calculated using the 3.5 to 4 km/s launch VEL required for its

  18. Building the oceanic crust: Insights on volcanic emplacement processes at the hotspot-influenced Galápagos Spreading Center, 92°W

    Science.gov (United States)

    McClinton, J. T.; White, S. M.; Colman, A.; Sinton, J. M.

    2011-12-01

    The Galápagos Spreading Center (GSC) displays a range of axial morphology due to increased magma supply from the adjacent Galápagos mantle plume. Over 30 years of scientific exploration has also documented the associated variations in volcanic terrain, crustal thickness, and geochemistry of erupted basalts, but until recently the fine-scale ("lava flow scale") volcanic features of the GSC had not been investigated. Using the Alvin submersible and aided by near-bottom photographic surveys by TowCam and sub-meter-scale sonar surveys by AUV Sentry, we mapped and sampled 12 individual eruptive units covering ~16km2 of seafloor on the ridge axis of the GSC at 92°W. Variations in AUV Sentry bathymetry and DSL-120A backscatter enabled us to characterize the fine-scale surface morphology within each eruptive unit. Lava flow morphologies within each unit were identified using a neuro-fuzzy classifier which assigns pixels as pillows, lobates, sheets, or fissures by using attributes derived from high-resolution sonar bathymetry and backscatter (McClinton et al., submitted PE&RS). An accuracy assessment indicates approximately 90% agreement between the lava morphology map and an independent set of visual observations. The result of this classification effort is that we are able to quantitatively examine the spatial distribution of lava flow morphology as it relates to the emplacement of lava flows within each eruptive unit at a mid-ocean ridge. Preliminary analyses show that a large, segment-centered volcanic cone which straddles the axial summit graben (the "Empanada") is constructed mostly of pillow lavas, while volcanism in the rifted center of the cone consists of lobate and sheet flows. Conversely, along the rest of the segment, on-axis eruptions consist mainly of pillow lava with most sheet and lobate flows found outside of a small axial summit graben. At least some of these sheet flows are fed by lava channels, suggesting emplacement over distances up to 1km, while

  19. From an ocean floor wrench zone origin to transpressional tectonic emplacement of the Sithonia ophiolite, eastern Vardar Suture Zone, northern Greece

    Science.gov (United States)

    Bonev, Nikolay; Filipov, Petyo

    2017-12-01

    In the Hellenides of northern Greece, the Sithonia back-arc ophiolite constitute an element of the Vardar suture zone against the Chortiatis island arc magmatic suite, the Melissochori Formation and the Serbo-Macedonian Massif further north at the Mesozoic continental margin of Eurasia. A granodiorite from the Chortiatis island arc magmatic suite crystallized at 160 Ma as derived from new U-Pb zircon geochronology and confirms the end of arc magmatic activity that started at around 173 Ma. Located southerly of the Chortiatis island arc magmatic suite, the Sithonia ophiolite had igneous life from 159 to 149 Ma, and the ophiolite interfinger with clastic-carbonate Kimmeridgian sediments. Magmatic structures (i.e., sheeted dykes) in the ophiolite witness for NE-trending rift axis, while the transform faults and fracture zones sketch NW-SE transcurrent transtension-like propagation of the rift-spreading center at Sithonia that is consistent with a dextral wrench corridor already proposed for the ophiolite origin in the eastern Vardar zone. The tectonic emplacement of the Sithonia ophiolite involved dextral ENE to SE strike-slip sense of shear and SW and NE reverse thrust sense of shear on mostly steep foliation S1, subhorizontal lineation L1 and associated variably inclined F1 fold axes. This structural grain and kinematics are shared by adjacent Chortiatis island arc magmatic suite and the Melissochori Formation. The coexistence of strike-parallel and thrust components of displacement along discrete dextral strike-slip shear zones and internal deformation of the mentioned units is interpreted to result from a bulk dextral transpressive deformation regime developed in greenschist-facies metamorphic conditions. The back-arc ocean floor previous structural architecture with faults and fracture zones where Kimmeridgian sediments deposited in troughs was used by discrete strike-slip shear zones in which these sediments involved, and the shear zones become the sites for

  20. Timing of Hydrocarbon Fluid Emplacement in Sandstone Reservoirs in Neogene in Huizhou Sag, Southern China Sea, by Authigenic Illite 40Ar- 39Ar Laser Stepwise Heating

    Science.gov (United States)

    Hesheng, Shi; Junzhang, Zhu; Huaning, Qiu; yu, Shu; Jianyao, Wu; Zulie, Long

    Timing of oil or gas emplacements is a new subject in isotopic geochronology and petroleum geology. Hamilton et al. expounded the principle of the illite K-Ar age: Illite is often the last or one of the latest mineral cements to form prior to hydrocarbon accumulation. Since the displacement of formation water by hydrocarbons will cause silicate diagenesis to cease, K-Ar ages for illite will constrain the timing of this event, and also constrain the maximum age of formation of the trap structure. In this study, the possibility of authigenic illites 40Ar- 39Ar dating has been investigated. The illite samples were separated from the Tertiary sandstones in three rich oil reservoir belts within the Huizhou sag by cleaning, fracturing by cycled cooling-heating, soxhlet-extraction with solvents of benzene and methanol and separating with centrifugal machine. If oil is present in the separated samples, ionized organic fragments with m/e ratios of 36 to 40 covering the argon isotopes will be yielded by the ion source of a mass spectrometer, resulting in wrong argon isotopic analyses and wrong 40Ar- 39Ar ages. The preliminary experiments of illite by heating did show the presence of ionized organic fragments with m/e ratios of 36 to 44. In order to clean up the organic gases completely and obtain reliable analysis results, a special purification apparatus has been established by Qiu et al. and proved valid by the sequent illite analyses. All the illite samples by 40Ar- 39Ar IR-laser stepwise heating yield stair-up age spectra in lower laser steps and plateaux in higher laser steps. The youngest apparent ages corresponding to the beginning steps are reasonable to be interpreted for the hydrocarbon accumulation ages. The weighted mean ages of the illites from the Zhuhai and Zhujiang Formations are (12.1 ± 1.1) Ma and (9.9 ± 1.2) Ma, respectively. Therefore, the critical emplacement of petroleum accumulation in Zhujiang Formation in Huizhou sag took place in ca 10 Ma. Late

  1. From Crustal Anatexis to Pluton Emplacement: High-Precision Zircon Geochronology Reveals the Thermal History of the Larderello-Travale Geothermal System (Italy)

    Science.gov (United States)

    Farina, F.; Dini, A.; Ovtcharova, M.; Davies, J.; Bouvier, A. S.; Baumgartner, L. P.; Caricchi, L.; Schaltegger, U.

    2017-12-01

    Late Miocene to recent post-collisional extension in Tuscany (Italy) led to the emplacement of shallow-level granitic plutons and to the eruption of small rhyolitic bodies. The intrusion of peraluminous two-mica and tourmaline-bearing granites triggered the formation of the steam-dominated Larderello-Travale geothermal system. In this study, zircon crystals from granite samples obtained from drill holes at 3.0-4.5 km depth were investigated by combining in-situ oxygen isotopes analysis and high-precision CA-ID-TIMS U-Pb age determinations to gain insight into the nature of the magmatic heat source fuelling the geothermal field. Magmatic zircon crystals display δ18O values ranging from 8.6 to 13.5‰ and crystals from individual samples exhibit inter- and intra-grain oxygen isotope variability exceeding 3‰. The geochronological data indicates the existence of three magmatic pulses with ages between 3.637 ± 0.008 and 1.671 ± 0.004 Ma. More importantly, zircon crystals from individual samples exhibit an age spread as large as 200-400 ky. This age dispersion, which is more than one order of magnitude greater than the uncertainty on a single date, suggest that most of the zircon did not crystallize at the emplacement level, but within isolated and isotopically distinct magma batches before large-scale homogenization in a magmatic reservoir at depth. The rate of assembly and final volume of this reservoir is estimated using the distribution of precise U-Pb zircon dates following the approach of Caricchi et al. (2014). Thermal modelling indicates that the heat flow at the surface in the geothermal field cannot be sustained by the inferred reservoir or by heat advection from the mantle. Our data suggest the existence of a younger shallow-level intrusion, whose occurrence also accounts for the existence of confined magmatic fluids at the top of the Larderello-Travale intrusion. We conclude that a multi-disciplinary approach, integrating high-precision zircon dating, in

  2. Late Palaeozoic to Triassic formations unconformably deposited over the Ronda peridotites (Betic Cordilleras): Evidence for their Variscan time of crustal emplacement

    Energy Technology Data Exchange (ETDEWEB)

    Sanz de Galdeano, C.; Ruiz Cruz, M.D.

    2016-07-01

    The age of the emplacement of the Ronda Peridotites has been widely debated during recent decades, and ages ranging from the Palaeozoic to the early Miocene have been proposed, although most of the current interpretations suggest an Oligocene-Miocene age. In this article, we describe two meta-sedimentary formations (the lower one formed by detrital sediments and the upper one by marbles) that were unconformably deposited over the Ronda peridotites and now record low-grade metamorphism. The detrital formation contains layers of acidic rocks with an age of 269±9 Ma and the overlying marbles are assumed to be Triassic. The existence of these unconformable formations over the peridotites is crucial for the dating of the exhumation of the latter. The presence of peridotite clasts in the detrital formation indicates that peridotites were exposed during the Permian and other data suggest that peridotites were exhumed during the late Carboniferous. During the Alpine cycle, the peridotites operated as an element situated at the bottom of the tectonically higher Alpujarride/Sebtide unit (the Jubrique unit) and forming part of it, then being incorporated to the Alpine thrusts of this unit. (Author)

  3. Injection of colloidal size particles of Fe0 in porous media with shearthinning fluids as a method to emplace a permeable reactive zone

    International Nuclear Information System (INIS)

    Cantrell, K.J.; Kaplan, D.I.; Gilmore, T.J.

    1997-01-01

    Previous work has demonstrated the feasibility of injecting suspensions of micron-size zero-valent (FeO) particles into porous media as a method to emplace a permeable reactive zone. Further studies were conducted to evaluate the effects of several shearthinning fluids on enhancing the injectability of micron-size FeO particles into porous media. In contrast to Newtonian fluids, whose viscosities are constant with shear rate, certain non-Newtonian fluids are shearthinning, that is, the viscosity of these fluids decreases with increasing shear rate. The primary benefit of using these fluids for this application is that they increase the viscosity of the aqueous phase without adversely decreasing the hydraulic conductivity. A suspension formulated with a shearthinning fluid will maintain a relatively high viscosity in solution near the FeO particles (where the shear stress is low) relative to locations near the surfaces of the porous media, where the shear stress is high. The increased viscosity decreases the rate of gravitational settling of the dense FeO colloids (7.6 9/cm3) while maintaining a relatively high hydraulic conductivity that permits pumping the colloid suspensions into porous media at greater flowrates and distances. Aqueous solutions of three polymers at different concentrations were investigated. It was determined that, the use of shear thinning fluids greatly increases the injectability of the colloidal FeO suspensions in porous media

  4. Preliminary thermal/thermomechanical analyses of the Site Characterization Plan's Conceptual Design for a repository containing horizontally emplaced waste packages at the Deaf Smith County site

    International Nuclear Information System (INIS)

    Ghantous, N.Y.; Raines, G.E.

    1987-10-01

    This report presents thermal/thermomechanical analyses of the Site Characterization Plan Conceptual Design for horizontal package emplacement at the Deaf Smith County site, Texas. The repository was divided into three geometric regions. Then two-dimensional finite-element models were set up to approximate the three-dimensional nature of each region. Thermal and quasistatic thermomechanical finite-element analyses were performed to evaluate the thermal/thermomechanical responses of the three regions. The exponential-time creep law was used to represent the creep behavior of salt rock. The repository design was evaluated by comparing the thermal/thermomechanical responses obtained for the three regions with interim performance constraints. The preliminary results show that all the performance constraints are met except for those of the waste package. The following factors were considered in interpreting these results: (1) the qualitative description of the analytical responses; (2) the limitations of the analyses; and (3) either the conclusions based on overall evaluation of limitations and analytical results or the conclusions based on the fact that the repository design may be evaluated only after further analyses. Furthermore, a parametric analysis was performed to estimate the effect of material parameters on the predicted thermal/thermomechanical response. 23 refs., 34 figs., 9 tabs

  5. Evaluation of emplacement sensors for detecting radiation and volatile organic compounds and for long-term monitoring access tubes for the BWCS

    International Nuclear Information System (INIS)

    Lord, D.L.; Averill, R.H.

    1997-10-01

    This document evaluates sensors for detecting contaminants in the excavated waste generated by the Buried Waste Containment System (BWCS). The Barrier Placement Machine (BPM) removes spoils from under a landfill or plume and places it on a conveyor belt on the left and right sides of the BPM. The spoils will travel down the conveyor belts past assay monitors and be deposited on top of the site being worked. The belts are 5 ft wide and transport approximately 15 ft3 /minute of spoils. This corresponds to a 10 ft per hour BPM advance rate. With a 2 in. spoils height the belt speed would be 3.6 in. per second. The spoils being removed are expected to be open-quotes cleanclose quotes (no radiation or volatile organics above background levels). To ensure that the equipment is not digging through a contaminated area, assay equipment will monitor the spoils for mg radiation and volatile organic compounds (VOCs). The radiation monitors will check for gross radiation indication. Upon detection of radiation levels above a predetermined setpoint, further evaluation will be performed to determine the isotopes present and their quantity. This will require hand held monitors and a remote monitoring station. Simultaneously, VOC monitors will monitor for predetermined volatile/semi-volatile organic compounds. A Fourier-Transform Infrared Spectrometer (FTIR) monitor is recommended for this operation. Specific site requirements and regulations will determine setpoints and operation scenarios. If VOCs are detected, the data will be collected and recorded. A flat panel display will be mounted in the BPM operator''s cab showing the radio nuclide and VOC monitoring data. As the BPM advances, a 3-in. diameter PVC tube will be placed on the bottom of the barrier slot in front of the 12 to 16-in. containment barrier being emplaced

  6. Duration of and decoupling between carbon isotope excursions during the end-Triassic mass extinction and Central Atlantic Magmatic Province emplacement

    Science.gov (United States)

    Yager, Joyce A.; West, A. Joshua; Corsetti, Frank A.; Berelson, William M.; Rollins, Nick E.; Rosas, Silvia; Bottjer, David J.

    2017-09-01

    Changes in δ13Ccarb and δ13Corg from marine strata occur globally in association with the end-Triassic mass extinction and the emplacement of the Central Atlantic Magmatic Province (CAMP) during the break up of Pangea. As is typical in deep time, the timing and duration of these isotopic excursions has remained elusive, hampering attempts to link carbon cycle perturbations to specific processes. Here, we report δ13Ccarb and δ13Corg from Late Triassic and Early Jurassic strata near Levanto, Peru, where intercalated dated ash beds permit temporal calibration of the carbon isotope record. Both δ13Ccarb and δ13Corg exhibit a broad positive excursion through the latest Triassic into the earliest Jurassic. The first order positive excursion in δ13Corg is interrupted by a negative shift noted in many sections around the world coincident with the extinction horizon. Our data indicate that the negative excursion lasts 85 ± 25 kyrs, longer than inferred by previous studies based on cyclostratigraphy. A 260 ± 80 kyr positive δ13Corg shift follows, during which the first Jurassic ammonites appear. The overall excursion culminates in a return to pre-perturbation carbon isotopic values over the next 1090 ± 70 kyrs. Via chronologic, isotopic, and biostratigraphic correlation to other successions, we find that δ13Ccarb and δ13Corg return to pre-perturbation values as CAMP volcanism ceases and in association with the recovery of pelagic and benthic biota. However, the initiation of the carbon isotope excursion at Levanto predates the well-dated CAMP sills from North America, indicating that CAMP may have started earlier than thought based on these exposures, or that the onset of carbon cycle perturbations was not related to CAMP.

  7. An Experimental Study of Micron-Size Zero-Valent Iron Emplacement in Permeable Porous Media Using Polymer-Enhanced Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Oostrom, Mart; Wietsma, Thomas W.; Covert, Matthew A.; Vermeul, Vince R.

    2005-12-22

    At the Hanford Site, an extensive In Situ Redox Manipulation (ISRM) permeable reactive barrier was installed to prevent chromate from reaching the Columbia River. However, chromium has been detected in several wells, indicating a premature loss of the reductive capacity in the aquifer. One possible cause for premature chromate breakthrough is associated with the presence of high-permeability zones in the aquifer. In these zones, groundwater moves relatively fast and is able to oxidize iron more rapidly. There is also a possibility that the high-permeability flow paths are deficient in reducing equivalents (e.g. reactive iron), required for barrier performance. One way enhancement of the current barrier reductive capacity can be achieved is by the addition of micron-scale zero-valent iron to the high-permeability zones within the aquifer. The potential emplacement of zero-valent iron (Fe0) into high-permeability Hanford sediments (Ringold Unit E gravels) using shear-thinning fluids containing polymers was investigated in three-dimensional wedge-shaped aquifer models. Polymers were used to create a suspension viscous enough to keep the Fe0 in solution for extended time periods to improve colloid movement into the porous media without causing a permanent detrimental decrease in hydraulic conductivity. Porous media were packed in the wedge-shaped flow cell to create either a heterogeneous layered system with a high-permeability zone in between two low-permeability zones or a high-permeability channel surrounded by low-permeability materials. The injection flow rate, polymer type, polymer concentration, and injected pore volumes were determined based on preliminary short- and long-column experiments.

  8. Lunar mare deposits associated with the Orientale impact basin: New insights into mineralogy, history, mode of emplacement, and relation to Orientale Basin evolution from Moon Mineralogy Mapper (M3) data from Chandrayaan-1

    Science.gov (United States)

    Whitten, J.; Head, J.W.; Staid, M.; Pieters, C.M.; Mustard, J.; Clark, R.; Nettles, J.; Klima, R.L.; Taylor, L.

    2011-01-01

    Moon Mineralogy Mapper (M3) image and spectral reflectance data are combined to analyze mare basalt units in and adjacent to the Orientale multiring impact basin. Models are assessed for the relationships between basin formation and mare basalt emplacement. Mare basalt emplacement on the western nearside limb began prior to the Orientale event as evidenced by the presence of cryptomaria. The earliest post-Orientale-event mare basalt emplacement occurred in the center of the basin (Mare Orientale) and postdated the formation of the Orientale Basin by about 60-100 Ma. Over the next several hundred million years, basalt patches were emplaced first along the base of the Outer Rook ring (Lacus Veris) and then along the base of the Cordillera ring (Lacus Autumni), with some overlap in ages. The latest basalt patches are as young as some of the youngest basalt deposits on the lunar nearside. M3 data show several previously undetected mare patches on the southwestern margins of the basin interior. Regardless, the previously documented increase in mare abundance from the southwest toward the northeast is still prominent. We attribute this to crustal and lithospheric trends moving from the farside to the nearside, with correspondingly shallower density and thermal barriers to basaltic magma ascent and eruption toward the nearside. The wide range of model ages for Orientale mare deposits (3.70-1.66 Ga) mirrors the range of nearside mare ages, indicating that the small amount of mare fill in Orientale is not due to early cessation of mare emplacement but rather to limited volumes of extrusion for each phase during the entire period of nearside mare basalt volcanism. This suggests that nearside and farside source regions may be similar but that other factors, such as thermal and crustal thickness barriers to magma ascent and eruption, may be determining the abundance of surface deposits on the limbs and farside. The sequence, timing, and elevation of mare basalt deposits

  9. Effect of emplaced nZVI mass and groundwater velocity on PCE dechlorination and hydrogen evolution in water-saturated sand

    International Nuclear Information System (INIS)

    Kim, Hye-Jin; Leitch, Megan; Naknakorn, Bhanuphong; Tilton, Robert D.; Lowry, Gregory V.

    2017-01-01

    Highlights: • Reactivity of nZVI increased linearly with nZVI concentration above 10 g/L, but was non-linear below 10 g/L. • nZVI reactivity with PCE is more sensitive to solution redox potential than solution pH. • Mass transfer limits the reactivity of emplaced nZVI under typical groundwater flow velocity. • Lowering pH increases H_2 evolution from nZVI more than reactivity with PCE. • Design of nZVI remediation strategies should consider mass loading and flow velocity on performance and lifetime. - Abstract: The effect of nZVI mass loading and groundwater velocity on the tetrachloroethylene (PCE) dechlorination rate and the hydrogen evolution rate for poly(maleic acid-co-olefin) (MW = 12 K) coated nZVI was examined. In batch reactors, the PCE reaction rate constant (3.7 × 10"−"4 L hr"−"1 m"−"2) and hydrogen evolution rate constant (1.4 nanomol L hr"−"1 m"−"2) were independent of nZVI concentration above 10 g/L, but the PCE dechlorination rate decreased and the hydrogen evolution rate increased for nZVI concentration below 10 g/L. The nonlinearity between nZVI mass loading and PCE dechlorination and H_2 evolution was explained by differences in pH and E_h at each nZVI mass loading; PCE reactivity increased when solution E_h decreased, and the H_2 evolution rate increased with decreasing pH. Thus, nZVI mass loading of <5 g/L yields lower reactivity with PCE and lower efficiency of Fe° utilization than for higher nZVI mass loading. The PCE dechlorination rate increased with increasing pore-water velocity, suggesting that mass transfer limits the reaction at low porewater velocity. Overall, this work suggests that design of nZVI-based reactive barriers for groundwater treatment should consider the non-linear effects of both mass loading and flow velocity on performance and expected reactive lifetime.

  10. The emplacement and crystallization of the U-Th-REE-rich agpaitic and hyperagpaitic lujavrites at Kvanefjeld, Ilimaussaq alkaline complex, South Greenland

    International Nuclear Information System (INIS)

    Soerensen, H.; Bailey, J.C.; Rose-Hansen, J.

    2011-01-01

    The U-Th-REE deposit located at the Kvanefjeld plateau in the north-west corner of the Ilimaussaq alkaline complex, South Greenland, consists of lujavrites which are melanocratic agpaitic nepheline syenites. The fine-grained lujavrites of the Kvanefjeld plateau can be divided into a northern and a southern part with an intermediate zone between them. The northern part is situated along the north contact of the Ilimaussaq complex and continues east of the Kvanefjeld plateau as a lujavrite belt along the contact. This part has relatively 'low' contents of U, Th, and REE, and hyperagpaitic mineralogy is restricted to its highest-lying parts. The fine-grained lujavrites of the intermediate and southern part of the Kvanefjeld plateau occur between and below huge masses of country rocks which we show are practically in situ remnants of the roof of the lujavrite magma chamber. These lujavrites have high contents of U, Th, and REE, and hyperagpaitic varieties with naujakasite, steenstrupine and villiaumite are widespread. We present a model for the formation of the fine-grained lujavrites of the Kvanefjeld plateau. In this model, an off-shoot from the large lujavrite magma body in the central part of the complex intruded into a fracture zone along the north contact of the Ilimaussaq complex and was forcefully emplaced from north-west to south-east. The intruding lujavrite magma was bounded to the west, north, and at its roof by strong volcanic country rocks, and to the south by the weaker, earlier rocks of the complex. The magma stored in the fracture crystallized, squeezing volatile and residual ele-ments upwards. A subsequent violent explosion opened up fractures in the weaker southern rocks, and the residual volatile-enriched magma was squeezed into fractures in augite syenite, naujaite, and also in the overlying volcanic roof rocks. The removal of the volatile-rich lujavrite magma in the upper part of the fracture-bounded magma chamber made room for the rise of

  11. Effect of emplaced nZVI mass and groundwater velocity on PCE dechlorination and hydrogen evolution in water-saturated sand

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hye-Jin [Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Chemical Research Division, Environmental Health Research Department, National Institute of Environmental Research, Incheon 404-708 (Korea, Republic of); Leitch, Megan [Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Center for Environmental Implications of Nanotechnology, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Naknakorn, Bhanuphong [Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Tilton, Robert D. [Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Center for Environmental Implications of Nanotechnology, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Lowry, Gregory V., E-mail: glowry@cmu.edu [Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States); Center for Environmental Implications of Nanotechnology, Carnegie Mellon University, Pittsburgh, PA 15213-3890 (United States)

    2017-01-15

    Highlights: • Reactivity of nZVI increased linearly with nZVI concentration above 10 g/L, but was non-linear below 10 g/L. • nZVI reactivity with PCE is more sensitive to solution redox potential than solution pH. • Mass transfer limits the reactivity of emplaced nZVI under typical groundwater flow velocity. • Lowering pH increases H{sub 2} evolution from nZVI more than reactivity with PCE. • Design of nZVI remediation strategies should consider mass loading and flow velocity on performance and lifetime. - Abstract: The effect of nZVI mass loading and groundwater velocity on the tetrachloroethylene (PCE) dechlorination rate and the hydrogen evolution rate for poly(maleic acid-co-olefin) (MW = 12 K) coated nZVI was examined. In batch reactors, the PCE reaction rate constant (3.7 × 10{sup −4} L hr{sup −1} m{sup −2}) and hydrogen evolution rate constant (1.4 nanomol L hr{sup −1} m{sup −2}) were independent of nZVI concentration above 10 g/L, but the PCE dechlorination rate decreased and the hydrogen evolution rate increased for nZVI concentration below 10 g/L. The nonlinearity between nZVI mass loading and PCE dechlorination and H{sub 2} evolution was explained by differences in pH and E{sub h} at each nZVI mass loading; PCE reactivity increased when solution E{sub h} decreased, and the H{sub 2} evolution rate increased with decreasing pH. Thus, nZVI mass loading of <5 g/L yields lower reactivity with PCE and lower efficiency of Fe° utilization than for higher nZVI mass loading. The PCE dechlorination rate increased with increasing pore-water velocity, suggesting that mass transfer limits the reaction at low porewater velocity. Overall, this work suggests that design of nZVI-based reactive barriers for groundwater treatment should consider the non-linear effects of both mass loading and flow velocity on performance and expected reactive lifetime.

  12. Nonexplosive and explosive magma/wet-sediment interaction during emplacement of Eocene intrusions into Cretaceous to Eocene strata, Trans-Pecos igneous province, West Texas

    Science.gov (United States)

    Befus, K.S.; Hanson, R.E.; Miggins, D.P.; Breyer, J.A.; Busbey, A.B.

    2009-01-01

    Eocene intrusion of alkaline basaltic to trachyandesitic magmas into unlithified, Upper Cretaceous (Maastrichtian) to Eocene fluvial strata in part of the Trans-Pecos igneous province in West Texas produced an array of features recording both nonexplosive and explosive magma/wet-sediment interaction. Intrusive complexes with 40Ar/39Ar dates of ~ 47-46??Ma consist of coherent basalt, peperite, and disrupted sediment. Two of the complexes cutting Cretaceous strata contain masses of conglomerate derived from Eocene fluvial deposits that, at the onset of intrusive activity, would have been > 400-500??m above the present level of exposure. These intrusive complexes are inferred to be remnants of diatremes that fed maar volcanoes during an early stage of magmatism in this part of the Trans-Pecos province. Disrupted Cretaceous strata along diatreme margins record collapse of conduit walls during and after subsurface phreatomagmatic explosions. Eocene conglomerate slumped downward from higher levels during vent excavation. Coherent to pillowed basaltic intrusions emplaced at the close of explosive activity formed peperite within the conglomerate, within disrupted Cretaceous strata in the conduit walls, and within inferred remnants of the phreatomagmatic slurry that filled the vents during explosive volcanism. A younger series of intrusions with 40Ar/39Ar dates of ~ 42??Ma underwent nonexplosive interaction with Upper Cretaceous to Paleocene mud and sand. Dikes and sills show fluidal, billowed, quenched margins against the host strata, recording development of surface instabilities between magma and groundwater-rich sediment. Accentuation of billowed margins resulted in propagation of intrusive pillows into the adjacent sediment. More intense disruption and mingling of quenched magma with sediment locally produced fluidal and blocky peperite, but sufficient volumes of pore fluid were not heated rapidly enough to generate phreatomagmatic explosions. This work suggests that

  13. The disposal of Canada`s nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock volume 1: summary

    Energy Technology Data Exchange (ETDEWEB)

    Wikjord, A G; Baumgartner, P; Johnson, L H; Stanchell, F W; Zach, R; Goodwin, B W

    1996-06-01

    The concept for disposal of Canada`s nuclear fuel waste involves isolating the waste in corrosion-resistant containers emplaced and sealed within a vault at a depth of 500 to 1000 m in plutonic rock of the Canadian Shield. The case for the acceptability of the concept as a means of safely disposing of Canada`s nuclear fuel waste is presented in an Environmental Impact Statement (EIS) The disposal concept permits a choice of methods, materials, site locations and designs. The EIS presents a case study of the long-term (i.e., postclosure) performance of a hypothetical implementation of the concept, referred to in this report as the reference disposal system. The reference disposal system is based on borehole emplacement of used CANDU fuel in Grade-2 titanium alloy containers in low-permeability, sparsely fractured plutonic rock of the Canadian Shield. We evaluate the long-term performance of another hypothetical implementation of the concept based on in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. The geological characteristics of the geosphere assumed for this study result in short groundwater travel times from the disposal vault to the surface. In the present study, the principal barrier to the movement of contaminants is the long-lasting copper container. We show that the long-lasting container can effectively compensate for a permeable host rock which results in an unfavourable groundwater flow condition. These studies illustrate the flexibility of AECL`s disposal concept to take advantage of the retention, delay, dispersion, dilution and radioactive decay of contaminants in a system of natural barriers provided by the geosphere and hydrosphere and of engineered barriers provided by the waste form, container, buffer, backfills, other vault seals and grouts. In an actual implementation, the engineered system would be designed for the geological conditions encountered at the host site. 34 refs., 2 tabs., 11 figs.

  14. The disposal of Canada's nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock volume 1: summary

    International Nuclear Information System (INIS)

    Wikjord, A.G.; Baumgartner, P.; Johnson, L.H.; Stanchell, F.W.; Zach, R.; Goodwin, B.W.

    1996-06-01

    The concept for disposal of Canada's nuclear fuel waste involves isolating the waste in corrosion-resistant containers emplaced and sealed within a vault at a depth of 500 to 1000 m in plutonic rock of the Canadian Shield. The case for the acceptability of the concept as a means of safely disposing of Canada's nuclear fuel waste is presented in an Environmental Impact Statement (EIS) The disposal concept permits a choice of methods, materials, site locations and designs. The EIS presents a case study of the long-term (i.e., postclosure) performance of a hypothetical implementation of the concept, referred to in this report as the reference disposal system. The reference disposal system is based on borehole emplacement of used CANDU fuel in Grade-2 titanium alloy containers in low-permeability, sparsely fractured plutonic rock of the Canadian Shield. We evaluate the long-term performance of another hypothetical implementation of the concept based on in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. The geological characteristics of the geosphere assumed for this study result in short groundwater travel times from the disposal vault to the surface. In the present study, the principal barrier to the movement of contaminants is the long-lasting copper container. We show that the long-lasting container can effectively compensate for a permeable host rock which results in an unfavourable groundwater flow condition. These studies illustrate the flexibility of AECL's disposal concept to take advantage of the retention, delay, dispersion, dilution and radioactive decay of contaminants in a system of natural barriers provided by the geosphere and hydrosphere and of engineered barriers provided by the waste form, container, buffer, backfills, other vault seals and grouts. In an actual implementation, the engineered system would be designed for the geological conditions encountered at the host site. 34 refs., 2 tabs., 11 figs

  15. Structural control on the emplacement of contemporaneous Sn-Ta-Nb mineralized LCT pegmatites and Sn bearing quartz veins: Insights from the Musha and Ntunga deposits of the Karagwe-Ankole Belt, Rwanda

    Science.gov (United States)

    Hulsbosch, Niels; Van Daele, Johanna; Reinders, Nathan; Dewaele, Stijn; Jacques, Dominique; Muchez, Philippe

    2017-10-01

    The Nb-Ta-Sn pegmatites and Sn quartz veins of the Rwamagana-Musha-Ntunga area in eastern Rwanda are part of the Mesoproterozoic Karagwe-Ankole Belt. These commodities are on a regional scale spatiotemporally associated to the early Neoproterozoic fertile G4-granite generation. Although a transition from the lithium-cesium-tantalum pegmatites to cassiterite-microcline-quartz veins has been observed in the Rwamagana-Musha-Ntunga area, the structural control and the paragenetic relationship between the mineralized pegmatites and the Sn bearing quartz veins is largely unknown. Consequently, this study investigates the occurrence of pegmatites and quartz veins and the structural and lithological controls on their emplacement. The metasediments in the area are affected by a regional compressional regime with a shortening direction oriented N70E, which resulted in a N20W-oriented fold sequence. The Lake Muhazi granite is present in center of the Karehe anticline. The structural orientations of pegmatites and quartz veins show that two important factors control their emplacement. The first control is the reactivation of pre-existing discontinuities such as the bedding, bedding-parallel joints or strike-slip fault planes. In view of the regional structural grain in the Rwamagana-Musha-Ntunga area, this corresponds with abundant N20W-oriented pegmatites and quartz veins. The reactivation is strongly related to the lithology of the host rocks. The Musha Formation, which mainly consists of decimeter- to meter-scale lithological alternations of metapelite, metasiltstone and metasandstone, represents the most suitable environment for bedding reactivation. This is reflected in the predominance of bedding-parallel pegmatites and quartz veins hosted by the Musha Formation. Strike-parallel joints were mainly observed in the competent lithologies. The second controlling factor is related to the regional post-compressional stress regime. New joints initiated upon emplacement of the

  16. Potential migration of buoyant LNAPL from intermediate level waste (ILW) emplaced in a geological disposal facility (GDF) for U.K. radioactive waste.

    Science.gov (United States)

    Benbow, Steven J; Rivett, Michael O; Chittenden, Neil; Herbert, Alan W; Watson, Sarah; Williams, Steve J; Norris, Simon

    2014-10-15

    A safety case for the disposal of Intermediate Level (radioactive) Waste (ILW) in a deep geological disposal facility (GDF) requires consideration of the potential for waste-derived light non-aqueous phase liquid (LNAPL) to migrate under positive buoyancy from disposed waste packages. Were entrainment of waste-derived radionuclides in LNAPL to occur, such migration could result in a shorter overall travel time to environmental or human receptors than radionuclide migration solely associated with the movement of groundwater. This paper provides a contribution to the assessment of this issue through multiphase-flow numerical modelling underpinned by a review of the UK's ILW inventory and literature to define the nature of the associated ILW LNAPL source term. Examination has been at the waste package-local GDF environment scale to determine whether proposed disposal of ILW would lead to significant likelihood of LNAPL migration, both from waste packages and from a GDF vault into the local host rock. Our review and numerical modelling support the proposition that the release of a discrete free phase LNAPL from ILW would not present a significant challenge to the safety case even with conservative approximations. 'As-disposed' LNAPL emplaced with the waste is not expected to pose a significant issue. 'Secondary LNAPL' generated in situ within the disposed ILW, arising from the decomposition of plastics, in particular PVC (polyvinyl chloride), could form the predominant LNAPL source term. Released high molecular weight phthalate plasticizers are judged to be the primary LNAPL potentially generated. These are expected to have low buoyancy-based mobility due to their very low density contrast with water and high viscosity. Due to the inherent uncertainties, significant conservatisms were adopted within the numerical modelling approach, including: the simulation of a deliberately high organic material--PVC content wastestream (2D03) within an annular grouted waste package

  17. Emplacement of the La Peña alkaline igneous complex, Mendoza, Argentina (33° S): Implications for the early Miocene tectonic regime in the retroarc of the Andes

    Science.gov (United States)

    Pagano, D. S.; Galliski, M. A.; Márquez-Zavalía, M. F.

    2014-03-01

    The La Peña alkaline complex (LPC) of Miocene age (18-19 Ma) lies on the eastern front of the Precordillera (32°41ʹ34ʺS, 68°59ʹ48″W, 1400-2900 m a.s.l.), 30 km northwest of Mendoza city, Argentina. It is a subcircular massif of 19 km2 and 5 km in diameter, intruded in the metasedimentary sequence of the Villavicencio Formation of Silurian-Devonian age. It is the result of integration of multiple pulses derived from one or more deep magma chambers, which form a suite of silicate rocks grouped into: a clinopyroxenite body, a central syenite facies with a large breccia zone at the contact with the clinopyroxenite, bodies of malignite, trachyte and syenite porphyry necks, and a system of radial and annular dikes of different compositions. Its subcircular geometry and dike system distribution are frequent features of intraplate plutons or plutons emplaced in post-orogenic settings. These morphostructural features characterize numerous alkaline complexes worldwide and denote the importance of magmatic pressures that cause doming with radial and annular fracturing, in a brittle country rock. However, in the LPC, the attitude of the internal fabric of plutonic and subvolcanic units and the preferential layout of dikes match the NW-SE extensional fractures widely distributed in the host rock. This feature indicates a strong tectonic control linked to the structure that facilitate space for emplacement, corresponding to the brittle shear zone parallel to the N-S stratigraphy of the country rock. Shearing produced a system of discontinuities, with a K fractal fracture pattern, given by the combination of Riedel (R), anti-Riedel (R‧), (P) and extensional (T) fracture systems, responsible for the control of melt migration by the opening of various fracture branches, but particularly through the NW-SE (T) fractures. Five different pulses would have ascent, (1) an initial one from which cumulate clinopyroxenite was formed, (2) a phase of mafic composition represented by

  18. Hanford 100N Area Apatite Emplacement: Laboratory Results of Ca-Citrate-PO4 Solution Injection and Sr-90 Immobilization in 100N Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Szecsody, James E.; Burns, Carolyn A.; Moore, Robert C.; Fruchter, Jonathan S.; Vermeul, Vincent R.; Williams, Mark D.; Girvin, Donald C.; McKinley, James P.; Truex, Michael J.; Phillips, Jerry L.

    2007-10-01

    This report summarizes laboratory scale studies investigating the remediation of Sr-90 by Ca-citrate-PO4 solution injection/infiltration to support field injection activities in the Hanford 100N area. This study is focused on experimentally testing whether this remediation technology can be effective under field scale conditions to mitigate Sr-90 migration 100N area sediments into the Columbia River. Sr-90 is found primarily adsorbed to sediments by ion exchange (99% adsorbed, < 1% in groundwater) in the upper portion of the unconfined aquifer and lower vadose zone. Although primarily adsorbed, Sr-90 is still considered a high mobility risk as it is mobilized by seasonal river stage increases and by plumes of higher ionic strength relative to groundwater. This remediation technology relies upon the Ca-citrate-PO4 solution forming apatite precipitate [Ca6(PO4)10(OH)2], which incorporates some Sr-90 during initial precipitation and additionally slowly incorporates Sr-90 by solid phase substitution for Ca. Sr substitution occurs because Sr-apatite is thermodynamically more stable than Ca-apatite. Once the Sr-90 is in the apatite structure, Sr-90 will decay to Y-90 (29.1 y half-life) then Zr-90 (64.1 h half-life) without the potential for migration into the Columbia River. For this technology to be effective, sufficient apatite needs to be emplaced in sediments to incorporate Sr and Sr-90 for 300 years (~10 half-lives of Sr-90), and the rate of incorporation needs to exceed the natural groundwater flux rate of Sr in the 100N area. A primary objective of this study is to supply an injection sequence to deliver sufficient apatite into subsurface sediments that minimizes initial mobility of Sr-90, which occurs because the injection solution has a higher ionic strength compared to groundwater. This can be accomplished by sequential injections of low, then high concentration injection of Ca-citrate-PO4 solutions. Assessment of low concentration Ca-citrate-PO4, citrate-PO4

  19. Emplacement mechanisms and structural influences of a younger granite intrusion into older wall rocks - a principal study with application to the Goetemar and Uthammar granites. Site-descriptive modelling SDM-Site Laxemar

    International Nuclear Information System (INIS)

    Cruden, Alexander R.

    2008-12-01

    The c. 1.80 Ga old bedrock in the Laxemar-Simpevarp area, which is the focus of the site investigation at Oskarshamn, is dominated by intrusive rocks belonging to the c. 1.86-1.65 Ga Transscandinavian Igneous Belt (TIB). However, the site investigation area is situated in between two c. 1.45 Ga old anorogenic granites, the Goetemar granite in the north and the Uthammar granite in the south. This study evaluates the emplacement mechanism of these intrusions and their structural influence on the older bedrock. Field observations and structural measurements indicate that both the Goetemar and the Uthammar granites are discordant and have not imposed any significant ductile deformation on their wall-rocks. The apparent conformity of geological contacts and fabrics in the wall rocks and the southern margin of the Goetemar granite is coincidental and inherited from the pattern of Svecokarelian deformation of the TIB. However, interpretation of regional aeromagnetic data suggests that the granites occur within a broad, NNE-SSW trending linear belt, pointing to deep seated tectonic control on their generation, ascent and emplacement. Thermochronology indicates that the granites were emplaced at depths between 4 and 8 km into brittle wall rocks. The 3-D shape of the Goetemar and Uthammar plutons has been investigated by 2.75D forward modelling of the residual gravity anomalies due to both granites. Both granites are associated with strong residual gravity anomalies of up to -10 mgal. Constraints on the geometry of the plutons at the surface are provided from surface geology maps and several deep boreholes located on or close to the model profiles. A further variable in the gravity modelling is introduced by either allowing the upper contact of the plutons to assume the most suitable orientation to produce the best fit between the modelled and observed gravity ('unconstrained models') or by forcing the near surface orientation of the contacts to be vertical ('constrained

  20. Emplacement mechanisms and structural influences of a younger granite intrusion into older wall rocks - a principal study with application to the Goetemar and Uthammar granites. Site-descriptive modelling SDM-Site Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Cruden, Alexander R. (Dept. of Geology, Univ. of Toronto (Canada))

    2008-12-15

    The c. 1.80 Ga old bedrock in the Laxemar-Simpevarp area, which is the focus of the site investigation at Oskarshamn, is dominated by intrusive rocks belonging to the c. 1.86-1.65 Ga Transscandinavian Igneous Belt (TIB). However, the site investigation area is situated in between two c. 1.45 Ga old anorogenic granites, the Goetemar granite in the north and the Uthammar granite in the south. This study evaluates the emplacement mechanism of these intrusions and their structural influence on the older bedrock. Field observations and structural measurements indicate that both the Goetemar and the Uthammar granites are discordant and have not imposed any significant ductile deformation on their wall-rocks. The apparent conformity of geological contacts and fabrics in the wall rocks and the southern margin of the Goetemar granite is coincidental and inherited from the pattern of Svecokarelian deformation of the TIB. However, interpretation of regional aeromagnetic data suggests that the granites occur within a broad, NNE-SSW trending linear belt, pointing to deep seated tectonic control on their generation, ascent and emplacement. Thermochronology indicates that the granites were emplaced at depths between 4 and 8 km into brittle wall rocks. The 3-D shape of the Goetemar and Uthammar plutons has been investigated by 2.75D forward modelling of the residual gravity anomalies due to both granites. Both granites are associated with strong residual gravity anomalies of up to -10 mgal. Constraints on the geometry of the plutons at the surface are provided from surface geology maps and several deep boreholes located on or close to the model profiles. A further variable in the gravity modelling is introduced by either allowing the upper contact of the plutons to assume the most suitable orientation to produce the best fit between the modelled and observed gravity ('unconstrained models') or by forcing the near surface orientation of the contacts to be vertical (&apos

  1. Insights into the emplacement of upper-crustal plutons and their relationship to large silicic calderas, from field relationships, geochronology, and zircon trace element geochemistry in the Stillwater - Clan Alpine caldera complex, western Nevada, USA

    Science.gov (United States)

    Colgan, Joseph P.; John, David A.; Henry, Christopher D.; Watts, Kathryn E.

    2018-01-01

    Geologic mapping, new U-Pb zircon ages, and new and published 40Ar/39Ar sanidine ages document the timing and extent of Oligocene magmatism in the southern Stillwater Range and Clan Alpine Mountains of western Nevada, where Miocene extension has exposed at least six nested silicic calderas and underlying granitic plutons to crustal depths locally ≥ 9 km. Both caldera-forming rhyolitic tuffs and underlying plutons were emplaced in two episodes, one from about 30.4-28.2 Ma that included the Deep Canyon, Job Canyon, and Campbell Creek calderas and underlying plutons, and one from about 25.3-24.8 Ma that included the Louderback Mountains, Poco Canyon, and Elevenmile Canyon calderas and underlying plutons. In these two 1-2 m.y. periods, almost the entire Mesozoic upper crust was replaced by Oligocene intrusive and extrusive rocks to depths ≥ 9 km over an estimated total area of 1500 km2 (pre-extension). Zircon trace element geochemistry indicates that some plutonic rock can be solidified residual magma from the tuff eruptions. Most plutons are not solidified residual magma, although they directly underlie calderas and were emplaced along the same structures shortly after to as much as one million years after caldera formation. Magma chambers and plutons grew by floor subsidence accommodated by downward transfer of country rocks. If other Great Basin calderas are similar, the dense concentration of shallowly exposed calderas in central Nevada is underlain by a complexly zoned mid-Cenozoic batholith assembled in discrete pulses that coincided with formation of large silicic calderas up to 2500-5000 km3.

  2. The disposal of Canada's nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. Volume 2: vault model

    International Nuclear Information System (INIS)

    Johnson, L.H.; LeNeveu, D.M.; King, F.; Shoesmith, D.W.; Kolar, M.; Oscarson, D.W.; Sunder, S.; Onofrei, C.; Crosthwaite, J.L.

    1996-06-01

    A study has been undertaken to evaluate the design and long-term performance of a nuclear fuel waste disposal vault based on a concept of in-room emplacement of copper containers at a depth of 500 m in plutonic rock in the Canadian Shield. The containers, each with 72 used CANDU fuel bundles, would be surrounded by clay-based buffer and backfill materials in an array of parallel rooms, with the excavation boundary assumed to have an excavation-disturbed zone (EDZ) with a higher permeability than the surrounding rock. In the anoxic conditions of deep rock of the Canadian Shield, the copper containers are expected to survive for >10 6 a. Thus container manufacturing defects, which are assumed to affect approximately 1 in 5000 containers, would be the only potential source of radionuclide release in the vault. The vault model is a computer code that simulates the release of radionuclides that would occur upon contact of the used fuel with groundwater, the diffusive transport of these radionuclides through the defect in the container shell and the surrounding buffer, and their dispersive and convective transport through the backfill and EDZ into the surrounding rock. The vault model uses a computationally efficient boundary integral model (BIM) that simulates radionuclide mass transport in the engineered barrier system as a point source (representing the defective container) that releases radionuclides into concentric cylinders, that represent the buffer, backfill and EDZ. A 3-dimensional finite-element model is used to verify the accuracy of the BIM. The results obtained in the present study indicates the effectiveness of a design using in-room emplacement of long-lived containers in providing a safe disposal system even under permeable geosphere conditions. (author). refs., tabs., figs

  3. Insights into the emplacement of upper-crustal plutons and their relationship to large silicic calderas, from field relationships, geochronology, and zircon trace element geochemistry in the Stillwater – Clan Alpine caldera complex, western Nevada, USA

    Science.gov (United States)

    Colgan, Joseph P.; John, David A.; Henry, Christopher D.; Watts, Kathryn E.

    2018-01-01

    Geologic mapping, new U-Pb zircon ages, and new and published 40Ar/39Ar sanidine ages document the timing and extent of Oligocene magmatism in the southern Stillwater Range and Clan Alpine Mountains of western Nevada, where Miocene extension has exposed at least six nested silicic calderas and underlying granitic plutons to crustal depths locally ≥ 9 km. Both caldera-forming rhyolitic tuffs and underlying plutons were emplaced in two episodes, one from about 30.4–28.2 Ma that included the Deep Canyon, Job Canyon, and Campbell Creek calderas and underlying plutons, and one from about 25.3–24.8 Ma that included the Louderback Mountains, Poco Canyon, and Elevenmile Canyon calderas and underlying plutons. In these two 1–2 m.y. periods, almost the entire Mesozoic upper crust was replaced by Oligocene intrusive and extrusive rocks to depths ≥ 9 km over an estimated total area of ~ 1500 km2 (pre-extension). Zircon trace element geochemistry indicates that some plutonic rock can be solidified residual magma from the tuff eruptions. Most plutons are not solidified residual magma, although they directly underlie calderas and were emplaced along the same structures shortly after to as much as one million years after caldera formation. Magma chambers and plutons grew by floor subsidence accommodated by downward transfer of country rocks. If other Great Basin calderas are similar, the dense concentration of shallowly exposed calderas in central Nevada is underlain by a complexly zoned mid-Cenozoic batholith assembled in discrete pulses that coincided with formation of large silicic calderas up to 2500–5000 km3.

  4. Calculation of the inventory and near-field release rates of radioactivity from neutron-activated metal parts discharged from the high flux isotope reactor and emplaced in solid waste storage area 6 at Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kelmers, A.D.; Hightower, J.R.

    1987-05-01

    Emplacement of contaminated reactor components involves disposal in lined and unlined auger holes in soil above the water table. The radionuclide inventory of disposed components was calculated. Information on the composition and weight of the components, as well as reasonable assumptions for the neutron flux fueling use, the time of neutron exposure, and radioactive decay after discharge, were employed in the inventory calculation. Near-field release rates of /sup 152/Eu, /sup 154/Eu, and /sup 155/Eu from control plates and cylinders were calculated for 50 years after emplacement. Release rates of the europium isotopes were uncertain. Two release-rate-limiting models were considered and a range of reasonable values were assumed for the time-to-failure of the auger-hole linear and aluminum cladding and europium solubility in SWSA-6 groundwater. The bounding europium radionuclide near-field release rates peaked at about 1.3 Ci/year total for /sup 152,154,155/Eu in 1987 for the lower bound, and at about 420 Ci/year in 1992 for the upper bound. The near-field release rates of /sup 55/Fe, /sup 59/Ni, /sup 60/Co, and /sup 63/Ni from stainless steel and cobalt alloy components, as well as of /sup 10/Be, /sup 41/Ca, and /sup 55/Fe from beryllium reflectors, were calculated for the next 100 years, assuming bulk waste corrosion was the release-rate-limiting step. Under the most conservative assumptions for the reflectors, the current (1986) total radionuclide release rate was calculated to be about 1.2 x 10/sup -4/ Ci/year, decreasing by 1992 to a steady release of about 1.5 x 10/sup -5/ Ci/year due primarily to /sup 41/Ca. 50 refs., 13 figs., 8 tabs.

  5. Subduction initiation and recycling of Alboran domain derived crustal components prior to the intra-crustal emplacement of mantle peridotites in the Westernmost Mediterranean: isotopic evidence from the Ronda peridotite

    Science.gov (United States)

    Varas-Reus, María Isabel; Garrido, Carlos J.; Bosch, Delphine; Marchesi, Claudio Claudio; Acosta-Vigil, Antonio; Hidas, Károly; Barich, Amel

    2014-05-01

    During Late Oligocene-Early Miocene different domains formed in the region between Iberia and Africa in the westernmost Mediterranean, including thinned continental crust and a Flysch Trough turbiditic deposits likely floored by oceanic crust [1]. At this time, the Ronda peridotite likely constituted the subcontinental lithospheric mantle of the Alboran domain, which mantle lithosphere was undergoing strong thinning and melting [2] [3] coevally with Early Miocene extension in the overlying Alpujárride-Maláguide stacked crust [4, 5]. Intrusive Cr- rich pyroxenites in the Ronda massif records the geochemical processes occurring in the subcontinental mantle of the Alboran domain during the Late Oligocene [6]. Recent isotopic studies of these pyroxenites indicate that their mantle source was contaminated by a subduction component released by detrital crustal sediments [6]. This new data is consistent with a subduction setting for the late evolution of the Alboran lithospheric mantle just prior to its final intracrustal emplacement in the early Miocene Further detailed structural studies of the Ronda plagioclase peridotites-related to the initial stages of ductile emplacement of the peridotite-have led to Hidas et al. [7] to propose a geodynamic model where folding and shearing of an attenuated mantle lithosphere occurred by backarc basin inversion followed by failed subduction initiation that ended into the intracrustal emplacement of peridotite into the Alboran wedge in the earliest Miocene. This hypothesis implies that the crustal component recorded in late, Cr-rich websterite dykes might come from underthrusted crustal rocks from the Flysch and/or Alpujárrides units that might have been involved in the earliest stages of this subduction initiation stage. To investigate the origin of crustal component in the mantle source of this late magmatic event recorded by Cr-pyroxenites, we have carried out a detail Sr-Nd-Pb-Hf isotopic study of a variety of Betic

  6. Permian basalts and trachytes from Esterel (SE France): a transitional tholeiitic suite emplaced during lithosphere thinning; Basaltes et trachytes permiens de l`Esterel (SE France): une serie tholeiitique transitionnelle epanchee pendant l`amincissement lithospherique

    Energy Technology Data Exchange (ETDEWEB)

    Lapierre, H.; Basile, Ch. [Grenoble-1 Univ., 38 - Grenoble (France). Laboratoire de Geodynamique des Chaines Alpines, CNRS UPRES-A5025; Dupuis, V. [Institut de Geodynamique, UMR Geosciences Azur, 06 - Valbonne (France)

    1999-11-01

    Geochemical (major, trace and rare earth elements) and isotopic ({sup 143}Nd/{sup 144}Nd) compositions of lavas emplaced in the Esterel Massif (eastern Provence, France) at the end of the Permian allow to estimate the evolution of the continental lithosphere between the end of the Hercynian orogenesis and the beginning of the Tethyan rifting. Basalts from Agay basin and trachyte from Batterie des Lions belong to a transitional tholeiitic suite, characterized by negative Nb and Ta anomalies (relative to N-MORB) and homogeneous {epsilon}Nd{sub (T=250Ma)} ratios, close to the Bulk Earth. This suggests that the basalts from Agay basin and trachyte from Batterie des Lions derived from the partial melting of a mantle contaminated by lower continental crust. Maure Vieille trachytes differ from the differentiated rocks of the transitional suite by higher heavy rare earth abundances and {epsilon}Nd{sub (T=250Ma)} of +4/+5. These high {xi}Nd ratios suggest that the Maure Vieille trachytes could derive from the partial melting of a more depleted source, likely an asthenospheric mantle. The isotopic compositions of the Permian lavas from Esterel suggest the thinning (and perhaps the disappearance) of the lithospheric mantle which is associated at the surface with a NNW-SSE extension. The progressive change recorded in Agay basin from a stretching regime to a strike-slip regime may be related to the end of the lithospheric thinning and of the Permian magmatism. (authors) 37 refs.

  7. Measurement methods for radiological characterisation of low-active and mid-active radioactive waste for emplacement; Messmethoden fuer die radiologische Charakterisierung von niedrig - und mittelaktiven radioaktiven Abfaellen fuer die Einlagerung

    Energy Technology Data Exchange (ETDEWEB)

    Sokcic-Kostic, Marina; Schultheis, Roland [NUKEM Technologies GmbH, Alzenau (Germany)

    2014-03-15

    For radiological classification and characterisation of radioactive waste - as it is here considered - the specification of a multitude of parameters is necessary. The measurement or rather definition of parameter ought to guarantee, that waste packages can be handled safely, that radioactive waste repository corresponds to the respective waste and that safety of emplacement is assured. From the parameters further properties of waste, such as the share of long-living isotopes, as well as activity limiting values, are deducted. For this purpose necessary measurements can be divided into non-destructive and destructive ones. The validity, sensitiveness and accuracy of both measurement methods differ. For the destructive methods, samples from the waste packages are retrieved and examined at the laboratory. In case of non-destructive methods, the entire package is scanned, whereby depending on the nuclides and their specific emissions (Gamma- and Neutron radiation, both the Beta- as well as Alpha- radiation) specific measurement methods arise. Available methods are evaluated and introduced with regard to accuracy, reliability as well as handling. Regarding the hardware- with exception of neutron evaluation technics - progress lies less in the development of new methods, rather than in the production line of robust and reliable measurement devices, which can be applied in automated infrastructures. During the evaluation routine simulation with the Monte-Carlo-Methods establishes itself more and more. Main focus regarding changes lies nevertheless in the introduction of the Bayes-Theory, which calculates consistently, and reliably measurement values and their errors, as well as trust intervals. (orig.)

  8. Seismic signals of rockfalls as indicators of the origin of lava fragments emplaced during the 2010 endogenous and exogenous growth in the crater of Volcán de Colima, México

    Science.gov (United States)

    Zobin, Vyacheslav M.; Tellez, Armando; Aguilar, José E.; Cruz, Karla G.

    2017-06-01

    The 2010-2011 exogenous emplacement of a lava lobe during the 2007-2011 lava dome growth at andesitic Volcán de Colima, México, interrupted the previous endogenous regime and allowed us to obtain seismic signals associated with rockfalls triggered by both exogenous and endogenous growth. We analyzed a total of 410 seismic signals of rockfalls with durations from 50 to 150 s recorded during January-April 2010. Two characteristic populations of seismic signal peak frequencies were identified: a low frequency (LF) group (mean = 1.76 ± 0.44 Hz) and a high frequency (HF) group (mean = 3.13 ± 0.63 Hz), associated respectively with rockfalls caused by endogenous and exogenous growth in the crater. Application of the Kolmogorov-Smirnov test showed at the 0.01 significance level that the databases of LF and HF seismic signals of rockfalls belong to different groups of signals and may be considered as having different origins. The results show that the spectral properties of the seismic signals produced by rockfalls may serve as indicators of the origin of falling lava fragments and thus can be used to monitor effusive volcanic activity.

  9. The disposal of Canada's nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. Volume 3: geosphere model

    International Nuclear Information System (INIS)

    Stanchell, F.W.; Davison, C.C.; Melnyk, T.W.; Scheier, N.W.; Chan, T.

    1996-06-01

    This report discusses the approach we used to develop a model of the 3-D network of transport pathways through the geosphere from the location of a nuclear fuel waste disposal vault at a depth of 500 m in a hypothetical permeable plutonic rock mass. The transport pathways correspond to the pathways of advective groundwater movement through this permeable rock from the disposal vault to discharge areas at groundsurface. In this analysis we assumed the permeability of the region of rock immediately surrounding the waste emplacement areas of the disposal vault was considerably higher than the permeability used in the geosphere model for the EIS case study. We also assumed the porosity of the rock could fall within the range 10 -3 to 10 -5 to represent the range of effects by alternative conceptual models of flow through fracture networks in the rock. Advection by the groundwater flow field in the rock surrounding the disposal vault entirely controls the rate and direction of transport from the vault in this geosphere model. The hydrogeological environment we assumed for this geosphere model is entirely hypothetical, unlike the model we developed for the EIS case study which was a conservative, yet realistic, representation of the hydrogeological conditions encountered at the site of our Underground Research Laboratory in the Whiteshell Research Area. We used the same geometry of rock structures for this model as we used in the geosphere model for the EIS case study but we assigned hydrogeologic properties to the various rock domains of the model that result in relatively rapid groundwater flow from the depth of the disposal vault to surface discharge areas. This report desribes the modelling and sensitivity analyses we performed with the MOTIF finite element model to develop the GEONET transport network for this hypothetical geosphere situation. The geosphere model accounts for the effects of natural geothermal heat and vault-induced heat on transport pathways

  10. Post emplacement environment of waste packages

    International Nuclear Information System (INIS)

    Knauss, K.G.; Oversby, V.M.; Wolery, T.J.

    1983-01-01

    Experiments have been conducted as part of the Nevada Nuclear Waste Storage Investigations Project to determine the changes in water chemistry due to reaction of the Topopah Spring tuff with natural groundwater at temperatures up to 150 0 C. The reaction extent has been investigated as a function of rock-to-water ratio, temperature, reaction time, physical state of the samples, and geographic location of the samples within the tuff unit. Results of these experiments will be used to provide information on the water chemistry to be expected if a high-level waste repository were to be constructed in the Topopah Spring tuff. 6 references, 5 figures, 1 table

  11. Transpressional granite-emplacement model: Structural and ...

    Indian Academy of Sciences (India)

    2Ministry of Water Resources and Energy, DR/C, Gas and Petroleum ... Magnetic lineation shows an 'S' shape trend that allows to (1) consider ..... j = 1–4). The magnetic susceptibility is mea- sured for different orientations of the cylindrical.

  12. Cost Estimate for Gun Liner Emplacement

    Science.gov (United States)

    2011-08-01

    excellent material to resist wear and erosion in gun tubes, it is applied by an electrolytic process that involves hexavalent chromium, a known carcinogen...A recent Department of Defense memorandum has strongly urged that, wherever possible, processes involving hexavalent chromium be eliminated from...might be affordable.) Other refractory metals, such as the Stellite series, BioDur CCM* (a cobalt, chrome , molybdenum alloy), or niobium are less

  13. Generation, ascent and eruption of magma on the Moon: New insights into source depths, magma supply, intrusions and effusive/explosive eruptions (Part 2: Predicted emplacement processes and observations)

    Science.gov (United States)

    Head, James W.; Wilson, Lionel

    2017-02-01

    We utilize a theoretical analysis of the generation, ascent, intrusion and eruption of basaltic magma on the Moon to develop new insights into magma source depths, supply processes, transport and emplacement mechanisms via dike intrusions, and effusive and explosive eruptions. We make predictions about the intrusion and eruption processes and compare these with the range of observed styles of mare volcanism, and related features and deposits. Density contrasts between the bulk mantle and regions with a greater abundance of heat sources will cause larger heated regions to rise as buoyant melt-rich diapirs that generate partial melts that can undergo collection into magma source regions; diapirs rise to the base of the anorthositic crustal density trap (when the crust is thicker than the elastic lithosphere) or, later in history, to the base of the lithospheric rheological trap (when the thickening lithosphere exceeds the thickness of the crust). Residual diapiric buoyancy, and continued production and arrival of diapiric material, enhances melt volume and overpressurizes the source regions, producing sufficient stress to cause brittle deformation of the elastic part of the overlying lithosphere; a magma-filled crack initiates and propagates toward the surface as a convex upward, blade-shaped dike. The volume of magma released in a single event is likely to lie in the range 102 km3 to 103 km3, corresponding to dikes with widths of 40-100 m and both vertical and horizontal extents of 60-100 km, favoring eruption on the lunar nearside. Shallower magma sources produce dikes that are continuous from the source region to the surface, but deeper sources will propagate dikes that detach from the source region and ascend as discrete penny-shaped structures. As the Moon cools with time, the lithosphere thickens, source regions become less abundant, and rheological traps become increasingly deep; the state of stress in the lithosphere becomes increasingly contractional

  14. Datation U_Pb : âge de mise en place du magmatisme bimodal des Jebilet centrales (chaîne Varisque, Maroc). Implications géodynamiquesU_Pb dating: emplacement age of the bimodal magmatism of central Jebilet (Variscan Belt, Morocco). Geodynamic implications

    Science.gov (United States)

    Essaifi, Abderrahim; Potrel, Alain; Capdevila, Ramon; Lagarde, Jean-Louis

    2003-01-01

    The bimodal magmatism of central Jebilet is dated to 330.5 +0.68-0.83 Ma by UPb dating on zircons. This age, similar to that of the syntectonic Jebilet cordierite-bearing granitoids, corresponds to the age of the local major tectonometamorphic event. The syntectonic plutonism of the Jebilet massif, composed of tholeiitic, alkaline, and peraluminous calc-alkaline series, is variegated. Magmas emplacement was favoured by the local extension induced by the motion along the western boundary of the Carboniferous basins of the Moroccan Meseta. The Jebilet massif exemplifies the activation of various magmas sources during an episode of continental convergence and crustal wrenching.

  15. Geology of the Curimatau medium region (Paraiba State, Brazil) and the emplacement of the Dona Ines granite associated to the Brasiliano transcurrent shear zones; Geologia da Regiao do Medio Curimatau (PB) e o alojamento do granito de Dona Ines associado a zonas de cisalhamento transcorrentes brasilianas

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Sergio Vieira Freire

    1996-12-31

    In an area of about 700 Km{sup 2} located in the northeast of Paraiba State and having as main point the town of Dona Ines, a geologic/structural mapping, a gravimetric survey and radiometric dating using the Rb/Sr method in whole rock and Sm.Nd model ages were undertaken in order to study and to understand the geology of this portion of terrain, the emplacement of the Dona Ines granitoids and its relationship with the enclosing rocks and the deformation acting at the time of the intrusion. The age of the pluton of Dona Ines was determined by the Rb/Sr whole rock method as 560 {+-} 20 Ma (end of Brasiliano Cycle in the region). Sm.Nd model ages in granitoids of Araras, Belem and Dona Ines have revealed paleoproterozoic ages for their crustal sources, as indicated by the negative {epsilon}{sub nd} of this rock 128 refs., 95 figs., 6 tabs., 7 maps

  16. Geology of the Curimatau medium region (Paraiba State, Brazil) and the emplacement of the Dona Ines granite associated to the Brasiliano transcurrent shear zones; Geologia da Regiao do Medio Curimatau (PB) e o alojamento do granito de Dona Ines associado a zonas de cisalhamento transcorrentes brasilianas

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Sergio Vieira Freire

    1997-12-31

    In an area of about 700 Km{sup 2} located in the northeast of Paraiba State and having as main point the town of Dona Ines, a geologic/structural mapping, a gravimetric survey and radiometric dating using the Rb/Sr method in whole rock and Sm.Nd model ages were undertaken in order to study and to understand the geology of this portion of terrain, the emplacement of the Dona Ines granitoids and its relationship with the enclosing rocks and the deformation acting at the time of the intrusion. The age of the pluton of Dona Ines was determined by the Rb/Sr whole rock method as 560 {+-} 20 Ma (end of Brasiliano Cycle in the region). Sm.Nd model ages in granitoids of Araras, Belem and Dona Ines have revealed paleoproterozoic ages for their crustal sources, as indicated by the negative {epsilon}{sub nd} of this rock 128 refs., 95 figs., 6 tabs., 7 maps

  17. Emplacement of Antarctic ice sheet mass affects circumpolar ocean flow

    NARCIS (Netherlands)

    Rugenstein, Maria; Stocchi, Paolo; von der Heydt, Anna; Dijkstra, Hendrik; Brinkhuis, Henk

    2014-01-01

    During the Cenozoic the Antarctic continent experienced large fluctuations in ice-sheet volume. We investigate the effects of Glacial Isostatic Adjustment (GIA) on Southern Ocean circulation for the first continental scale glaciation of Antarctica (~34 Myr) by combining solid Earth and ocean dynamic

  18. Automation of IED Threat Emplacement for Training Scenarios

    Science.gov (United States)

    2012-03-01

    pendant le processus d’analyse des exigences ont été prototypés. Importance : En modélisant les scénarios d’attaque par IED possibles en fonction des... bridges – The ontology engine would provide “roads” as the feature layer/class, “3m” and the narrowed width and “buildings” and “ bridges ” as the feature

  19. Longevity of Emplacement Drift Ground Support Materials for LA

    Energy Technology Data Exchange (ETDEWEB)

    D. Tang

    2003-09-16

    The purpose of this analysis report is to evaluate and document the inclusion or exclusion of the disruptive events features, events, and processes (FEPs) with respect to modeling used to support the total system performance assessment for license application (TSPA-LA). A screening decision, either ''Included'' or ''Excluded,'' is given for each FEP, along with the technical basis for screening decisions. This information is required by the U.S. Nuclear Regulatory Commission (NRC) at 10 CFR 63.114 (d), (e), and (f) [DIRS 156605]. The FEPs addressed in this report deal with both seismic and igneous disruptive events, such as fault displacements through the repository and an igneous intrusion into the repository. For included FEPs, this analysis summarizes the implementation of the FEP in TSPA-LA (i.e., how the FEP is included). For excluded FEPs, this analysis provides the technical basis for exclusion from TSPA-LA (i.e., why the FEP is excluded). Previous versions of this report were developed to support the total system performance assessments (TSPA) for various prior repository designs. This revision addresses the repository design for the license application (LA).

  20. High level waste canister emplacement and retrieval concepts study

    International Nuclear Information System (INIS)

    1975-09-01

    Several concepts are described for the interim (20 to 30 years) storage of canisters containing high level waste, cladding waste, and intermediate level-TRU wastes. It includes requirements, ground rules and assumptions for the entire storage pilot plant. Concepts are generally evaluated and the most promising are selected for additional work. Follow-on recommendations are made

  1. Stratigraphy of Oceanus Procellarum basalts - Sources and styles of emplacement

    Science.gov (United States)

    Whitford-Stark, J. L.; Head, J. W., III

    1980-01-01

    The basaltic fill of Oceanus Procellarum has been formally subdivided into four lithostratigraphic formations: The Repsold Formation, the Telemann Formation, the Hermann Formation, and the Sharp Formation. The Repsold Formation is composed of high-Ti basalts and pyroclastic deposits with an estimated age of 3.75 + or - 0.05 b.y. and an estimated volume of about 2.1 x 10 to the 5th cu km. This is overlain by the Telemann Formation composed of very low-Ti basalts and pyroclastic deposits with an estimated age of 3.6 + or - 0.2 b.y. and a volume of 4.2 x 10 to the 5th cu km. The Hermann Formation, composed of intermediate basalts with an estimated age of 3.3 + or - 0.3 b.y., represents the next youngest unit with an estimated volume of 2.2 x 10 to the 5th cu km. The youngest materials in Procellarum are the medium-to-high-Ti basalts comprising the Sharp Formation with an estimated age of 2.7 + or - 0.7 b.y. and a volume of 1.8 x 10 to the 4th cu km.

  2. Mapping Emplaced Articulated Concrete Mattress Using Geoelectrical and Electromagnetic Techniques

    National Research Council Canada - National Science Library

    Sjostrom, Keith

    1998-01-01

    Articulated concrete mattresses (ACM) are structures placed parallel to the river current for the purpose of stabilizing the concave banks in river bends, reduce the effects of erosion, and maintain the river channel...

  3. Tracker Mindset for Explosive Device Emplacement Indicator Detection

    Science.gov (United States)

    2014-09-01

    good impressions, though due to the coarseness of the sand particles some spoor yielded less crisp edges than would occur in finer soils. The pit...where conditions such as ambient light and soil moisture were confounds that varied over the course of the day. Given the very applied nature of...where best to intercept the trail, etc. To be a good tracker the officer insists that the person must love the job. If the person has no love for the

  4. Emplacement of Antarctic ice sheet mass affects circumpolar ocean flow

    NARCIS (Netherlands)

    Rugenstein, M.; Stocchi, P.; van der Heydt, A.; Brinkhuis, H.

    2014-01-01

    During the Cenozoic the Antarctic continent experienced large fluctuations in ice-sheet volume. We investigate the effects of Glacial Isostatic Adjustment (GIA) on Southern Ocean circulation for the first continental scale glaciation of Antarctica (~ 34 Myr) by combining solid Earth and ocean

  5. Micrometeorological study of the emplacement at the Ezeiza Atomic Center

    International Nuclear Information System (INIS)

    Berri, G.J.; Robbio, C.A.

    1986-01-01

    An evaluation of meteorological conditions searched at the Ezeiza Atomic Center is presented by means of the data obtained at the micrometeorological station of the Atomic Center during the period January-December 1979. The daily and yearly mean behaviour of the temperature, humidity and wind's directions and speed is shown as well as extreme values persistence of temperature and humidity, the annual behaviour of the precipitation and its relation with the wind's direction. Special attention is given to the atmospheric dispersion characteristic through the study of the low-wind-speed persistence, wind direction persistence and wind's direction distribution confronted with the stability classes. An evaluation of the dispersion factor or normalized concentration, both for short term releases (1 hour), as well as long term releases (time integrated concentration annual factor) is shown. Those factors are representative for mean situations; they can not be employed for isolated situations. Finally, it is emphasized that although the results were obtained by means of 1979 data, significative differences are no expected for other years. (M.E.L.) [es

  6. Emplacement kinematics of nepheline syenites from the Terrane ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    tiled up in an imbricate fashion (figure 3b). The majority of the minerals in nepheline syenite show uniform extinction, feldspars show straight twin lamellae and hornblende and biotite flakes lack any kind of kink on their cleavage. Thus it has been inferred that the minerals are predominantly of magmatic origin and have not ...

  7. SCATTER: Source and Transport of Emplaced Radionuclides: Code documentation

    International Nuclear Information System (INIS)

    Longsine, D.E.

    1987-03-01

    SCATTER simulated several processes leading to the release of radionuclides to the site subsystem and then simulates transport via the groundwater of the released radionuclides to the biosphere. The processes accounted for to quantify release rates to a ground-water migration path include radioactive decay and production, leaching, solubilities, and the mixing of particles with incoming uncontaminated fluid. Several decay chains of arbitrary length can be considered simultaneously. The release rates then serve as source rates to a numerical technique which solves convective-dispersive transport for each decay chain. The decay chains are allowed to have branches and each member can have a different radioactive factor. Results are cast as radionuclide discharge rates to the accessible environment

  8. Geologic appraisal of Paradox basin salt deposits for water emplacement

    Science.gov (United States)

    Hite, Robert J.; Lohman, Stanley William

    1973-01-01

    Thick salt deposits of Middle Pennsylvanian age are present in an area of 12,000 square miles in the Paradox basin of southeast Utah and southwest Colorado. The deposits are in the Paradox Member of the Hermosa Formation. The greatest thickness of this evaporite sequence is in a troughlike depression adjacent to the Uncompahgre uplift on the northeast side of the basin.The salt deposits consist of a cyclical sequence of thick halite units separated by thin units of black shale, dolomite, and anhydrite. Many halite units are several hundred feet thick and locally contain economically valuable potash deposits.Over much of the Paradox basin the salt deposits occur at depths of more than 5,000 feet. Only in a series of salt anticlines located along the northeastern side of the basin do the salt deposits rise to relatively shallow depths. The salt anticlines can be divided geographically and structurally into five major systems. Each system consists of a long undulating welt of thickened salt over which younger rocks are arched in anticlinal form. Locally there are areas along the axes of the anticlines where the Paradox Member was never covered by younger sediments. This allowed large-scale migration of Paradox strata toward and up through these holes in the sediment cover forming diapiric anticlines.The central or salt-bearing cores of the anticlines range in thickness from about 2,500 to 14,000 feet. Structure in the central core of the salt anticlines is the result of both regional-compression and flowage of the Paradox Member into the anticlines from adjacent synclines. Structure in the central cores of the salt anticlines ranges from relatively undeformed beds to complexly folded and faulted masses, in which stratigraphic continuity is undemonstrable.The presence of thick cap rock .over many of the salt anticlines is evidence of removal of large volumes of halite by groundwater. Available geologic and hydrologic information suggests that this is a relatively slow process and that any waste-storage or disposal sites in these structures should remain dry for hundreds of thousands of years.Trace to commercial quantities of oil and gas are found in all of the black shale-dolomite-anhydrite interbeds of the Paradox Member. These hydrocarbons constitute a definite hazard in the construction and operation of underground waste-storage or disposal facilities. However, many individual halite beds are of. sufficient thickness that a protective seal of halite can be left between the openings and the gassy beds.A total of 12 different localities were considered to be potential waste-storage or disposal sites in the Paradox basin. Two Sharer dome and Salt Valley anticline, were considered to have the most favorable characteristics.

  9. Ophiolite Emplacement and the Effects of the Subduction of the Active Chile Ridge System: Heterogeneous Paleostress Regimes Recorded in the Taitao Ophiolite (Southern Chile Emplazamiento de ofiolitas y los efectos de la subducción de la dorsal activa de Chile: Regímenes heterogéneos de paleostress registrados en la Oflolita Taitao (Sur de Chile

    Directory of Open Access Journals (Sweden)

    Eugenio E Veloso

    2009-01-01

    Full Text Available The repeated north and southward migration of the Chile Triple junction, offshore the Península de Taitao, is expected to have imposed contrasting stress fields in the forearc for the last 6 Ma because of changes in convergence direction and rate of subducting plates. NNW-SSE to E-W and minor NE-SW striking brittle faults developed in the plutonic units of the Mio-Pliocene Taitao Ophiolite, whereas NNE-SSW and minor NW-SE trending faults developed in its eastern border (Bahía Barrientes fault-zone. These brittle faults are studied to elucídate the style of ophiolite emplacement and the tectonic effects resulting from the alternated migration of the Chile Triple junction in the área. Analyses of heterogeneous fault-slip data on both áreas suggest that faults were activated by different stress fields. Two different compressional stress fields were identified in the plutomc units (A and B, whereas three different stress fields, ranging from compressional to strike-slip, were identified in the BahíaBarrientos fault-zone (C, D and E. Calculated directions of Oj axes for A, C, D and E solutions are mostly E-W trending, roughly similar to the convergence direction of subducting plates, whereas that for B solution is counterclockwise rotated ca. 60° with respect to the previous E-W trend. Brittle structures related to solution B were attributed to an early deformation of the ophiolite, most probably developed shortly after its emplacement {ca. 6 Ma. These structures were further counterclockwise rotated, while new structures (related to solution A developed in the plutomc units in order to absorb the continuous deformation. In the eastern margin of the ophiolite, the stress field divided inte compressional and strike-slip components. During periods of relatively strong compression (fast subduction of the Nazca píate, the fault-zone experienced well defined compressional and strike-slip movements (solutions C and D. In contrast, during periods of

  10. Very deep borehole. Deutag's opinion on boring, canister emplacement and retrievability

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Tim [Well Engineering Partners BV, The Hague (Netherlands)

    2000-05-01

    An engineering feasibility study has been carried out to determine whether or not it is possible to drill the proposed Very Deep Borehole concept wells required by SKB for nuclear waste disposal. A conceptual well design has been proposed. All aspects of well design have been considered, including drilling tools, rig design, drilling fluids, casing design and annulus isolation. The proposed well design is for 1168.4 mm hole to be drilled to 500 m. A 1066.8 mm outer diameter (OD) casing will be run and cemented. A 1016 mm hole will be drilled to approximately 2000 m, where 914.4 mm OD casing will be run. This annulus will be sealed with bentonite slurry apart from the bottom 100 m which will be cemented. 838.2 mm hole will be drilled to a final depth of 4000 m, where 762 mm OD slotted casing will be run. All the hole sections will be drilled using a downhole hammer with foam as the drilling fluid medium. Prior to running each casing string, the hole will be displaced to mud to assist with casing running and cementing. The waste canisters will be run on a simple J-slot tool, with integral backup system in case the J-slot fails. The canisters will all be centralised. Canisters can be retrieved using the same tool as used to run them. Procedures are given for both running and retrieving. Logging and testing is recommended only in the exploratory wells, in a maximum hole size of 311.1 mm. This will require the drilling of pilot holes to enable logging and testing to take place. It is estimated that each well will take approximately 137 days to drill and case, at an estimated cost of 4.65 Meuro per well. This time and cost estimate does not include any logging, testing, pilot hole drilling or time taken to run the canisters. New technology developments to enhance the drilling process are required in recyclable foam systems, in hammer bit technology, and in the development of robust under-reamers. It is the authors conclusion that it is possible to drill the well with currently existing technology, although it represents one of the biggest challenges to be presented to the drilling industry.

  11. Very deep borehole. Deutag's opinion on boring, canister emplacement and retrievability

    International Nuclear Information System (INIS)

    Harrison, Tim

    2000-05-01

    An engineering feasibility study has been carried out to determine whether or not it is possible to drill the proposed Very Deep Borehole concept wells required by SKB for nuclear waste disposal. A conceptual well design has been proposed. All aspects of well design have been considered, including drilling tools, rig design, drilling fluids, casing design and annulus isolation. The proposed well design is for 1168.4 mm hole to be drilled to 500 m. A 1066.8 mm outer diameter (OD) casing will be run and cemented. A 1016 mm hole will be drilled to approximately 2000 m, where 914.4 mm OD casing will be run. This annulus will be sealed with bentonite slurry apart from the bottom 100 m which will be cemented. 838.2 mm hole will be drilled to a final depth of 4000 m, where 762 mm OD slotted casing will be run. All the hole sections will be drilled using a downhole hammer with foam as the drilling fluid medium. Prior to running each casing string, the hole will be displaced to mud to assist with casing running and cementing. The waste canisters will be run on a simple J-slot tool, with integral backup system in case the J-slot fails. The canisters will all be centralised. Canisters can be retrieved using the same tool as used to run them. Procedures are given for both running and retrieving. Logging and testing is recommended only in the exploratory wells, in a maximum hole size of 311.1 mm. This will require the drilling of pilot holes to enable logging and testing to take place. It is estimated that each well will take approximately 137 days to drill and case, at an estimated cost of 4.65 Meuro per well. This time and cost estimate does not include any logging, testing, pilot hole drilling or time taken to run the canisters. New technology developments to enhance the drilling process are required in recyclable foam systems, in hammer bit technology, and in the development of robust under-reamers. It is the authors conclusion that it is possible to drill the well with currently existing technology, although it represents one of the biggest challenges to be presented to the drilling industry

  12. Emplacement of ideas. The development of geographical thought in Brazil in the early 20th century

    Directory of Open Access Journals (Sweden)

    Lia Osorio Machado

    1998-06-01

    Full Text Available This paper looks at the circulation of modern geographical ideas in Brazil. The focus is on the relationship between geographical source models and the target model of domestic modernization. Three corresponding "mechanisms" provided the translation from one to the other: gradualism, adaptation and essentialism.

  13. Analysis of heat and mass transport processes near an emplaced nuclear waste canister

    International Nuclear Information System (INIS)

    Keller, C.

    1990-01-01

    A review has been performed of the models and experimental plans for evaluation of the spent fuel canister environment in a nuclear repository, e.g., the planned Yucca Mountain facilities. Special emphasis was placed on the relevance of the models and experiments to the 100 to 10,000 year prediction. The question was addressed whether one could justify testing in materials other than Yucca Mountain rock and obtain results in a relatively short time which would be relevant to the long time in Yucca Mountain. The paper discusses steam evolution in calculations and experiments, fracture models, possible measurements of relative permeability, and long time scale effects. 5 figs. (MB)

  14. Repository emplacement costs for Al-clad high enriched uranium spent fuel

    International Nuclear Information System (INIS)

    McDonell, W.R.; Parks, P.B.

    1994-01-01

    A range of strategies for treatment and packaging of Al-clad high-enriched uranium (HEU) spent fuels to prevent or delay the onset of criticality in a geologic repository was evaluated in terms of the number of canisters produced and associated repository costs incurred. The results indicated that strategies in which neutron poisons were added to consolidated forms of the U-Al alloy fuel generally produced the lowest number of canisters and associated repository costs. Chemical processing whereby the HEU was removed from the waste form was also a low cost option. The repository costs generally increased for isotopic dilution strategies, because of the substantial depleted uranium added. Chemical dissolution strategies without HEU removal were also penalized because of the inert constituents in the final waste glass form. Avoiding repository criticality by limiting the fissile mass content of each canister incurred the highest repository costs

  15. Design of a nuclear-waste package for emplacement in tuff

    International Nuclear Information System (INIS)

    O'Neal, W.C.; Rothman, A.J.; Gregg, D.W.; Hockman, J.N.; Revelli, M.A.; Russell, E.W.; Schornhorst, J.R.

    1983-01-01

    Design, modeling, and testing activities are under way at LLNL in the development of high level nuclear waste package designs. We discuss the geological characteristics affecting design, the 10CFR60 design requirements, conceptual designs, metals for containment barriers, economic analysis, thermal modeling, and performance modeling

  16. Glacial removal of late Cenozoic subglacially emplaced volcanic edifices by the West Antarctic ice sheet

    Science.gov (United States)

    Behrendt, John C.; Blankenship, D.D.; Damaske, D.; Cooper, A. K.

    1995-01-01

    Local maxima of the horizontal gradient of pseudogravity from closely spaced aeromagnetic surveys over the Ross Sea, northwestern Ross Ice Shelf, and the West Antarctic ice sheet, reveal a linear magnetic rift fabric and numerous subcircular, high-amplitude anomalies. Geophysical data indicate two or three youthful volcanic edifices at widely separated areas beneath the sea and ice cover in the West Antarctic rift system. In contrast, we suggest glacial removal of edifices of volcanic sources of many more anomalies. Magnetic models, controlled by marine seismic reflection and radar ice-sounding data, allow us to infer that glacial removal of the associated late Cenozoic volcanic edifices (probably debris, comprising pillow breccias, and hyaloclastites) has occurred essentially concomitantly with their subglacial eruption. "Removal' of unconsolidated volcanic debris erupted beneath the ice is probably a more appropriate term than "erosion', given its fragmented, ice-contact origin. The exposed volcanoes may have been protected from erosion by the surrounding ice sheet because of more competent rock or high elevation above the ice sheet. -from Authors

  17. Stratigraphic constraints on the timing and emplacement of the Alika 2 giant Hawaiian submarine landslide

    Science.gov (United States)

    McMurtry, Gary M.; Herrero-Bervera, Emilio; Cremer, Maximilian D.; Smith, John R.; Resig, Johanna; Sherman, Clark; Torresan, Michael E.

    1999-01-01

    Previous work has found evidence for giant tsunami waves that impacted the coasts of Lanai, Molokai and other southern Hawaiian Islands, tentatively dated at 100 + and 200 + ka by U-series methods on uplifted coral clasts. Seafloor imaging and related work off Hawaii Island has suggested the Alika phase 2 debris avalanche as the source of the ~ 100 ka "giant wave deposits", although its precise age has been elusive. More recently, a basaltic sand bed in ODP site 842 (~ 300 km west of Hawaii) estimated at 100 ?? 20 ka has been suggested to correlate with this or another large Hawaiian landslide. Our approach to the timing and linkage of giant submarine landslides and paleo-tsunami deposits is a detailed stratigraphic survey of pelagic deposits proximal to the landslide feature, beginning with a suite of seven piston, gravity and box cores collected in the vicinity of the Alika 2 slide. We used U-series dating techniques, including excess 230Th and 210Pb profiling, high-resolution paleomagnetic stratigraphy, including continuous, U-channel analysis, δ18O stratigraphy, visual and X-ray sediment lithology, and the petrology and geochemistry of the included turbidites and ash layers. Minimum ages for the Alika phase 2a slide from detailed investigation of two of the cores are 112 ± 15 ka and 125 ± 24 ka (2σ) based on excess 230Th dating. A less precise age for the Alika phase 1 and/or South Kona slide is 242 ± 80 ka (2σ), consistent with previous geological estimates. Oxygen isotope analyses of entrained planktonic foraminifera better constrain the Alika phase 2a maximum age at 127 ± 5 ka, which corresponds to the beginning of the stage 5e interglacial period. It is proposed that triggering of these giant landslides may be related to climate change when wetter periods increase the possibility of groundwater intrusion and consequent phreatomagmatic eruptions of shallow magma chambers. Our study indicates the contemporaneity of the Alika giant submarine landslides and distal deposits from enormous turbidity currents as well as coral clasts reported to be tsunami deposits on Lanai and Molokai through direct dating and compositional analysis of the landslide deposits.

  18. Investigating the stratigraphy of Mare Imbrium flow emplacement with Earth-based radar

    Science.gov (United States)

    Morgan, G. A.; Campbell, B. A.; Campbell, D. B.; Hawke, B. R.

    2016-08-01

    The lunar maria are the product of extensive basaltic volcanism that flooded widespread portions of the Moon's surface. Constraining mare volcanic history therefore provides a window into the endogenic processes responsible for shaping the Moon. Due to the low magma viscosity and the associated thin nature of lava units, the majority of mare surface structures are masked and subdued by impact regolith. Subtle individual mare flow morphologies, coupled with spatial limitations in the use of crater size distributions to distinguish surface units close in age, restrict our understanding of mare stratigraphy. Earth-based 70 cm wavelength (P band) radar can reveal features beneath the regolith and highlight very subtle changes in the ilmenite content of the flows, providing a unique means to map mare units. Here we map volcanic units in Mare Imbrium using high-resolution (200 m/pixel), Earth-based P band data. Situated within the heat-producing potassium, rare earth element, and phosphorus terrane, Mare Imbrium experienced some of the most long-lived (and recent) lunar volcanism, and its surface exhibits a significant diversity of basaltic chemistry. Our investigation identifies at least four distinct stages of volcanic activity, originating from multiple sources within Imbrium. The most recent of these stages comprises extensive, yet relatively thin volcanic flow units that left remnant kipukas of older mare material distributed across much of the basin. From a future mission perspective, it may be possible to collect samples expressing a wide range in age from small areas of Mare Imbrium. Our map also places important constraints on the interpretation of the Chang'e-3 Lunar Penetrating Radar measurements.

  19. A feasibility study of the offshore disposal of radioactive waste by drilled emplacement

    International Nuclear Information System (INIS)

    1984-01-01

    This report describes the third phase of a study of the feasibility of disposal and isolation of high level radioactive waste in holes drilled deep into the sediments of the ocean. In this phase, work has concentrated on establishing the logistics of disposing of up to 400 cubic metres of vitrified waste per year, and on the capital and running costs of doing so. The report concludes that the disposal of waste in the form produced by the AVM process is operationally feasible, and that disposal in this way will add approximately 0.2% to the cost of generation of the energy contributing to the waste. (author)

  20. Lava Eruption and Emplacement: Using Clues from Hawaii and Iceland to Probe the Lunar Past

    Science.gov (United States)

    Needham, Debra Hurwitz; Hamilton, C. W.; Bleacher, J. E.; Whelley, P. L.; Young, K. E.; Scheidt, S. P.; Richardson, J. A.; Sutton, S. S.

    2017-01-01

    Investigating recent eruptions on Earth is crucial to improving understanding of relationships between eruption dynamics and final lava flow morphologies. In this study, we investigated eruptions in Holuhraun, Iceland, and Kilauea, Hawaii to gain insight into the lava dynamics near the source vent, the initiation of lava channels, and the origin of down-channel features. Insights are applied to Rima Bode on the lunar nearside to deduce the sequence of events that formed this lunar sinuous rille system. These insights are crucial to correctly interpreting whether the volcanic features associated with Rima Bode directly relate to eruption conditions at the vent and, thus, can help us understand those eruption dynamics, or, alternatively, whether the features formed as a result of more localized influences on lava flow dynamics. For example, if the lava channel developed early in the eruption and was linked to pulses in vent activity, its morphology can be analyzed to interpret the flux and duration of the eruption. Conversely, if the lava channel initiated late in the eruption as the result of a catastrophic breaching of lava that had previously pooled within the vent [e.g., 1], then the final channel morphology will not indicate eruption dynamics but rather local dynamics associated with that breach event. Distinguishing between these two scenarios is crucial for correctly interpreting the intensity and duration of volcanic history on the Moon.

  1. Boulder emplacement and remobilisation by cyclone and submarine landslide tsunami waves near Suva City, Fiji

    Science.gov (United States)

    Lau, A. Y. Annie; Terry, James P.; Ziegler, Alan; Pratap, Arti; Harris, Daniel

    2018-02-01

    The characteristics of a reef-top boulder field created by a local submarine landslide tsunami are presented for the first time. Our examination of large reef-derived boulders deposited by the 1953 tsunami near Suva City, Fiji, revealed that shorter-than-normal-period tsunami waves generated by submarine landslides can create a boulder field resembling a storm boulder field due to relatively short boulder transport distances. The boulder-inferred 1953 tsunami flow velocity is estimated at over 9 m s- 1 at the reef edge. Subsequent events, for example Cyclone Kina (1993), appear to have remobilised some large boulders. While prior research has demonstrated headward retreat of Suva Canyon in response to the repeated occurrence of earthquakes over the past few millennia, our results highlight the lingering vulnerability of the Fijian coastlines to high-energy waves generated both in the presence (tsunami) and absence (storm) of submarine failures and/or earthquakes. To explain the age discrepancies of U-Th dated coral comprising the deposited boulders, we introduce a conceptual model showing the role of repeated episodes of tsunamigenic submarine landslides in removing reef front sections through collapse. Subsequent high-energy wave events transport boulders from exposed older sections of the reef front onto the reef where they are deposited as 'new' boulders, alongside freshly detached sections of the living reef. In similar situations where anachronistic deposits complicate the deposition signal, age-dating of the coral boulders should not be used as a proxy for determining the timing of the submarine landslides or the tsunamis that generated them.

  2. Dating emplacement and evolution of the orogenic magmatism in the internal Western Alps

    DEFF Research Database (Denmark)

    Berger, Alfons; Thomsen, Tonny B.; Ovtcharova, Maria

    2012-01-01

    The Canavese Line in the Western Alps represents the position in the Alpine chain, where alkaline and calc-alkaline magmatism occur in close spatial and temporal association. In addition to available data on the alkaline Valle del Cervo Pluton, we present petrological and geochemical data...... on the Miagliano tonalite. The latter is of special interest, because it is located in the south-eastern side of the Canavese Line, in contrast to most Periadriatic Plutons. The dioritic to tonalitic rocks of the Miagliano Pluton represent an intermediate stage of a calc-alkaline differentiation, demonstrated...... by relics of two different pyroxenes as well as the texture of allanite. Hornblende barometry indicates pressures of similar to 0.46 GPa consistent with the presence of magmatic epidote. Field relationships between the two Plutons, the volcanic and volcaniclastic rocks of the Biella Volcanic Suite...

  3. Pluton emplacement and magmatic arc construction: A model from the Patagonian batholith

    Science.gov (United States)

    Bruce, Robert; Nelson, Eric; Weaver, Stephen

    1988-01-01

    A model of batholithic construction in Andean arcs and its applicability to possibly similar environments in the past is described. Age and compositional data from the Patagonian batholith of southern Chile show a long history of magmatism in any given area (total age range is 15 to 157 Ma), but different regions appear to have different magmatic starting ages. Furthermore, mafic rocks seem to be the oldest components of any given region. An assembly line model involving semicontinuous magmatism and uplift was outlined, which has implications for other terranes: uplift rates will be proportional to observed ranges in age, and total uplift will be proportional to the age of the oldest pluton in any given area. It is suggested that misleading results would be obtained if only small areas of similar terranes in the Archean were available for study.

  4. The Effects of Unheated Sections on Moisture Transport in the Emplacement Drift

    International Nuclear Information System (INIS)

    G. Danko; D. Bahrami; J.T. Birkholzer

    2006-01-01

    A thermal-hydrologic natural-ventilation model is configured for simulating temperature, humidity, and condensate distributions in the coupled domains of the in-drift airspace and the near-field rockmass. Meaningful results are obtained from the model for a practical application in which the beneficial effects of unheated drift sections are analyzed. Sensitivity to the axial dispersion coefficient is also studied with the model

  5. The Effect of Unheated Sections on Moisture Transport in the Emplacement Drift

    International Nuclear Information System (INIS)

    G. Danko; J. Birkholzer; D. Bahrami

    2006-01-01

    The goals of this study are: (1) to configure a thermal-hydrological, natural-ventilation model for simulating temperature, humidity, and condensate distributions in the coupled domains of in-drift airspace and near-field rockmass. Rokmass model: TOUGH2, in-drift model: MULTIFLUX (MF); (2) obtain meaningful results from the model for a practical application in which the beneficial effects of unheated drift sections are analyzed; and (3) study the sensitivity to the axial dispersion coefficient with the model

  6. Constraints on Transport and Emplacement Mechanisms of Labile Fractions in Lunar Cold Traps

    Science.gov (United States)

    Rickman, D.; Gertsch, L.

    2014-01-01

    Sustaining the scientific exploration of the Solar System will require a significant proportion of the necessary fuels and propellants, as well as other bulk commodities, to be produced from local raw materials [1]. The viability of mineral production depends on the ability to locate and characterize mineable deposits of the necessary feedstocks. This requires, among other things, a workable understanding of the mechanisms by which such deposits form, which is the subject of Economic Geology. Multiple deposition scenarios are possible for labile materials on the Moon. This paper suggests labile fractions moved diffusely through space; deposits may grow richer with depth until low porosity rock; lateral transport is likely to have occurred with the regolith, at least for short distances; crystalline ice may not exist; the constituent phases could be extremely complex. At present we can constrain the sources only mildly; once on the Moon, the transport mechanisms inherently mix and therefore obscure the origins. However, the importance of expanding our understanding of ore-forming processes on the Moon behooves us to make the attempt. Thus begins a time of new inquiry for Economic Geology.

  7. Discussion on spatial emplacement of exogenic-epigenetic infiltration-type uranium deposit

    International Nuclear Information System (INIS)

    Zhao Fengmin

    2005-01-01

    Exogenic-epigenetic infiltration-type uranium deposit is a kind of deposit with large resources, low exploitation cost, and less environmental pollution being the recent important prospecting target in China. Prospecting practice for uranium during recent decade indicates that the metallogenic model and prospecting-evaluation criteria obtained from sandstone-hosted uranium deposits in Middle Asia are not applicable to the case in China. China is a country which has been subject to intense neotectonism, and Meso-Cenozoic basins in China have experienced various tectonic reworking. According to the spatial relation to orogenic belts sedimentary basins may be divided into: basins in orogenic belt; basins near orogenic belt and basins with weak tectonic activation far away from orogenic belt. Then, based on the structural features, basins may be further divided into corresponding subtypes. The author discusses the favourability of each type basin for the formation of exogenic-epigenetic uranium mineralization, as well as the paleo-climatic conditions for uranium ore-formation. Then, the author proposes that, for small intracontinental basins recharged by natural groundwater, the arid climatic period is not totally a favourable factor for uranium ore-formation, it even could be an unfavourable factor. In contrast, basins located in humid climatic region may be advantageous to uranium ore-formation. For improving the prospecting efficiency, a metallogenic model for exogenic-epigenetic infiltration uranium deposits and corresponding prospecting-evaluation criteria suitable for geologic situation of China have to be established as soon as possible. (authors)

  8. Analysis of heat transfer regulation and modification employing intermittently emplaced porous cavities

    International Nuclear Information System (INIS)

    Vafai, K.; Huang, P.C.

    1994-01-01

    The present work forms a fundamental investigation on the effects of using intermittently porous cavities for regulating and modifying the flow and temperature fields and therefore changing the skin friction and heat transfer characteristics of an external surface. A general flow model that accounts for the effects of the impermeable boundary and inertial effects is used to describe the flow inside the porous region. Solutions of the problem have been carried out using a finite-difference method through the use of a stream function-vorticity transformation. Various interesting characteristics of the flow and temperature fields in the composite layer are analyzed and discussed in detail. The effects of various governing dimensionless parameters, such as the Darcy number, Reynolds number, Prandtl number, the inertia parameter as well as the effects of pertinent geometric parameters are thoroughly explored. Furthermore, the interactive effects of the embedded porous substrates on skin friction and heat transfer characteristics of an external surface are analyzed. The configuration analyzed in this work provides an innovative approach in altering the frictional and heat transfer characteristics of an external surface. 27 refs., 12 figs., 1 tab

  9. Étude de l'emplacement des produits agricoles sur les principaux ...

    African Journals Online (AJOL)

    English Title: Marketing of food grain products on the main markets of Lome: analysis of the retail sites and appreciation by buyers. English Abstract. The choice of site is a significant factor of success of the marketing strategy lay out by retailers to distribute agricultural products on the various public opened markets. Indeed ...

  10. Displacement and Emplacement in Narratives of Relocation by Romanian Women Authors

    Directory of Open Access Journals (Sweden)

    Adriana Elena Stoican

    2016-05-01

    Full Text Available The present paper analyses recent Romanian accounts of women's uprooting from a communist regime, foregrounding manners in which the migrants' transnational itineraries are punctuated by instances of groundedness that temporary anchor the protagonists in their translocal settings. More specifically, the article discusses the segmented itineraries of women migrants from Romania via different European countries to their final destination, the United States. I have chosen the syntagm "accounts of uprooting" instead of "migration literature", as the primary corpus of this analysis is made up of different literary genres: a novel, Train to Trieste by Domnica Radulescu and a memoir, The Gypsy Saw Two Lives, by Rodica Mihalis. The analysis of these creations introduces a comparative perspective on the shaping of translocal perceptions in the context of transnational migration. Consequently, the body of the paper investigates the migrant characters' relation to the European spaces where they settle before preparing their relocation to the USA. By adopting this approach, the discussion blends the axes of embeddedness and disembeddedness in order to provide a more comprehensive account of the intersections between gender and migration placed in a transnational context. Therefore, the discussion considers both the transgressive, fluid connotations of transnational processes and the individuals' need for stable structures despite their discontinuous itineraries.

  11. The Chimborazo sector collapse and debris avalanche : deposit characteristics as evidence of emplacement mechanisms

    OpenAIRE

    Bernard, B.; Vries de, B. V.; Barba, D.; Leyrit, H.; Robin, Claude; Alcaraz, S.; Samaniego, Pablo

    2008-01-01

    Chimborazo is a Late Pleistocene to Holocene stratovolcano located at the southwest end of the main Ecuadorian volcanic arc. It experienced a large sector collapse and debris avalanche (DA) of the initial edifice (CH-1). This left a 4 km wide scar, removing 8.0 +/- 0.5 km(3) of the edifice. The debris avalanche deposit (DAD) is abundantly exposed throughout the Riobamba Basin to the Rio Chambo, more than 35 km southeast of the volcano. The DAD averages a thickness of 40 m, covers about 280 km...

  12. A copper container corrosion model for the in-room emplacement of used CANDU fuel

    International Nuclear Information System (INIS)

    King, F.

    1996-11-01

    Copper containers in a Canadian nuclear fuel waste disposal vault are expected to undergo uniform corrosion and, possibly, pitting. The corrosion behaviour of the containers will be dictated by the evolution of environmental conditions within the disposal vault. The environment will evolve from an early warm, oxidizing phase, during which fast uniform corrosion and pitting may occur, to an indefinite period of cool, anoxic conditions, during which the container will only be susceptible to slow uniform corrosion. The results of corrosion and electrochemical studies of the uniform corrosion of Cu in O 2 -containing Cl - solutions are discussed and a detailed reaction mechanism presented. The relevant literature on pitting corrosion is briefly reviewed and models for the prediction of pit depth discussed. The potential for microbially influenced corrosion and stress-corrosion cracking is discussed, as are vapour-phase corrosion and the effects of β-radiation. The use of natural analogues for justifying long-term corrosion predictions is also considered. Finally, a model for uniform corrosion and pitting is presented and container lifetimes predicted. Copper containers having a minimum wall thickness of 25.4 mm are not predicted to fail by corrosion in periods 6 a. Thus, despite the assumption of poor rock quality made here, the safety of the entire disposal concept can be assured by the use of a long-lived container. (author). 125 refs., 1 tab., 24 figs

  13. Diffusion Dominant Solute Transport Modelling In Deep Repository Under The Effect of Emplacement Media Degradation - 13285

    International Nuclear Information System (INIS)

    Kwong, S.; Jivkov, A.P.

    2013-01-01

    Deep geologic disposal of high activity and long-lived radioactive waste is being actively considered and pursued in many countries, where low permeability geological formations are used to provide long term waste contaminant with minimum impact to the environment and risk to the biosphere. A multi-barrier approach that makes use of both engineered and natural barriers (i.e. geological formations) is often used to further enhance the containment performance of the repository. As the deep repository system subjects to a variety of thermo-hydro-chemo-mechanical (THCM) effects over its long 'operational' lifespan (e.g. 0.1 to 1.0 million years, the integrity of the barrier system will decrease over time (e.g. fracturing in rock or clay)). This is broadly referred as media degradation in the present study. This modelling study examines the effects of media degradation on diffusion dominant solute transport in fractured media that are typical of deep geological environment. In particular, reactive solute transport through fractured media is studied using a 2-D model, that considers advection and diffusion, to explore the coupled effects of kinetic and equilibrium chemical processes, while the effects of degradation is studied using a pore network model that considers the media diffusivity and network changes. Model results are presented to demonstrate the use of a 3D pore-network model, using a novel architecture, to calculate macroscopic properties of the medium such as diffusivity, subject to pore space changes as the media degrade. Results from a reactive transport model of a representative geological waste disposal package are also presented to demonstrate the effect of media property change on the solute migration behaviour, illustrating the complex interplay between kinetic biogeochemical processes and diffusion dominant transport. The initial modelling results demonstrate the feasibility of a coupled modelling approach (using pore-network model and reactive transport model) to examine the long term behaviour of deep geological repositories with media property change under complex geochemical conditions. (authors)

  14. Emplacement of Widespread Fe/Mg Phyllosilicate Layer in West Margaritifer Terra, Mars

    Science.gov (United States)

    Seelos, K. D.; Maxwell, R. E.; Seelos, F. P.; Buczkowski, D.; Viviano-Beck, C. E.

    2017-12-01

    West Margaritifer Terra is located at the eastern end of Valles Marineris at the complex intersection of chaos terrains, cratered highlands, and multiple generations of outflow channels. Adjacent regions host layered phyllosilicates thought to indicate early Mars pedogenic and/or ground water-based alteration (e.g., Le Deit et al., 2012), and indeed, hydrologic modeling supports prolonged aqueous activity in the Noachian and Hesperian eras (Andrews-Hanna and Lewis, 2011). The remnant high-standing plateaus in West Margaritifer (0-15°S, 325-345°E) host numerous phyllosilicate-bearing outcrops as well and are the focus of this study. Here, we performed a systematic mapping and characterization of mineralogy and morphology of these deposits in order to assess similarity to other layered phyllosilicates and evaluate potential formation mechanisms. Utilizing multiple remote sensing datasets, we identified three types of phyllosilicate exposures distributed throughout the region: 1) along upper chaos fracture walls, 2) in erosional windows on the plains, and 3) in crater walls and ejecta. Outcrops are spectrally indicative of Fe/Mg smectite (most similar to saponite) and only rare, isolated occurrences of Al-phyllosilicate were observed. Morphologically, the layer is a few to 10 m thick, light-toned, polygonally fractured at decameter scales, and vertical subparallel banding is evident in places. These characteristics were used along with spatial distribution, elevation, and geologic context to evaluate 4 potential formation mechanisms: fluvio-lacustrine, pedogenesis, diagenesis, and hydrothermal alteration. We find that the widespread distribution and spectral homogeneity of the layer favors formation via groundwater alteration and/or pedogenic weathering. This is consistent with interpretations of similar layered phyllosilicates in NW Noachis Terra and the Valles Marineris plains to the west, and significantly extends the area over which these aqueous processes operated in Noachian times.

  15. Morphological characteristics and emplacement mechanism of the seamounts in the Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.; Kodagali, V.N.

    Minimum elevation High E values characterize a broad somewhat level surface with occasional presence of depressions while low values typify a terrain with isolated relief features standing above extensive level surfaces. The average elevation relief ratio... of 0.788 indicates the region to have a fair number of depressions and highs. We defined the lower cutoff height of 100 m for the seamounts and divided them into three groups: large (N800 m), medium (N400 to 800 m) and small (100 to≤400m...

  16. Effects of mechanical layering on hydrofracture emplacement and fluid transport in reservoirs

    Directory of Open Access Journals (Sweden)

    Sonja Leonie Philipp

    2013-12-01

    Full Text Available Fractures generated by internal fluid pressure, for example, dykes, mineral veins, many joints and man-made hydraulic fractures, are referred to as hydrofractures. Together with shear fractures, they contribute significantly to the permeability of fluid reservoirs such as those of petroleum, geothermal water, and groundwater. Analytical and numerical models show that – in homogeneous host rocks – any significant overpressure in hydrofractures theoretically generates very high crack tip tensile stresses. Consequently, overpressured hydrofractures should propagate and help to form interconnected fracture systems that would then contribute to the permeability of fluid reservoirs. Field observations, however, show that in heterogeneous and anisotropic, e.g., layered, rocks many hydrofractures become arrested or offset at layer contacts and do not form vertically interconnected networks. The most important factors that contribute to hydrofracture arrest are discontinuities (including contacts, stiffness changes between layers, and stress barriers, where the local stress field is unfavourable to hydrofracture propagation. A necessary condition for a hydrofracture to propagate to the surface is that the stress field along its potential path is everywhere favourable to extension-fracture formation so that the probability of hydrofracture arrest is minimised. Mechanical layering and the resulting heterogeneous stress field largely control whether evolving hydrofractures become confined to single layers (strata¬bound frac¬tures or not (non-stratabound fractures and, there¬fore, if a vertically intercon¬nec¬ted fracture system forms. Non-stratabound hydrofractures may propagate through many layers and generate interconnected fracture systems. Such systems commonly reach the percolation threshold and largely control the overall permeability of the fluid reservoirs within which they develop.

  17. Knowing and Teaching Kinaesthetic Experience in Skateboarding: An Example of Sensory Emplacement

    Science.gov (United States)

    Bäckström, Åsa

    2014-01-01

    The body has become a vital research object in several disciplines in recent years. Indeed, in the social sciences and humanities, a corporeal turn in which embodiment has become a key concept related to learning and socialisation is discussed. This cross-disciplinary paper addresses the epistemological question of how we know what we know and…

  18. The Design and Development of a Robotically Emplaced Hand Packed Shaped Charge

    National Research Council Canada - National Science Library

    DeFisher, S; Baker, E; Wu, Yi; Wu, J; Richwald, A; Miller, G

    2006-01-01

    .... Army, in terms of both lives and materiel lost in the South West Asian (SWA) theater. The safe destruction of these types of devices is currently the responsibility of explosive ordnance disposal...

  19. Automated waste canister docking and emplacement using a sensor-based intelligent controller

    International Nuclear Information System (INIS)

    Drotning, W.D.

    1992-08-01

    A sensor-based intelligent control system is described that utilizes a multiple degree-of-freedom robotic system for the automated remote manipulation and precision docking of large payloads such as waste canisters. Computer vision and ultrasonic proximity sensing are used to control the automated precision docking of a large object with a passive target cavity. Real-time sensor processing and model-based analysis are used to control payload position to a precision of ± 0.5 millimeter

  20. Emplacement and deformation of the A-type Madeira granite (Amazonian Craton, Brazil)

    Science.gov (United States)

    Siachoque, Astrid; Salazar, Carlos Alejandro; Trindade, Ricardo

    2017-04-01

    The Madeira granite is one of the Paleoproterozoic (1.82 Ga) A-type granite intrusions in the Amazonian Craton. It is elongated in the NE-SW direction and is composed of four facies. Classical structural techniques and the anisotropy of magnetic susceptibility (AMS) method were applied to the study of its internal fabric. Magnetic susceptibility measurements, thermomagnetic curves, remanent coercivity spectra, optical microscopy and SEM (scanning electron microscopy) analyses were carried out on the earlier and later facies of the Madeira granite: the rapakivi granite (RG) and the albite granite (AG) respectively. The last one is subdivided into the border albite granite (BAG) and the core albite granite (CAG) subfacies. AMS fabric pattern is controlled by pure magnetite in all facies, despite significant amounts of hematite in the BAG subfacies. Microstructural observations show that in almost all sites, magnetic fabric correlates to magmatic state fabrics that are defined by a weak NE-SW orientation of mafic and felsic silicates. However, strain mechanisms in both subfacies of AG also exhibit evidence for solid-state deformation at high to moderate temperatures. Pegmatite dyke, strike slip fault (SFA-B-C), hydrothermal vein, normal fault (F1-2) and joint (J) structures were observed and their orientation and kinematics is consistent with the magmatic and solid-state structures. Dykes, SFA-C and F1, are usually orientated along the N70°E/40°N plane, which is nearly parallel to the strike of AMS and magmatic foliations. In contrast, veins, SFB, F2 and some J are oriented perpendicular to the N70°E trend. Kinematic analysis in these structures shows evidence for a dextral sense of movement in the system in the brittle regime. The coherent structural pattern for the three facies of Madeira granite suggests that the different facies form a nested pluton. The coherence in orientation and kinematics from magmatic to high-temperature solid-state, and into the brittle regime indicates the continuity in the stress regime from the last magmatic stages until the complete cooling of the pluton, likely along a NE-SW dextral corridor related to the regional deformation in the Uatumã-Anauá Domain of the Amazonian Craton.

  1. Occurrence and emplacement of chromite ores in Sindhudurg district, Maharashtra, India

    Digital Repository Service at National Institute of Oceanography (India)

    Iyer, S.D.; Babu, E.V.S.S.K.; Mislankar, P.G.; Gujar, A.R.; Ambre, N.V.; Loveson, V.J.

    and are associated with metamorphic and ultrabasic rocks, consist of octahedral grains of chromite, while clinochlore is present between the interstices of these grains. The Kankavali (janoli) and Wagda ores revealed a dominance of Cr sub(2) O sub(3) followed by Fe...

  2. Emplacement and geochemical evolution of eocene plutonic rocks in the Colville batholith

    International Nuclear Information System (INIS)

    Holder, R.W.

    1986-01-01

    Eocene plutonic rocks in the Colville batholith are divided on the basis of field evidence and chemical composition into, in order of decreasing age, (1) several calc-alkalic biotite-hornblende monzodiorite to granodiorite intrusions referred to as the Devils Elbow suite, and (2) compositionally variable calc-alkalic to alkali-calcic intrusions referred to as the Herron Creek suite. These Eocene suites are distinct from older, more voluminous, leucocratic granite and granodiorite intrusions, designated the Keller Butte suite, which are calcic and characteristically lack hornblende. Results of qualitative and computer modeling of major element variation and quantitative models of trace element variation in the chemically coherent Bridge Creek intrusions, a member of the Herron Creek suite, are compatible with fractionation of plagioclase feldspar + hornblende + biotite + magnetite + apatite from a parent magma of andesitic composition to account for the observed variation. Strongly curved variation trends preclude mixing as the primary mechanism for the observed variation. It is suggested that parallel variation trends in the other Eocene intrusions are also the result of crystal fractionation. Lateral chemical variations including a decrease in silica saturation suggest the chemical characteristics of these rocks reflect those of parental magmas derived from the mantle, with an unknown amount of crustal contribution. Rotated and angular xenoliths, discordant contacts, and temporal and spatial proximity to graben structures indicate that the Eocene plutons were passively implaced into the upper crust along graben-bounding faults during graben formation, the earlier stages of which appear to have been contemporaneous with regional mylonitic deformation

  3. Chemical implications for the presence of introduced materials in the post-emplacement environment

    International Nuclear Information System (INIS)

    Meike, A.

    1993-11-01

    This paper addresses our ability to predict the chemical consequences of the presence of introduced materials, many of them man-made, in a radioactive waste repository. The chemical modeling ability required to describe this environment over a 10,000 year period is unique and unprecedented. It requires knowledge of parameters that have never been measured, many of them with respect to introduced materials. This paper discusses considerations that are required to establish the potential significance of introduced materials, especially those that could compromise the lifetime of the waste packages or affect the transport of radionuclides from breached containers. The paper presents issues related to the stability of individual compounds, the potential alteration of predicted natural chemical reactions, the potential moderation of those effects by natural zeolites, and the potential for interactions at elevated temperatures between rock, water, water vapor, radiation, waste package, and introduced materials

  4. Emplacement of inflated Pāhoehoe flows in the Naude's Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement

    Science.gov (United States)

    Jay, Anne E.; Marsh, Julian S.; Fluteau, Frédéric; Courtillot, Vincent

    2018-02-01

    Physical volcanological features are presented for a 710-m-thick section, of the Naude's Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pāhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pāhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are `medial or distal to source' are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source.

  5. Experiments to determine the migration potential for water and contaminants in shallow land burial facilities design, emplacement, and preliminary results

    International Nuclear Information System (INIS)

    DePoorter, G.L.; Abeele, W.V.; Burton, B.W.

    1982-01-01

    Leaching and transport of radionuclides by water has been a primary mode of radioactive contamination from low-level radioactive waste disposal facilities. Similarly, the infiltration of water into nonradioactive hazardous waste disposal facilities has resulted in the movement of contaminants out of these disposal facilities. Although there have been many laboratory studies on water movement and contaminant transport, there is a need for more large scale field experiments. Large scale field experiments are necessary to (1) measure hydraulic conductivities on a scale typical of actual shallow land burial facilities and hazardous waste disposal facilities, (2) allow comparisons to be made between full scale and laboratory measurements, (3) verify the applicability of calculational methods for determining unsaturated hydraulic conductivities from water retention curves, and (4) for model validation. Experiments that will provide the information to do this are described in this paper

  6. Depositional features and stratigraphic sections in granitic plutons: implications for the emplacement and crystallization of granitic magma

    Science.gov (United States)

    Wiebe, R. A.; Collins, W. J.

    1998-09-01

    Many granitic plutons contain sheet-like masses of dioritic to gabbroic rocks or swarms of mafic to intermediate enclaves which represent the input of higher temperature, more mafic magma during crystallization of the granitic plutons. Small-scale structures associated with these bodies (e.g. load-cast and compaction features, silicic pipes extending from granitic layers into adjacent gabbroic sheets) indicate that the sheets and enclave swarms were deposited on a floor of the magma chamber (on granitic crystal mush and beneath crystal-poor magma) while the mafic magma was incompletely crystallized. These structures indicate 'way up', typically toward the interior of the intrusions, and appear to indicate that packages of mafic sheets and enclave concentrations in these plutons are a record of sequential deposition. Hence, these plutons preserve a stratigraphic history of events involved in the construction (filling, replenishment) and crystallization of the magma chamber. The distinctive features of these depositional portions of plutons allow them to be distinguished from sheeted intrusions, which usually preserve mutual intrusive contacts and 'dike-sill' relations of different magma types. The considerable thickness of material that can be interpreted as depositional, and the evidence for replenishment, suggest that magma chamber volumes at any one time were probably much less than the final size of the pluton. Thus, magma chambers may be constructed much more slowly than presently envisaged. The present steep attitudes of these structures in many plutons may have developed gradually as the floor of the chamber (along with the underlying solidified granite and country rock) sank during continuing episodes of magma chamber replenishment. These internal magmatic structures support recent suggestions that the room problem for granites could be largely accommodated by downward movement of country rock beneath the magma chamber.

  7. Formation of colloids from introduced materials in the post-emplacement environment: A report on the state of understanding

    International Nuclear Information System (INIS)

    Meike, A.; Wittwer, C.

    1993-09-01

    This literature review examines potential sources of colloids and enhanced adsorption that may stem from materials introduced into a repository setting, with a view towards prioritizing future studies. Three major sources of colloids are reviewed: metals, cements, and organics. Know chemical influences on colloid formation and mechanisms by which introduced materials may become involved are considered with respect to gradients, chemical species, pH, time, temperature, radiolysis, redox state, and microbial activity. Areas that have not been addressed but may have significant consequences in a repository setting are identified

  8. Geochemical and Geophysical Characteristics of the Balud Ophiolitic Complex (BOC, Masbate Island, Philippines: Implications for its Generation, Evolution and Emplacement

    Directory of Open Access Journals (Sweden)

    Pearlyn C. Manalo

    2015-01-01

    Full Text Available This paper presents the first field, geochemical and geophysical information on the recently recognized Early Cretaceous Balud Ophiolitic Complex (BOC in the island of Masbate in the Central Philippines. Mapping of the western limb of the island revealed that only the upper crustal section of the BOC is exposed in this area. Geochemically, the pillow basalts are characterized by transitional mid-oceanic ridge basalt-island arc tholeiitic compositions. Gravity surveys yielded low Bouguer anomaly values that are consistent with the highly dismembered nature of the BOC. Short wavelength, high amplitude magnetic anomalies registered across the study area are attributed to shallow magnetic sources. This is taken to support the model that the ophiolitic complex occurs as thin crustal slivers that are not deeply-rooted in the mantle. Comparing BOC with other ophiolites in the Central Philippines, such as those in the islands of Sibuyan, Leyte and Bohol, suggests the possibility of a common or contiguous source for similarly-aged and geochemically composed crust-mantle sequences in the region.

  9. The age and emplacement of obducted oceanic crust in the Urals from Sm-Nd and Rb-Sr systematics

    International Nuclear Information System (INIS)

    Edwards, R.L.; Wasserburg, G.J.

    1985-01-01

    The Urals contain a 2000 km belt of mafic-ultramafic bodies. The Sm-Nd and Rb-Sr systematics of two of these bodies, the Kempersai Massif in the South Ural Mountains and the Voykar-Syninsky Ophiolite Complex in the Polar Ural Mountains have been examined. These data confirm the hypothesis that these bodies represent fragments of pre-collision oceanic crust and establish constraints on the nature and timing of events in the Uralian Orogeny. Two Kempersai gabbros define Sm-Nd internal isochrons of 397 +- 20 My and 396 +- 33 My with epsilonsub(Nd)(T) = +8.7 -+ 0.6 and +8.4 -+ 1.3, respectively. Whole rock samples of pillow basalt, diabase, gabbros, troctolite, and a metasediment give Sm-Nd values which lie on this isochron indicating that these rocks are genetically related and have an igneous crystallization age of 397 My. Whole rock samples of Voykar-Syninsky diabase, gabbros, and clinopyroxenite give Sm-Nd values which lie on or within proportional 1 epsilon-unit of this isochron indicating an age and epsilonsub(Nd)(T) virtually identical to those of Kempersai. epsilonsub(Nd)(T) for the Kempersai and Voykar-Syninsky mafic samples range from +7.3 to +9.0 with an average value of +8.4. This indicates that the Urals ophiolites are derived from an ancient depleted mantle source and are most plausibly pieces of the oceanic crust and lithosphere. The fact that a metasediment has the same epsilonsub(Nd)(397 My) as the other samples indicates derivation from an oceanic source with negligible continental input. epsilonsub(Nd)(T) for the massifs is proportional 1.5 epsilon-units lower than the average for modern MORBs. (orig./HSI)

  10. Intense and widespread seismicity during the end-Triassic mass extinction due to emplacement of a large igneous province

    DEFF Research Database (Denmark)

    Lindström, Sofie; Pedersen, Gunver Krarup; Schootbrugge, Bas van de

    2015-01-01

    Multiple levels of earthquake-induced soft-sediment deformations (seismites) are concentrated in the end-Triassic mass extinction interval across Europe. The repetitive nature of the seismites rules out an origin by an extraterrestrial impact. Instead, this intense seismic activity is linked...

  11. Thermal history of Hawaiian pāhoehoe lava crusts at the glass transition: implications for flow rheology and emplacement

    Science.gov (United States)

    Gottsmann, Joachim; Harris, Andrew J. L.; Dingwell, Donald B.

    2004-12-01

    We have investigated the thermal history of glassy pāhoehoe crusts across their glass transition. Ten different samples obtained between 1993 and 2003 from the active flow field of the Pu'u 'O'o-Kupaianaha eruption on Hawaii (USA) have been analysed using relaxation geospeedometry. This method employs differential scanning calorimetry to quantify the enthalpic relaxation of the glass to monitor the natural time-temperature (t-T) path followed by the melt during cooling across its glass transition. Cooling rates across the glass transition interval (at 1000- 900 K) have been found to vary between 8 and 140 K/min. The associated glass transition temperatures are up to 400 K, lower than previously anticipated by others. Melt viscosities at the glass transition for these crusts range from 10 9.4 to 10 10.7 Pa s. We have compared the t-T paths quantified via relaxation geospeedometry with those obtained from direct measurements on the active flow field. The calorimetrically determined cooling rates are consistent with either simple cooling from eruption temperatures to temperatures below the glass transition or more complex cooling paths, including periods of reheating and short-term annealing within the glass transition interval. By quantifying the relaxation times associated with these contrasting cooling histories, we show that secondary vesiculation of pāhoehoe flow crusts may be favoured by complex, nonlinear t-T paths within the glass transition. These constraints also allow us to evaluate the time scales associated with the crystallisation and inflation of flow lobes at the glass transition for different pāhoehoe lava flow types. Our results provide important quantifications of rheological parameters at the lower temperature range of viscoelastic deformation in basaltic lava flows. As such, the results may be helpful in refining models for the generation of continental flood basalt flows, as well as models of basaltic lava flow propagation for hazard assessment at active volcanic areas.

  12. Constraining the Timing of Lobate Debris Apron Emplacement at Martian Mid-Latitudes Using a Numerical Model of Ice Flow

    Science.gov (United States)

    Parsons, R. A.; Nimmo, F.

    2010-03-01

    SHARAD observations constrain the thickness and dust content of lobate debris aprons (LDAs). Simulations of dust-free ice-sheet flow over a flat surface at 205 K for 10-100 m.y. give LDA lengths and thicknesses that are consistent with observations.

  13. Case study of a traditional material (adobe) for facilities design destined to X-ray equipment emplacement

    International Nuclear Information System (INIS)

    Aguilar Serrano, Lola

    2008-01-01

    The objective of this work is to use the existent material (adobe) in the national market as an alternative for an optimum design that counts with the conditions for radiological protection as well as an adequate infrastructure to service assistance. Therefore, it gives a tool of professional use for an X-ray installation design, because the adobes represent an adequate protection for employees as Worker occupational exposed (WOE) and for general public, also for economics reasons and construction technical aspects. With the study of above material is demonstrated that in X-ray facilities construction is not always necessary the use of lead sheets or another materials for walls, which are used as shielding elements against ionizing radiation. The adobe election for this study, is because Bolivia counts with a great percentage of constructed areas whit this type of material because is economical and raw material is accessible for users. From the experimental tests we get the graphics that allow to found the half value thickness (HVT) of the half layer (HVL) of this adobe, is that thickness of material with when placed in the path of the radiation will attenuate it to one half its original value. A tenth value thickness (TVT) similarly reduces the radiation to one tenth of its original value. Material which contains heavy atoms and molecules such as steel and lead provide the most effective (thinnest) shields for X-rays. The contribute of this study, carried out with the construction material (adobe) that exists in the national market will be of great utility for society because there is no values recorded in the bibliography. (author)

  14. Predicted peak temperature-rises around a high-level radioactive waste canister emplaced in the deep ocean bed

    International Nuclear Information System (INIS)

    Kipp, K.L.

    1978-06-01

    A simple mathematical model of heat conduction was used to evaluate the peak temperature-rise along the wall of a canister of high-level radioactive waste buried in deep ocean sediment. Three different amounts of vitrified waste, corresponding to standard Harvest, large Harvest, and AVM canisters, and three different waste loadings were studied. Peak temperature-rise was computed for the nine cases as a function of canister geometry and storage time between reprocessing and burial. Lower waste loadings or longer storage times than initially envisaged are necessary to prevent the peak temperature-rise from exceeding 200 0 C. The use of longer, thinner cylinders only modestly reduces the storage time for a given peak temperature. Effects of stacking of waste canisters and of close-packing were also studied. (author)

  15. Numerical studies of fluid and heat flow near high-level nuclear waste packages emplaced in partially saturated fractured tuff

    International Nuclear Information System (INIS)

    Pruess, K.; Tsang, Y.W.; Wang, J.S.Y.

    1984-11-01

    We have performed modeling studies on the simultaneous transport of heat, liquid water, vapor, and air in partially saturated fractured porous rock. Formation parameters were chosen as representative of the potential repository horizon in the Topopah Spring Unit of the Yucca Mountain tuffs. The presence of fractures makes the transport problem very complex, both in terms of flow geometry and physics. The numerical simulator ''TOUGH'' used for our flow calculations takes into account most of the physical effects which are important in multi-phase fluid and heat flow. It has provisions for handling the extreme non-linearities which arise in phase transitions, component disappearances, and capillary discontinuities at fracture faces. We model a region around an infinite linear string of nuclear waste canisters, taking into account both the discrete fractures and the porous matrix. From an analysis of the results obtained with explicit fractures, we develop equivalent continuum models which can reproduce the temperature, saturation, and pressure variation, and gas and liquid flow rates of the discrete fracture-porous matrix calculations. The equivalent continuum approach makes use of a generalized relative permeability concept to take into account the fracture effects. This results in a substantial simplification of the flow problem which makes larger scale modeling of complicated unsaturated fractured porous systems feasible. Potential applications for regional scale simulations and limitations of the continuum approach are discussed. 35 refs., 14 figs., 4 tabs

  16. Geochronology and magnetic fabrics of the Altenberg-Teplice granite porphyry: implications for emplacement style of a caldera ring dike

    Czech Academy of Sciences Publication Activity Database

    Tomek, Filip; Žák, J.; Svojtka, Martin

    2016-01-01

    Roč. 46 (2016), s. 39-40 E-ISSN 1434-7512. [Late Paleozoic magmatism in the Erzgebirge / Krušné hory: Magma genesis, tectonics, geophysics, and mineral deposits : abstracts. 11.11.2016-12.11.2016, Freiberg] Institutional support: RVO:67985831 Keywords : porphyry * magnetic fabrics * geochronology * Altenberg-Teplice Subject RIV: DB - Geology ; Mineralogy http://tu-freiberg.de/sites/default/files/media/institut-fuer-geologie-718/pdf/fog_volume_46.pdf

  17. Engineering feasibility for the fabrication and emplacement of cementitious repository materials: results from the EC-ESDRED project

    International Nuclear Information System (INIS)

    Alonso, Maria Cruz; Garcia-Sineriz, Jose Luis

    2012-01-01

    Maria Cruz Alonso of the Spanish National Research Council gave a presentation that summarised relevant findings on cementitious materials from the EC ESDRED (Engineering Studies and Demonstration of Repository Designs) Project. Concrete will be used for different purposes during the construction of geologic repositories for radioactive waste. These purposes include grouting, tunnel and drift lining, and tunnel plugging and sealing. Although some of the concrete may be removed before repository closure, a significant amount of concrete will remain in the repository. An important concern regarding the use of cementitious materials in geologic repositories for HLW and spent fuel is their interaction with the bentonite buffer, backfill material, and the host rock close to the repository near-field. For this reason, the ESDRED project has developed a low-pH concrete formulation as an alternative to standard ordinary Portland cement (OPC) concrete formulations with the aim of reducing the interaction of the cementitious materials with the near-field components. The main functional requirement required in the development of the low-pH material was a pore fluid pH < 11, which is considered acceptable for preventing or reducing the alteration of the bentonite EBS. Other functional requirements considered in the development of the low-pH concrete were: - Hydraulic conductivity. - Mechanical properties. - Durability. - Workability and pumpability. - Slumping. - Peak hydration temperature. - Thermal conductivity. - Use of organic components. - Use of other products. The development of the low-pH concrete involved laboratory work, as well as field testing at the Aespoe underground research laboratory (URL) in Sweden, and in the Grimsel URL and at the Hagerbach site in Switzerland. The ESDRED project demonstrated that low-pH cements can be formulated and used for production of concrete plugs and rock support. OPC can be used as the cement included in low-pH blends, but at least 55% of SiO 2 must be in the binder, or pozzolana additions above 40% have to be employed. However, uncertainties still remain with respect to the use of low-pH concrete, including its long-term performance and durability in contact with groundwaters, and associated with the risk of corrosion of carbon steel, which may be present in the form of reinforcement or fibres

  18. Thermal/fluid modeling of the response of saturated marine red clays to emplacement of nuclear waste

    International Nuclear Information System (INIS)

    McVey, D.F.; Gartling, D.K.; Russo, A.J.

    1980-01-01

    In this report, we discuss heat and mass transport in marine red clay sediments being considered as a nuclear waste isolation medium. Development of two computer codes, one to determine temperature and convective velocity fields, the other to analyze the nuclide migration problem, is discussed and preliminary results from the codes reviewed. The calculations indicate that for a maximum allowable sediment/canister temperature range of 200 0 C to 250 0 C, the sediment can absorb about 1.5 kW initial power from waste in a 3 m long by 0.3 m diameter canister. The resulting fluid displacement due to convection is found to be small, less than 1 m. The migration of four nuclides, 239 Pu, 137 Cs, 129 I and 99 Tc were computed for a canister buried 30 m deep in 60 m thick sediment. It was found that the 239 Pu and 137 Cs, which migrate as cations and have relatively high distribution coefficients, are essentially completely contained in the sediment. The anionic species, 129 I and 99 Tc, which have relatively low distribution coefficients, broke through the sediment in about 5000 years. The resultant peak injection rates which occur at about 15,000 years were extremely small (0.5 μCi/year for 129 I and 180 μCi/year for 99 Tc)

  19. Characterization of the acidic cold seep emplaced jarositic Golden Deposit, NWT, Canada, as an analogue for jarosite deposition on Mars

    Science.gov (United States)

    Battler, Melissa M.; Osinski, Gordon R.; Lim, Darlene S. S.; Davila, Alfonso F.; Michel, Frederick A.; Craig, Michael A.; Izawa, Matthew R. M.; Leoni, Lisa; Slater, Gregory F.; Fairén, Alberto G.; Preston, Louisa J.; Banerjee, Neil R.

    2013-06-01

    Surficial deposits of the OH-bearing iron sulfate mineral jarosite have been observed in several places on Mars, such as Meridiani Planum and Mawrth Vallis. The specific depositional conditions and mechanisms are not known, but by comparing martian sites to analogous locations on Earth, the conditions of formation and, thus, the martian depositional paleoenvironments may be postulated. Located in a cold semi-arid desert ˜100 km east of Norman Wells, Northwest Territories, Canada, the Golden Deposit (GD) is visible from the air as a brilliant golden-yellow patch of unvegetated soil, approximately 140 m × 50 m. The GD is underlain by permafrost and consists of yellow sediment, which is precipitating from seeps of acidic, iron-bearing groundwater. On the surface, the GD appears as a patchwork of raised polygons, with acidic waters flowing from seeps in troughs between polygonal islands. Although UV-Vis-NIR spectral analysis detects only jarosite, mineralogy, as determined by X-ray diffraction and inductively coupled plasma emission spectrometry, is predominantly natrojarosite and jarosite, with hydronium jarosite, goethite, quartz, clays, and small amounts of hematite. Water pH varies significantly over short distances depending on proximity to acid seeps, from 2.3 directly above seeps, to 5.7 several m downstream from seeps within the deposit, and up to 6.5 in ponds proximal to the deposit. Visual observations of microbial filament communities and phospholipid fatty acid analyses confirm that the GD is capable of supporting life for at least part of the year. Jarosite-bearing sediments extend beneath vegetation up to 70 m out from the deposit and are mixed with plant debris and minerals presumably weathered from bedrock and glacial till. This site is of particular interest because mineralogy (natrojarosite, jarosite, hematite, and goethite) and environmental conditions (permafrost and arid conditions) at the time of deposition are conceivably analogous to jarosite deposits on Mars. Most terrestrial analogues for Mars jarosites have been identified in temperate environments, where evaporation rates are very high and jarosites form along with other sulfates due to rapid evaporation (e.g. Rio Tinto, Spain; Western Australian acidic saline lake deposits). The GD is a rare example of an analogue site where jarosite precipitates under dominant freezing processes similar to those which could have prevailed on early Mars. Thus, the GD offers a new perspective on jarosite deposition by the upwelling of acidic waters through permafrost at Meridiani Planum and Mawrth Vallis, Mars. The GD also demonstrates that martian deposits may show considerably more chemical and mineral variability than indicated by the current remote sensing data sets.

  20. Lattice-preferred orientations of late-Variscan granitoids derived from neutron diffraction data: implications for magma emplacement mechanisms

    Czech Academy of Sciences Publication Activity Database

    Müller, A.; Leiss, B.; Ullemeyer, K.; Breiter, Karel

    2011-01-01

    Roč. 100, č. 7 (2011), s. 1515-1532 ISSN 1437-3254 Institutional research plan: CEZ:AV0Z30130516 Keywords : neutron diffraction * lattice-preferred orientation * shape-preferred orientation * magma tic flow * Podlesí granite * Meissen massif Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.342, year: 2011

  1. Multistage magma emplacement and progressive strain accumulation in the shallow-level Krkonose-Jizera plutonic complex, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Žák, J.; Verner, K.; Sláma, Jiří; Kachlík, V.; Chlupáčová, M.

    2013-01-01

    Roč. 32, č. 5 (2013), s. 1493-1512 ISSN 0278-7407 Institutional support: RVO:67985831 Keywords : strike-slip tectonics * magnetic-susceptibility * Central-Europe * SW Poland * Krkonose granite * Variscan belt * Northeastern Brazil * fabric development * Sierra-Nevada * shrimp zircon Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.994, year: 2013

  2. Structure, emplacement, and tectonic setting of Late Devonian granitoid plutons in the Teplá–Barrandian unit, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Žák, J.; Kratinová, Zuzana; Trubač, J.; Janoušek, V.; Sláma, Jiří; Mrlina, Jan

    2011-01-01

    Roč. 100, č. 7 (2011), s. 1477-1495 ISSN 1437-3254 R&D Projects: GA AV ČR KJB300120702 Institutional research plan: CEZ:AV0Z30120515; CEZ:AV0Z30130516 Keywords : Bohemian Massif * Teplá-Barrandian unit * Variscan orogeny * granite * pluton * subduction Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.342, year: 2011

  3. Thermal, chemical, and mass transport processes induced in abyssal sediments by the emplacement of nuclear wastes: Experimental and modelling results

    International Nuclear Information System (INIS)

    McVey, D.F.; Erickson, K.L.; Seyfried, W.E. Jr.

    1983-01-01

    In this chapter the authors discuss the current status of heat and mass transport studies in the marine red clay sediments that are being considered as a nuclear waste isolation medium and review analytical and experimental studies. Calculations based on numerical models indicate that for a maximum allowable sediment-canister interface temperatures of 200 0 to 250 0 C, the sediment can absorb about 1.5kW initial power from waste buried 30 m in the sediment in a canister that is 3 m long and 0.3 m in diameter. The resulting fluid displacement due to convections is found to be small, less than 1 m. Laboratory studies of the geochemical effects induced by heating sediment-seawater mixtures indicate that the canister and waste form should be designed to resist a hot, relatively acidic oxidizing environment. Since the thermally altered sediment volume of about 5.5 m/sup 3/ is small relative to the sediment volume overlying the canister, the acid and oxidizing conditions should significantly affect the properties of the far field only if thermodiffusional process (Soret effect) prove to be significant. If thermodiffusional effects are important, however, near-field chemistry will differ considerably from that predicted from results of constant temperature sediment-seawater interaction experiments

  4. Chemical and mineralogical concerns for the use of man-made materials in the post-emplacement environment

    International Nuclear Information System (INIS)

    Meike, A.

    1993-01-01

    In a radioactive waste repository, materials will be introduced for a variety of reasons. Some materials such as metals, bonding agents, and concrete will serve as active parts of the designed engineered barrier system (EBS). Other materials will be introduced to serve a number of purposes that include any or all of the following: surveillance (thermocouples, gauges), construction and operation (drilling rigs, roadbeds, exhaust fumes, chemical toilets, concrete, grout, rebar), lubrication (petroleum-based products, rope dressing) and other functions. Water chemistry will directly affect the corrosion of containers, the dissolution of spent fuel and waste glass and the concentration of dissolved or suspended radionuclides in water that exits breached containers. To predict the water quality requires a knowledge of the dissolution kinetics of the phases present in man-made materials, and the precipitation kinetics of product phases. The chemical evolution of man-made materials of interest to the Yucca Mountain project are by and large not presently known. Prediction of the long-term behavior (10,000 years) required of the modeling efforts is an additional layer of complexity that is not addressed by current models of water chemistry. Man-made modifications to the environment may significantly alter the thermal, chemical and radionuclide transportation attributes of the natural environment that are presently being considered in order to determine a waste package design. The specific chemical concerns addressed here are: solubility and stability of solid phases; liquid and gas phase stability; long term effects; radiolysis effects; colloids; and interactions between man-made material, rock, and J-13 or concentrated J-13 water. The report concludes with recommendations

  5. Modelling of surface stresses and fracturing during dyke emplacement: Application to the 2009 episode at Harrat Lunayyir, Saudi Arabia

    Science.gov (United States)

    Al Shehri, Azizah; Gudmundsson, Agust

    2018-05-01

    Correct interpretation of surface stresses and deformation or displacement during volcanotectonic episodes is of fundamental importance for hazard assessment and dyke-path forecasting. Here we present new general numerical models on the local stresses induced by arrested dykes. In the models, the crustal segments hosting the dyke vary greatly in mechanical properties, from uniform or non-layered (elastic half-spaces) to highly anisotropic (layers with strong contrast in Young's modulus). The shallow parts of active volcanoes and volcanic zones are normally highly anisotropic and some with open contacts. The numerical results show that, for a given surface deformation, non-layered (half-space) models underestimate the dyke overpressure/thickness needed and overestimate the likely depth to the tip of the dyke. Also, as the mechanical contrast between the layers increases, so does the stress dissipation and associated reduction in surface stresses (and associated fracturing). In the absence of open contacts, the distance between the two dyke-induced tensile and shear stress peaks (and fractures, if any) at the surface is roughly twice the depth to the tip of the dyke. The width of a graben, if it forms, should therefore be roughly twice the depth to the tip of the associated arrested dyke. When applied to the 2009 episode at Harrat Lunayyir, the main results are as follows. The entire 3-7 km wide fracture zone/graben formed during the episode is far too wide to have been generated by induced stresses of a single, arrested dyke. The eastern part of the zone/graben may have been generated by the inferred, arrested dyke, but the western zone primarily by regional extensional loading. The dyke tip was arrested at only a few hundred metres below the surface, the estimated thickness of the uppermost part of the dyke being between about 6 and 12 m. For the inferred dyke length (strike dimension) of about 14 km, this yields a dyke length/thickness ratio between 2400 and 1200, similar to commonly measured ratios of regional dykes in the field.

  6. The role of porosity in discriminating between tsunami and hurricane emplacement of boulders — A case study from the Lesser Antilles, southern Caribbean

    Science.gov (United States)

    Spiske, Michaela; Böröcz, Zoltán; Bahlburg, Heinrich

    2008-04-01

    Coastal boulder deposits are a consequence of high-energy wave impacts, such as storms, hurricanes or tsunami. Parameters useful for distinguishing between hurricane and tsunami origins include distance of a deposit from the coast, boulder weight and inferred wave height. In order to investigate the role of porosity on boulder transport and elucidate the distinction between tsunami and hurricane impacts, we performed Archimedean and optical 3D-profilometry measurements for the determination of accurate physical parameters for porous reef and coral limestone boulders from the islands of Aruba, Bonaire and Curaçao (ABC Islands, Netherlands Antilles, Leeward Islands). Subsets of different coral species and lithotypes constituting the boulders were sampled, the physical parameters of boulders were analyzed, and each boulder component was attributed to a certain range of porosity and density. Lowest porosities were observed in calcarenite (5-8%), whereas highest porosities were measured for serpulid reef rock (47-68%). Porous serpulid reef rock (0.8-1.2 g/cm 3) and the coral Diploria sp. (0.6-1.0 g/cm 3) possess the lowest bulk densities, while less porous calcarenite (2.0-2.7 g/cm 3) and the coral Montastrea cavernosa yield the highest bulk density values (1.6-2.7 g/cm 3). The obtained physical parameters were used to calculate boulder weights and both hurricane and tsunami wave heights necessary to initiate transport of these boulders. Boulders are up to 5.6 times lighter than given in previously published data, and hence required minimum hurricane or tsunami waves are lower than hitherto assumed. The calculated wave heights, the high frequency of tropical storms and hurricanes in the southern Caribbean and the occurrence of boulders exclusively on the windward sides of the islands, implicate that for boulders on the ABC Islands a hurricane origin is more likely than a tsunami origin.

  7. Discovery of Latest Cretaceous OIB-type alkaline gabbros in the Eastern Pontides Orogenic Belt, NE Turkey: Evidence for tectonic emplacement of seamounts

    Science.gov (United States)

    Eyuboglu, Yener; Dudas, Francis O.; Chatterjee, Nilanjan; Liu, Ze; Yılmaz-Değerli, Sedanur

    2018-06-01

    The Meso-Cenozoic geodynamic evolution of the Eastern Pontides Orogenic Belt, a mountain chain extending parallel to the southeastern margin of the Black Sea, has been controversial for the last forty years. Here we present data for a newly discovered alkaline gabbro body and its surrounding basaltic rocks in the northern part of the Eastern Pontides Orogenic Belt. We also provide a comprehensive assessment of the Late Mesozoic-Cenozoic geodynamic evolution of the Eastern Mediterranean region. The gabbroic body is bounded by reverse faults along its northern and southern borders and is surrounded by vesicular, pillow-fragment breccias and pillow basalts. Mineral compositions suggest that crystallization of the gabbros began at about 1170 °C, and the lowest preserved crystallization T is near 1000 °C. Estimated pressure at the beginning of crystallization is 5.7-7.4 kb. The 40Ar/39Ar dating of kaersutite and plagioclase and Usbnd Pb dating of titanite indicated that the Hayrat gabbro crystallized at 67 Ma (Late Maastrichtian). Whole rock major-trace-rare earth element and Sr-Nd-Pb isotope data indicate that the gabbros and basalts have different origins. The gabbros are alkaline and exhibit the geochemical features of OIB, whereas the basalts are tholeiitic and reveal depletions of HFSE that are similar to those of arc rocks. The gabbros are strongly fractionated, and derive from an enriched, lithospheric mantle source, with partial melting occurring in a garnet-stable environment. The basalts are less fractionated, and probably derive from a shallower source in which spinel peridotite was the predominant lithology. Considering all new and old geological, geochemical, geochronological and geophysical data from the Black Sea Basin and the Eastern Pontides-Lesser Caucasus-Alborz Orogenic Belt, we suggest that the alkaline Hayrat gabbro formed in an oceanic intraplate setting, and was accreted to the forearc region of the Eastern Pontides Orogenic Belt during southward subduction of Paleotethyan lithosphere. It was later tectonically juxtaposed with subaqueously erupted, arc-related basalts.

  8. Geodetic evidence for en echelon dike emplacement and concurrent slow slip during the June 2007 intrusion and eruption at Kīlauea volcano, Hawaii

    Science.gov (United States)

    Montgomery-Brown, E. K.; Sinnett, D.K.; Poland, M.; Segall, P.; Orr, T.; Zebker, H.; Miklius, Asta

    2010-01-01

    A series of complex events at Kīlauea Volcano, Hawaii, 17 June to 19 June 2007, began with an intrusion in the upper east rift zone (ERZ) and culminated with a small eruption (1500 m3). Surface deformation due to the intrusion was recorded in unprecedented detail by Global Positioning System (GPS) and tilt networks as well as interferometric synthetic aperture radar (InSAR) data acquired by the ENVISAT and ALOS satellites. A joint nonlinear inversion of GPS, tilt, and InSAR data yields a deflationary source beneath the summit caldera and an ENE-striking uniform-opening dislocation with ~2 m opening, a dip of ∼80° to the south, and extending from the surface to ~2 km depth. This simple model reasonably fits the overall pattern of deformation but significantly misfits data near the western end of an inferred dike-like source. Three more complex dike models are tested that allow for distributed opening including (1) a dike that follows the surface trace of the active rift zone, (2) a dike that follows the symmetry axis of InSAR deformation, and (3) two en echelon dike segments beneath mapped surface cracks and newly formed steaming areas. The en echelon dike model best fits near-field GPS and tilt data. Maximum opening of 2.4 m occurred on the eastern segment beneath the eruptive vent. Although this model represents the best fit to the ERZ data, it still fails to explain data from a coastal tiltmeter and GPS sites on Kīlauea's southwestern flank. The southwest flank GPS sites and the coastal tiltmeter exhibit deformation consistent with observations of previous slow slip events beneath Kīlauea's south flank, but inconsistent with observations of previous intrusions. Slow slip events at Kīlauea and elsewhere are thought to occur in a transition zone between locked and stably sliding zones of a fault. An inversion including slip on a basal decollement improves fit to these data and suggests a maximum of ~15 cm of seaward fault motion, comparable to previous slow-slip events.

  9. Constraints on the depth of generation and emplacement of a magmatic epidote-bearing quartz diorite pluton in the Coast Plutonic Complex, British Columbia

    Science.gov (United States)

    Chang, J.M.; Andronicos, C.L.

    2009-01-01

    Petrology and P-T estimates indicate that a magmatic epidote-bearing quartz diorite pluton from Mt. Gamsby, Coast Plutonic Complex, British Columbia, was sourced at pressures below ???1.4 GPa and cooled nearly isobarically at ???0.9 GPa. The P-T path indicates that the magma was within the stability field of magmatic epidote early and remained there upon final crystallization. The pluton formed and crystallized at depths greater than ???30 km. REE data indicate that garnet was absent in the melting region and did not fractionate during crystallization. This suggests that the crust was less than or equal to ???55 km thick at 188 Ma during the early phases of magmatism in the Coast Plutonic Complex. Late Cretaceous contractional deformation and early Tertiary extension exhumed the rocks to upper crustal levels. Textures of magmatic epidote and other magmatic phases, combined with REE data, can be important for constraining the P-T path followed by magmas. ?? 2009 Blackwell Publishing Ltd.

  10. A mathematical model for two-phase water, air, and heat flow around a linear heat source emplaced in a permeable medium

    International Nuclear Information System (INIS)

    Doughty, C.; Pruess, K.

    1991-03-01

    A semianalytical solution for transient two-phase water, air, and heat flow in a uniform porous medium surrounding a constant-strength linear heat source has been developed, using a similarity variable η=r/√t (r is radial distance, t is time). Although the similarity transformation requires a simplified radial geometry, all the physical mechanisms involved in two-phase fluid and heat flow may be taken into account in a rigorous way. The solution includes nonlinear thermophysical fluid and material properties, such as relative permeability and capillary pressure variations with saturation, and density and viscosity variations with temperature and pressure. The resulting governing equations form a set of coupled nonlinear ODEs, necessitating numerical integration. The solution has been applied to a partially saturated porous medium initially at a temperature well below the saturation temperature, which is the setting for the potential nuclear waste repository site at Yucca Mountain, Nevada. The resulting heat and fluid flows provide a stringent test of many of the capabilities of numerical simulation models, making the similarity solution a useful tool for model verification. Comparisons to date have shown excellent agreement between the TOUGH2 simulator and the similarity solution for a variety of conditions. 13 refs., 6 figs., 1 tab

  11. Effusive silicic volcanism in the Paraná Magmatic Province, South Brazil: Physico-chemical conditions of storage and eruption and considerations on the rheological behavior during emplacement

    Science.gov (United States)

    Polo, L. A.; Giordano, D.; Janasi, V. A.; Guimarães, L. F.

    2018-04-01

    Expressive occurrences of effusive deposits were identified in silicic units from the Paraná Magmatic Province outcropping in a key area in south Brazil where three units with different compositions occur (Caxias do Sul dacites, CSd, Barros Cassal andesites to dacites, BCs, and Santa Maria rhyolites, SMr). Textural and chemical characteristics of phenocrysts, microphenocrysts and microlites suggest that crystallization started in a shallow magma chamber and continued during ascent to the surface. These magmas had an unique character (e.g., very high temperatures 1000 °C and low H2O contents 1-2 wt%), and formed several types of deposits that are clearly indicative of locally fed lava flows and had physical properties consistent with this mode of eruption (e.g., viscosities as low as 104.2 Pa·s at ca. 1000 °C for the CSd). The very low estimated H2O contents are a consequence of their petrogenesis (i.e., fractionation from tholeiitic basalts plus assimilation of crustal melts from water-poor granitic sources), and was probably a key factor influencing the non-explosive nature of these deposits. The comparatively higher viscosity calculated for the Santa Maria rhyolite (> 1-2 orders of magnitude greater than CSd) would make it a better candidate to generate expressive pyroclastic deposits, but this might be offset by its remarkably low H2O contents (≤ 1 wt%) and low discharge ratios.

  12. Geochronology of the Sleeper deposit, Humboldt County, Nevada: epithermal gold-silver mineralization following emplacement of a silicic flow-dome complex

    Science.gov (United States)

    Conrad, J.E.; McKee, E.H.; Rytuba, J.J.; Nash, J.T.; Utterback, W.C.

    1993-01-01

    The high-grade gold-silver deposits at the Sleeper mine are low sulfidation, quartz-adularia-type epithermal deposits, formed during the final stages of igneous hydrothermal activity of a small middle Miocene silicic flow-dome complex in north-central Nevada. There were multiple pulses of alteration and mineralization but all occurred within a period of less than 2 m.y. Later supergene alteration formed opal and alunite about 5.4 Ma but produced no Au or Ag mineralization other than some remobilization to produce locally rich pockets of secondary Au and Ag enrichment and is unrelated to the older magmatic hydrothermal system. The Sleeper deposit in the northern part of the Great Basin is genetically related to bimodal volcanism that followed a long period of arc-related andesitic volcanism in the same general region. -from Authors

  13. Analysis of the wind influence on the aerodynamic drag in the case of a certain emplacement of the pantograph on the electric rail vehicles

    Directory of Open Access Journals (Sweden)

    Sorin ARSENE

    2015-03-01

    Full Text Available The wind gusts with high speed can negative affect the operation of the railway electric vehicles. These vehicles can achieve high performances, as long as the power supply is ensured, without discontinuities or interruptions in the process. This work aims at conducting an analysis regarding the wind influence with regard to the energy collector placed on the vehicle bodywork taking in account a certain positioning of the active pantograph. To this end, in a first step, the EP3 pantograph which was raised to its maximum working height was 3-D modeled. As regards the simulation, we consider the case in which the equipment is placed on the vehicle so that the angle formed by the articulation of the arms is pointing in the direction of the air flow. The simulation is carried out for different points of the angles ranging between [0o, 180o] at the relative velocity of the fluid of 0m / s, 10m / s, 20m / s and 30m / s.

  14. Thermal, chemical, and mass-transport processes induced in abyssal sediments by the emplacement of nuclear waste: experimental and modeling results

    International Nuclear Information System (INIS)

    McVey, D.F.; Erickson, K.L.; Seyfried, W.

    1980-01-01

    This paper discusses heat and mass transport studies of marine red clay sediments being considered as a nuclear waste isolation medium. Numerical models indicate that for a maximum allowable sediment/canister interface temperature of 200 to 250 0 C, the sediment can absorb about 1.5 kW initial power from waste in a 3 m long by 0.3 m dia canister buried 30 m in the sediment. Fluid displacement due to convection is found to be less than 1 m. Laboratory studies of the geochemical effects induced by heating sediment/seawater mixtures indicate that the canister and waste form must be designed to resist a hot, acid (pH 3 to 4) oxidizing environment. Since the thermally altered sediment volume of about 5.5 m 3 is small relative to the sediment volume overlying the canister, the acid and oxidizing conditions are not anticipated to effect the properties of the far field. Using sorption coefficient correlations, the migration of four nuclides 239 Pu, 137 Cs, 129 I, and 99 Tc were computer for a canister buried 30 m deep in a 60 m thick red clay sediment layer. It was found that the 239 Pu and 137 Cs are essentially completely contained in the sediments, while 129 I and 99 Tc broke through the 30 m of sediment in about 5000 years. The resultant peak injection rates of 4.6 x 10 -5 μCi/year-m 2 for 129 I and 1.6 x 10 -2 μCi/year-m 2 for 99 Tc were less than the natural radioactive flux of 226 Ra (3.5 to 8.8 x 10 -4 μCi/year-m 2 ) and 222 Rn

  15. Modeling approach to determine short- and long-term thermal and thermomechanical effects of waste emplacement in a repository in basalt

    International Nuclear Information System (INIS)

    Lehnhoff, T.F.; Thirumalai, K.; Krug, A.D.

    1982-01-01

    Basalt, in general, is characteristicaly a jointed and fractured rock. Preliminary field measurements to date, however, indicate that major portions of the deep basalt flows are highly impermeable to groundwater flow because of mineral infilling and large lithostatic pressure. For near-field considerations, the intraflow structures in jointed basalt have a governing influence on the rock mass-property parameters and their response to the repository environment. Much of the early work was done with closed-form solutions or boundary-element methods. These techniques are seen as the only reasonable and practical appraoch to scoping studies. The large number of parameter variations necessary for conceptual design of a repository preclude the initial application of elaborate and detailed finite-element methods. The thermomechanical analysis completed at the BWIP has progressed through much of the scoping phase and is now entering the detailed analysis and design phase in some areas. Methods for detailed analysis are being demonstrated and many uncertainties are being clarified. Final repository-design studies will warrant the special effort necessary to produce extensive finite-element analyses. The resulting finite-element models then permit analysis of design details and can expose various problem areas for inspection and final evaluation. Nonlinear effects of all types can be evaluated to determine if concerns exist as real problems. The detailed finite-element modeling will contribute to the basis for making rational correct decisions that will result in a safe repository in basalt for storing nuclear waste

  16. Experiments to determine the migration potential for water and contaminants in shallow land-burial facilities: design, emplacement, and preliminary results

    International Nuclear Information System (INIS)

    DePoorter, G.L.; Abeele, W.V.; Burton, B.W.

    1982-01-01

    Although there have been many laboratory studies on water movement and contaminant transport, there is a need for more large scale field experiments. Large scale field experiments are necessary to (1) measure hydraulic conductivities on a scale typical of actual shallow land burial facilities and hazardous waste disposal facilities, (2) allow comparisons to be made between full scale and laboratory measurements, (3) verify the applicability of calculational methods for determining unsaturated hydraulic conductivities from water retention curves, and (4) for model validation. Experiments that will provide the information to do this are described in this paper. The results of these experiments will have applications for both the shallow land burial of low level radioactive wastes and the disposal of hazardous chemical wastes. These experiments will provide results that can be used in model verification for system performance. This type of data on experiments done at this scale has not been available, and are necessary for validating unsaturated transport models and other models used to predict long term system performance. Even though these experiments are done on crushed Bandelier Tuff, most models use physical properties of the backfill material such as density, porosity, and water retention curves. For this reason, once the models are validated in these experiments, they can be applied with confidence to other materials as long as the material properties are well characterized. In addition, from known water movement rates, calculable from the results of these experiments, requirements for other parts of the system such as liners, water diversion systems, and system cap requirements can be determined. Lastly, the results of these experiments and their use in model verification will provide a sound scientific basis on which to base decisions on system requirements and system design

  17. Westinghouse Hanford Company plan for certifying newly generated contact-handled transuranic waste for emplacement in the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Lipinski, R.M.; Sheehan, J.S.

    1992-07-01

    Westinghouse Hanford Company (Westinghouse Hanford) currently manages an interim storage site for Westinghouse Hanford and non-Westinghouse Hanford-generated transuranic (TRU) waste and operates TRU waste generating facilities within the Hanford Site in Washington State. Approval has been received from the Waste Acceptance Criteria Certification Committee (WACCC) and Westinghouse Hanford TRU waste generating facilities to certify newly generated contact-handled TRU (CH-TRU) solid waste to meet the Waste Acceptance Criteria (WAC). This document describes the plan for certifying newly generated CH-TRU solid waste to meet the WAC requirements for storage at the Waste Isolation Pilot Plant (WIPP) site. Attached to this document are facility-specific certification plans for the Westinghouse Hanford TRU waste generators that have received WACCC approval. The certification plans describe operations that generate CH-TRU solid waste and the specific procedures by which these wastes will be certified and segregated from uncertified wastes at the generating facilities. All newly generated CH-TRU solid waste is being transferred to the Transuranic Storage and Assay Facility (TRUSAF) and/or a controlled storage facility. These facilities will store the waste until the certified TRU waste can be sent to the WIPP site and the non-certified TRU waste can be sent to the Waste Receiving and Processing Facility. All non-certifiable TRU waste will be segregated and clearly identified

  18. Neoproterozoic igneous complex emplaced along major tectonic boundary in the Kaoko Belt (NW Namibia): ion probe and LA-ICP-MS dating of magmatic and metamorphic zircons

    Czech Academy of Sciences Publication Activity Database

    Konopásek, J.; Košler, J.; Tajčmanová, L.; Ulrich, Stanislav; Kitt, S. L.

    2008-01-01

    Roč. 165, č. 1 (2008), s. 153-166 ISSN 0016-7649 Institutional research plan: CEZ:AV0Z30120515 Keywords : boundary igneous complex * Kaoko Belt * zircon Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.797, year: 2008

  19. Syn-tectonic emplacement of deep-marine reservoir sands at rifting margins : Including a case study from the Vøring Basin

    NARCIS (Netherlands)

    Athmer, W.

    2010-01-01

    This study focuses on the interplay between large-scale relay ramps and sedimentladen flows, specifically low-density turbidity currents that form one end-member of subaqueous sediment gravity flows. The main objective is to better understand the impact of syn-rift faulting on subaqueous sediment

  20. The quest for chron E23r at Partridge Island, bay of Fundy, Canada: CAMP emplacement postdates the end-Triassic extinction event at the North American craton

    NARCIS (Netherlands)

    Deenen, M.H.L.; Krijgsman, W.; Ruhl, M.

    2011-01-01

    The Partridge Island stratigraphic section at the Bay of Fundy, Maritime Canada, reveals a continental sedimentary succession with the end-Triassic mass extinction level closely followed by basalts of the Central Atlantic Magmatic Province (CAMP). New Paleomagnetic data show that a short reverse

  1. Tectonics and sedimentation during convergence of the ALCAPA and Tisza-Dacia continental blocks: The Pienide nappe emplacement and its foredeep (N. Romania)

    NARCIS (Netherlands)

    Tischler, M.; Matenco, L.C.; Filipescu, S.; Gröger, H.; Wetzel, A.; Fügenschuh, B.

    2008-01-01

    The juxtaposition of the ALCAPA and Tisza-Dacia continental blocks, although one of the key issues in the evolution of the Carpathians, is not well known in terms of associated effects on the sedimentary systems during frontal foreland development. Most of the Contact between ALCAPA and Tisza-Dacia

  2. How are the emplacement of rare-element pegmatites, regional metamorphism and magmatism interrelated in the Moldanubian domain of the Variscan Bohemian Massif, Czech Republic?

    Czech Academy of Sciences Publication Activity Database

    Melleton, J.; Gloaguen, E.; Frei, D.; Novák, M.; Breiter, Karel

    2012-01-01

    Roč. 50, č. 6 (2012), s. 1751-1773 ISSN 0008-4476 Institutional support: RVO:67985831 Keywords : LCT pegmatite * rare-element-enriched magma * columbite-tantalite * LA-SF-ICP-MS dating * Variscan orogeny * Bohemian Massif * Moldanubian domain * Bohemian Massif (Czech Republic) Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.180, year: 2012

  3. Vehicle Detection in Emplaced Sensor Fields: A User’s Guide to a Simulation Model and a Track-Identification Algorithm

    Science.gov (United States)

    1973-01-01

    KCNOT NRTRUK* NRTJC , NBRTRK* NENI ) , NSIZ3 ,CHKA 100 5 NSNS 9 RETA , IWCNT , NSENSR, MSFNS 9 CSENS ,CHKA 110 NO, NB9 1 9 NTRAJC, LSTCNV9 WCAP, NqARAY...CELL COVI. 760 N aN + I COVI 770 If (N .GT. NENI ’, N a 1 CUVI 7RO 18(IK) 0 N COVI 790 c CDVI 791 C**** THIS SECTION T’STS TO SEE IF THIS NEW WINDOW NOW...TMELST9 TSHAR , UPW.\\j0 9 14 VALO 110 3 WL14TM, W0PTM , IK o 9EGTME, FINTME, NRGEN , VALn 120 4 NCNDT 9 NRTROK, NRTJC 9 NH4RTRK, NENI ) , NSIz3 ,VALO 130

  4. Surface morphology of caldera-forming eruption deposits revealed by lidar mapping of Crater Lake National Park, Oregon- Implications for emplacement and surface modification

    Science.gov (United States)

    Robinson, Joel E.; Bacon, Charles R.; Major, Jon J.; Wright, Heather M.; Vallance, James W.

    2017-01-01

    Large explosive eruptions of silicic magma can produce widespread pumice fall, extensive ignimbrite sheets, and collapse calderas. The surfaces of voluminous ignimbrites are rarely preserved or documented because most terrestrial examples are heavily vegetated, or severely modified by post-depositional processes. Much research addresses the internal sedimentary characteristics, flow processes, and depositional mechanisms of ignimbrites, however, surface features of ignimbrites are less well documented and understood, except for comparatively small-volume deposits of historical eruptions. The ~7,700 calendar year B.P. climactic eruption of Mount Mazama, USA vented ~50 km3 of magma, deposited first as rhyodacite pumice fall and then as a zoned rhyodacite-to-andesite ignimbrite as Crater Lake caldera collapsed. Lidar collected during summer 2010 reveals the remarkably well-preserved surface of the Mazama ignimbrite and related deposits surrounding Crater Lake caldera in unprecedented detail despite forest cover. The ±1 m lateral and ±4 cm vertical resolution lidar allows surface morphologies to be classified. Surface morphologies are created by internal depositional processes and can point to the processes at work when pyroclastic flows come to rest. We describe nine surface features including furrow-ridge sets and wedge-shaped mounds in pumice fall eroded by high-energy pyroclastic surges, flow- parallel ridges that record the passage of multiple pyroclastic flows, perched benches of marginal deposits stranded by more-mobile pyroclastic-flow cores, hummocks of dense clasts interpreted as lag deposit, transverse ridges that mark the compression and imbrication of flows as they came to rest, scarps indicating ignimbrite remobilization, fields of pit craters caused by phreatic explosions, fractures and cracks caused by extensional processes resulting from ignimbrite volume loss, and stream channels eroded in the newly formed surface. The nine morphologies presented here illustrate a dynamic depositional environment that varied spatially and with time during the eruption, and show that multiple processes modified the ignimbrite after deposition, both during and after the eruption.

  5. Lunar floor-fractured craters as magmatic intrusions: Geometry, modes of emplacement, associated tectonic and volcanic features, and implications for gravity anomalies

    Science.gov (United States)

    Jozwiak, Lauren M.; Head, James W.; Wilson, Lionel

    2015-03-01

    Lunar floor-fractured craters are a class of 170 lunar craters with anomalously shallow, fractured floors. Two end-member processes have been proposed for the floor formation: viscous relaxation, and subcrater magmatic intrusion and sill formation. Recent morphometric analysis with new Lunar Reconnaissance Orbiter Laser Altimeter (LOLA) and image (LROC) data supports an origin related to shallow magmatic intrusion and uplift. We find that the distribution and characteristics of the FFC population correlates strongly with crustal thickness and the predicted frequency distribution of overpressurization values of magmatic dikes. For a typical nearside lunar crustal thickness, dikes with high overpressurization values favor surface effusive eruptions, medium values favor intrusion and sill formation, and low values favor formation of solidified dikes concentrated lower in the crust. We develop a model for this process, make predictions for the morphologic, morphometric, volcanic, and geophysical consequences of the process and then compare these predictions with the population of observed floor-fractured craters. In our model, the process of magmatic intrusion and sill formation begins when a dike propagates vertically towards the surface; as the dike encounters the underdense brecciated region beneath the crater, the magmatic driving pressure is insufficient to continue vertical propagation, but pressure in the stalled dike exceeds the local lithostatic pressure. The dike then begins to propagate laterally forming a sill which does not propagate past the crater floor region because increased overburden pressure from the crater wall and rim crest pinch off the dike at this boundary; the sill then continues to inflate, further raising and fracturing the brittle crater floor. When the intrusion diameter to intrusion depth ratio is smaller than a critical value, the intrusion assumes a laccolith shape with a domed central region. When the ratio exceeds a critical value, the intrusion concentrates bending primarily at the periphery, resulting in a flat, tabular intrusion. We predict that this process will result in concentric fractures over the region of greatest bending. This location is close to the crater wall in large, flat-floored craters, as observed in the crater Humboldt, and interior to the crater over the domed floor in smaller craters, as observed in the crater Vitello. A variety of volcanic features are predicted to be associated with the solidification and degassing of the intrusion; these include: (1) surface lava flows associated with concentric fractures (e.g., in the crater Humboldt); (2) vents with no associated pyroclastic material, from the deflation of under-pressurized magmatic foam (e.g., the crater Damoiseau); and (3) vents with associated pyroclastic deposits from vulcanian eruptions of highly pressurized magmatic foam (e.g., the crater Alphonsus). The intrusion of basaltic magma beneath the crater is predicted to contribute a positive component to the Bouguer gravity anomaly; we assess the predicted Bouguer anomalies associated with FFCs and outline a process for their future interpretation. We conclude that our proposed mechanism serves as a viable formation process for FFCs and accurately predicts numerous morphologic, morphometric, and geophysical features associated with FFCs. These predictions can be further tested using GRAIL (Gravity Recovery and Interior Laboratory) data.

  6. Intrusive hyaloclastite and peperitic breccias associated to sill and cryptodome emplacement on an Early Paleocene polymagmatic compound cone-dome volcanic complex from El Guanaco mine, Northern Chile

    Science.gov (United States)

    Páez, G. N.; Permuy Vidal, C.; Galina, M.; López, L.; Jovic, S. M.; Guido, D. M.

    2018-04-01

    This work explores the textural characteristics, morphology and facies architecture of well-preserved Paleocene hyaloclastic and peperitic breccias associated with subvolcanic intrusions at El Guanaco gold mine (Northern Chile). The El Guanaco mine volcanic sequence is part of a polymagmatic compound cone-dome volcanic complex grouping several dacitic domes and maar-diatremes, and subordinated subvolcanic intrusions of basaltic, andesitic and dacitic compositions. The Soledad-Peñafiel Fault System is a first order regional structure controlling the location and style of the volcanism in the region. Three different intrusive bodies (Basaltic sills, Dacitic cryptodomes and Andesitic cryptodomes) were found to intrude into a wet and poorly consolidated pyroclastic sequence representing the upper portions of a maar-diatreme. Consequently, extensive quench fragmentation and fluidization along their contacts occurred, leading to the formation of widespread breccia bodies enclosing a coherent nucleus. Differences in matrix composition allows to define two main breccias types: 1) poorly-sorted monomictic breccias (intrusive hyaloclastites) and 2) poorly-sorted tuff-matrix breccias (peperites). The observed facies architecture is interpreted as the result of the interplay of several factors, including: 1) magma viscosity, 2) the geometry of the intrusives, and 3) variations on the consolidation degree of the host rocks. Additionally, the overall geometry of each intrusive is interpreted to be controlled by the effective viscosity of the magmas along with the available magma volume at the time of the intrusions. The presence of three compositionally different subvolcanic bodies with intrusive hyaloclastite and peperite envelopes indicate, not only that all these intrusions occurred in a short period of time (probably less than 2-3 Ma), but also that the volcaniciclastic pile suffer little or none compaction nor consolidation during that time. The presence of three compositionally variated synvolcanic intrusives can be explained either by the presence of a zoned magmatic chamber feeding the volcanic complex, or more likely by the influence of the Soledad-Peñafiel Fault Zone acting as a preferential pathway for different magma compositions/sources to rise to the surface.

  7. Kimberlite emplacement time and duration of kimberlite magmatism in the Zimnii Bereg diamond-diferrous district, Arkhangelsk Region: Rb-Sr age of kimberlite sills, Mela River

    International Nuclear Information System (INIS)

    Pervov, V.A.; Larchenko, V.A.; Minchenko, G.V.; Stepanov, V.P.; Bogomolov, E.S.; Levskij, L.K.; Sergeev, S.A.

    2006-01-01

    The Rb-Sr isotope data for kimberlites and carbonate-rich sills of the Mela River were obtained for identifying the age and duration of magmatism in the Zimnii Bereg district of the Archangelsk region. It is shown that estimated age of the kimberlite (366.4 mln. years) falls in the age range corresponding to the main phase of alkaline magmatism in the Kola Peninsula (410-362 mln. years) [ru

  8. Micron-Size Zero-Valent Iron Emplacement in Porous Media Using Polymer Additives: Column and Flow Cell Ex-periments

    Energy Technology Data Exchange (ETDEWEB)

    Oostrom, Mart; Wietsma, Thomas W.; Covert, Matthew A.; Vermeul, Vince R.

    2006-03-20

    At the Hanford Site, an extensive In Situ Redox Manipulation (ISRM) permeable reactive barrier was installed to prevent chromate from reaching the Columbia River. However, chromium has been detected in several wells, indicating a premature loss of the reductive capacity in the aquifer. Laboratory experiments have been conducted to investigate whether barrier reductive capacity can be enhanced by adding micron-scale zero-valent iron to the high-permeability zones within the aquifer using shear-thinning fluids containing polymers. Porous media were packed in a wedge-shaped flow cell to create either a heterogeneous layered system with a high-permeability zone between two low-permeability zones or a high-permeability channel sur-rounded by low-permeability materials. The injection flow rate, polymer type, polymer concentration, and injected pore volumes were determined based on preliminary short- and long-column experiments. The flow cell experiments indicated that iron concentration enhancements of at least 0.6% (w/w) could be obtained using moderate flow rates and injection of 30 pore volumes. The 0.6% amended Fe0 concentration would provide approximately 20 times the average reductive capacity that is provided by the dithionite-reduced iron in the ISRM barrier. Calculations show that a 1-m-long Fe0 amended zone with an average concentration of 0.6% w/w iron subject to a groundwater velocity of 1 m/day will have an estimated longevity of 7.2 years.

  9. A feasibility study of the disposal of radioactive waste in deep ocean sediments by drilled emplacement: 1. A review of alternatives

    International Nuclear Information System (INIS)

    1983-01-01

    This report describes the first stage of an engineering study of the disposal of high level radioactive waste in holes formed deep in the ocean floor. In this phase, the emphasis has been on establishing reference criteria, assessing the problems and evaluating potential solutions. The report concludes that there are no aspects that appear technically infeasible, but questions of safety and reliability of certain aspects require further investigation. (author)

  10. Layered/Pancake-like Ejecta on Ceres: Inferring the Composition and Mechanical Properties of the Cerean Surface through Modeling of Ejecta Emplacement

    Science.gov (United States)

    Hughson, K.; Russell, C. T.; Schmidt, B. E.; Chilton, H.; Scully, J. E. C.; Sizemore, H. G.; Byrne, S.; Platz, T.; Raymond, C. A.

    2017-12-01

    During the Survey, High Altitude Mapping Orbit, and Low Altitude Mapping Orbit phases of the primary mission Dawn's Framing Camera observed a multitude of globally distributed lobate deposits. These flows were broadly interpreted as either similar to ice-cored/ice-cemented flows (Type 1 flows) on Earth and Mars, long run-out terrestrial or martian landslides (Type 2 flows), or highly mobile fluidized ejecta-like deposits (Type 3 flows) (Buczckowski et al., 2016; Schmidt et al., 2017). The Type 3 flows are morphologically similar to layered/pancake ejecta found on Mars and Ganymede where they are thought to be caused by impacts into ground ice rich substrates (Mouginis-Mark, 1979; Boyce et al., 2010). We assess the effects of target material strength, sliding friction, and vapor entrainment on the production of these features by comparing the ejecta mobility (EM: the ratio of the radius of the ejecta blanket to the radius of the parent crater) values for all Type 3 cerean flows to a ballistic/kinematic sliding model similar to the one developed by Weiss et al. (2014) to model EM for impacts into a variety of ground ice rich substrates of differing volatile content on Mars. Initial results suggest that, in order for these features to form, the cerean surface requires a large coefficient of sliding friction (>0.1), and that significant amounts of water be vaporized during impact. However, the model does not tightly constrain the strength of the target material (best-fit values range from granite-like to unconsolidated-sand-like). These results are consistent with a largely dry, rough, and thin surface layer underlain by material rich in pore-filling ground ice, even at low latitudes. Additionally, before the Fall Meeting we will attempt to constrain the thickness of the ice-poor surface layer. This will be done through a combined analysis of model results and morphometric parameters of individual Type 3 flows. Future implementation of this model will further incorporate compositional and geophysical knowledge attained from Dawn in order to better constrain the strength of the cerean surface.

  11. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, horizontal emplacement mode: Volume 2

    International Nuclear Information System (INIS)

    1987-12-01

    Chapter 6 discusses the repository design features and operating procedures that will be used to ensure compliance with regulatory limits for preclosure releases, performance objectives for waste retrieval, and performance objectives for post closure or long-term waste isolation. Chapter 7 discusses the analyses that were conducted in developing the repository design and the impacts of various external factors on the design of repository elements and the repository as a whole. These discussions are divided into preclosure design analysis, post closure design analysis, and engineering analysis of design. Also discussed are the structures, systems, and components that have been identified as important to safety and the barriers that have been, or need to be, identified as important to waste isolation. Chapter 8 discusses the engineering design information needs that were identified during conceptual design as necessary to advance the current conceptual design to Licence Application Design. These information needs should be resolved during the site characterization program or by other technology development studies. The discussion of these design issues and data needs is arranged according to the major elements of the repository. Chapter describes the quality assurance program. 146 refs., 40 figs., 22 tabs

  12. Site characterization plan conceptual design report for a high-level nuclear waste repository in salt, vertical emplacement mode: Volume 2

    International Nuclear Information System (INIS)

    1987-12-01

    Chapter 6 discusses the repository design features and operating procedures that will be used to ensure compliance with regulatory limits for preclosure releases, performance objectives for waste retrieval, and performance objectives for postclosure or long-term waste isolation. Chapter 7 discusses the analyses that were conducted in developing the repository design and the impacts of various external factors on the design of repository elements and the repository as a whole. Chapter 8 discusses the engineering design information needs that were identified during conceptual design as necessary to advance the current conceptual design to License Application Design (LAD). The quality assurance (QA) program applicable to the Architect/Engineer (A/E) activities during the repository conceptual design effort is defined in Chapter 9. 146 refs., 44 figs., 21 tabs

  13. Pressure-induced brine migration in consolidated salt in a repository

    International Nuclear Information System (INIS)

    Hwang, Y.; Chambre, P.L.; Lee, W.W.L.; Pigford, T.H.

    1987-06-01

    This report describes a mathematical model for brine migration through intact salt near a radioactive waste package emplaced in salt. Solutions indicate limited movement following ten years emplacement

  14. Lu-Hf isotope constraints on plume-lithosphere interaction during emplacement of the Bushveld Large Igneous Province at 2.06 Ga: Implications for the structure and evolution of the Kaapvaal Craton's lithospheric mantle

    Science.gov (United States)

    Zirakparvar, N. A.; Mathez, E. A.; Rajesh, H.; Vervoort, J. D.; Choe, S.

    2016-12-01

    The Bushveld Large Igneous Province (B-LIP) comprises a diverse array of >30 magma bodies that intruded the Kaapvaal Craton at 2.06 Ga. In this talk we use zircon and bulk-rock Lu-Hf isotope data to show that the B-LIP formed in response to the arrival of a plume(s) from the deep mantle. New zircon Hf isotope compositions for four B-LIP bodies yield intrusion-specific average ɛHf (2.06 Ga) values that range from -20.7 ± 2.8 to -2.7 ± 2.8, largely consistent with literature zircon data for other B-LIP intrusions. Bulk-rock solution ɛHf (2.06 Ga) values for a variety of B-LIP intrusions range from -2.1 ± 0.2 to -10.6 ± 0.2. Because the most radiogenic Hf isotope compositions across the entire B-LIP are nearly primordial with an ɛHf (2.06 Ga) close to 0, it is likely that the heat source of the B-LIP was a plume(s) from deep mantle. The Hf isotope data further suggests that individual intrusions in the B-LIP can be grouped into four categories based on their ultimate sources: 1) melts generated in subduction and plume modified continental lithospheric mantle; 2) melts generated by melting of a mafic-ultramafic reservoir composed of older ( 2.7 Ga) plume-related material trapped in the Kaapvaal lithosphere; 3) melts generated in the mid- to upper crust; and 4) melts generated from the 2.06 Ga mantle plume itself. The presence of 2.7 Ga mafic-ultramafic material in the Kaapvaal lithosphere may have acted to strengthen the lithosphere so that it was able to resist being dispered by the arrival of the B-LIP plume at 2.06 Ga. Because the B-LIP extends into a 2.7 Ga aged suture zone between the Kaapvaal and Zimbabwe cratons, it is also possible to understand the role of the lithospheric mantle in producing the Lu-Hf signatures observed in the various B-LIP intrusions as a function of two different types of the continental lithosphere: The very old lithosphere comprising the Kaapvaal Craton and the somewhat younger lithosphere comprising the suture zone. A basic observation is that the Hf isotope signature of the plume source is only directly expressed in B-LIP bodies that intruded the suture zone, providing further evidence that the craton was already underlain by thick lithospheric mantle at the time of B-LIP magmatism.

  15. The disposal of Canada's nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. Volume 5: radiological assessment

    International Nuclear Information System (INIS)

    Goodwin, B.W.; Andres, T.H.; Hajas, W.C.

    1996-06-01

    The concept for disposal of Canada's nuclear fuel waste involves isolating the waste in long-lived containers placed in a sealed vault at a depth of 500 to 1000 m in plutonic rock of the Canadian Shield. The concept permits a choice of methods, materials, sites and designs. The engineered system would be designed for the geological conditions of the disposal site. The technical feasibility of the disposal concept, and its impact on the environment and human health, have been presented in an Environmental Impact Statement (EIS) (AECL 1994a,b), supported by nine primary references (Davis et al. 1993; Davison et al. 1994a,b; Goodwin et al. 1994; Greber et al. 1994; Grondin et al. 1994; Johnson et al. 1994a,b; Simmons and Baumgartner 1994). In this report, we evaluate the long-term safety of a second hypothetical implementation of the concept that has several notable differences in site and design features compared to the EIS case study. We assume that the containers are constructed from copper, that they are placed within the disposal rooms, and that the vault is located in a more permeable rock domain. In this study, we consider the groundwater transport scenario and the radionuclides expected to be the most important contributors to dose and radiological risk. We use a prototype systems assessment code, comprising the SYVAC3 executive (the third generation of the SYstems Variability Analysis Code) and models representing the vault, geosphere and biosphere. We have not dealt with other, less likely scenarios, other radionuclides, chemically toxic elements, and some aspects of software quality assurance. The present study provides evidence that the second hypothetical implementation of the disposal concept would meet the radiological risk criterion established by the Atomic Energy Control Board by about an order of magnitude. The study illustrates the flexibility for designing engineered barriers to accommodate a permeable host-rock condition in which advection is the dominant contaminant transport process. (author). 63 refs., 9 tabs., 27 figs

  16. Paleomagnetic and chronostratigraphic constraints on the Middle to Late Miocene evolution of the Transylvanian Basin (Romania): Implications for Central Paratethys stratigraphy and emplacement of the Tisza-Dacia plate

    NARCIS (Netherlands)

    Leeuw, A. de; Filipescu, S.; Matenco, L.C.; Krijgsman, W.; Kuiper, K.; Stoica, M.

    2012-01-01

    From the Oligocene onwards, the complex tectonic evolution of the Africa–Eurasia collision zone led to paleogeographic and biogeographic differentiation of the Mediterranean and Paratethys, two almost land-locked seas, in the area formerly occupied by the western Tethys Ocean. Episodic isolation of

  17. Paleomagnetic and chronostratigraphic constraints on the middle to late miocene evolution of the transylvanian basin (Romania) : Implications for central paratethys stratigraphy and emplacement of the tisza-dacia plate

    NARCIS (Netherlands)

    De Leeuw, Arjan; Filipescu, Sorin; Maţenco, Liviu; Krijgsman, Wout; Kuiper, Klaudia; Stoica, Marius

    2013-01-01

    From the Oligocene onwards, the complex tectonic evolution of the Africa-Eurasia collision zone led to paleogeographic and biogeographic differentiation of theMediterranean and Paratethys, two almost land-locked seas, in the area formerly occupied by the western Tethys Ocean. Episodic isolation of

  18. The disposal of Canada's nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. Volume 4: biosphere model

    International Nuclear Information System (INIS)

    Zach, R.; Amiro, B.D.; Bird, G.A.; Macdonald, C.R.; Sheppard, M.I.; Sheppard, S.C.; Szekely, J.G.

    1996-06-01

    AECL (Atomic Energy of Canada Limited) has developed a disposal concept for Canada's nuclear fuel waste, which calls for a vault deep in plutonic rock of the Canadian Shield. The concept has been fully, documented in an environmental impact statement (EIS) for review by a panel under the Canadian Environmental Assessment Agency. The EIS includes the results of the EIS postclosure assessment case study to address the long term safety of the disposal concept. To more fully demonstrate the flexibility of the disposal concept and our assessment methodology, we are now carrying out another postclosure assessment study, which involves different assumptions and engineering options than those used in the EIS. In response to these changes, we have updated the BIOTRAC (BIOsphere Transport and Assessment Code) model developed for the EIS postclosure assessment case study. The main changes made to the BIOTRAC model are the inclusion of 36 Cl, 137 Cs, 239 Np and 243 Am; animals inhalation pathway; International Commission on Radiological Protection 60/61 human internal dose conversion factors; all the postclosure assessment nuclides in the dose calculations for non-human biota; and groundwater dose limits for 14 C, 16 C1 and 129 I for non-human biota to parallel these limits for humans. We have also reviewed and changed several parameter values, including evasion rates of gaseous nuclides from soil and release fractions of various nuclides from domestic water, and indicated changes that affect the geosphere/biosphere interface model. These changes make the BIOTRAC model more flexible. As a result of all of these changes, the BIOTRAC model has been significantly expanded and improved, although the changes do not greatly affect model predictions. The modified model for the present study is called BIOTRAC2 (BIOTRAC - Version 2). The full documentation of the BIOTRAC2 model includes the report by Davis et al. (1993a) and this report. (author). 105 refs., 13 tabs., 8 figs

  19. The disposal of Canada`s nuclear fuel waste: a study of postclosure safety of in-room emplacement of used CANDU fuel in copper containers in permeable plutonic rock. Volume 4: biosphere model

    Energy Technology Data Exchange (ETDEWEB)

    Zach, R; Amiro, B D; Bird, G A; Macdonald, C R; Sheppard, M I; Sheppard, S C; Szekely, J G

    1996-06-01

    AECL (Atomic Energy of Canada Limited) has developed a disposal concept for Canada`s nuclear fuel waste, which calls for a vault deep in plutonic rock of the Canadian Shield. The concept has been fully, documented in an environmental impact statement (EIS) for review by a panel under the Canadian Environmental Assessment Agency. The EIS includes the results of the EIS postclosure assessment case study to address the long term safety of the disposal concept. To more fully demonstrate the flexibility of the disposal concept and our assessment methodology, we are now carrying out another postclosure assessment study, which involves different assumptions and engineering options than those used in the EIS. In response to these changes, we have updated the BIOTRAC (BIOsphere Transport and Assessment Code) model developed for the EIS postclosure assessment case study. The main changes made to the BIOTRAC model are the inclusion of {sup 36}Cl, {sup 137}Cs, {sup 239}Np and {sup 243}Am; animals inhalation pathway; International Commission on Radiological Protection 60/61 human internal dose conversion factors; all the postclosure assessment nuclides in the dose calculations for non-human biota; and groundwater dose limits for {sup 14}C, {sup 16}C1 and {sup 129}I for non-human biota to parallel these limits for humans. We have also reviewed and changed several parameter values, including evasion rates of gaseous nuclides from soil and release fractions of various nuclides from domestic water, and indicated changes that affect the geosphere/biosphere interface model. These changes make the BIOTRAC model more flexible. As a result of all of these changes, the BIOTRAC model has been significantly expanded and improved, although the changes do not greatly affect model predictions. The modified model for the present study is called BIOTRAC2 (BIOTRAC - Version 2). The full documentation of the BIOTRAC2 model includes the report by Davis et al. (1993a) and this report. (author). 105 refs., 13 tabs., 8 figs.

  20. Basal Ottawa Limestone, Chattanooga Shale, Floyd Shale, Porters Creek Clay, and Yazoo Clay in parts of Alabama, Mississippi and Tennessee as potential host rocks for underground emplacement of waste

    International Nuclear Information System (INIS)

    Mellen, F.F.

    1976-01-01

    Impermeable rock units, preferably at least 500 feet thick and lying 1000 to 3000 feet below land surface, were sought in the region consisting roughly of the western 3 / 5 ths of Tennessee and the northern 3 / 5 ths of Alabama and Mississippi. All rock sequences, Cambrian through Eocene, were examined in varying detail, except the Cretaceous Selma Chalk and except the diapiric salt. These rocks were studied for their relative impermeable homogeneity, their continuity, their background of structural and seismic stability and their hydrologic associations. The Central Mississippi Ridge of north-central Mississippi is overlain by a long-stable mass of Porters Creek Clay 500-700 feet thick, in an area roughly 50-60 miles wide and about 150 miles long. The Yazoo Clay, where best developed in the west-central and southwest part of Mississippi, is in the 400-500 foot thickness range, but locally exceeds 500 feet. The entire area mapped is underlain by the Louann Salt which has produced many deep-seated salt domes and numerous piercement salt domes. Salt flow has complicated shallow structural geology throughout that area. The Chattanooga Shale rarely exceeds 60 feet in thickness in the region studied and is generally much thinner and is absent in many places. In the lower part of the Middle Ordovician (Ottawa Megagroup), the Murphreesboro and associated dense limestones appear to offer a potential disposal unit 250-400 feet thick, having the advantages of rock competency and freedom from association with prolific aquifers in the overburden or beneath. Other less conspicuous stratigraphic units are reviewed

  1. Paleomagnetic and chronostratigraphic constraints on the Middle to Late Miocene evolution of the Transylvanian Basin (Romania): Implications for Central Paratethys stratigraphy and emplacement of the Tisza-Dacia plate

    Science.gov (United States)

    de Leeuw, Arjan; Filipescu, Sorin; Maţenco, Liviu; Krijgsman, Wout; Kuiper, Klaudia; Stoica, Marius

    2013-04-01

    From the Oligocene onwards, the complex tectonic evolution of the Africa-Eurasia collision zone led to paleogeographic and biogeographic differentiation of the Mediterranean and Paratethys, two almost land-locked seas, in the area formerly occupied by the western Tethys Ocean. Episodic isolation of the basins triggered strong faunal endemism leading to the introduction of regional stratigraphic stages for the Paratethys. Chronostratigraphic control on the Paratethys stages remains rudimentary compared to the cyclostratigraphically constrained Mediterranean stages. This lack of chronostratigraphic control restricts the insight in the timing of geodynamic, climatic, and paleobiogeographic events and thereby hinders the identification of their causes and effects. In this paper, we here derive better age constraints on the Badenian, Sarmatian and Pannonian Central Paratethys regional stages through integrated 40Ar/39Ar, magnetostratigraphic, and biostratigraphic research in the Transylvanian Basin. The obtained results help to clarify the regions Middle Miocene geodynamic and paleobiogeographic evolution. Six new 40Ar/39Ar ages were determined for tuffs intercalating with the generally deep marine basin infill. Together with data from previous studies, there is now a total of 9 radio-isotopically dated horizons in the basin. These were traced along seismic lines into a synthetic seismic stratigraphic column in the basin center and serve as first order tie-points to the astronomically tuned Neogene timescale (ATNTS). Paleomagnetically investigated sections were treated similarly and their polarity in general corroborates the 40Ar/39Ar results. The integrated radio-isotopic and magnetostratigraphic results provide an improved high-resolution time-frame for the sedimentary infill of the Transylvanian Basin. Early Badenian deep water sedimentation is characterized by accumulation of the Dej Tuff Complex in response to a period of intensive volcanism, the onset of which is constrained between the first occurrence (FO) of Orbulina suturalis at 14.56 Ma and 14.38 ± 0.06 Ma. During the subsequent Badenian Salinity Crisis (BSC) up to 300 m of salt accumulate in the basin center. The faunal turnover that marks the Badenian-Sarmatian Boundary is dated at 12.80 ± 0.05 Ma. A second phase of intense volcanism occurs at 12.4 Ma and leads to deposition of the middle Sarmatian tuff complex (Ghiriş, Hădăreni, Turda and Câmpia Turzii tuffs). Rates of sediment accumulation strongly diminish in the basin center at the onset of the Pannonian stage coincident with an approximately 20° CW tectonic rotation of the Tisza-Dacia plate. Concurrent enhanced uplift in the Eastern a'nd Southern Carpathians leads to the isolation of the Central Paratethys and triggers the transition from marine to freshwater conditions. An additional Pannonian to post-Pannonian 6° of CW rotation is related to the creation of antiform geometries in the Eastern Carpathians which are notably larger in the north than in the south. An 8.4 Ma age is determined for the uppermost Pannonian sediments preserved in the central part of the Transylvanian Basin. Two sections belonging to middle Pannonian Zone D, and the lower part of Zone E (Subzone E1) are found to cover the 10.6-9.9 Ma time-interval.

  2. Magnetic fabric and petrology of Miocene sub-volcanic sills and dykes emplaced into the SW Flysch Belt of the West Carpathians (S Moravia, Czech Republic) and their volcanological and tectonic implications

    Czech Academy of Sciences Publication Activity Database

    Hrouda, F.; Buriánek, D.; Krejčí, O.; Chadima, Martin

    2015-01-01

    Roč. 290, č. 1 (2015), s. 38 ISSN 0377-0273 Institutional support: RVO:67985831 Keywords : Miocene volcanics * Outer Western Carpathian Flysch belt * magnetic fabric Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 2.674, year: 2015

  3. Determination of the pipe stemming load

    International Nuclear Information System (INIS)

    Cowin, S.C.

    1979-01-01

    A mechanical model for the emplacement pipe system is developed. The model is then employed to determine the force applied to the surface collar of the emplacement pipe, the pipe-stemming load, and the stress along the emplacement pipe as a function of stemming height. These results are presented as integrals and a method for their numerical integration is given

  4. Mise en place syntectonique des minéralisations cuprifères du gîte d'Ifri (district du Haut Seksaoua, Haut Atlas occidental, Maroc)Syntectonic emplacement of the Ifri copper mineralization (High Seksaoua, western High Atlas, Morocco)

    Science.gov (United States)

    Gaouzi, Abdelaziz; Chauvet, Alain; Barbanson, Luc; Badra, Lakhlifi; Touray, Jean-Claude; Oukarou, Saı̈d; El Wartiti, Mohamed

    2001-09-01

    Structural and metallogenic studies of the Ifri copper deposit (western High Atlas, Morocco) demonstrate that a great part of the mineralization was linked to a stockwork developed during a Late-Variscan NNW-verging shearing event. With this significant result, the until now accepted syngenetic character for this mineralization has to be reconsidered and allows to suggest a new guide of prospection for this kind of deposit.

  5. Subseabed disposal safety analysis

    International Nuclear Information System (INIS)

    Koplick, C.M.; Kabele, T.J.

    1982-01-01

    This report summarizes the status of work performed by Analytic Sciences Corporation (TASC) in FY'81 on subseabed disposal safety analysis. Safety analysis for subseabed disposal is divided into two phases: pre-emplacement which includes all transportation, handling, and emplacement activities; and long-term (post-emplacement), which is concerned with the potential hazard after waste is safely emplaced. Details of TASC work in these two areas are provided in two technical reports. The work to date, while preliminary, supports the technical and environmental feasibility of subseabed disposal of HLW

  6. Geology and Environmental Impact Assessment and Benefit of ...

    African Journals Online (AJOL)

    Nigeria basement complex has shown that the older granites are high level intrusions emplaced by stoping and diapiric process and include spectrum of rocks varying in composition from tonalite through granodiorite to granite. The intense regional deformation which accompanied and preceded the emplacement of the ...

  7. Design Feature 7: Continuous Preclosure Ventilation

    International Nuclear Information System (INIS)

    A.T. Watkins

    1999-01-01

    This design feature (DF) is intended to evaluate the effects of continuous ventilation in the emplacement drifts during preclosure and how the effects, if any, compare to the Viability Assessment (VA) reference design for postclosure long term performance. This DF will be evaluated against a set of criteria provided by the License Application Design Selection (LADS) group. The VA reference design included a continuous ventilation airflow quantity of 0.1 m 3 /s in the emplacement drifts in the design of the repository subsurface facilities. The effects of this continuous ventilation during the preclosure was considered to have a negligible effect on postclosure performance and therefore is not included during postclosure in the assessment of the long term performance. This DF discusses the effects of continuous ventilation on the emplacement drift environment and surrounding rock conditions during preclosure for three increased airflow quantities. The three cases of continuous ventilation systems are: System A, 1.0 m 3 /s (Section 8), System B, 5.0 m 3 /s (Section 9), and System C, 10.0 m 3 /s (Section 10) in each emplacement drift split. An emplacement drift split is half total length of emplacement drift going from the east or west main to the exhaust main. The difference in each system is the quantity of airflow in the emplacement drifts

  8. Ventilation Model

    International Nuclear Information System (INIS)

    Yang, H.

    1999-01-01

    The purpose of this analysis and model report (AMR) for the Ventilation Model is to analyze the effects of pre-closure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts and provide heat removal data to support EBS design. It will also provide input data (initial conditions, and time varying boundary conditions) for the EBS post-closure performance assessment and the EBS Water Distribution and Removal Process Model. The objective of the analysis is to develop, describe, and apply calculation methods and models that can be used to predict thermal conditions within emplacement drifts under forced ventilation during the pre-closure period. The scope of this analysis includes: (1) Provide a general description of effects and heat transfer process of emplacement drift ventilation. (2) Develop a modeling approach to simulate the impacts of pre-closure ventilation on the thermal conditions in emplacement drifts. (3) Identify and document inputs to be used for modeling emplacement ventilation. (4) Perform calculations of temperatures and heat removal in the emplacement drift. (5) Address general considerations of the effect of water/moisture removal by ventilation on the repository thermal conditions. The numerical modeling in this document will be limited to heat-only modeling and calculations. Only a preliminary assessment of the heat/moisture ventilation effects and modeling method will be performed in this revision. Modeling of moisture effects on heat removal and emplacement drift temperature may be performed in the future

  9. Lessons learned in demonstration projects regarding operational safety during final disposal of vitrified waste and spent fuel

    International Nuclear Information System (INIS)

    Filbert, Wolfgang; Herold, Philipp

    2015-01-01

    The paper summarizes the lessons learned in demonstration projects regarding operational safety during the final disposal of vitrified waste and spent fuel. The three demonstration projects for the direct disposal of vitrified waste and spent fuel are described. The first two demonstration projects concern the shaft transport of heavy payloads of up to 85 t and the emplacement operations in the mine. The third demonstration project concerns the borehole emplacement operation. Finally, open issues for the next steps up to licensing of the emplacement and disposal systems are summarized.

  10. Reconsolidation of salt as applied to permanent seals for the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Hansen, F.D.; Callahan, G.D.; Van Sembeek, L.L.

    1993-01-01

    Reconsolidated salt is a fundamental component of the permanent seals for the Waste Isolation Pilot Plant. As regulations are currently understood and seal concepts envisioned, emplaced salt is the sole long-term seal component designed to prevent the shafts from becoming preferred pathways for rating gases or liquids. Studies under way in support of the sealing function of emplaced salt include laboratory testing of crushed salt small-scale in situ tests, constitutive modeling of crushed salt, calculations of the opening responses during operation and closure, and design practicalities including emplacement techniques. This paper briefly summarizes aspects of these efforts and key areas of future work

  11. Disposal Of Spent Fuel In Salt Using Borehole Technology: BSK 3 Concept

    Energy Technology Data Exchange (ETDEWEB)

    Fopp, Stefan; Graf, Reinhold [GNS Gesellschaft fuer Nuklear-Service mbH, Hollestrasse 7A, D-45127 Essen (Germany); Filbert, Wolfgang [DBE TECHNOLOGY GmbH, Eschenstrasse 55, D-31224 Peine (Germany)

    2008-07-01

    The BSK 3 concept was developed for the direct disposal of spent fuel in rock salt. It is based on the conditioning of fuel assemblies and inserting fuel rods into a steel canister which can be placed in vertical boreholes. The BSK 3 canister is suitable for spent fuel rods from 3 PWR or 9 BWR fuel assemblies. The emplacement system developed for the handling and disposal of BSK 3 canisters comprises a transfer cask which provides appropriate shielding during the transport and emplacement process, a transport cart, and an emplacement device. Using the emplacement device the transfer cask will be positioned onto the top of the borehole lock. The presentation describes the development and the design of the transfer cask and the borehole lock. A technically feasible and safe design for the transfer cask and the borehole lock was found regarding the existing safety requirements for radiation shielding, heat dissipation and handling procedure. (authors)

  12. Geophysical signatures over and around the northern segment of the 85 degrees E Ridge, Mahanadi offshore, Eastern Continental Margin of India: Tectonic implications

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, M.; Ramana, M.V.; Ramprasad, T.; Anuradha, M.; Lall, M.V.; Kumar, B.J.P.

    composition, intrusive bodies and discrete nature of underlying crust. The ridge is associated with large amplitude negative magnetic and gravity anomalies. The negative gravity response across the ridge is probably due to emplacement of relatively low density...

  13. Analyses of Rock Size-Frequency Distributions and Morphometry of Modified Hawaiian Lava Flows: Implications for Future Martian Landing Sites

    Science.gov (United States)

    Craddock, Robert A.; Golombek, Matthew; Howard, Alan D.

    2000-01-01

    Both the size-frequency distribution and morphometry of rock populations emplaced by a variety of geologic processes in Hawaii indicate that such information may be useful in planning future landing sites on Mars and interpreting the surface geology.

  14. Evidence for non-coaxiality of ferrimagnetic and paramagnetic fabrics, developed during magma flow and cooling in a thick mafic dyke

    Czech Academy of Sciences Publication Activity Database

    Silva, P. F.; Marques, F. O.; Machek, Matěj; Henry, B.; Hirt, A. M.; Roxerová, Zuzana; Madureira, P.; Vratislav, S.

    2014-01-01

    Roč. 629, August (2014), s. 155-164 ISSN 0040-1951 Institutional support: RVO:67985530 Keywords : paramagnetic * ferrimagnetic * fabrics * microstructures * dyke emplacement * stress field Subject RIV: DB - Geology ; Mineralogy Impact factor: 2.872, year: 2014

  15. Platinum group elements geochemistry of ultramafic and associated ...

    Indian Academy of Sciences (India)

    group element (PGE) and associated gold mineralization in these ultramafic rocks. A mineral ... Paleoproterozoic age, mostly emplaced into the .... tified reference materials (CRM) from the US Geo- ..... Classification diagram (Barnes et al.

  16. Regional stratigraphy and geologic history of Mare Crisium

    Science.gov (United States)

    Head, J. W., III; Adams, J. B.; Mccord, T. B.; Pieters, C.; Zisk, S.

    1978-01-01

    Remote sensing and Luna 24 sample data are used to develop a summary of the regional stratigraphy and geologic history of Mare Crisium. Laboratory spectra of Luna 24 samples, telescopic reflectance spectra in the 0.3 to 1.1 micron range and orbital X-ray data have identified three major basalt groups in the region. Group I soil is derived from iron- and magnesium-rich titaniferous basalts and was apparently emplaced over the majority of the basin, however is presently exposed as a shelf in the southwest part. Group II soils, derived from very low titanium ferrobasalts, were emplaced in two stages subsequent to Group I emplacement and now appear as part of the outer shelf and topographic annulus. Subsidence of the basin interior preceded and continued after the emplacement of the third basalt group, a soil derived from a low titanium ferrobasalt. The Luna 24 site is found to be within a patch of Group II material.

  17. Three-Dimensional Characterization and Modeling of Permeability in a Field-Scale Control Volume

    National Research Council Canada - National Science Library

    Barrash, Warren

    2003-01-01

    ...) hydrogeologic information. The BHRS consists of 18 wells emplaced in 2O-m-thick coarse fluvial deposits that may be divided into five stratigraphic units with layered and patchy heterogeneity at three scales...

  18. Jak může prostředí ovlivnit sopky na Marsu? Odpověď nabízí sypané kužele

    Czech Academy of Sciences Publication Activity Database

    Brož, Petr

    2015-01-01

    Roč. 13, č. 10 (2015) ISSN 1214-1674 Institutional support: RVO:67985530 Keywords : Mars * scoria cone * ballistic emplacement Subject RIV: DC - Siesmology, Volcanology, Earth Structure http://www.aldebaran.cz/bulletin/2015_10_bum.php

  19. Ballistic Missile Defense in the European Theater: Political, Military and Technical Considerations

    National Research Council Canada - National Science Library

    Terstegge, Stephen D

    2007-01-01

    ... that threatens the homeland of the United States. Therefore, the United States faces the complex security challenge of emplacing ballistic missile defense assets on European soil in the very near-term to mitigate this threat...

  20. A brief comparison of lava flows from the Deccan Volcanic Province ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    In this paper, we first present a short overview of important studies pertaining to the emplacement ... activity on the surface of the earth. They cover ... Of primary importance is the amount of .... recent developments in physical volcanology. Com-.

  1. 10 CFR 960.4-2-1 - Geohydrology.

    Science.gov (United States)

    2010-01-01

    ... rock that would divert the downward infiltration of water beyond the limits of the emplaced waste. (iv... the guidelines as necessary, to ensure consistency with the final NRC regulations on the unsaturated...

  2. Orogeny, migmatites and leucogranites: A review

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Based on geochemical data, we can use statistical methods and modeling to evaluate whether migmatites are sources ...... interrelated factors, but in which the style of this switch and ..... ballooning plutons: A return to nested diapirs emplaced.

  3. REPOSITORY LAYOUT SUPPORTING DESIGN FEATURE NO.13 - WASTE PACKAGE SELF SHIELDING

    International Nuclear Information System (INIS)

    Owen, J.

    1999-01-01

    The objective of this analysis is to develop a repository layout, for Feature No. 13, that will accommodate self-shielding waste packages (WP) with an areal mass loading of 25 metric tons of uranium per acre (MTU/acre). The scope of this analysis includes determination of the number of emplacement drifts, amount of emplacement drift excavation required, and a preliminary layout for illustrative purposes

  4. Thermomechanical analysis of underground excavations in the vicinity of a nuclear waste isolation panel

    International Nuclear Information System (INIS)

    St John, C.M.

    1987-06-01

    This report summarizes the results of a series of analyses of excavations in the vicinity of waste emplacement panels. Specific consideration is given to the access drifts running between adjacent emplacement panels, the drift intersection at the entrance to the emplacement panels, and the waste emplacement excavations. Both horizontal and vertical emplacement models are considered, but greater emphasis is placed on the former. Three numerical modeling procedures were used in this study: a finite-element model was used for three-dimensional stress analysis of the tunnel intersection, a model based on the closed-form solution for point heat sources was used to predict temperatures and stresses in the vicinity of the emplacement panel, and simple two-dimensional boundary-element models were used to predict temperatures and stresses around excavations of various shapes. The results of two-dimensional stress analyses were postprocessed to determine the extent to which the strength of a rock mass, containing a set of vertical joints, was exceeded. The results presented in this report do not indicate that there will be any particular stability problems at the tunnel intersection investigated. Further, the effect of waste emplacement within the adjacent panels is to decrease the vertical rock stresses and increase the horizontal rock stresses at the intersection. These stress changes will tend to enhance the stability of larger-span excavations, including the tunnel intersection and the alcoves necessary for horizontal emplacement of waste canisters. The relatively high horizontal stresses experienced by the access were identified as a potential concern. However, evaluation of recent data on the thermomechanical properties of the rock mass modeled here has indicated that the stress changes will not be as severe as stated herein

  5. Observational constraints on the identification of shallow lunar magmatism : insights from floor-fractured craters

    OpenAIRE

    Jozwiak, Lauren; Head, James; Neumann, G. A.; Wilson, Lionel

    2017-01-01

    Floor-fractured craters are a class of lunar crater hypothesized to form in response to the emplacement of a shallow magmatic intrusion beneath the crater floor. The emplacement of a shallow magmatic body should result in a positive Bouguer anomaly relative to unaltered complex craters, a signal which is observed for the average Bouguer anomaly interior to the crater walls. We observe the Bouguer anomaly of floor-fractured craters on an individual basis using the unfiltered Bouguer gravity so...

  6. Subsurface Ventilation System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    Eric Loros

    2001-07-25

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  7. Subsurface Ventilation System Description Document

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-10-12

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  8. Army Engineer Divers: First In Port-Au-Prince Harbor

    Science.gov (United States)

    2010-12-01

    to the pile once the concrete was poured. This step was com- pleted in a few minutes for each pile. Last, a prefabricated wooden form was emplaced...September-December 201010 Engineer This prefabricated wooden form was emplaced around a rebar cage at the top of damaged piles to hold concrete until it...the mainland into the harbor. Waste from tugboats and sewage from the mainland compounded ecological hazards. The only alternative for the Army and

  9. Engineer: The Professional Bulletin of Army Engineers. Volume 40, September-December 2010

    Science.gov (United States)

    2010-12-01

    minutes for each pile. Last, a prefabricated wooden form was emplaced around each cage on the piles, and concrete was pumped into the form. After 24...in this austere environment. For instance, when one hydraulic September-December 201010 Engineer This prefabricated wooden form was emplaced around...mainland compounded ecological hazards. The only alternative for the Army and Navy divers came in initiat- ing preventive measures—including constantly

  10. Caractéristiques de l’évolution de la partie orientale du bloc de Chine du Sud au Mésozoïque supérieur et implications géodynamiques : Etude pluridisciplinaire de la mise en place des massifs granitiques de Qingyang-Jiuhua, Hengshan et de la côte du Fujian et des structures tectoniques associées

    OpenAIRE

    Wei , Wei

    2013-01-01

    The vast distribution and long duration of the Late Mesozoic magmatism in the eastern part of South China presents a unique case in the world. This offers a natural laboratory to study the process of magma genesis, the magma emplacement mode, the relationship between magmatism and tectonics, the geodynamic role on the magma emplacement and lithospheric evolution. Since 50’s, particularly 90’s of the last century, geoscientists have made important efforts in geological cartography and carried ...

  11. Thermal modeling of nuclear waste package designs for disposal in tuff

    International Nuclear Information System (INIS)

    Hockman, J.N.; O'Neal, W.C.

    1983-09-01

    Lawrence Livermore National Laboratory is involved in the design and testing of high-level nuclear waste packages. Many of the aspects of waste package design and testing (e.g., corrosion and leaching) depend in part on the temperature history of the emplaced packages. This paper discusses thermal modeling and analysis of various emplaced waste package conceptual designs including the models used, the assumptions and approximations made, and the results obtained. 6 references, 6 figures, 3 tables

  12. Thermal analysis of NNWSI conceptual waste package designs

    International Nuclear Information System (INIS)

    Stein, W.; Hockman, J.N.; O'Neal, W.C.

    1984-04-01

    Lawrence Livermore National Laboratory is involved in the design and testing of high-level nuclear waste packages. Many of the aspects of waste package design and testing (e.g., corrosion and leaching) depend in part on the temperature history of the emplaced packages. This report discusses thermal modeling and analysis of various emplaced waste package conceptual designs including the models used, the assumptions and approximations made, and the results obtained. 16 references

  13. Thermal modeling of nuclear waste package designs for disposal in tuff

    International Nuclear Information System (INIS)

    Hockman, J.N.; O'Neal, W.C.

    1984-02-01

    Lawrence Livermore National Laboratory is involved in the design and testing of high-level nuclear waste packages. Many of the aspects of waste package design and testing (e.g., corrosion and leaching) depend in part on the temperature history of the emplaced packages. This paper discusses thermal modeling and analysis of various emplaced waste package conceptual designs including the models used, the assumptions and approximations made, and the results obtained. 6 references, 6 figures, 4 tables

  14. License Application Design Selection Feature Report Canistered Assemblies

    International Nuclear Information System (INIS)

    Bennett, Scott M.

    1999-01-01

    The objective of the Modified Waste Emplacement Mode Design Alternative Report is to identify, describe, and evaluate waste package emplacement modes against a specified set of evaluation criteria. This evaluation of the design alternative will be used as input to the decision-making process used to identify the EDAs. The EDAs will, in turn, be evaluated against a set of evaluation criteria, and their evaluations will be used as the basis for an M and O recommendation on the LA design

  15. Test plan: Potash Core Test. WIPP experimental program borehole plugging

    International Nuclear Information System (INIS)

    Christensen, C.L.

    1979-09-01

    The Potash Core Test will utilize a WIPP emplaced plug to obtain samples of an in-situ cured plug of known mix constituents for bench scale testing. An earlier effort involved recovery at the salt horizon of Plug 217, a 17 year old plug in a potash exploration hole for bond testing, but the lack of particulars in the emplacement precluded significant determination of plug performance

  16. Engineering design study for storage and disposal of intermediate level waste

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, J R; Hackney, S; Richardson, J A; Heafield, W

    1982-11-01

    A conceptual design study is presented which covers both the storage and disposal of intermediate level waste; repositories in several rock formations are considered at a 300m depth. A total system is proposed including an engineered trench for ..beta gamma.. waste, emplacement systems and off site transportation. Safety during the emplacement phase and the radiological effects of human intrusion and geological catastrophies are considered.

  17. Thermal, operational, and economic aspects of repository design alternatives

    International Nuclear Information System (INIS)

    Closs, K.D.; Papp, R.; Bechthold, W.; Engelmann, H.J.; Hartje, B.

    1989-01-01

    This paper discusses how a broad spectrum of heat-generating nuclear waste types like reprocessing waste (HLW, ILW), spent LWR, and spent HTR fuel will be disposed of in a future German repository located in a salt dome. Different package and emplacement concepts for the various waste forms are feasible, ranging from pure borehole emplacement of canisters and drums to pure drift emplacement of heavily shielded casks as well as combinations of both concepts. Optimization of the whole back-end system (waste treatment, interim storage, and disposal) is performed taking into account thermal, operational, and economic aspects. From a radiological viewpoint, the drift emplacement concept is superior to all concepts in as much as the occupational dose is lowest and zero release from the casks is attainable during normal and anomalous repository operation. As far as economics are concerned, the cost of the heavily shielded casks necessary for drift emplacement contributes markedly to the overall cost of the whole back-end system. Drift emplacement can compete economically with the other concepts only if the casks are used both for interim storage and disposal

  18. Generic Crystalline Disposal Reference Case

    Energy Technology Data Exchange (ETDEWEB)

    Painter, Scott Leroy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chu, Shaoping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Harp, Dylan Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Perry, Frank Vinton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-20

    A generic reference case for disposal of spent nuclear fuel and high-level radioactive waste in crystalline rock is outlined. The generic cases are intended to support development of disposal system modeling capability by establishing relevant baseline conditions and parameters. Establishment of a generic reference case requires that the emplacement concept, waste inventory, waste form, waste package, backfill/buffer properties, EBS failure scenarios, host rock properties, and biosphere be specified. The focus in this report is on those elements that are unique to crystalline disposal, especially the geosphere representation. Three emplacement concepts are suggested for further analyses: a waste packages containing 4 PWR assemblies emplaced in boreholes in the floors of tunnels (KBS-3 concept), a 12-assembly waste package emplaced in tunnels, and a 32-assembly dual purpose canister emplaced in tunnels. In addition, three failure scenarios were suggested for future use: a nominal scenario involving corrosion of the waste package in the tunnel emplacement concepts, a manufacturing defect scenario applicable to the KBS-3 concept, and a disruptive glaciation scenario applicable to both emplacement concepts. The computational approaches required to analyze EBS failure and transport processes in a crystalline rock repository are similar to those of argillite/shale, with the most significant difference being that the EBS in a crystalline rock repository will likely experience highly heterogeneous flow rates, which should be represented in the model. The computational approaches required to analyze radionuclide transport in the natural system are very different because of the highly channelized nature of fracture flow. Computational workflows tailored to crystalline rock based on discrete transport pathways extracted from discrete fracture network models are recommended.

  19. Underground transportation and handling system for Pollux-casks

    International Nuclear Information System (INIS)

    Schrimpf, C.

    1988-01-01

    The concept for the underground transportation and handling system for Pollux-casks was optimized in a first phase by dividing the process in the repository up into the several transportation and manipulation steps. For each step, the possibilities were described and evaluated by means of a list of criteria (technical, safety and economical criteria). The following concept for the transportation and handling was developed: The casks are transported to the unloading area of the surface facilities by railway or truck. After removal of the transport protection, the entry control is performed. The cask is lifted from the vehicle and placed on a railbound transportation vehicle. This transport unit is transferred to the shaft and placed there ready for shaft hoisting. With the hoisting cage protruding, the transport unit is placed on the hoisting cage by means of a pushing-on device, locked, and then conveyed underground. After arrival on the emplacement level, the transport unit is pulled-off from the hoisting cage and taken over by a mine locomotive and transferred through the transportation and access drifts as far as to the emplacement site. There the locomotive pushed the rail transport vehicle into the emplacement drift, as far as to the designated emplacement position. At the emplacement position, the cask is again lifted by means of hoisting equipment. The rail transport vehicle is pulled out of the emplacement drift and returned to the surface for reloading. After deposition of the cask on the drift floor, the emplacement equipment is pulled back in order to give the operation space free for the slinger backfill truck. Within preceding tests two different backfilling techniques were investigated under realistic conditions: pneumatic backfilling and slinger backfilling. The slinger truck was found to be the most suitable for the designated purpose

  20. Multiscale Model Simulations of Temperature and Relative Humidity for the License Application of the Proposed Yucca Mountain Repository

    Science.gov (United States)

    Buscheck, T.; Glascoe, L.; Sun, Y.; Gansemer, J.; Lee, K.

    2003-12-01

    For the proposed Yucca Mountain geologic repository for high-level nuclear waste, the planned method of disposal involves the emplacement of cylindrical packages containing the waste inside horizontal tunnels, called emplacement drifts, bored several hundred meters below the ground surface. The emplacement drifts reside in highly fractured, partially saturated volcanic tuff. An important phenomenological consideration for the licensing of the proposed repository at Yucca Mountain is the generation of decay heat by the emplaced waste and the consequences of this decay heat. Changes in temperature will affect the hydrologic and chemical environment at Yucca Mountain. A thermohydrologic-modeling tool is necessary to support the performance assessment of the Engineered Barrier System (EBS) of the proposed repository. This modeling tool must simultaneously account for processes occurring at a scale of a few tens of centimeters around individual waste packages, for processes occurring around the emplacement drifts themselves, and for processes occurring at the multi-kilometer scale of the mountain. Additionally, many other features must be considered including non-isothermal, multiphase-flow in fractured porous rock of variable liquid-phase saturation and thermal radiation and convection in open cavities. The Multiscale Thermohydrologic Model (MSTHM) calculates the following thermohydrologic (TH) variables: temperature, relative humidity, liquid-phase saturation, evaporation rate, air-mass fraction, gas-phase pressure, capillary pressure, and liquid- and gas-phase fluxes. The TH variables are determined as a function of position along each of the emplacement drifts in the repository and as a function of waste-package (WP) type. These variables are determined at various generic locations within the emplacement drifts, including the waste package and drip-shield surfaces and in the invert; they are also determined at various generic locations in the adjoining host rock

  1. Subsurface Facility System Description Document

    International Nuclear Information System (INIS)

    Eric Loros

    2001-01-01

    The Subsurface Facility System encompasses the location, arrangement, size, and spacing of the underground openings. This subsurface system includes accesses, alcoves, and drifts. This system provides access to the underground, provides for the emplacement of waste packages, provides openings to allow safe and secure work conditions, and interfaces with the natural barrier. This system includes what is now the Exploratory Studies Facility. The Subsurface Facility System physical location and general arrangement help support the long-term waste isolation objectives of the repository. The Subsurface Facility System locates the repository openings away from main traces of major faults, away from exposure to erosion, above the probable maximum flood elevation, and above the water table. The general arrangement, size, and spacing of the emplacement drifts support disposal of the entire inventory of waste packages based on the emplacement strategy. The Subsurface Facility System provides access ramps to safely facilitate development and emplacement operations. The Subsurface Facility System supports the development and emplacement operations by providing subsurface space for such systems as ventilation, utilities, safety, monitoring, and transportation

  2. Advanced three-dimensional thermal modeling of a baseline spent fuel repository

    International Nuclear Information System (INIS)

    Altenbach, T.J.; Lowry, W.E.

    1980-01-01

    A three-dimensional thermal analysis using finite difference techniques was performed to determine the near-field response of a baseline spent fuel repository in a deep geologic salt medium. A baseline design incorporates previous thermal modeling experience and OWI recommendations for areal thermal loading in specifying the waste form properties, package details, and emplacement configuration. The base case in this thermal analysis considers one 10-year old PWR spent fuel assembly emplaced to yield a 36 kW/acre (8.9 W/m 2 ) loading. A unit cell model in an infinite array is used to simplify the problem and provide upper-bound temperatures. Boundary conditions are imposed which allow simulations to 1000 years. Variations studied include a comparison of ventilated and unventilated storage room conditions, emplacement packages with and without air gaps surrounding the canister, and room cool-down scenarios with ventilation following an unventilated state for retrieval purposes. It was found that at this low-power level, ventilating the emplacement room has an immediate cooling influence on the canister and effectively maintains the emplacement room floor near the temperature of the ventilating air

  3. Vertical boreholes in salt - An industrial demonstration program -

    International Nuclear Information System (INIS)

    Bollingerfehr, W.; Filbert, W.

    2006-01-01

    In order to synchronize and optimize the emplacement technologies used for both categories of waste (vitrified waste and spent fuel) the borehole emplacement technique for consolidated spent fuel was reconsidered in Germany. The appropriate design resulted in a fuel rod canister of the type 'BSK 3'. This BSK 3 steel canister is of the same diameter as the standard HLW-canister which allows the use of a common transfer and handling technique. The canister is tightly sealed by welding and designed to withstand petrostatic pressure. Thermal calculations showed that the emplacement of a BSK 3-canister into a vertical borehole in a salt repository is possible after only about 3 to 7 years after reactor unloading of the fuel assemblies. Thus, the emplacement of BSK 3-canisters allows a complete revision of the schedule of spent fuel disposal concepts and may lead to a considerable reduction of time and costs. Accordingly, a research program was launched in 2004 within the framework of the 6th European Research Program to develop the transport and emplacement components, the functionality and reliability of which are to be tested in a one-year demonstration phase which will commence at the beginning of 2008. (author)

  4. Time-scales of assembly and thermal history of a composite felsic pluton: constraints from the Emerald Lake area, northern Canadian Cordillera, Yukon

    Science.gov (United States)

    Coulson, Ian M.; Villeneuve, Mike E.; Dipple, Gregory M.; Duncan, Robert A.; Russell, James K.; Mortensen, James K.

    2002-05-01

    Knowledge of the time-scales of emplacement and thermal history during assembly of composite felsic plutons in the shallow crust are critical to deciphering the processes of crustal growth and magma chamber development. Detailed petrological and chemical study of the mid-Cretaceous, composite Emerald Lake pluton, from the northern Canadian Cordillera, Yukon Territory, coupled with U-Pb and 40Ar/ 39Ar geochronology, indicates that this pluton was intruded as a series of magmatic pulses. Intrusion of these pulses produced a strong petrological zonation from augite syenite, hornblende quartz syenite and monzonite, to biotite granite. Our data further indicate that multiple phases were emplaced and cooled to below the mineral closure temperatures over a time-scale on the order of the resolution of the 40Ar/ 39Ar technique (˜1 Myr), and that emplacement occurred at 94.3 Ma. Simple thermal modelling and heat conduction calculations were used to further constrain the temporal relationships within the intrusion. These calculations are consistent with the geochronology and show that emplacement and cooling were complete in less than 100 kyr and probably 70±5 kyr. These results demonstrate that production, transport and emplacement of the different phases of the Emerald Lake pluton occurred essentially simultaneously, and that these processes must also have been closely related in time and space. By analogy, these results provide insights into the assembly and petrogenesis of other complex intrusions and ultimately lead to an understanding of the processes involved in crustal development.

  5. Precise U-Pb Zircon Dating of the Syenite Phase from the Ditrau Alkaline Igneous Complex

    Directory of Open Access Journals (Sweden)

    Pană Dinu

    2000-04-01

    Full Text Available The Ditrău igneous complex represents the largest alkaline intrusion in the Carpathian-Pannonian region consisting of a plethora of rock types formed by complicated magmatic and metasomatic processes. A detailed U-Pb zircon age study is currently underway and the results for the syenite intrusion phase is reported herein. The U-Pb zircon emplacement age of the syenite of 229.6 +1.7/-1.2 Ma documents the quasi-contemporaneous production and emplacement of the gabbro and syenite magmas. We suggest that the syenite and associated granite formed by crustal melting during the emplacement of the mantle derived gabbroic magma around 230 Ma. The thermal contact aureole produced by the Ditrău alkaline igneous complex constrains the main tectonism recorded by surrounding metamorphic lithotectonic assemblages to be pre-Ladinian.

  6. Martian volcanism: festoon-like ridges on terrestrial basalt flows and implications for Mars

    International Nuclear Information System (INIS)

    Theilig, E.; Greeley, R.

    1987-01-01

    The Fink and Fletcher, and Fink model was used to assess and compare flow rheology for two terrestrial basalt flows and one Martian flow with previous studies. Based on the morphologic similarities between the Martian flows and the Icelandic flows and knowledge of the emplacement of the terrestrial flows, the flows west of Arsia Mons are considered to have been emplaced as large sheet flows from basaltic flood style eruptions. Festoon ridges represent folding of the surface crust in the last stages of emplacement when viscosities would be high due to cooling. Alternatively, the lava may have had a high crystallinity or was erupted at low temperatures. In addition, increased compressive stress behind halted flow fronts or in ponded areas may have contributed to ridge formation

  7. The Gondwana Orogeny in northern North Patagonian Massif: Evidences from the Caita Có granite, La Seña and Pangaré mylonites, Argentina

    Directory of Open Access Journals (Sweden)

    Daniel A. Gregori

    2016-07-01

    Full Text Available Structural analyses in the northern part of the North Patagonia Massif, in the foliated Caita Có granite and in La Seña and Pangaré mylonites, indicate that the pluton was intruded as a sheet-like body into an opening pull-apart structure during the Gondwana Orogeny. Geochronological studies in the massif indicate a first, lower to middle Permian stage of regional deformation, related to movements during indentation tectonics, with emplacement of foliated granites in the western and central areas of the North Patagonian Massif. Between the upper Permian and lower Triassic, evidence indicates emplacement of undeformed granitic bodies in the central part of the North Patagonian Massif. A second pulse of deformation between the middle and upper Triassic is related to the emplacement of the Caita Có granite, the development of mylonitic belts, and the opening of the Los Menucos Basin. During this pulse of deformation, compression direction was from the eastern quadrant.

  8. Progress in waste package and engineered barrier system performance assessment and design

    International Nuclear Information System (INIS)

    Van Luik, A.; Stahl, D.; Harrison, D.

    1993-01-01

    As part of the U.S. Department of Energy's evaluation of site suitability for a potential high-level radioactive waste repository, long-term interactions between the engineered barrier system and the site must be determined. This requires a waste-package/engineered-system design, a description of the environment around the emplacement zone, and models that simulate operative processes describing these engineered/natural systems interactions. Candidate designs are being evaluated, including a more robust, multi-barrier waste package, and a drift emplacement mode. Tools for evaluating designs, and emplacement mode are the currently available waste-package/engineered-system performance assessment codes development for the project. For assessments that support site suitability, environmental impact, or licensing decisions, more capable codes are needed. Code capability requirements are being written, and existing codes are to be evaluated against those requirements. Recommendations are being made to focus waste-packaging/engineered-system code-development

  9. Dike-induced contraction along oceanic and continental divergent plate boundaries

    KAUST Repository

    Trippanera, D.

    2014-10-28

    The axis of divergent plate boundaries shows extension fractures and normal faults at the surface. Here we present evidence of contraction along the axis of the oceanic ridge of Iceland and the continental Main Ethiopian Rift. Contraction is found at the base of the tilted hanging wall of dilational normal faults, balancing part of their extension. Our experiments suggest that these structures result from dike emplacement. Multiple dike injection induces subsidence above and uplift to the sides of the dikes; the transition in between is accommodated by reverse faults and subsequent peripheral inward dipping normal faults. Our results suggest that contraction is a direct product of magma emplacement along divergent plate boundaries, at various scales, marking a precise evolutionary stage and initiating part of the extensional structures (extension fractures and normal faults). Key Points Contraction along divergent plate boundaries results from dike emplacementContraction generates extensional structures along divergent plate boundariesSurface deformation along divergent plate boundaries may be magma induced

  10. RETRIEVAL EQUIPMENT DESCRIPTIONS

    International Nuclear Information System (INIS)

    J. Steinhoff

    1997-01-01

    The objective and the scope of this document are to list and briefly describe the major mobile equipment necessary for waste package (WP) retrieval from the proposed subsurface nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the equipment are explained and summarized in the individual subsections of this document. There are no quality assurance requirements or QA controls in this document. Retrieval under normal conditions is accomplished with the same fleet of equipment as is used for emplacement. Descriptions of equipment used for retrieval under normal conditions is found in Emplacement Equipment Descriptions, DI: BCAF00000-01717-5705-00002 (a document in progress). Equipment used for retrieval under abnormal conditions is addressed in this document and consists of the following: (1) Inclined Plane Hauler; (2) Bottom Lift Transporter; (3) Load Haul Dump (LHD) Loader; (4) Heavy Duty Forklift for Emplacement Drifts; (5) Covered Shuttle Car; (6) Multipurpose Vehicle; and (7) Scaler

  11. Intraflow width variations in Martian and terrestrial lava flows

    Science.gov (United States)

    Peitersen, Matthew N.; Crown, David A.

    1997-03-01

    Flow morphology is used to interpret emplacement processes for lava flows on Earth and Mars. Accurate measurements of flow geometry are essential, particularly for planetary flows where neither compositional sampling nor direct observations of active flows may be possible. Width behavior may indicate a flow's response to topography, its emplacement regime, and its physical properties. Variations in width with downflow distance from the vent may therefore provide critical clues to flow emplacement processes. Flow width is also one of the few characteristics that can be readily measured from planetary mission data with accuracy. Recent analyses of individual flows at two terrestrial and four Martian sites show that widths within an individual flow vary by up to an order of magnitude. Width is generally thought to be correlated to topography; however, recent studies show that this relationship is neither straightforward nor easily quantifiable.

  12. Dike-induced contraction along oceanic and continental divergent plate boundaries

    KAUST Repository

    Trippanera, D.; Acocella, V.; Ruch, Joel

    2014-01-01

    The axis of divergent plate boundaries shows extension fractures and normal faults at the surface. Here we present evidence of contraction along the axis of the oceanic ridge of Iceland and the continental Main Ethiopian Rift. Contraction is found at the base of the tilted hanging wall of dilational normal faults, balancing part of their extension. Our experiments suggest that these structures result from dike emplacement. Multiple dike injection induces subsidence above and uplift to the sides of the dikes; the transition in between is accommodated by reverse faults and subsequent peripheral inward dipping normal faults. Our results suggest that contraction is a direct product of magma emplacement along divergent plate boundaries, at various scales, marking a precise evolutionary stage and initiating part of the extensional structures (extension fractures and normal faults). Key Points Contraction along divergent plate boundaries results from dike emplacementContraction generates extensional structures along divergent plate boundariesSurface deformation along divergent plate boundaries may be magma induced

  13. Rio Blanco: nuclear operations and chimney reentry

    International Nuclear Information System (INIS)

    Woodruff, W.R.; Guido, R.S.

    1975-01-01

    Rio Blanco was the third experiment in the U.S. Atomic Energy Commission's Plowshare Program to develop technology to stimulate gas production from geologic formations not conducive to production by conventional means. The project was sponsored by CER Geonuclear Corporation, with the Lawrence Livermore Laboratory providing the explosives and several technical programs, such as spall measurement. Three nuclear explosives specifically designed for this application were detonated simultaneously in a minimum-diameter emplacement well using many commercially available but established-reliability components. The explosive system performed properly under extreme temperature and pressure conditions. Emplacement and stemming operations were designed with the aim of simplifying both the emplacement and reentry and fully containing the detonation products. An integrated command and control system was used with communication to all three explosives through a single coaxial cable. Reentry and the initial production testing are completed. To date 98 million standard ft 3 of chimney gas have been produced. (auth)

  14. VENTILATION MODEL

    International Nuclear Information System (INIS)

    V. Chipman

    2002-01-01

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses

  15. Explosive performance on the non-proliferation experiment

    Energy Technology Data Exchange (ETDEWEB)

    McKown, T.O. [Los Alamos National Lab., NM (United States)

    1994-12-31

    The Explosive Effects Physics Project at the Los Alamos National Laboratory planned and conducted experiments on the Non-Proliferation Experiment (NPE) as part of its effort to define source functions for seismic waves. Since all investigations were contingent on the performance of the emplaced chemical explosive, an array of diagnostic measurements was fielded in the emplaced explosive. The CORRTEX (COntinuous Reflectometry for Radius vs Time EXperiment) system was used to investigate the explosive initiation and to determine the detonation velocities on three levels and in a number of radial directions. The CORRTEX experiments fielded in the explosive chamber will be described, including a description of the explosive emplacement from the perspective of its impact on the CORRTEX results. The data obtained are reviewed and the resulting detonation velocities are reported. A variation of detonation velocity with depth in the explosive and the apparent underdetonation and overdetonation of the explosive in different radial directions is reported.

  16. VENTILATION NEEDS DURING CONSTRUCTION

    International Nuclear Information System (INIS)

    C.R. Gorrell

    1998-01-01

    The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options

  17. Underground layout tradeoff study

    International Nuclear Information System (INIS)

    1988-01-01

    This report presents the results of a technical and economic comparative study of four alternative underground layouts for a nuclear waste geologic repository in salt. The four alternatives considered in this study are (1) separate areas for spent fuel (SF) and commercial high-level waste (CHLW); (2) panel alternation, in which SF and CHLW are emplaced in adjacent panels of rooms; (3) room alternation, in which SF and CHLW are emplaced in adjacent rooms within each panel; and (4) intimate mixture, in which SF and CHLW are emplaced in random order within each storage room. The study concludes that (1) cost is not an important factor; (2) the separate-areas and intimate-mixture alternatives appear, technically, to be more desirable than the other alternatives; and (3) the selection between the separate-areas and intimate mixture alternatives depends upon future resolution of site-specific and reprocessing questions. 5 refs., 6 figs., 12 tabs

  18. Repository Waste Package Transporter Shielding Weight Optimization

    International Nuclear Information System (INIS)

    C.E. Sanders; Shiaw-Der Su

    2005-01-01

    The Yucca Mountain repository requires the use of a waste package (WP) transporter to transport a WP from a process facility on the surface to the subsurface for underground emplacement. The transporter is a part of the waste emplacement transport systems, which includes a primary locomotive at the front end and a secondary locomotive at the rear end. The overall system with a WP on board weights over 350 metric tons (MT). With the shielding mass constituting approximately one-third of the total system weight, shielding optimization for minimal weight will benefit the overall transport system with reduced axle requirements and improved maneuverability. With a high contact dose rate on the WP external surface and minimal personnel shielding afforded by the WP, the transporter provides radiation shielding to workers during waste emplacement and retrieval operations. This paper presents the design approach and optimization method used in achieving a shielding configuration with minimal weight

  19. Room at the Mountain: Estimated Maximum Amounts of Commercial Spent Nuclear Fuel Capable of Disposal in a Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Kessler, John H.; Kemeny, John; King, Fraser; Ross, Alan M.; Ross, Benjamen

    2006-01-01

    The purpose of this paper is to present an initial analysis of the maximum amount of commercial spent nuclear fuel (CSNF) that could be emplaced into a geological repository at Yucca Mountain. This analysis identifies and uses programmatic, material, and geological constraints and factors that affect this estimation of maximum amount of CSNF for disposal. The conclusion of this initial analysis is that the current legislative limit on Yucca Mountain disposal capacity, 63,000 MTHM of CSNF, is a small fraction of the available physical capacity of the Yucca Mountain system assuming the current high-temperature operating mode (HTOM) design. EPRI is confident that at least four times the legislative limit for CSNF (∼260,000 MTHM) can be emplaced in the Yucca Mountain system. It is possible that with additional site characterization, upwards of nine times the legislative limit (∼570,000 MTHM) could be emplaced. (authors)

  20. Effects of temperature, temperature gradients, stress, and irradiation on migration of brine inclusions in a salt repository

    International Nuclear Information System (INIS)

    Jenks, G.H.

    1979-07-01

    Available experimental and theoretical information on brine migration in bedded salt are reviewed and analyzed. The effects of temperature, thermal gradients, stress, irradiation, and pressure in a salt repository are among the factors considered. The theoretical and experimental (with KCl) results of Anthony and Cline were used to correlate and explain the available data for rates of brine migration at temperatures up to 250 0 C in naturally occurring crystals of bedded salt from Lyons and Hutchinson, Kansas. Considerations of the effects of stressing crystals of bedded salt on the migratin properties of brine inclusions within the crystals led to the conclusion that the most probable effects are a small fractional increase in the solubility of the salt within the liquid and a concomitant and equal fractional increase in the rate of the thermal gradient-induced migration of the brine. The greatest uncertainty relative to the prediction of rates of migration of brine into a waste emplacement cavity in bedded salt is associated with questions concerning the effects of the grain boundaries (within the aggregates of single crystals which comprise a bedded salt deposit) on brine migration through the deposit. The results of some of the estimates of rates and total amounts of brine inflow to HLW and SURF waste packages emplaced in bedded salt were included to illustrate the inflow volumes which might occur in a repository. The results of the brine inflow estimates for 10-year-old HLW emplaced at 150 kW/acre indicated inflow rates starting at 0.7 liter/year and totaling 12 liters at 30 years after emplacement. The results of the estimates for 10-year-old PWR SURF emplaced at 60 kW/acre indicated a constant inflow of 0.035 liter/year for the first 35 years after emplacement

  1. Three-dimensional thermal analysis of a baseline spent fuel repository

    International Nuclear Information System (INIS)

    Altenbach, T.J.; Lowry, W.E.

    1980-01-01

    A three-dimensional thermal analysis has been performed using finite difference techniques to determine the near-field response of a baseline spent fuel repository in a deep geologic salt medium. A baseline design incorporates previous thermal modeling experience and OWI recommendations for areal thermal loading in specifying the waste form properties, package details, and emplacement configuration. The base case in this thermal analysis considers one 10-year old PWR spent fuel assembly emplaced to yield a 36 kw/acre (8.9 w/m 2 ) loading. A unit cell model in an infinite array is used to simplify the problem and provide upper-bound temperatures. Boundary conditions are imposed which allow simulations to 1000 years. Variations studied include a comparison of ventilated and unventilated storage room conditions, emplacement packages with and without air gaps surrounding the canister, and room cool-down scenarios with ventilation following an unventilated state for retrieval purposes. At this low power level ventilating the emplacement room has an immediate cooling influence on the canister and effectively maintains the emplacement room floor near the temperature of the ventilating air. The annular gap separating the canister and sleeve causes the peak temperature of the canister surface to rise by 10 0 F (5.6 0 C) over that from a no gap case assuming perfect thermal contact. It was also shown that the time required for the emplacement room to cool down to 100 0 F (38 0 C) from an unventilated state ranged from 2 weeks to 6 months; when ventilation initiated after times of 5 years to 50 years, respectively. As the work was performed for the Nuclear Regulatory Commission, these results provide a significant addition to the regulatory data base for spent fuel performance in a geologic repository

  2. UCRL--84153

    International Nuclear Information System (INIS)

    Altenbach, T.J.; Lowry, W.E.

    1980-01-01

    A three-dimensional thermal analysis has been performed using finite difference techniques to determine the near-field response of a baseline spent fuel repository in a deep geologic salt medium. A baseline design incorporates previous thermal modeling experience and OWI recommendations for areal thermal loading in specifying the waste form properties, package details, and emplacement configuration. The base case in this thermal analysis considers one 10-year old PWR spent fuel assembly emplaced to yield a 36 kw/acre (8.9 w/m 2 ) loading. A unit cell model in an infinite array is used to simplify the problem and provide upper-bound temperatures. Boundary conditions are imposed which allow simulations to 1000 years. Variations studied include a comparison of ventilated and unventilated storage room conditions, emplacement packages with and without air gaps surrounding the canister, and room cool-down scenarios with ventilation following an unventilated state for retrieval purposes. At this low power level ventilating the emplacement room has an immediate cooling influence on the canister and effectively maintains the emplacement room floor near the temperature of the ventilating air. The annular gap separating the canister and sleeve causes the peak temperature of the canister surface to rise by 10 0 F (5.6 0 C) over that from a no gap case assuming perfect thermal contact. It was also shown that the time required for the emplacement room to cool down to 1000 0 C) from an unventilated state ranged from 2 weeks to 6 months; when ventilation initiated after times of 5 years to 50 years, respectively. As the work was performed for the Nuclear Regulatory Commission, these results provide a significant addition to the regulatory data base for spent fuel performance in a geological repository

  3. Ground Control System Description Document

    International Nuclear Information System (INIS)

    Eric Loros

    2001-01-01

    The Ground Control System contributes to the safe construction and operation of the subsurface facility, including accesses and waste emplacement drifts, by maintaining the configuration and stability of the openings during construction, development, emplacement, and caretaker modes for the duration of preclosure repository life. The Ground Control System consists of ground support structures installed within the subsurface excavated openings, any reinforcement made to the rock surrounding the opening, and inverts if designed as an integral part of the system. The Ground Control System maintains stability for the range of geologic conditions expected at the repository and for all expected loading conditions, including in situ rock, construction, operation, thermal, and seismic loads. The system maintains the size and geometry of operating envelopes for all openings, including alcoves, accesses, and emplacement drifts. The system provides for the installation and operation of sensors and equipment for any required inspection and monitoring. In addition, the Ground Control System provides protection against rockfall for all subsurface personnel, equipment, and the engineered barrier system, including the waste package during the preclosure period. The Ground Control System uses materials that are sufficiently maintainable and that retain the necessary engineering properties for the anticipated conditions of the preclosure service life. These materials are also compatible with postclosure waste isolation performance requirements of the repository. The Ground Control System interfaces with the Subsurface Facility System for operating envelopes, drift orientation, and excavated opening dimensions, Emplacement Drift System for material compatibility, Monitored Geologic Repository Operations Monitoring and Control System for ground control instrument readings, Waste Emplacement/Retrieval System to support waste emplacement operations, and the Subsurface Excavation System

  4. DRIFT-SCALE COUPLED PROCESSES (DST AND TH SEEPAGE) MODELS

    International Nuclear Information System (INIS)

    J.T. Birkholzer; S. Mukhopadhyay

    2005-01-01

    The purpose of this report is to document drift-scale modeling work performed to evaluate the thermal-hydrological (TH) behavior in Yucca Mountain fractured rock close to waste emplacement drifts. The heat generated by the decay of radioactive waste results in rock temperatures elevated from ambient for thousands of years after emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling conditions in the rock, giving rise to water redistribution and altered flow paths. The predictive simulations described in this report are intended to investigate fluid flow in the vicinity of an emplacement drift for a range of thermal loads. Understanding the TH coupled processes is important for the performance of the repository because the thermally driven water saturation changes affect the potential seepage of water into waste emplacement drifts. Seepage of water is important because if enough water gets into the emplacement drifts and comes into contact with any exposed radionuclides, it may then be possible for the radionuclides to be transported out of the drifts and to the groundwater below the drifts. For above-boiling rock temperatures, vaporization of percolating water in the fractured rock overlying the repository can provide an important barrier capability that greatly reduces (and possibly eliminates) the potential of water seeping into the emplacement drifts. In addition to this thermal process, water is inhibited from entering the drift opening by capillary forces, which occur under both ambient and thermal conditions (capillary barrier). The combined barrier capability of vaporization processes and capillary forces in the near-field rock during the thermal period of the repository is analyzed and discussed in this report

  5. Waste disposal developments within BNFL

    International Nuclear Information System (INIS)

    Johnson, L.F.

    1989-01-01

    British Nuclear Fuels plc has broad involvement in topics of radioactive waste generation, treatment, storage and disposal. The Company's site at Drigg has been used since 1959 for the disposal of low level waste and its facilities are now being upgraded and extended for that purpose. Since September 1987, BNFL on behalf of UK Nirex Limited has been managing an investigation of the Sellafield area to assess its suitability for deep underground emplacement of low and intermediate level radioactive wastes. An approach will be described to establish a partnership with the local community to work towards a concept of monitored, underground emplacement appropriate for each waste category. (author)

  6. Feasibility of permeation grouting for constructing subsurface barriers

    International Nuclear Information System (INIS)

    Dwyer, B.P.

    1994-03-01

    The technical feasibility of emplacing a barrier beneath a waste site using directionally drilled boreholes and permeation grouting was investigated. The benefits of this emplacement system are: (1) Directionally drilled boreholes provide access beneath a waste site without disturbing the waste; (2) interim containment of contaminants allows time for the development of remediation options; (3) in the interim, the volume of waste remains fixed; (4) barriers may enhance the effectiveness of in situ remediation actions; and (5) barrier systems may provide permanent waste containment

  7. Therapeutic experiences of community gardens: putting flow in its place.

    Science.gov (United States)

    Pitt, Hannah

    2014-05-01

    This paper develops the concept of therapeutic place experiences by considering the role of activity. Research of community gardening finds that particular tasks are therapeutic and exhibit the characteristics of flow, but those who lack influence over their community gardening are less likely to benefit from flow as their sense of control is reduced. The notion of emplaced flow is proposed to locate individual experiences amongst socio-spatial factors which limit self-determinacy and therefore affect wellbeing. Emplacing flow prompts critical reflection on who is excluded from therapeutic place experiences, and whether sites offering momentary escape have an enduring impact on wellbeing. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Tectono-volcanic control of fissure type vents for the 28 Ma Panalillo ignimbrite in the Villa de Reyes Graben, San Luis PotosI, Mexico

    International Nuclear Information System (INIS)

    Tristan-Gonzalez, Margarito; Labarthe-Hernandez, Guillermo; Aguillon-Robles, Alfredo; Aguirre-DIaz, Gerardo J

    2008-01-01

    The volcano-tectonic events at the Villa de Reyes Graben (VRG), in the southern Sierra Madre Occidental, Mexico, include 1) a regional NNE fault system developed before 32 Ma, 2) this pre-32 Ma faulting controlled the emplacement of 31.5 Ma dacitic domes, 3) NE faulting at 28 Ma that displaced the 31.5 Ma dacitic domes and formed the VRG, as well as the oblique grabens of Bledos and Enramadas oriented NW, 4) emplacement of Panalillo ignimbrite at 28 Ma filling the VRG and erupting from fissures related to the oblique grabens, and eruption of Placa basalt apparently also from fault-controlled vents.

  9. Magma sources during Gondwana breakup: chemistry and chronology of Cretaceous magmatism in Westland, New Zealand

    DEFF Research Database (Denmark)

    van der Meer, Quinten Har Adriaan; Waight, Tod Earle; Scott, James M.

    2013-01-01

    by emplacement of granitoid plutons, the deposition of terrestrial Pororari Group sediments in extensional half-grabens across on- and offshore Westland, and the intrusion of mafic dikes from 90 Ma. These dikes are concentrated in the swarms of the Paparoa and Hohonu Ranges and were intruded prior...... to and simultaneous with volumetrically minor A-type plutonism at 82 Ma. The emplacement of mafic dikes and A-type plutonism at 82 Ma is significant as it coincides with the age of the oldest seafloor in the Tasman Sea, therefore it represents magmatism coincident with the initiation of seafloor spreading which...

  10. U-Pb zircon dating of the Bassies granite (Pyrenees): a syn-tectonic pluton of Westphalian age

    International Nuclear Information System (INIS)

    Paquette, J.L.

    1997-01-01

    A new U-Pb zircon age of 312 ± 2 Ma for the Bassies pluton (Pyrenees) contradicts the previous whole-rock Rb-Sr dating at 276 ± 16 Ma, which was considered as the age of emplacement, therefore regarded as post-tectonic. The new date is in agreement with recent structural studies which suggest a Hercynian syn-tectonic emplacement for the Bassies pluton. These results strengthen the few U-Pb ages already published for the Pyrenean granites and indicate that the Hercynian plutonism of the Pyrenees is essentially Carboniferous in age and syn-tectonic. (authors)

  11. Avance de la interpretación Geotectónica del emplazamiento del plutón granítico de Madridejos (Toledo, basada en determinaciones gravimétricas

    Directory of Open Access Journals (Sweden)

    Berjamín, J. F.

    1986-10-01

    Full Text Available The outcrops and subsurface geometry of Madridejos granitic body, has been studied using gravimetric and geological methods.
    This pluton is emplaced in a border of Urda-Consuegra antiform, this structure is high modification in the border where the pluton is emplaced.

    En función de datos gravimétricos y geológicos se establecen los límites del plutón granítico de Madridejos, tanto superficialmente como en profundidad.
    Este plutón se aloja en un extremo del domo de Urda-Consuegra, estructura a la que modifica sustancialmente.

  12. Mechanical and thermomechanical calculations related to the storage of spent nuclear-fuel assemblies in granite

    International Nuclear Information System (INIS)

    Butkovich, T.R.

    1980-05-01

    A generic test of the geologic storage of spent-fuel assemblies is being made at Nevada Test Site. The spent-fuel assemblies were emplaced at a depth of 420 m (1370 ft) below the surface in a typical granite and will be retrieved at a later time. The early time, close-in thermal history of this type of repository is being simulated with spent-fuel and electrically heated canisters in a central drift, with auxiliary heaters in two parallel side drifts. Prior to emplacement of the spent-fuel canisters, preliminary calculations were made using a pair of existing finite-element codes, ADINA and ADINAT

  13. Executive summary

    International Nuclear Information System (INIS)

    1981-02-01

    This paper is an 'executive summary' of work undertaken to review proposals for transport, handling and emplacement of high level radioactive wastes in an underground repository, appropriate to the U.K. context, with particular reference to: waste block size and configuration; self-shielded or partially-shielded block; stages of disposal; transportation within the repository; emplacement in vertical holes or horizontal tunnels; repository access by adit, incline or shaft; and costs. The paper contains a section on general conclusions and recommendations. (U.K.)

  14. Scoping calculations for canister-tunnel migration of corrodants, oxidants and radionuclides

    International Nuclear Information System (INIS)

    Shaw, W.; Worth, D.

    1992-03-01

    This report presents the mathematical models and results obtained for a set of scooping calculations which estimate the possible extent of the vertical migration of canister corrodants, oxidants (forming a redox front) and radionuclides between a copper canister containing spent nuclear fuel, and an overlying emplacement tunnel. The KBS-3 concept for the disposal of spent nuclear fuel is copper canisters, vertically emplaced in deposition holes bored in the floor of a tunnel, situated deep underground. The deposition holes are filled with a buffer of bentonite and the tunnel is backfilled with a mixture of sand and bentonite. (au)

  15. Evidence of syn tectonic tephrites with nepheline in the Sidi Said Maachou Cambrian basin (coastal Meseta, Morocco); geo dynamic implications; Mise en evidence de tephrites a nepheline syntectoniques dans le bassin cambrien de Sidi Said Maachou (Meseta cotiere, Maroc); signification geodynamique

    Energy Technology Data Exchange (ETDEWEB)

    Remmal, T.; Mohsine, A.; El Hatimi, N.

    2009-07-01

    Based on a combined structural, petrographic, and geochemical analysis, a new interpretation of the basic magmatism of Sidi Said Maachou (coastal Meseta) in two stages of emplacement is proposed. The first stage is characterized by transitional pyroclastic flows that have accompanied the opening of the West-Mesetian basin, during the Cambrian; the second stage is made of dykes of basalts, dolerites, and tephrites bearing nepheline. The emplacement of this undersaturated alkaline magma is associated to a sinistral sub meridian shear zone which has been activated at the end of the Caledonian orogenesis, by a mantellic advection. (Author) 32 refs.

  16. Determination of performance criteria for high-level solidified nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Heckman, R.A.; Holdsworth, T.

    1979-05-07

    To minimize radiological risk from the operation of a waste management system, performance limits on volatilization, particulate dispersion, and dissolution characteristics of solidified high level waste must be specified. The results show clearly that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. Absolute values of expected risk are very sensitive to modeling assumptions. The transportation and interim storage operations appear to be most limiting in determining the performance characteristics required. The expected values of risk do not rely upon the repositories remaining intact over the potentially hazardous lifetime of the waste.

  17. Determination of performance criteria for high-level solidified nuclear waste from the commercial nuclear fuel cycle: a probabilistic safety analysis

    International Nuclear Information System (INIS)

    Heckman, R.A.

    1978-01-01

    To minimize the radiological risk from the operation of a waste management system for the safe disposal of high-level waste, performance characteristics of the solidified waste form must be specified. The minimum waste form characteristics that must be specified are the radionuclide volatilization fraction, airborne particulate dispersion fraction, and the aqueous dissolution characteristics. The results indicate that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. The actual values of expected risk are sensitive to modeling assumptions and data base uncertainties. The transportation step appears to be the most limiting in determining the required performance characteristics

  18. Determination of performance criteria for high-level solidified nuclear waste

    International Nuclear Information System (INIS)

    Heckman, R.A.; Holdsworth, T.

    1979-01-01

    To minimize radiological risk from the operation of a waste management system, performance limits on volatilization, particulate dispersion, and dissolution characteristics of solidified high level waste must be specified. The results show clearly that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. Absolute values of expected risk are very sensitive to modeling assumptions. The transportation and interim storage operations appear to be most limiting in determining the performance characteristics required. The expected values of risk do not rely upon the repositories remaining intact over the potentially hazardous lifetime of the waste

  19. Thermal analyses for a nuclear-waste repository in tuff using USW-G1 borehole data

    International Nuclear Information System (INIS)

    Johnson, R.L.

    1982-10-01

    Thermal calculations using properties of tuffs obtained from the USW-G1 borehole, located near the SW margin of the Nevada Test Site (NTS), have been completed for a nuclear waste repository sited in welded tuff below the water table. The analyses considered two wasteforms, high level waste and spent fuel, emplaced at two different, gross thermal loadings, 50 and 75 kW/Acre (20.24 and 30.36 kW/ha). Calculations were made assuming that no boiling of the groundwater occurs; i.e., that the hydrostatic head potential was reestablished soon after waste emplacement. 23 figures, 2 tables

  20. The NPE gas tracer test and the development of on-site inspection techniques

    International Nuclear Information System (INIS)

    Carrigan, C.; Heinle, R.; Zucca, J.J.

    1995-01-01

    Tracer gases emplaced in or near the detonation cavity of the 1-kiloton Non-Proliferation Event required 1.5 and 13.5 months for sulfur hexaflouride and helium-3, respectively, to reach the surface of Rainier Mesa from an emplacement depth of 400 meters. The sites that first produced tracer gases are those located in known faults and fractures. Numerical modeling suggests that transport to the surface is accomplished within this time frame through atmospheric pumping along high permeability pathways such as fractures. The difference in travel time between the two tracers is due to differences in gas diffusivity and can also be explained by our numerical modeling. (author)

  1. The Nirex Safety Assessment Research Programme; annual report for 1988/89

    International Nuclear Information System (INIS)

    Cooper, M.J.

    1989-07-01

    This report summarises progress of the Nirex Safety Assessment Research Programme during 1988/89, in support of assessments of the post-emplacement radiological safety of a repository for the disposal of low-level and intermediate-level radioactive waste. During this period the assessments were concentrating on a comparative study of concepts and areas for deep emplacement of waste, in order to assist in the selection of preferred sites, and the research programme was therefore focussed on providing the data necessary for broad comparisons between different options to be made. (author)

  2. Thermoelastic/plastic analysis of waste-container sleeve: IV. Air gap influence on hole closure. Technical memorandum report (RSI-0019)

    International Nuclear Information System (INIS)

    Pariseau, W.G.

    1975-01-01

    A thermoelastic/plastic finite element analysis of the influence of an air-gap on hole closure about a waste-container/sleeve assembly emplaced in a typical repository room (SALT/4T Model) indicates that hole closure would be of the order of hundredths of an inch. Acceptable air-gap width is thus governed by the hole size required for emplacement efficiency. A refined mesh analysis and laboratory testing is suggested in order to further explore the possibility of eliminating the engineering necessity of the sleeve

  3. Tectono-volcanic control of fissure type vents for the 28 Ma Panalillo ignimbrite in the Villa de Reyes Graben, San Luis PotosI, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tristan-Gonzalez, Margarito; Labarthe-Hernandez, Guillermo; Aguillon-Robles, Alfredo [Instituto de Geologia/DES IngenierIa, UASLP, Av. Dr. Manuel Nava 5, Zona Universitaria, C.P. 78240, San Luis PotosI, S.L.P. (Mexico); Aguirre-DIaz, Gerardo J [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, 76230 (Mexico)], E-mail: mtiistan@uasln.mx, E-mail: ger@geociencias.unam.mx

    2008-10-01

    The volcano-tectonic events at the Villa de Reyes Graben (VRG), in the southern Sierra Madre Occidental, Mexico, include 1) a regional NNE fault system developed before 32 Ma, 2) this pre-32 Ma faulting controlled the emplacement of 31.5 Ma dacitic domes, 3) NE faulting at 28 Ma that displaced the 31.5 Ma dacitic domes and formed the VRG, as well as the oblique grabens of Bledos and Enramadas oriented NW, 4) emplacement of Panalillo ignimbrite at 28 Ma filling the VRG and erupting from fissures related to the oblique grabens, and eruption of Placa basalt apparently also from fault-controlled vents.

  4. 10 CFR 60.17 - Contents of site characterization plan.

    Science.gov (United States)

    2010-01-01

    ....17 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) DISPOSAL OF HIGH-LEVEL RADIOACTIVE WASTES IN... radioactive waste; (iv) Plans to control any adverse impacts from such site characterization activities that...-level radioactive waste to be emplaced in such geologic repository, a description (to the extent...

  5. The HAW-project: Demonstration facility for the disposal of high-level waste in salt

    International Nuclear Information System (INIS)

    Rothfuchs, T.; Duijves, K.A.

    1990-04-01

    The HAW-project plants the testwise emplacement of 30 vitrified highly radioactive canisters containing Cs-137 and Sr-90 at the 800 m level of the Asse salt mine for a testing period of approximately five years. The major objective of this project is the pilot testing and demonstration of safe methods for the final disposal of high-level radioactive waste (HAW) in geological salt formations. During the years 1985 to 1989 the underground test field was excavated, the measuring equipment installed, and two preceedings inactive electrical tests taken into operation. Furthermore, the components of a system for transportation and emplacement of highly radioactive canisters was fabricated, installed, and preliminarily tested. After some delays in the licensing procedure the emplacement of the 30 radioactive canisters is now envisaged for early 1991. For handling of the radioactive canisters and their emplacement into the boreholes a system consisting of a transport cask, a transport vehicle, a disposal machine, and of a borehole slider has been developed and will be tested. The actual scientific investigation programme is based on the estimation and observation of the interaction between the radioactive canisters and the rock salt. This programme includes measurement of thermally and radiolytically induced water and gas release from the rock salt and the radiolytical decomposition of salt minerals. Also the thermally induced stress and deformation fields in the surrounding rock mass will be investigated carefully. (orig./HP)

  6. SUBSURFACE DESIGN SUPPORT LOW THERMAL LOAD REPOSITORY (25 MTU/ACRE)

    International Nuclear Information System (INIS)

    T.M. Lahnalampi

    1999-01-01

    The objective of this document is to present a comparison between the Viability Assessment Design Layout and a 25 MTU/acre conceptual repository design. The scope of this analysis is comparing the linear dimensions and the quantities of the major design elements, for example, emplacement drifts, perimeter mains, exhaust mains, performance confirmation drifts, connecting ramps and vertical development

  7. 10 CFR 61.2 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Definitions. 61.2 Section 61.2 Energy NUCLEAR REGULATORY....2 Definitions. As used in this part: Active maintenance means any significant remedial activity... biosphere inhabited by man and containing his food chains by emplacement in a land disposal facility...

  8. Geophysical characterization of subsurface barriers

    International Nuclear Information System (INIS)

    Borns, D.J.

    1995-08-01

    An option for controlling contaminant migration from plumes and buried waste sites is to construct a subsurface barrier of a low-permeability material. The successful application of subsurface barriers requires processes to verify the emplacement and effectiveness of barrier and to monitor the performance of a barrier after emplacement. Non destructive and remote sensing techniques, such as geophysical methods, are possible technologies to address these needs. The changes in mechanical, hydrologic and chemical properties associated with the emplacement of an engineered barrier will affect geophysical properties such a seismic velocity, electrical conductivity, and dielectric constant. Also, the barrier, once emplaced and interacting with the in situ geologic system, may affect the paths along which electrical current flows in the subsurface. These changes in properties and processes facilitate the detection and monitoring of the barrier. The approaches to characterizing and monitoring engineered barriers can be divided between (1) methods that directly image the barrier using the contrasts in physical properties between the barrier and the host soil or rock and (2) methods that reflect flow processes around or through the barrier. For example, seismic methods that delineate the changes in density and stiffness associated with the barrier represents a direct imaging method. Electrical self potential methods and flow probes based on heat flow methods represent techniques that can delineate the flow path or flow processes around and through a barrier

  9. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Google Earth Image and cross-cutting field relationships of distinct Paleoproterozoic mafic dykes from south of Devarakonda area in the Eastern Dharwar Craton has been studied to establish relative emplacement ages. The Devarakonda, covering an area of ∼700 km2, shows spectacular cross-cutting field relationships ...

  10. Project Rio Blanco: detonation related activities. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    Project Rio Blanco is described in relation to detonation, its history, execution, and results. Topics discussed include generalized site activities, emplacement well, explosive services and operations, operational safety, environmental protection program, seismic effects and damage claims, and add-on programs. (U.S.)