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1

Fundamentals of Structural Geology  

Science.gov (United States)

Fundamentals of Structural Geology provides a new framework for the investigation of geological structures by integrating field mapping and mechanical analysis. Assuming a basic knowledge of physical geology, introductory calculus and physics, it emphasizes the observational data, modern mapping technology, principles of continuum mechanics, and the mathematical and computational skills, necessary to quantitatively map, describe, model, and explain deformation in Earth's lithosphere. By starting from the fundamental conservation laws of mass and momentum, the constitutive laws of material behavior, and the kinematic relationships for strain and rate of deformation, the authors demonstrate the relevance of solid and fluid mechanics to structural geology. This book offers a modern quantitative approach to structural geology for advanced students and researchers in structural geology and tectonics. It is supported by a website hosting images from the book, additional colour images, student exercises and MATLAB scripts. Solutions to the exercises are available to instructors. The book integrates field mapping using modern technology with the analysis of structures based on a complete mechanics MATLAB is used to visualize physical fields and analytical results and MATLAB scripts can be downloaded from the website to recreate textbook graphics and enable students to explore their choice of parameters and boundary conditions The supplementary website hosts color images of outcrop photographs used in the text, supplementary color images, and images of textbook figures for classroom presentations The textbook website also includes student exercises designed to instill the fundamental relationships, and to encourage the visualization of the evolution of geological structures; solutions are available to instructors

Pollard, David D.; Fletcher, Raymond C.

2005-09-01

2

Analysis of effects of geological structures in rock driving by TBM  

Directory of Open Access Journals (Sweden)

Full Text Available Although mechanical properties belongs to important parameter for the excavation modelling, effect of geological structures on the rock massive fragmentation is often much higher than varying rock properties. This paper deals with the analysis of geological structures. It is focused on the schistosity orientation towards the tunnel azimuth. The aim is to define of schistosity effect on the penetration rate. It is a basis creating of fuzzy rules for the performance model full-profile tunnel boring machine

?udmila Tréfová

2006-12-01

3

OpenStereo: Open Source, Cross-Platform Software for Structural Geology Analysis  

Science.gov (United States)

Free and open source software (FOSS) are increasingly seen as synonyms of innovation and progress. Freedom to run, copy, distribute, study, change and improve the software (through access to the source code) assure a high level of positive feedback between users and developers, which results in stable, secure and constantly updated systems. Several software packages for structural geology analysis are available to the user, with commercial licenses or that can be downloaded at no cost from the Internet. Some provide basic tools of stereographic projections such as plotting poles, great circles, density contouring, eigenvector analysis, data rotation etc, while others perform more specific tasks, such as paleostress or geotechnical/rock stability analysis. This variety also means a wide range of data formating for input, Graphical User Interface (GUI) design and graphic export format. The majority of packages is built for MS-Windows and even though there are packages for the UNIX-based MacOS, there aren't native packages for *nix (UNIX, Linux, BSD etc) Operating Systems (OS), forcing the users to run these programs with emulators or virtual machines. Those limitations lead us to develop OpenStereo, an open source, cross-platform software for stereographic projections and structural geology. The software is written in Python, a high-level, cross-platform programming language and the GUI is designed with wxPython, which provide a consistent look regardless the OS. Numeric operations (like matrix and linear algebra) are performed with the Numpy module and all graphic capabilities are provided by the Matplolib library, including on-screen plotting and graphic exporting to common desktop formats (emf, eps, ps, pdf, png, svg). Data input is done with simple ASCII text files, with values of dip direction and dip/plunge separated by spaces, tabs or commas. The user can open multiple file at the same time (or the same file more than once), and overlay different elements of each dataset (poles, great circles etc). The GUI shows the opened files in a tree structure, similar to “layers” of many illustration software, where the vertical order of the files in the tree reflects the drawing order of the selected elements. At this stage, the software performs plotting operations of poles to planes, lineations, great circles, density contours and rose diagrams. A set of statistics is calculated for each file and its eigenvalues and eigenvectors are used to suggest if the data is clustered about a mean value or distributed along a girdle. Modified Flinn, Triangular and histograms plots are also available. Next step of development will focus on tools as merging and rotation of datasets, possibility to save 'projects' and paleostress analysis. In its current state, OpenStereo requires Python, wxPython, Numpy and Matplotlib installed in the system. We recommend installing PythonXY or the Enthought Python Distribution on MS-Windows and MacOS machines, since all dependencies are provided. Most Linux distributions provide an easy way to install all dependencies through software repositories. OpenStereo is released under the GNU General Public License. Programmers willing to contribute are encouraged to contact the authors directly. FAPESP Grant #09/17675-5

Grohmann, C. H.; Campanha, G. A.

2010-12-01

4

Geologic structure analysis using radar imagery of the coal mining area of Buchanan County, Va. [Side-looking Airborne Radar  

Energy Technology Data Exchange (ETDEWEB)

An analysis of the geologic structure of an area of Buchanan County, Va., was made using imagery from an airborne AN/APQ-97 side-looking radar system to evaluate that mapping technique for delineating structural features that may cause mining problems. Side-looking airborne radar (SLAR) was found to be a useful remote sensing tool for geologic structural analysis. Fault and joint systems identified by lineaments and linear patterns in the imagery were verified by surface and in-mine observations. Little Paw Paw fault was extended 10 miles by SLAR lineament analysis. A 22-mile fault, here named the Bishop-Bradshaw Creek fault, was mapped by lineament analysis and verified by observation of the fault on the Bishop Coal Co. mine map and on offset patterns of commercial gas production along the fault and surface observation of lineament along the fault. Three major superimposed joint sets and several fault or fractured zones were identified by SLAR lineament analysis, showing more complex structure than earlier mapping indicated. SLAR imagery accurately delineated structural features known to affect gas migration and accumulation and that weaken the rock forming the immediate roof to mine workings, causing mining problems and potentially hazardous environment in the mines. The value of this remote sensing technique is greatest in areas where aerial photographic sensors working in the visible and near-infrared part of the electromagnetic spectrum are unable to achieve usable imagery and where ground investigations are time consuming and difficult.

Elder, C.H.; Jeran, P.W.; Keck, D.A.

1974-01-01

5

Seismic structural analysis of a conceptual waste package design for disposal of high level nuclear waste in a geologic repository  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the methodology used to perform seismic structural analyses on a conceptual waste package design for the disposal of high-level nuclear waste in a geologic respository. The waste package design analyzed is intended to hold uncanistered spent fuel. The purpose of this analysis is to determine if the proposed waste package design can withstand the seismic loads caused by nearby fault movement during the preclosure period of the repository without breaching the inner or outer waste package barriers or damaging the internal structures, which would affect their ability to separate the waste forms. For uncanistered spent fuel waste packages, this is interpreted to mean that no yielding of the basket structure is permitted.

Ceylan, Z.; Bennett, S.M.; Doering, T.W.

1995-12-31

6

Structural geology of impact craters  

Science.gov (United States)

The formation of impact craters is a highly dynamic and complex process that subjects the impacted target rocks to numerous types of deformation mechanisms. Understanding and interpreting these styles of micro-, meso- and macroscale deformation has proved itself challenging for the field of structural geology. In this paper, we give an overview of the structural inventory found in craters of all size ranges on Earth, and look into the structures of craters on other planetary bodies. Structural features are discussed here that are caused by i) extremely high pressures and temperatures that occur during the initial passage of the shock wave through the target rock and projectile, ii) the resulting flow field in the target that excavates and ejects rock materials, and iii) the gravitationally induced modification of the crater cavity into the final crater form. A special focus is put on the effects that low-angle impacting bodies have on crater formation. We hope that this review will help both planetary scientists and structural geologists understand the deformation processes and resulting structures generated by meteorite impact.

Kenkmann, Thomas; Poelchau, Michael H.; Wulf, Gerwin

2014-05-01

7

Analysis of spatial geologic data using surface modeling and geographic information system software - Applications to regional geologic mapping, San Juan structural basin, New Mexico, Colorado, Arizona, and Utah  

Energy Technology Data Exchange (ETDEWEB)

Surface-generating software is being used to construct geologic contour maps of aquifers in the San Juan basin. The maps are being prepared for the US Geological Survey's San Juan Basin Regional Aquifer-System Analysis. Geologic tops picked from geophysical logs are selected primarily from a data base of approximately 24,000 oil and gas test wells, supplemented with data from water wells and outcrops. A program was developed to eliminate suspected inaccurate data points intersecting the geographic information system coverage of control points with a polygon coverage of a fine-mesh grid. Points are collected by grid cell, and a mean value is determined for tops and map-unit coordinates. Points whose tops deviate significantly from the mean are deleted if incorrect. Geologic tops and map-unit coordinates of remaining control points in the same grid cell are reaveraged to reduce (1) small discrepancies at specific points and (2) the number of points used. Formatted data are gridded by the surface-generating software, and a contour map is produced. If the map is satisfactory, the grid is smoothed to reduce abrupt meandering of contours. The map is redrawn using an option that produces a contour-output file containing map-unit coordinates and numerical-attribute values of contours. This file is used to create a geographic information system coverage. When a satisfactory contour map is produced and converted to a line coverage, the geographic information system edits, annotates, and clips contours with another line coverage consisting of the basinward part of the outcrop.

Craigg, S.D. (Geological Survey, Albuquerque, NM (USA))

1989-09-01

8

Seismic hazard analysis of nuclear power plant site using geological structure data  

International Nuclear Information System (INIS)

The seismic hazard assessment for the nuclear power plant is mainly controlled by the instrumental earthquake data, the record of historical earthquake damages, and the data of recent faulting. The important problems of the seismic hazard analysis in Korea are the evaluation of the Quaternary fault activities and the calculation of earthquake potential from the faults. Generally, the evaluation of earthquake potential from the fault parameters could be obtained from the empirical relationship equations among the fault rupture length, fault displacement, fault area and earthquake magnitude. In spite of the these empirical equations have some problems, these equations have been usefully applied to the siting of the nuclear power plant in Japan and the academic research. However, because of these equations are not considered the characteristics of fault behavior, there are some problems of overestimation and uncertainty to evaluate the earthquake potential. Ultimately, to evaluate the adequate earthquake potential we suggest that the characteristics of fault behavior should be considered in analyzing the seismic hazard

2001-05-01

9

Google Earth Exercises for Structural Geology  

Science.gov (United States)

We use these Google Earth Exercises (GEE) in the undergraduate structural geology course. Students construct a complete geologic map of each 'field area' outside of class; in class, the students display their map and discuss their observations, interpretations, assumptions, and reasoning. This exercise promotes discussion among the students, and also provides students with the opportunity to develop speaking skills, as well as 'on-your feet' reasoning and analysis. Mapping can be done digitally using graphic software such as Adobe IllustratorTM or using hard copy images and overhead transparencies. (Digital mapping requires that the students have knowledge of working with, and access, to a graphics program such as Adobe IllustratorTM). Students also draw stratigraphic columns and cross-sections as needed; and they determine a relative sequence of events for each 'field' area. Cross section lines are included in the .kmz (Google Earth) file (not on the map images). This allows the instructor to move cross-section locations as needed. We have 3-4 students display and discuss maps for each exercise (usually takes about 30-45 min.); we encourage student to question their classmates; with time, our encouragement becomes less necessary. We have students construct geologic maps on transparencies and display the maps via an overhear projector keeping the LCD projector free to run Google Earth. Students can use Google Earth (flying to specific locations, or zooming in and out, or viewing specific locations from different perspectives) during their presentation to illustrate or support their interpretation, and logic path that lead to that interpretation to the class. This provides the opportunity for students to see how different people interpret the same area; they also learn that although each maps is different, each map tells a similar story; that is first-order relationships emerge from the family of maps constructed by their fellow classmates. After each discussion, all of the students display their maps on a side table in the classroom, providing the students with the opportunity to compare all of the maps of the same area. As a result they clearly see that all maps are different, yet each can be valid, and they also see how others handled both geologic relations, and, at a more basic level, clarity and neatness in presentation. As the semester progresses we see a sharp increase in the quality of the maps, both geologically and in terms of clarity and neatness, likely a direct result of students both viewing their classmates maps, and having their maps viewed by classmates. Peer pressure can be a wonderful learning tool. Each exercise focuses on a different area. An individual exercise or any combination of exercises maybe used at the instructor's discretion to compliment topics in either lecture or lab. The exercises, as presented, are ordered in such a way that they take the student progressively from relatively straightforward map areas to increasing complicated map areas. We begin the geologic mapping sequence using a Venus mapping exercise available on the SERC site http://serc.carleton.edu/NAGTWorkshops/structure04/activities/3875.html in order to get the students to feel comfortable identifying and delineating patterns; we develop concepts about material units versus structural elements (and in some cases primary verses secondary structures; please see the Venus exercise for the range of students goals, which we do not repeat here). The first Google Earth Exercise, (GEE1) follows the SERC exercise 'Visualizing Inclined Contacts' by Barbara Tewksbury http://serc.carleton.edu/NAGTWorkshops/structure/visualizing_inclined.html . Our GEE1 exercise is included below with all credit to Barbara Tewksbury. Subsequent exercises (GEE2, GEE3, etc.) include: faults and topographic interactions; folds and topographic interactions; faults and crosscutting dikes; refolded folds. These exercises may be used in any order and/or positioning within a course. We find that both the repetition of GEE exercises, and the progression of incre

Dyess, Jonathan

10

Seismic interpretation of circular geological structures  

Energy Technology Data Exchange (ETDEWEB)

3D seismic data provide images of geological features which are approximately circular in plan view but whose shape and origin may be possible to constrain using 2D seismic data. As 3D seismic data become more commonly employed in hydrocarbon exploration, the number of demonstrably 'circular' structures will increase. At least ten different geological processes can result in seismically resolvable 'circular' structures in sedimentary basins. These include salt/shale diapirs, salt withdrawal basins, polygonal fault blocks, dissolution collapse hollows, breccia pipes, calderas, gas pockmarks, bioherms, sand volcanoes, pull-aparts, impact craters and tectonic folds. Geometrical and geological criteria for each are summarized to facilitate identification of such features should they be encountered in the course of a 3D seismic interpretation. Certain types of geological feature have distinctive properties, others are less straightforward to recognize on the basis of individual criteria. (Author)

Stewart, S.A. [Amerada Hess Ltd., London (United Kingdom)

1999-08-01

11

The need for the geologic hazard analysis  

International Nuclear Information System (INIS)

The parameters which are considered in the hazard analysis associated with the movements of the Earth Crust are considered. These movements are classified as: fast movements or seismic movements, which are produced in a certain geologic moment at a speed measured in cm/sg, and slow movements or secular movements, which take place within a long span of time at a speed measured by cm/year. The relations space/time are established after Poisson and Gumbel's probabilistic models. Their application is analyzed according to the structural gradient fields, which fall within Matteron's geostatistics studies. These statistic criteria should be analyzed or checked up in each geo-tectonic environment. This allows the definition of neotectonic and seismogenetic zones, because it is only in these zones where the probabilistic or deterministic criteria can be applied to evaluate the hazard and vulnerability, that is, to know the geologic hazard of every ''Uniform'' piece of the Earth Crust. (author)

1984-01-01

12

GIS-technologies as a mechanism to study geological structures  

Science.gov (United States)

Specialized GIS-technologies allow creating multi-parameter models, completing multi-criteria optimisation tasks, and issues of geological profile forecasts using miscellaneous data. Pictorial and attributive geological and geophysical information collected to create GIS database is supplemented by the ERS (Earth's Remote Sensing) data, air spectrometry, space images, and topographic data. Among the important tasks are as follows: a unification of initial geological, geophysical and other types of information on a tectonic position, rock classification and stratigraphic scale; topographic bases (various projectures, scales); the levels of detail and exhaustibility; colors and symbols of legends; data structures and their correlation; units of measurement of physical quantities, and attribute systems of descriptions. Methods of the geological environment investigation using GIS-technology are based on a principle of the research target analogy with a standard. A similarity ratio is quantitative estimate. A geological forecast model is formed by structuring of geological information based on detailed analysis and aggregation of geological and formal knowledge bases on standard targets. Development of a bank of models of the analyzed geological structures of various range, ore-bearing features described by numerous prospecting indicators is the way to aggregate geological knowledge. The south terrain of the Valerianovskaya structure-facies zone (SFZ) of the Torgai paleo-rift structure covered with thick Mesozoic and Cenozoic rocks up to 2,000m is considered a so-called training ground for the development of GIS-technology. Parameters of known magnetite deposits located in the north of the SFZ (Sarybaiskoye, Sokolovskoye, etc.) are used to create the standard model. A meaning of the job implemented involves the following: - A goal-seeking nature of the research being performed and integration of the geological, geo-physical and other data (in many cases, efforts of the Earth scientists are odd, thus, solving only local tasks); - Development of specialized GIS-technology that ensures creating multi-parameter models, completing multi-criteria optimisation tasks, and issues of geological profile forecasts using miscellaneous data; - Application of the modern approach to the geological, petrological and genetic modeling of the targets in the geological zone under survey; determination of the structural and tectonic position of the Valerianovskaya SFZ and its relations to the mineralization; - A possibility to apply the GIS created for the region as a desk (local) system integrated to the regional or national bank of geospatial information with a corporate access via local and global networks.

Sharapatov, Abish

2014-05-01

13

Formation of secondary phases during deep geological final disposal of research reactor fuel elements. Structure and phase analysis  

International Nuclear Information System (INIS)

For the assessment of a confident und sustainable final disposal of high level radioactive waste - fuel elements of german research reactors also account for such waste - in suitable, deep geological facilities, processes of the alteration of the disposed of waste and therefore the formation of the corrosion products, i. e. secondary phases must be well understood considering an accident scenario of a potential water inflow. In order to obtain secondary phases non-irradiated research reactor fuel elements (FR-BE) consisting of UAlx-Al were subjected to magnesium chloride rich brine (brine 2, salt repository) and to clay pore solution, respectively and furthermore of the type U3Si2-Al were solely subjected to magnesium chloride rich brine. Considering environmental aspects of final repositories the test conditions of the corrosion experiments were adjusted in a way that the temperature was kept constant at 90 C and a reducing anaerobic environment was ensured. As major objective of this research secondary phases, obtained from the autoclave experiments after appropriate processing and grain size separation have been identified and quantified. Powder X-ray diffraction (PXRD) and the application of Rietveld refinement methods allowed the identification of the corrosion products and a quantitative assessment of crystalline and amorphous contents. Scanning and transmission electron microscopy were additionally applied as a complementary method for the characterisation of the secondary phases. The qualitative phase analysis of the preprocessed secondary phases of the systems UAlx-Al and U3Si2-Al in brine 2 shows many similarities. Lesukite - an aluminium chloro hydrate - was observed for the first time considering the given experimental conditions. Further on different layered structures of the LDH type, iron oxyhydroxide and possibly iron chlorides, uncorroded residues of nuclear fuel and elementary iron were identified as well. Depending on preceding preparation procedures of the secondary phases the phase mixture resulted in different constituents. By preparation in water the stable phases obtained were aluminium hydroxides and not lesukite. Crystalline phases containing silicon were solely observed in the system U3Si2-Al in brine 2 being prepared with water. Contrary to these observations the system UAlx-Al in Mont Terri solution (clay pore water) qualitatively exhibits distinct different phase contents. Goethite, gypsum, hemi hydrate (bassanite), and accessory hematite were the only crystalline phases observed. Additionally aluminium and UAl4 as residues of nuclear fuel were also found. Considering the quantification of the brine 2 systems many common observations could be made. With respect to the corrosion products of UAlx-Al und U3Si2-Al prepared with isopropanol, lesukite and LDH compounds are the most abundant phases. The amorphous content, elemental iron and uncorroded residues of the nuclear fuel are mainly enriched in the coarse grain size fraction > 63 ?m. The water treatment of the secondary phases resulted in much less yield of solids. Quantitatively aluminium hydroxides exhibited the highest abundance. Clear differences could be observed in the system UAlx-Al in Mont Terri solution in view of the fact that the amorphous phases show the highest content of the corrosion products. The secondary phases could retain radioactive isotopes on the one hand by in situ formation and on the other hand by additionally being placed into stock as backfill, respectively. As special objective for assessing the potential of retention the amount of incorporation of europium into the crystal lattice of LDH compounds has also been investigated. Up to 20 mole percent considering the amount of aluminium were substituted by inactive europium acting as a trivalent simulant homologue for actinides. The refinement of the lattice parameters clearly indicated a linear relationship between the increase of the europium amount and the increase of the lattice parameters. The capacity of the incorporation of repository relevant isotopes in th

2012-01-01

14

Recent activity of the regional geologic structures in western Slovenia  

Directory of Open Access Journals (Sweden)

Full Text Available Several important geological structures in the western Slovenia were identifiedas active and their activity was quantified. Geologic interpretation is based on the analysis of repeated leveling line campaigns data along the Se?ovlje–Bled polygon. Taking intoaccount the limitations of the method – only the vertical component of displacement is measured – the following structures were identified as active:a juvenile syncline between Strunjan and Koper, the Kras Imbricate Structure, the Diva~a fault, the Ra{a fault, the Southalpine Front and the Julian Alps thrust. Vertical movement rate is relative, calculated with respect to the benchmark in Se?ovlje. The largest uplift rate difference between Se?ovlje and Bled is 7 mm/a.Vertical Geodynamic Activity (VGA is introduced as a link between geologic interpretation of geodetic measurements on one side and possible applications on the other as well as a mean of comparison between tectonically active regions.

Miloš Bavec

2007-06-01

15

Applied Structural Geology – Case Studies of Underground Constructions and Rockslides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An understanding of the structural elements in the sub-surface is of great importance when establishing new constructions in bedrock, or surveying areas prone to rockslides. In this thesis the focus has been on combining methods within geology, structural geology, geophysics and engineering geology to reach an interdisciplinary understanding and predict sub-surface structures. Geological feasibility studies for tunnel projects are a good aid to foresee areas of construction problems, such as ...

Ganerød, Guri Venvik

2008-01-01

16

Geological structure of the Semipalatinsk test site area  

International Nuclear Information System (INIS)

Semipalatinsk test site territory is situated at the turn of Chengiz-Torbagatay (Caledonian) and Irtysh-Zajsan (Hercynian) structural-formation zones, distinguishing by geological structure and metallogeny, and they are divided by Kalba-Chengiz deep-seated break. In the geological structure of the Upper Pre-Cambrian formation and by the all systems of Paleozoic era. The Upper Pre-Cambrian is presented with three rock masses of porphyrites and porphyritoides, peach stones, micro-quartzite developed in the Chengiz sub-zone. The Cambrian system is presented in the Chengiz sub-zone with volcano-gen-terrigenous rock mass. Analysis of formation precipitation types by elementary content and assumed condition of formation, separated formation series by all structure-formation sub-zones is carried out

1999-04-26

17

Discrete computer analysis in petroleum geology  

Energy Technology Data Exchange (ETDEWEB)

Computer analysis must not be resembling on geologist`s work, having its own way because of uncertainty and shortness of geological information even on mature stage of exploration, when our original system of formal discrete computer analysis, realised on {open_quotes}FoxPro for Windows{close_quotes} with not substantial but probabilistic (without ever driving the usual maps) representation of geological situation was used for picking out the sets of best points for exploration drilling in south part of Dheprovsko-Donetzky oil-gas basin.

Zakharian, A.Z.

1995-08-01

18

Three-dimensional Geological and Geo-mechanical Modelling of Repositories for Nuclear Waste Disposal in Deep Geological Structures  

Energy Technology Data Exchange (ETDEWEB)

To prove the suitability and safety of underground structures for the disposal of radioactive waste extensive geo-scientific research and development has been carried out by BGR over the last decades. Basic steps of the safety analysis are the geological modelling of the entire structure including the host rock, the overburden and the repository geometry as well as the geo-mechanical modelling taking into account the 3-D modelling of the underground structure. The geological models are generated using the special-construction openGEO{sup TM} code to improve the visualisation an d interpretation of the geological data basis, e.g. borehole, mine, and geophysical data. For the geo-mechanical analysis the new JIFE finite-element code has been used to consider large 3-D structures with complex inelastic material behaviour. To establish the finite-element models needed for stability and integrity calculations, the geological models are simplified with respect to homogenous rock layers with uniform material behaviour. The modelling results are basic values for the evaluation of the stability of the repository mine and the long-term integrity of the geological barrier. As an example of application, the results of geological and geo-mechanical investigations of the Morsleben repository based on 3-D modelling are presented. (authors)

Fahland, Sandra; Hofmann, Michael; Bornemann, Otto; Heusermann, Stefan [Federal Institute for Geosciences and Natural Resources, Stilleweg 2, D-30655-Hannover (Germany)

2008-07-01

19

Three-dimensional Geological and Geo-mechanical Modelling of Repositories for Nuclear Waste Disposal in Deep Geological Structures  

International Nuclear Information System (INIS)

To prove the suitability and safety of underground structures for the disposal of radioactive waste extensive geo-scientific research and development has been carried out by BGR over the last decades. Basic steps of the safety analysis are the geological modelling of the entire structure including the host rock, the overburden and the repository geometry as well as the geo-mechanical modelling taking into account the 3-D modelling of the underground structure. The geological models are generated using the special-construction openGEOTM code to improve the visualisation an d interpretation of the geological data basis, e.g. borehole, mine, and geophysical data. For the geo-mechanical analysis the new JIFE finite-element code has been used to consider large 3-D structures with complex inelastic material behaviour. To establish the finite-element models needed for stability and integrity calculations, the geological models are simplified with respect to homogenous rock layers with uniform material behaviour. The modelling results are basic values for the evaluation of the stability of the repository mine and the long-term integrity of the geological barrier. As an example of application, the results of geological and geo-mechanical investigations of the Morsleben repository based on 3-D modelling are presented. (authors)

2008-09-21

20

MSc Structural Geology with Geophysics: Earth and Environment  

...The course provides training in all aspects of applied structural geology and seismic techniques for direct entry into the hydrocarbons or mining industries, ...receive advanced training in the practical application of structural geology in interpreting seismic and the principals underlying data acquisition and processing. You will ...on understanding the geology behind basin evolution and use of 3D and 4D thinking in geological contexts, skills that are essential for industry ...an appreciation of both the geological and geophysical contraints with respect to seismic interpreation and model building. This will allow you to use ...

 
 
 
 
21

Forensic Analysis using Geological and Geochemical Techniques  

Science.gov (United States)

Due to the globalisation of legal (and illegal) trade there is an increasing demand for techniques which can verify the geographical origin and transfer routes of many legal and illegal commodities and products. Although geological techniques have been used in forensic investigations since the emergence of forensics as a science in the late eighteen hundreds, the last decade has seen a marked increase in geo-scientists initiating concept studies using the latest analytical techniques, including studying natural abundance isotope variations, micro analysis with laser ablation ICPMS and geochemical mapping. Most of the concept studies have shown a good potential but uptake by the law enforcement and legal community has been limited due to concerns about the admissibility of the new methods. As an introduction to the UGU2009 session "Forensic Provenancing using Geological and Geochemical Techniques" I will give an overview of the state of the art of forensic geology and the issues that concern the admissibility of geological forensic evidence. I will use examples from the NITECRIME and FIRMS networks, the EU TRACE project and other projects and literature to illustrate the important issues at hand.

Hoogewerff, J.

2009-04-01

22

Relationship between hypocentral distribution and geological structure in the Horonobe area, northern Hokkaido, Japan  

International Nuclear Information System (INIS)

In this paper, we discuss the relationship between the accurate hypocentral distribution and three-dimensional (3-D) geological structure in and around the Horonobe area in northern Hokkaido, Japan. The multiplet-clustering analysis was applied to the 421 micro-earthquakes which occurred from 1 September, 2003 to 30 September, 2007. The 3-D geological structure model was mainly constructed from previous seismic reflection profiles and borehole data. As a result of this analysis, although with slight differences in depth between them, the hypocenters were found to be distributed in the NNW-SSE direction and become deeper from the west toward the east. The distributed pattern of the hypocenters is similar to that of the geological structure. These results indicate that the hypocentral distribution may represent existence of active zone related to the geological structure, and provide effective information which can contribute to establishing methods for estimating the future evolution of the geological environment. (author)

2010-10-03

23

Fracture analysis for engineering geological utilization  

Energy Technology Data Exchange (ETDEWEB)

The problem of geological hazards (earthquakes) and water or thermal resources urges us to understand the regional tectonic setting or recent tectonics. The Uisong Subbasin is located in one of the seismicity zones in Korea. Because the reactivity of the Gaeum Fault System is an important problem focussing on these faults, we studied their whole extension and timing of faulting in terms of tectonics. Fault tectonic analysis is so effective as to easily reconstruct the tectonic sequence and each stress state at each site, eventually in a region. One can get insights for faulting timing in terms of the restored tectonic sequence, and discriminating the active faults or the faults active in the last (present) tectonics. Examining the filling materials in tension gashes, one can get raw knowledge regarding the thermal states at each site. For this study, we first analyzed the topographic textures (lineament, drainage and circular structures) on the relief map produced based on the topographic maps of 1:100,000 scale. Through investigations of susceptible area along the faults, their existence and movement modes were studied, and we can get information about movement history and whole extension of the faults belonging to the WNW-ESE trending Gaeum Fault System. In order to reconstruct the tectonic sequence, we measured fault slip data, tension gashes and dikes, from which fault populations were classified and stress (and thermal) states were determined. Seven compressional tectonic events and six extensional events were reconstructed. Because coaxial events partially coexisted, we bundled these events in one, finally we get seven tectonic events. Determining the types of minerals filling the tension gashes, we suggested the possibility of investigation of geothermal resources with less efforts. (author). 162 refs., 14 tabs., 51 figs.

Choi, H.I.; Choi, P.Y.; Hong, S.H.; Chi, K.H.; Kim, J.Y.; Lee, S.R.; Lee, S.G.; Park, D.W.; Han, J.G. [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1997-12-01

24

A 3D analysis of spatial relationship between geological structure and groundwater profile around Kobe City, Japan: based on ARCGIS 3D Analyst.  

Science.gov (United States)

Kobe city is located on the northern side of Osaka sedimentary basin, Japan, containing 1,000-2,000 m thick Quaternary sediments. After the Hanshin-Awaji Earthquake (January 17, 1995), a number of geological and geophysical surveys were conducted in this region. Then high-temperature anomaly of groundwater accompanied with high Cl concentration was detected along fault systems in this area. In addition, dissolved He in groundwater showed nearly upper mantle-like 3He/4He ratio, although there were no Quaternary volcanic activities in this region. Some recent studies have assumed that these groundwater profiles are related with geological structure because some faults and joints can function as pathways for groundwater flow, and mantle-derived water can upwell through the fault system to the ground surface. To verify these hypotheses, we established 3D geological and hydrological model around Osaka sedimentary basin. Our primary goal is to analyze spatial relationship between geological structure and groundwater profile. In the study region, a number of geological and hydrological datasets, such as boring log data, seismic profiling data, groundwater chemical profile, were reported. We converted these datasets to meshed data on the GIS, and plotted in the three dimensional space to visualize spatial distribution. Furthermore, we projected seismic profiling data into three dimensional space and calculated distance between faults and sampling points, using Visual Basic for Applications (VBA) scripts. All 3D models are converted into VRML format, and can be used as a versatile dataset on personal computer. This research project has been conducted under the research contract with the Japan Nuclear Energy Safety Organization (JNES).

Shibahara, A.; Tsukamoto, H.; Kazahaya, K.; Morikawa, N.; Takahashi, M.; Takahashi, H.; Yasuhara, M.; Ohwada, M.; Oyama, Y.; Inamura, A.; Handa, H.; Nakama, J.

2008-12-01

25

Deep geological disposal system development; thermal stress analysis and nonlinear structural analysis of spent nuclear fuel disposal canister under sudden rock movement  

Energy Technology Data Exchange (ETDEWEB)

This work constitutes a summary of research and development made for design and dimensioning of the spent nuclear fuel disposal canister. Since the spent nuclear fuel disposal emits high temperature heats and much radiation, its careful treatment is required. For that, a long term(usually 10,000 years) safe repository for the spent nuclear fuel disposal should be secured. Usually this repository is expected to locate at a depth of 500m underground. In this work the thermal stress analysis of the spent nuclear fuel disposal canister in a deep repository at 500m underground is performed for the underground pressure variation. Thermal stresses of the canister due to thermal loads of the heat generation of spent nuclear fuels inside baskets are computed. The thermal stress analysis result shows that even though some high thermal stresses occur due to the heat generation of nuclear fuels inside baskets, the canister is still structurally safe because the maximum stress occurred in the canister is smaller than the yield strength of the cast iron. In this work, the nonlinear structural analysis for the composite structure of the spent nuclear fuel disposal canister and the 50cm thick bentonite buffer is also carried out to predict the collapse of the canister while the sudden rock movement of 10cm is applied on the composite structure. Elastoplastic material model is adopted. Drucker-Prager yield criterion is used for the material yield prediction of the bentonite buffer and von-Mises yield criterion is used for the material yield prediction of the canister(cast iron insert, copper outer shell and lid and bottom). The analysis result shows that even though very large deformations occur beyond the yield point in the bentonite buffer, the canister structure still endures elastic small strains and stresses below the yield strength. Analysis results also show that bending deformations occur in the canister structure due to the shear deformation of the bentonite buffer. 24 refs., 59 figs., 15 tabs. (Author)

Kwon, Young Joo; Kim, Jin An; Ha, Jun Yong [Hongik University, Seoul (Korea)

2002-04-01

26

Development of the quantitative evaluation information system of mining geology structure  

Energy Technology Data Exchange (ETDEWEB)

Quantitative analysis and comprehensive evaluation on geologic structures were carried out with appropriate indexes, methods and mathematic-geological models. Then, based on Visual Basic 6.0, ADO, ACCESS97, Surfer and so on, the Quantitative Evaluation Information System of Mining Geology Structure (MGS) was developed. This information system has many effective functions such as vector inputting, data management and processing, statistical analysis, spatial analysis, comprehensive evaluation and visualization in scientific computing. MGS has been implemented in Pansan Mine of Huainan area in Anhui Province. 8 refs., 2 figs., 1 tab.

Cao, D.; Zhou, Y.; Wei, Y. [China University of Mining and Technology, Beijing (China). Key Laboratory of Coal Resources

2002-08-01

27

Geological structure and mineral resources of Algeria  

Directory of Open Access Journals (Sweden)

Full Text Available The hydrocarbon System Ourd Mya is located in the Sahara Basin. It is one of the producing basins in Algeria. The stratigraphic section consists of Paleozoic and Mesosoic, it is about 5000 m thick. In the eastern part, the basin is limited by the Hassi-Messaoud high zone which is a giant oil field produced from the Cambrian sands. The western part is limited by Hassi R`mel which is one of the biggest gas field in the world, it is produced from the triassic sands. The Mesozoic section lays on the lower Devonian and in the eastern part, on the Cambrian. The main source rock is Silurian shale with an average thickness of 50 m and a total organic matter of 6 % (14 % in some cases. Results of maturation modeling indicate that the lower Silurian source is in the oil window. The Ordovician shales are also a source rock but in a second order. Clastic reservoirs are in the Triassic sequence which is mainly fluvial deposit with complex alluvial channels, it is the main target in the basin. Clastic reservoirs within the lower Devonian section have a good hydrocarbon potential in the east of the basin through a southwest-northeast orientation. The late Triassic-Early Jurassic evaporites overlie the Triassic clastic interval and extend over the entire Oued Mya Basin. This is considered as a super-seal evaporate package, which consists predominantly of anhydrite and halite. For Paleozoic targets, a large number of potential seals exist within the stratigraphic column.This paper describe the main geological structure and mineral resources of Algeria.

Eduard Dobra

2007-12-01

28

Improvement of seismic imaging of complex geologic structures  

Energy Technology Data Exchange (ETDEWEB)

Successful imaging of complex geologic structures by pre-stack depth migration requires a correct velocity model of the subsurface. In recent years, it has been proposed to use pre-stack depth migration of the cube of pre-stack depth migrated images and the subsequent use of the interpretation for velocity model update. However, in complex geologic structures, pre-stack depth migration does not yield results of sufficient quality for interpretation. We therefore propose a new wave-field imaging technique based on linearized inversion using the paraxial approximation of the wave equation. Using this technique we can remove the artifacts contaminating the individual depth images by integrating a priori information in the inverse problem. The application of the method to synthetic and real data shows that it allows us to largely improve the quality of the depth images at reasonable cost.We thus obtain an interpretable cube of depth images that makes migration velocity analysis feasible in complex structures. In 3D, due to the size of the problem there is still a large interest in using post stack techniques for velocity model determination. The quality of the results of such techniques relies on the quality of the stacking process. Classical data stacking techniques rely on simplifications that are not valid anymore in case of complex geologic structures. We propose a data stacking technique based on depth domain stacking after pre-stack depth migration, followed by explosive reflector modeling, to obtain the stacked seismic data. This method which is totally automatic yield 3 D stacked data that are suitable for 3D post stack velocity determination techniques.

Duquet, B.

1996-04-11

29

A fundamental problem with the kinematic interpretation of geological structures  

Science.gov (United States)

Non-steady flows are ubiquitous in nature. Not only do imposed boundary conditions vary with time and rock rheology change during the course of deformation but also deformation is generally heterogeneous and all of these conditions lead to non-steady flow histories. In modern kinematic analysis, flow apophyses, the instantaneous stretching axes and the vorticity vector, collectively referred to as the `eigen directions' of deformation, are used in place of Bruno Sander's kinematic axes. For deformation with a steady flow history, this practice is well justified and has led to great advances in structural geology. But for non-steady flow histories, the geometrical relationships among eigen directions (flow pattern) vary with time. This makes it inappropriate to correlate an association of structures and fabrics with certain `time-invariant' flow patterns and hence raises the question: How should we interpret geological structures and fabrics kinematically, without the assumption of homogeneous and steady deformation? We suggest that the answer lies primarily in forward-modeling of deformation, based on a knowledge of rock properties.

Jiang, Dazhi; Williams, Paul F.

1999-08-01

30

Geologic Framework Model Analysis Model Report  

International Nuclear Information System (INIS)

The purpose of this report is to document the Geologic Framework Model (GFM), Version 3.1 (GFM3.1) with regard to data input, modeling methods, assumptions, uncertainties, limitations, and validation of the model results, qualification status of the model, and the differences between Version 3.1 and previous versions. The GFM represents a three-dimensional interpretation of the stratigraphy and structural features of the location of the potential Yucca Mountain radioactive waste repository. The GFM encompasses an area of 65 square miles (170 square kilometers) and a volume of 185 cubic miles (771 cubic kilometers). The boundaries of the GFM were chosen to encompass the most widely distributed set of exploratory boreholes (the Water Table or WT series) and to provide a geologic framework over the area of interest for hydrologic flow and radionuclide transport modeling through the unsaturated zone (UZ). The depth of the model is constrained by the inferred depth of the Tertiary-Paleozoic unconformity. The GFM was constructed from geologic map and borehole data. Additional information from measured stratigraphy sections, gravity profiles, and seismic profiles was also considered. This interim change notice (ICN) was prepared in accordance with the Technical Work Plan for the Integrated Site Model Process Model Report Revision 01 (CRWMS M and O 2000). The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. The GFM is one component of the Integrated Site Model (ISM) (Figure l), which has been developed to provide a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site. The ISM consists of three components: (1) Geologic Framework Model (GFM); (2) Rock Properties Model (RPM); and (3) Mineralogic Model (MM). The ISM merges the detailed project stratigraphy into model stratigraphic units that are most useful for the primary downstream models and the repository design. These downstream models include the hydrologic flow models and the radionuclide transport models. All the models and the repository design, in turn, will be incorporated into the Total System Performance Assessment (TSPA) of the potential radioactive waste repository block and vicinity to determine the suitability of Yucca Mountain as a host for the repository. The interrelationship of the three components of the ISM and their interface with downstream uses are illustrated in Figure 2

2000-01-01

31

Geologic Framework Model Analysis Model Report  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this report is to document the Geologic Framework Model (GFM), Version 3.1 (GFM3.1) with regard to data input, modeling methods, assumptions, uncertainties, limitations, and validation of the model results, qualification status of the model, and the differences between Version 3.1 and previous versions. The GFM represents a three-dimensional interpretation of the stratigraphy and structural features of the location of the potential Yucca Mountain radioactive waste repository. The GFM encompasses an area of 65 square miles (170 square kilometers) and a volume of 185 cubic miles (771 cubic kilometers). The boundaries of the GFM were chosen to encompass the most widely distributed set of exploratory boreholes (the Water Table or WT series) and to provide a geologic framework over the area of interest for hydrologic flow and radionuclide transport modeling through the unsaturated zone (UZ). The depth of the model is constrained by the inferred depth of the Tertiary-Paleozoic unconformity. The GFM was constructed from geologic map and borehole data. Additional information from measured stratigraphy sections, gravity profiles, and seismic profiles was also considered. This interim change notice (ICN) was prepared in accordance with the Technical Work Plan for the Integrated Site Model Process Model Report Revision 01 (CRWMS M&O 2000). The constraints, caveats, and limitations associated with this model are discussed in the appropriate text sections that follow. The GFM is one component of the Integrated Site Model (ISM) (Figure l), which has been developed to provide a consistent volumetric portrayal of the rock layers, rock properties, and mineralogy of the Yucca Mountain site. The ISM consists of three components: (1) Geologic Framework Model (GFM); (2) Rock Properties Model (RPM); and (3) Mineralogic Model (MM). The ISM merges the detailed project stratigraphy into model stratigraphic units that are most useful for the primary downstream models and the repository design. These downstream models include the hydrologic flow models and the radionuclide transport models. All the models and the repository design, in turn, will be incorporated into the Total System Performance Assessment (TSPA) of the potential radioactive waste repository block and vicinity to determine the suitability of Yucca Mountain as a host for the repository. The interrelationship of the three components of the ISM and their interface with downstream uses are illustrated in Figure 2.

R. Clayton

2000-12-19

32

Using Computer Spatial Technologies (Geoplus Petra) for Subsurface Geological Analysis  

Science.gov (United States)

The student compiles oil field well data, including spatial locations and digital well logs, for analysis of subsurface, oil reservoir stratigraphy and lithology using computer spatial technologies software, Geoplus Petra. The students create well log cross sections, make lithologic picks, construct structure and isopach maps, and evaluate lithologic properties, including gross reservoir quality from petrophysical logs. These data are used to interpret depositional environment of the subject formation and make predictions for well bore perforations for oil production. The key value of the exercise is an introduction to the use of computer software to analyze geological data, guided by sedimentologic and stratigraphic insights, and make predictions for resource exploitation.

Barnes, Dave

33

Initial phases for the development of a Structural Geology database  

Science.gov (United States)

We are at the beginning stages of developing a Data System for Structural Geology and Tectonics (SG&T). This activity is prompted by the necessity of reporting our data from government-funded projects and the lack of any existing database. SG&T data is complex for a variety of reasons, including the wide range of temporal and spatial scales (many orders of magnitude each), the complex three-dimensional geometry of some geological structures, inherent spatial nature of the data, and the difficulty of making temporal inferences from spatial observations. To successful implement the step of developing a SG&T data system, we must simultaneously solve three problems: 1) How to digitize SG&T data; 2) How to design a software system that is applicable; and 3) How to construct a very flexible user interface. To address the first problem, we introduce the "Spot" concept, which allows tracking of hierarchical and spatial relations between structures at all scales, and will link map scale, mesoscale, and laboratory scale data. A Spot, in this sense, is analogous to the beam size of analytical equipment used for in situ analysis of rocks; it is the size over which a measurement or quantity is applicable. A Spot can be a single measurement, an aggregation of individual measurements, or even establish relationships between numerous other Spots. We propose to implement both a Spot and a more traditional Mapping mode for data input. The final challenge is to construct a user interface that is intuitive, open source, and spans as many operating systems and devices as possible. For these reasons, we propose to develop a web-application that can run in both a connected (on the internet) and disconnected mode. Our hope is to have extensive and international community input into the data system development process.

Tikoff, Basil; Babaie, Hassan; Clark, Ryan; Newman, Juile; Walker, Doug

2014-05-01

34

Definition imaging of anomalous geologic structure with radio waves  

International Nuclear Information System (INIS)

Diamond core drilling from the surface and access drifts are routinely used in acquiring subsurface geologic data. Examination of core from a constellation of drillholes enables the characterization of the prevailing geology in the deposit. Similar geologic members in adjacent drillholes suggest that layered rock continuity exists between drillholes. Mineralogical and physical examination of core along with computer generated stratigraphic cross sections graphically represents the correlation and classification of the rock in the deposit. CW radio waves propagating on ray paths between drillholes have been used to validate the stratigraphic cross section and image anomalous geologic structure between drillholes. This paper compares the crosshole radio wave tomography images of faults in a nuclear waste repository site and a coal seam with the in-mine mapping results

1990-02-01

35

A satellite remote sensing technique for geological structure horizon mapping  

Energy Technology Data Exchange (ETDEWEB)

A Satellite Remote Sensing Technique is demonstrated for generating near surface geological structure data. This technique enables the screening of large areas and targeting of seismic acquisition during hydrocarbon exploration. This is of particular advantage in terrains where surveying is logistically difficult. Landsat Thematic Mapper (TM) data and a high resolution Digital Elevation Model (DEM), are used to identify and map outcropping horizons. These are used to reconstruct the near surface structure. The technique is applied in Central Yemen which is characterised by a {open_quote}layer-cake{close_quote} geological and low dipping terrain. The results are validated using 2D seismic data. The near surface map images faults and structure not apparent in the raw data. Comparison with the structure map generated from a 2D seismic data indicates very good structural and fault correlation. The near surface map successfully highlights areas of potential closure at reservoir depths.

Fraser, A.; Huggins, P.; Rees, J. [Gas Research Centre, Loughborough (United Kingdom)] [and others

1996-08-01

36

Spreadsheet log analysis in subsurface geology  

Science.gov (United States)

Most of the direct knowledge of the geology of the subsurface is gained from the examination of core and drill-cuttings recovered from boreholes drilled by the petroleum and water industries. Wireline logs run in these same boreholes generally have been restricted to tasks of lithostratigraphic correlation and thee location of hydrocarbon pay zones. However, the range of petrophysical measurements has expanded markedly in recent years, so that log traces now can be transformed to estimates of rock composition. Increasingly, logs are available in a digital format that can be read easily by a desktop computer and processed by simple spreadsheet software methods. Taken together, these developments offer accessible tools for new insights into subsurface geology that complement the traditional, but limited, sources of core and cutting observations.

Doveton, J. H.

2000-01-01

37

Diagnostic expert systems: Encoding geological knowledge for an exploration play analysis  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Geological Survey is currently exploring the feasibility of applying diagnostic expert systems and knowledge-based acquisition techniques to the geologic analysis of sedimentary basins and petroleum exploration plays. This paper describes a unique approach to the design and application of a rule-based expert system to the analysis of exploration plays, a methodology commonly used to assess petroleum resources in a basin. This technique consists of using various geologic models and Monte Carlo simulation or probabilistic methods for analyzing geologic and reservoir conditions favorable to the occurrence of petroleum resources. Work is in progress to adapt the geologic model used in the play analysis to an expert-systems and knowledge base, the object being to capture the logic and reasoning used to characterize the geologic model and to evaluate the play. Expert systems techniques now being developed are capable of dealing with inexact reasoning or reasoning under uncertainty by incorporating degrees of uncertainty to deal effectively with incomplete, inferred, or interpretive data involved in the knowledge base. The goal of this study is to provide an embedded diagnostic expert-system approach for characterizing the geologic model to expand upon the play-analysis system. Such a system provides the geologist with capabilities to document major basin components, such as stratigraphy, structural geology, and sedimentation, and to analyze the traditional concepts of source, reservoir, and trapping mechanisms. This expert system will assist the geologist in compiling and interpreting the geologic and reservoir engineering data necessary for running the probabilistic methods to calculate the amount of probable petroleum resources within each play. Diagnostic expert-systems technology can provide challenging new tools in knowledge acquisition and data interpretation in petroleum geology.

Miller, B.M. (Geological Survey, Denver, CO (United States))

1993-08-01

38

Geologic Analysis of Priority Basins for Exploration and Drilling  

Energy Technology Data Exchange (ETDEWEB)

There has been a substantial decline in both exploratory drilling and seismic field crew activity in the United States over the last 10 years, due primarily to the declining price of oil. To reverse this trend and to preserve the entrepreneurial independent operator, the U.S. DOE is attempting to encourage hydrocarbon exploration activities in some of the under exploited regions of the United States. This goal is being accomplished by conducting broad regional reviews of potentially prospective areas within the lower 48 states. Data are being collected on selected areas, and studies are being done on a regional scale generally unavailable to the smaller independent. The results of this work will be made available to the public to encourage the undertaking of operations in areas which have been overlooked until this project. Fifteen criteria have been developed for the selection of study areas. Eight regions have been identified where regional geologic analysis will be performed. This report discusses preliminary findings concerning the geology, early tectonic history, structure and potential unconventional source rocks for the Black Mesa basin and South Central states region, the two highest priority study areas.

Carroll, H.B.; Reeves, T.K.

1999-04-27

39

Geological analysis of the Kakkonada geothermal reservoir  

Energy Technology Data Exchange (ETDEWEB)

As a part to develop geothermal reservoirs successfully, the permeable fracture distributions and their geneses in the Kakkonda geothermal field were discussed in connection with a geological subsidence, folding, magma intrusion. Seven production and reinjection wells drilled for a geothermal power plant revealed the geological conditions such as fractures, dykes, hornfels and temperature distributions in deeper depth. There were three types of permeable fractures in the genesis in the Kakkonda field. The first was the intensely fractured zone of 1000-1600m in depth in the NW-Se direction supposed to be formed by a subsidence in the early to middle Miocene age, the second was the folding fractures supposed to be related to the first type in the genesis, and the final was the magma intrusion fractures supposed to be formed by magma fracturing to wall rocks and flexural flows in viscous dacite magma, as was suggested from circulation losses at the margin and in the dyke. 5 refs., 6 figs.

Doi, N.; Muramatsu, Y.; Chiba, Y.; Tateno, M. (Japan Metals and Chemical Co., Ltd., Iwate)

1988-11-10

40

3D form line construction by structural field interpolation (SFI) of geologic strike and dip observations  

Science.gov (United States)

Interpreting and modelling geometries of complex geologic structures from strike/dip measurements using manually-drafted structural form lines is labour intensive, irreproducible and inherently limited to two dimensions. Herein, the structural field interpolation (SFI) algorithm is presented that overcomes these limitations by constructing 3D structural form lines from the vector components of strike/dip measurements. The SFI interpolation algorithm employs an anisotropic inverse distance weighting scheme derived from eigen analysis of the poles to strike/dip measurements within a neighbourhood of user defined dimension and shape (ellipsoidal to spherical) and honours younging directions, when available. The eigen analysis also provides local estimates of the plunge vector and associated Woodcock distribution properties to assure plunge-normal structural form line reconstruction with unidirectional propagation of form lines across fold and fan structures. The method is advantageous for modelling geometries of geologic structures from a wide range of structurally anisotropic data. Modelled vector fields from three case studies are presented that reproduce the expected bedding-foliation geometry and provide reasonable representation of complex folds from local to regional scales. Results illustrate the potential for using vector fields to support geologic interpretation through the direct visualization of geometric trends of structural features in 3D.

Hillier, Michael; de Kemp, Eric; Schetselaar, Ernst

2013-06-01

 
 
 
 
41

Geologic analysis by track etch method  

International Nuclear Information System (INIS)

The nuclear track technique has provided a versatile method for the analyses of geological samples. We have applied the method for the mapping of boron, lithium, uranium and thorium in minerals and rocks. The analyse of uranium in natural water is reported, too. The neutron source was Triga MK II research reactor at the Technical Research Centre of Finland. Cellulose foils have been used as alpha particle detectors while polycarbonate foils as fission particle detectors. The etch pits are counted in the microscope or with a spark replica counter similar to one described by Cross and Tommasino. In this study uranium is the element most interested. The accuracy, sensitivity and limits of the track etch technique in geochemical exploration are discussed, too. (orig.)

1976-09-30

42

Use of space imagery for studying geologic structure of the North-Ustyurtskaya oil and gas-bearing region  

Energy Technology Data Exchange (ETDEWEB)

Overview of issues concerning landscape and geomorphologic analysis of space imagery and the subsequent interpretation of structural and geologic values with use of geophysical data. Examples of clues of different value structural elements on images of differing generalization levels. Potential for studying overall patterns for local structures on the basis of structural and geomorphologic zonation is discussed.

Lion, Yu.A.; Solovyova, L.I.

1981-01-01

43

Use of space photographs to study the geological structure of the North Ustyurt gas and oil region  

Energy Technology Data Exchange (ETDEWEB)

General method questions are examined of landscape-geomorphical analysis of a photo image of space photographs and subsequent structural-geological interpretation using geophysical data. Examples are presented of indicating different-order structural elements on photographs of different levels of generalization. Possibilities are covered of studying general laws governing indication of local structures based on structural geomorphical zoning.

Lion, Yu.A.; Solov' yeva, L.I.

1981-01-01

44

2005 dossier: granite. Tome: safety analysis of the geologic disposal  

International Nuclear Information System (INIS)

This document makes a status of the researches carried out by the French national agency of radioactive wastes (ANDRA) about the safety aspects of the geologic disposal of high-level and long-lived (HLLL) radioactive wastes in granite formations. Content: 1 - safety approach: context and general goal, references, design approach by safety functions, safety approach during the construction-exploitation-observation-closure phase, safety analysis during the post-closure phase; 2 - general description: HLLL wastes, granitic environment, general structure of the architecture of a disposal facility; 3 - safety functions and disposal design: general context, safety functions of the long-term disposal, design dispositions retained to answer the functions; 4 - operational safety: people's protection, radiological risks during exploitation, risk analysis in accident situation; 5 - qualitative safety analysis: methodology, main results of the analysis of the features, events and processes (FEP) database; 6 - disposal efficiency evaluation during post-closure phase: calculation models, calculation tools used for the modeling of radionuclides transport, calculation results and main lessons. (J.S.)

2005-01-01

45

10 CFR 63.112 - Requirements for preclosure safety analysis of the geologic repository operations area.  

Science.gov (United States)

...for preclosure safety analysis of the geologic repository...The preclosure safety analysis of the geologic repository...sequences; (c) Data pertaining to the Yucca...analysis; (e) An analysis of the performance of...

2010-01-01

46

Known geologic structures as related to onshore oil and gas leasing  

Energy Technology Data Exchange (ETDEWEB)

The Bureau of Land Management (BLM) administers the onshore oil and gas leasing program for federally administered lands. The basis of this program is the 1920 Mineral Leasing Act. This law requires that oil and gas leases be issued competitively in areas designated as a Known Geologic Structure (KGS). Leases may be issued noncompetitively through the Simultaneous Oil and Gas filing (SIMO) system or by over-the-counter lease offers in areas outside known producing geologic structures. The petroleum industry and the general public may nominate areas for leasing. The BLM determines whether those nominated areas are, or should be, within a KGS. The KGS study areas are established where new or existing geologic information is evaluated in accordance with the KGS classification criteria. After a geologic analysis is prepared, the lands within a KGS study area are available for leasing by either competitive or noncompetitive methods. The purpose of this presentation is to inform the interested parties where KGS study areas exist in the Ventura and Santa Maria basins, to indicate where competitive leasing is proposed, and to promote the development of a geologic database for those areas to assist in completing the KGS studies.

Moore, T.S.

1988-03-01

47

Information Theory and the Analysis of Uncertainties in a Spatial Geological Context  

Science.gov (United States)

The interpretation of uncertainties in a spatial context is of fundamental importance for the generation of structural geological models; this applies to models for mineral exploration, to scientific structural geological studies and fundamental geological evaluations. With our work, we are addressing uncertainties in this spatial geological context. Encouraged by the interdisciplinary and interactive aspect of the session, we would like to present our method to other branches of geosciences. Structural geological models, here understood as structural representations of the dominant geological units in the subsurface, always contain uncertainties. The analysis of these uncertainties is intricate as these models are usually constructed on the basis of greatly varying data quality and spatial distribution. An additional complication is that, in most cases, the general distribution of uncertainties in space is of interest, and not a single outcome as, for example, the flow at a well. In the context of structural geological uncertainties, we therefore face two problems: (i) how can we estimate uncertainties in a complex 3-D geological model, and (ii) what is a meaningful measure to visualise and analyse these uncertainties quantitatively? In recent years, several approaches have been developed to solve the first problem. We show here an approach based on implicit stochastic geological modelling techniques, capable of handling complex geological settings. To address the second problem, we apply measures from information theory. We consider each subspace in a discretised model domain as a random variable. Based on the probability functions estimated from a suite of generated models, we evaluate the information entropy at each location in the subsurface as a measure of uncertainty. We subsequently estimate multivariate conditional entropy and mutual information between a set of locations and other regions in space, to determine spatial uncertainty correlations, and the potential reduction of uncertainty with additional information. We apply these information theoretic measures to a case study where uncertainties exist about the structure, and shape, of a bounded geological unit at depth. The results yield some, at first, surprising, but very reasonable results for the interpretation of uncertainties. The case study highlights the fact that information theoretic measures provide very intuitive measures of uncertainty, but, due to the relation of the measure to Bayesian theory, also combine them with a powerful quantitative meaning.

Wellmann, Florian; Jessell, Mark

2014-05-01

48

Geomass: geological modelling analysis and simulation software for the characterisation of fractured hard rock environments  

International Nuclear Information System (INIS)

This paper presents the development and functionality of a suite of applications which are being developed to support the geological investigations in the Tono URL. GEOMASS will include 3D geological modelling, 3D fluid flow and solute transport and 3D visualisation capabilities. The 3D geological modelling in GEOMASS will be undertaken using a commercially available 3D geological modelling system, EarthVision. EarthVision provides 3D mapping, interpolation, analysis and well planning software. It is being used in the GEOMASS system to provide the geological framework (structure of the tectonic faults and stratigraphic and lithological contacts) to the 3D flow code. It is also being used to gather the geological data into a standard format for use throughout the investigation programme. The 3D flow solver to be used in GEOMASS is called Frac-Affinity. Frac-Affinity models the 3D geometry of the flow system as a hybrid medium, in which the rock contains both permeable, intact rock and fractures. Frac-Affinity also performs interpolation of heterogeneous rock mass property data using a fractal based approach and the generation of stochastic fracture networks. The code solves for transient flow over a user defined sub-region of the geological framework supplied by EarthVision. The results from Frac-Affinity are passed back to EarthVision so that the flow simulation can be visualized alongside the geological structure. This work-flow allows rapid assessment of the role of geological features in controlling flow. This paper will present the concepts and approach of GEOMASS and illustrate the practical application of GEOMASS using data from Tono

1998-09-01

49

Applicability of neutron activation analysis to geological samples  

Energy Technology Data Exchange (ETDEWEB)

The applicability of neutron activation analysis (NAA) to geological samples in space is discussed by referring to future space mission programs, by which the extraterrestrial samples are to be delivered to the earth for scientific inspections. It is concluded that both destructive and non-destructive NAA are highly effective in analyzing these samples. (author)

Ebihara, Mitsuru [Tokyo Metropolitan Univ., Graduate School of Science, Tokyo (Japan)

2003-03-01

50

Risk analysis of geological disposal of radioactive waste  

International Nuclear Information System (INIS)

The problems of risk analysis of geological disposal of radioactive waste are briefly summarized. Several characteristics, such as the very long time span considered, make it rather unique among the problems of modern society. The safety of nuclear waste disposal in geological formations is based on several barriers, natural and man-made, which prevent disposed radionuclides from reaching the biosphere. They include a) the physico-chemical form of conditioned waste, b) the waste container, c) the geological isolation, d) buffering and backfilling materials, radionuclide retention in the geosphere and e) environmental dilution and isolation processes. The knowledge available on each barrier and its modelling is reviewed. Specific disposal strategies in clay, granite and salt formations are considered, outlining the performance of the barriers in each particular strategy, and results obtained in preliminary evaluations

1980-05-23

51

Thermal Analysis Of Geologic High-Level Radioactive Waste Packages  

International Nuclear Information System (INIS)

The engineering design of disposal of the high level waste (HLW) packages in a geologic repository requires a thermal analysis to provide the temperature history of the packages. Calculated temperatures are used to demonstrate compliance with criteria for waste acceptance into the geologic disposal gallery system and as input to assess the transient thermal characteristics of the vitrified HLW Package. The objective of the work was to evaluate the thermal performance of the supercontainer containing the vitrified HLW in a non-backfilled and unventilated underground disposal gallery. In order to achieve the objective, transient computational models for a geologic vitrified HLW package were developed by using a computational fluid dynamics method, and calculations for the HLW disposal gallery of the current Belgian geological repository reference design were performed. An initial two-dimensional model was used to conduct some parametric sensitivity studies to better understand the geologic system's thermal response. The effect of heat decay, number of co-disposed supercontainers, domain size, humidity, thermal conductivity and thermal emissivity were studied. Later, a more accurate three-dimensional model was developed by considering the conduction-convection cooling mechanism coupled with radiation, and the effect of the number of supercontainers (3, 4 and 8) was studied in more detail, as well as a bounding case with zero heat flux at both ends. The modeling methodology and results of the sensitivity studies will be presented.

2010-07-18

52

THERMAL ANALYSIS OF GEOLOGIC HIGH-LEVEL RADIOACTIVE WASTE PACKAGES  

Energy Technology Data Exchange (ETDEWEB)

The engineering design of disposal of the high level waste (HLW) packages in a geologic repository requires a thermal analysis to provide the temperature history of the packages. Calculated temperatures are used to demonstrate compliance with criteria for waste acceptance into the geologic disposal gallery system and as input to assess the transient thermal characteristics of the vitrified HLW Package. The objective of the work was to evaluate the thermal performance of the supercontainer containing the vitrified HLW in a non-backfilled and unventilated underground disposal gallery. In order to achieve the objective, transient computational models for a geologic vitrified HLW package were developed by using a computational fluid dynamics method, and calculations for the HLW disposal gallery of the current Belgian geological repository reference design were performed. An initial two-dimensional model was used to conduct some parametric sensitivity studies to better understand the geologic system's thermal response. The effect of heat decay, number of co-disposed supercontainers, domain size, humidity, thermal conductivity and thermal emissivity were studied. Later, a more accurate three-dimensional model was developed by considering the conduction-convection cooling mechanism coupled with radiation, and the effect of the number of supercontainers (3, 4 and 8) was studied in more detail, as well as a bounding case with zero heat flux at both ends. The modeling methodology and results of the sensitivity studies will be presented.

Hensel, S.; Lee, S.

2010-04-20

53

The EVEREST project: sensitivity analysis of geological disposal systems  

International Nuclear Information System (INIS)

The main objective of the EVEREST project is the evaluation of the sensitivity of the radiological consequences associated with the geological disposal of radioactive waste to the different elements in the performance assessment. Three types of geological host formations are considered: clay, granite and salt. The sensitivity studies that have been carried out can be partitioned into three categories according to the type of uncertainty taken into account: uncertainty in the model parameters, uncertainty in the conceptual models and uncertainty in the considered scenarios. Deterministic as well as stochastic calculational approaches have been applied for the sensitivity analyses. For the analysis of the sensitivity to parameter values, the reference technique, which has been applied in many evaluations, is stochastic and consists of a Monte Carlo simulation followed by a linear regression. For the analysis of conceptual model uncertainty, deterministic and stochastic approaches have been used. For the analysis of uncertainty in the considered scenarios, mainly deterministic approaches have been applied

1997-07-01

54

The EVEREST project: sensitivity analysis of geological disposal systems  

Energy Technology Data Exchange (ETDEWEB)

The main objective of the EVEREST project is the evaluation of the sensitivity of the radiological consequences associated with the geological disposal of radioactive waste to the different elements in the performance assessment. Three types of geological host formations are considered: clay, granite and salt. The sensitivity studies that have been carried out can be partitioned into three categories according to the type of uncertainty taken into account: uncertainty in the model parameters, uncertainty in the conceptual models and uncertainty in the considered scenarios. Deterministic as well as stochastic calculational approaches have been applied for the sensitivity analyses. For the analysis of the sensitivity to parameter values, the reference technique, which has been applied in many evaluations, is stochastic and consists of a Monte Carlo simulation followed by a linear regression. For the analysis of conceptual model uncertainty, deterministic and stochastic approaches have been used. For the analysis of uncertainty in the considered scenarios, mainly deterministic approaches have been applied.

Marivoet, Jan; Wemaere, Isabelle; Escalier des Orres, Pierre; Baudoin, Patrick; Certes, Catherine; Levassor, Andre; Prij, Jan; Martens, Karl-Heinz; Roehlig, Klaus

1997-07-01

55

SITE-94. Development of a geological and a structural model of Aespoe, southeastern Sweden  

International Nuclear Information System (INIS)

The objective of the present study is to construct three-dimensional geological and structural models to be used within the SKI SITE-94 project as a base for modelling hydrogeological, hydrochemical, and rock mechanical bedrock conditions, mass transport and layout of a hypothetical repository. The basic input data in the SITE-94 geological and structural models are restricted to geological and structural readings and geophysical measurements made prior to building the Hard Rock Laboratory. 114 refs, 82 figs, 28 tabs

1996-01-01

56

Uncertainty analysis for geologic disposal of radioactive waste  

International Nuclear Information System (INIS)

The incorporation and representation of uncertainty in the analysis of the consequences and risks associated with the geologic disposal of high-level radioactive waste are discussed. Such uncertainty has three primary components: process modeling uncertainty, model input data uncertainty, and scenario uncertainty. The following topics are considered in connection with the preceding components: propagation of uncertainty in the modeling of a disposal site, sampling of input data for models, and uncertainty associated with model output

1981-03-15

57

Combined NLCG/SBI magnetotelluric data inversion for recognition of complex geological structures  

International Nuclear Information System (INIS)

Complete text of publication follows. Geological interpretation of magnetotelluric data is a subject of some misunderstandings. Simplified geometrically and well contrasted in resistivity models do not response for real geological environment. The aim of outstripping magnetotelluric works widely made in Polish Outer Carpathians, is general structural and lithological recognising of geological environment and distinguishing of areas where oil prospection will be projected. The geological medium is formed by sedimentary formations, strongly deformed and containing relatively thin layers with essentially differentiated parameters, overlying rather flat, high resistivity basement. Application of simplified strongly contrasted interpretation model with fluently changing parameters gives frequently results not corresponding with geological reality. Presented analysis is based on surveys located in marginal zone of Carpathianst in the area relatively well recognised, where interpreted structural and lithologic model rather well reflects real geological medium. Then, it was used as reference model for obtained results of MT data inversion. Magnetotelluric continuous profiling located along reflection seismic profile, between two deep boreholes was made. Set of results of computations allows to evaluate of effectiveness of used procedures and suggest optimum way of dealing. First stage of data interpretation was based on 1D and EMAP inversion. The section was then applied as starting model for 2D NLCG inversion. Results of this method give rather generalized resistivity distribution well reflecting structure of flysch cover but not adequate for the basement. This models was applied as starting models for SBI inversion constrained by borehole data. Results of SBI procedure well reflects relatively flat complexes of the basement, but are rather unrealistic for folded flysch cover. The another NLCG inversion was computed with stabilised model of basement obtained from SBI inversion. Obtained resistivity cross section was relatively concordant to reference model. This paper is a result of the statutory research of the Department of General Geology, Environment Protection and Geotourism, project No 11.11.140.447. Results of project supported by grant from the Ministry of Scientific Research and Information Technology under contract no 5T12B 041 25 were also used.

2009-08-23

58

Multipass SAR interferometry. A tool for geologic analysis  

Energy Technology Data Exchange (ETDEWEB)

This paper investigates how the information content of repeat pass satellite SAR interferometric (INSAR) data can be used to provide the geologist with a tool which can improve his ability and efficacy in the geologic analysis of SAR imagery. INSAR processing produces interferometric fringes, coherence and amplitude images. To produce an interferometric DEM phase unwrapping is a critical step. For phase unwrapping, it is proposed the WLMS (Weighted Least Mean Square) estimation of the phase, which is a generalization of the least-mean square method. The crucial step in WLMS approach is the weighting procedure. It is proposed a weighting algorithm based on the fusion of a priori information extracted from different interferometric products. These different information channels-DEM, amplitude and coherence-can be effectively fused to convey information to the geologic interpreter using 3D stereoscopic visualization; SAR stereo pairs were artificially generated using the interferometric DEM and the intensity image or the coherence image of the area overlaid. In order to ascertain the performance of the procedure a number of tests were carried out over various sites in Matese (Southern Italy), which has a fairly demanding topography, using ERS SAR tandem data. The results demonstrate that WLMS unwrapping method is sufficiently robust in capturing the morphology of the area and that stereoscopic visualization greatly facilities geologic interpretation and the observation of detailed features of the terrain.

Fanelli, A.; Russo, L.; Celardo, G.; Murino, P. [Naples Univ. Federico 2., Naples (Italy). Dipt. di Scienza e Ingegneria dello Spazio L. G. Napolitan

2001-02-01

59

Kinematics of rock flow and the interpretation of geological structures, with particular reference to shear zones  

Science.gov (United States)

Current interpretations of structures are generally based on homogeneous and steady deformation models, despite the fact that both the heterogeneity of rocks (materially, rheologically and geometrically) and the time dependence of imposed geological conditions give rise to significant heterogeneous and non-steady flow. In concert with field observations, we emphasize that the expectation of heterogeneity and non-steadiness is the key to understanding natural deformation and that in order to carry out successful structural analysis and tectonic interpretation, it is necessary to recognize the first-order distinction between imposed boundary conditions typically used to define the tectonic regime (e.g. transcurrent, transpression) and the response recorded by rocks within the zone (structures and fabrics). Using S?C fabric as an example, it is demonstrated how flow with a non-zero spinning component resulting from the rheological contrasts and/or geologically realistic time-dependent boundary displacement can drastically change the 'ideal' geometric and kinematic relations between the fabric and the host zone. In agreement with both theoretical analysis and field observation, it is shown that natural flow regimes range from pure shear to pure rotation, including super-simple shear. In consideration of the heterogeneity and non-steadiness of natural deformation, kinematic analysis is justifiable only within a homogeneous domain and steady period. Flow kinematics and mechanisms are interrelated in that, firstly, mechanisms provide internal constraints on kinematics, ensuring that only certain flows are possible and, secondly, flow kinematics will favour development of certain mechanisms.

Jiang, Dazhi; White, Joseph Clancy

1995-09-01

60

Geological and Geophysical aspects of the Kurdashi structure, Azerbaijan  

International Nuclear Information System (INIS)

Full text: This paper is a case history of the improved characterization of a complex structure in the Azerbaijan offshore achieved by application of advanced seismic tools such as 3 D Pre-Stack Depth Migration and Continuity Depth Cube volumes.The investigation focuses on the Kurdashi Permit and adjacent areas of southern most Azerbaijan, near its boundary with Iran (Fig.1).It considers the techniques used to visualize the subsurface, the resulting subsurface model and implications for its geological history revealed by the more detailed seismic tools.The Kurdashi Permit is operated by AGIP AZERBAIJAN, a subsidiary of the Italian ENI Agip Division.The permit itself encompasses a faulted regional anticlinorium of Neogene series clastic rocks comprising three separate culminations.Seismic imaging in this area is challenged by widespread shallow or near-surface gas, steep dips, and mud volcanoes connected to irregularly shaped mud chambers and associated velocity anomalies.Targets are relatively deep measured in TWT due to both their actual depth and the relatively slow velocities of the sedimentary section.A 3D seismic survey covering about 900 sq km was acquired by Caspian Geophysical over the entire permit.The conventional time processing was executed by Veritas.Subsequently AGIP generated a 3D Pre-Stack Depth Migration and Continuity Cube and the relevant interpretations.

2002-09-01

 
 
 
 
61

Geological-structural interpretation using products of remote sensing in the region of Carrancas, Minas Gerais, Brazil  

Science.gov (United States)

The efficiency of some criteria developed for the utilization of small scale and low resolution remote sensing products to map geological and structural features was demonstrated. Those criteria were adapted from the Logical Method of Photointerpretation which consists of textural qualitative analysis of landforms and drainage net patterns. LANDSAT images of channel 5 and 7, 4 LANDSAT-RBV scenes, and 1 radar mosiac were utilized. The region of study is characterized by supracrustal metassediments (quartzites and micaschist) folded according to a "zig-zag" pattern and gnaissic basement. Lithological-structural definition was considered outstanding when compared to data acquired during field work, bibliographic data and geologic maps acquired in larger scales.

Parada, N. D. J. (principal investigator); Dossantos, A. R.; Dosanjos, C. E.; Barbosa, M. P.; Veneziani, P.

1982-01-01

62

Analysis of anions in geological brines using ion chromatography  

Energy Technology Data Exchange (ETDEWEB)

Ion chromatographic procedures for the determination of the anions bromide, sulfate, nitrite, nitrate, phosphate, and iodide in brine samples have been developed and are described. The techniques have been applied to the analysis of natural brines, and geologic evaporites. Sample matrices varied over a range from 15,000 mg/L to 200,000 mg/L total halogens, nearly all of which is chloride. The analyzed anion concentrations ranged from less than 5 mg/L in the cases of nitrite, nitrate, and phosphate, to 20,000 mg/L in the case of sulfate. A technique for suppressing chloride and sulfate ions to facilitate the analysis of lower concentration anions is presented. Analysis times are typically less than 20 minutes for each procedure and the ion chromatographic results compare well with those obtained using more time consuming classical chemical analyses. 10 references, 14 figures.

Merrill, R.M.

1985-03-01

63

A mathematical formulation for large strain analysis of geologic continua  

International Nuclear Information System (INIS)

A solution method is presented for finite-deformation analysis of geologic materials. The principle of virtual work is used to state the equations of equilibrium in a weak form. These equations are linearized about the last-established equilibrium configuration. A material constitutive relationship between the Green-Naghdi stress rate and the rate-of-deformation tensor is used to obtain the current stresses. The finite-element governing equations are expressed in a form suitable for an iterative solution strategy. The obtained gradient matrix contains the effects of both material and geometric nonlinearities. The primary application area of this formulation is the analysis of long-term deformation response of the region adjoining the mining shafts and the waste emplacement rooms within a nuclear waste repository. In this region, the strains are expected to be large, and the infinitesimal strain analysis would introduce inaccuracies in the solution. 19 refs., 6 figs

1987-01-01

64

A mathematical formulation for large strain analysis of geologic continua  

Energy Technology Data Exchange (ETDEWEB)

A solution method is presented for finite-deformation analysis of geologic materials. The principle of virtual work is used to state the equations of equilibrium in a weak form. These equations are linearized about the last-established equilibrium configuration. A material constitutive relationship between the Green-Naghdi stress rate and the rate-of-deformation tensor is used to obtain the current stresses. The finite-element governing equations are expressed in a form suitable for an iterative solution strategy. The obtained gradient matrix contains the effects of both material and geometric nonlinearities. The primary application area of this formulation is the analysis of long-term deformation response of the region adjoining the mining shafts and the waste emplacement rooms within a nuclear waste repository. In this region, the strains are expected to be large, and the infinitesimal strain analysis would introduce inaccuracies in the solution. 19 refs., 6 figs.

Chaudhary, A.B.; Vakili, J.E.; Hume, H.R.

1987-12-01

65

Diversion path analysis for the Swedish geological repository  

International Nuclear Information System (INIS)

The Swedish strategy to handle the spent fuel from the nuclear power plants is direct disposal in a geological repository. The safeguards regime covering all nuclear material in the state will be expanded to cover the new repository, which will require a novel safeguards approach due mainly to the inaccessibility of the fuel after disposal. The safeguards approach must be able to provide a high level of assurance that the fuel in the repository not diverted, but must also be resource efficient. An attractive approach with regards to use of resources is to monitor only the access points to the repository, i.e. the openings. The implementation of such an approach can only be allowed if it is shown to be sufficiently secure. With the purpose of determining the applicability of this 'black box' approach, a diversion path analysis for the Swedish geological repository has been carried out. The result from the analysis shows that all credible diversion paths could be covered by the black-box safeguards approach provided that the identified boundary conditions can be met

2008-01-01

66

Mineralogy influences structure and diversity of bacterial communities associated with geological substrata in a pristine aquifer.  

Science.gov (United States)

Our understanding of mineralogical influences on subsurface microbial community structure and diversity has been difficult to assess due to difficulties in isolating this variable from others in the subsurface environment. In this study, biofilm coupons were used to isolate specific geological substrata from the surrounding geological matrix during colonization by microorganisms suspended in the surrounding groundwater for an 8-week period. Upon retrieval, the structure and diversity of the microbial community associated with each type of substratum was evaluated using 16S rDNA-based terminal-restriction fragment length polymorphism (T-RFLP). Phylogenetic affiliations of the populations associated with each type of substratum were established based on sequence analysis of near full-length 16S rDNA obtained through construction of a clone library. Hematite, quartz, and saprolite each harbored a community dominated by members of the division Proteobacteria (>67% of community). However, the different substrata selected for different subdivisions of bacteria within the Proteobacteria. After accounting for the influence exerted by substratum type on recovery of DNA from the attached populations, both phylogenetic data and Jaccard and Bray-Curtis similarity indices derived from terminal-restriction fragment (T-RF) profiles suggested a strong mineralogical influence on the structure and composition of the solid phase-associated community. The results suggest that mineralogical heterogeneity influences microbial community structure and diversity in pristine aquifers. PMID:17364247

Boyd, Eric S; Cummings, David E; Geesey, Gill G

2007-07-01

67

Geological Interpretation of the Structure and Stratigraphy of the A/M Area, Savannah River Site, South Carolina  

International Nuclear Information System (INIS)

The geological interpretation of the structure and stratigraphy of the A/M Area was undertaken in order to evaluate the effects of deeper Cretaceous aged geological strata and structure on shallower Tertiary horizons

1997-01-01

68

Numerical analysis of nuclide migration through fissured geological media  

International Nuclear Information System (INIS)

A computational analysis of nuclide migration through fissured geological formations was performed. The migration behavior can be described by convective transport in the fissures, diffusive transport with radioactive decay chain in the bulk rock, and sorption on the fissure wall. The mathematical model employed is based on the finite element method (FEM) solution of transport equations, taking into account the interfissure two-dimensional diffusion. The decay chain, 234U?230Th?226Ra, was examined to illustrate the migration behavior. The FEM solution was in good agreement with the analytical solution using simpler assumptions. Numerically investigated were the effects of (a) the decay chain in pores, (b) two-dimensional diffusion in pores, (c) the axial dispersion in fissures, (d) the interaction between fissures, and (e) the fissure wall sorption. As a result, it can be said that the effect of the decay chain in pores is especially important in order not to have overestimates in terms of safety and that the fissure wall sorption is an important factor for realistic estimates because it has a remarkable effect on the extent of nuclide confinement within the geological media

1984-01-01

69

The main goal of engineering geology for designing and construction complex structures in urban areas  

Directory of Open Access Journals (Sweden)

Full Text Available Work for designing complex structures in urban areas consists of geological-geotechnical investigations and analysis of the quality of rocks, soft rocks and hard soils in the construction area. Urban areas limited the space for designing cutting slopes in stable inclination without reinforcement. In this paper will be presented designing and excavation works with different reinforcement of two different areas in Slovenia built of heterogeneous mixed hard to soft rock masses (Triassic dolomite, limestone and Eocene flysch sediments.Before the start of excavations work and after establishing the retaining measures, the analysis results are checked by monitoring. This monitoring will continue in the phase of exploitation of the objects. Since the cost of these additional investigations and precise analysis with monitoring (SIST - EN 7 - 2004 and measurements is negligible – in comparison with the costs of the permanent reinforcement – if variable conditions are not to intensive, we were able to reduce effectively the investment value of the object.

Drago Ocepek

2007-12-01

70

Structural geology of the earth's interior  

Energy Technology Data Exchange (ETDEWEB)

Current research in the stuctural geology of the earth's interior is reviewed with emphasis on global models of the mantle, regional models of the lithosphere, the mapping of boundaries in the deep mantle, and the mapping of elastic anisotropy. Particular consideration is given to several planned seismic experiments, including Iris, Pascal, Geoscope, and Orpheus. 8 references.

Vinnik, L.P.

1988-05-01

71

Neutron activation analysis of minerals from Cuddapah basin geological formations  

International Nuclear Information System (INIS)

Green and yellow serpentines along with two associated minerals namely dolomite and intrusive rock dolerite obtained from the asbestos mines of Cuddapah basin, Andhra Pradesh, India were analyzed by k0-based neutron activation analysis (k0-NAA) method. Gold (197Au) was used as the single comparator. Two reference materials namely USGS W-1 (geological) and IAEA Soil-7 (environmental) were analyzed as control samples to evaluate the accuracy of the method. A total of 21 elements present at major, minor and trace concentrations were determined in serpentines as well as associated minerals. The elemental concentrations were used for distinguishing and characterizing these minerals, and also to understand the extent of segregation of elements from the associated or host mineral rocks to serpentines. (author)

2014-01-20

72

Detailed fault structures in the Tarutung geothermal area derived from seismology and structural geology  

Science.gov (United States)

The oblique convergence between the Indo-Australian and Eurasian plates producing the subduction zone beneath south Indonesia causes the presence of the approximately 1650 km of dextral strike slip Sumatra fault (SF). The SF is segmented into 19 major sections featuring also pull-apart basins with different characteristics. One of the pull-apart basins along SF is the Tarutung basin located just south of the Toba caldera. We present the fault structure in the Tarutung geothermal area derived from seismological studies and supported by geological analysis. This information allows conclusions on the tectonic control of the geothermal system. The knowledge on the pattern of the fault system is highly beneficial to constrain prospective locations used in future exploitation. We detected the direct P and S wave arrivals of earthquakes recorded by a ten month deployment of 42 seismic stations in the Tarutung region. We relocated 809 events recorded by at least 8 stations with azimuthal gap angle less than 180 degrees by using 1D inversion for velocity structure and hypocenter locations (VELEST). The best solutions of VELEST are then used as the initials for the 3D inversion (SIMUL2000) to determine the 3D velocity models and more accurate earthquake locations. The seismicity distribution obtained from SIMUL2000 is compared with the earthquake locations obtained by the double difference relocation scheme (HYPODD) where 36,819 travel times and 766 waveform cross-correlations were involved. We analyzed the focal mechanisms for events having at least 11 clear first arrival polarities by using FPFIT. Surface structural study, measured striations and joints at 20 sites in the region, provide additional constraints on the deformation at shallower depth. South of the Tarutung basin, the seismicity distribution is well aligned to the main SF. The focal mechanisms show strike-slip behavior in agreement with the large-scale pattern of the SF. The application of HYPODD relocated the events even sharper and more focused. Along the Tarutung basin, the seismicity broadens and reveals interesting features. The seismicity aligned with the NW-SE main SF is mostly strike-slip with some normal component. The seismicity pattern shows some branches with normal faulting striking NE-SW crossing the main SF and the Tarutung basin. The pattern of seismicity and the focal mechanism provides evidence for the presence of the extensional duplex in the Tarutung area along the releasing bend of the SF. The fractures in NNW-SSE to NE-SW direction are notable from structural geology studies in the Tarutung area indicating conjugate synthetic and antithetic Riedel shears under compression at high angle to the NW-SE striking of SF System. The normal faulting trending SW-NE seems to be a preferred pathway of fluid flow. The dilatational zone as caused by clockwise rotation in a dextral simple shear induces dilation jog which may enhance the permeability in this part of the geothermal system.

Muksin, U.; Nukman, M.; Haberland, C. A.; Bauer, K.

2013-12-01

73

Entropy-Based Set Pair Analysis Model on Geological Disaster Risk for Military Engineering  

Directory of Open Access Journals (Sweden)

Full Text Available Measuring the geological disaster-risked situation, is a typical non-deterministic decision-making issue in disaster pre- vention and emergency response science for military engineering. Based on the given geological disaster risk analysis mechanism, geological disaster risk monitoring matrix was established, and risk characters’ value was obtained by mining the hidden information in the monitoring matrix with Entropy theory; with Identity, Discrepancy, and Contrary of Set Pair Analysis and distance measurement, geological disaster-risked model was erected for military engineering, and the steps were given for measuring geological disaster risk, which determined geological disaster-risked SPA force and order relationship of military engineering. Finally, case showed that model has the feasibility and effectiveness over measuring the geological disaster-risked situation for military engineering.

Fengshan Wang

2012-02-01

74

The Omeonga Structure, Democratic Republic of Congo: Geological and Petrographical Results, and Implications for its Origin  

Science.gov (United States)

For the first time, the origin of the ~38-km-diameter Omeonga structure, located in the Democratic Republic of Congo, is discussed using geological field observations and petrographic investigations on samples from our July 2011 field campaign.

Ferrière, L.; Kaseti, P. K.; Lubala, F. R. T.; Koeberl, C.

2012-03-01

75

Earthquakes and Geological Structures of the St. Lawrence Rift System  

Science.gov (United States)

The St. Lawrence Rift System (SLRS), which includes the Ottawa-Bonnechère and Saguenay grabens, is located well inside the North American plate. Most historic and the some 350 earthquakes recorded yearly occur in three main seismically active zones, namely Charlevoix (CSZ), Western Quebec (WQSZ), and Lower St. Lawrence (LSLSZ)). Outside these areas, most of the Canadian Shield and bordering regions have had a very low level of earthquake activity. In the SLRS, moderate to large earthquakes (Moment magnitude (M) 5.5 to M 7) are known to have occurred since 1663 causing landslides and damage mostly to unreinforced masonry elements of buildings located on ground capable of amplifying ground motions. Most earthquakes in these seismic zones share common characteristics such as mid- to upper crustal focal depths, no known surface ruptures and proximity to SLRS faults. Variations also exist such as vast seismically-active region (WQSZ and LSLSZ), presence of a large water body (CSZ and LSLSZ), and absence of SLRS faults near concentration of earthquakes (WQSZ). The CSZ is the best studied seismic zone and there, earthquakes occur in the Canadian Shield, mostly in a 30 X 85 km rectangle elongated along the trend of the St. Lawrence River with local variations in focal depth distribution. Faults related to the SLRS and to a meteor impact structure exist and earthquakes occur along the SLRS faults as well as in between these faults. Overall, the SLRS faults are probably reactivated by the larger earthquakes (M ? 4.5) of the 20th century (CSZ in 1925; WQCSZ in 1935 and 1944; Saguenay in 1988) for which we have focal mechanisms. We propose that caution be exercised when linking historical events that have uncertain epicentres with SLRS faults. Similarly, SLRS faults should not be necessarily considered to be the reactivated structures for most small to moderate earthquakes (M < 4.5). A good example of this is the earthquakes of the WQSZ that tend to concentrate in a well-defined NW-SE alignment with no obvious geological control, except perhaps, a hypothetical hotspot track. Two local factors can lead to the occurrence of SLRS earthquakes: weak faults or enhanced stress levels. We propose that local conditions, concentrated in a few seismic zones, can alter these factors and lead to the occurrence of earthquakes, especially those with M < 4.5. At a continent-wide scale, the correlation between the SLRS and earthquakes is appealing. We suggest, however, that pre-existing faults related to the SLRS do not explain all features of the seismicity. Seismicity is concentrated in more active areas, some with conspicuous normal faults and some with suspected weakening mechanisms such as intense pre-fracturing (e.g. due to a meteorite impact), the passage over a hot spot, or the presence of intrusions and lateral crustal density variations.

Lamontagne, M.; Ranalli, G.

2013-12-01

76

The advanced scenario analysis for performance assessment of geological disposal  

International Nuclear Information System (INIS)

First of all, with regard to the FEP information data on the Engineered Barrier System (EBS) developed by JNC, description level and content of the FEPs have been examined from various angles on the basis of the latest research information. Each content of the FEP data has been classified and modified by means of integrating descriptive items, checking detail levels and correlations with other FEPs, collating with the H12 report, and adding technical information after H12 report. Secondly, scenario-modeling process has been studied. The study has been conducted by evaluating representation of the repository system, definition of FEP properties, and process interactions based on the concept of the interaction matrix (RES format) which represents influences between physicochemical characteristics of the repository, followed by an experimental development of the actual RES interaction matrix based on the H12 report as the examination to improve the transparency, traceability and comprehensibility of the scenario analysis process. Lastly, in relation to the geological disposal system, assessment techniques have been examined for more practical scenario analysis on particularly strong perturbations. Possible conceptual models have been proposed for each of these scenarios; seismic, faulting, and dike intrusion. As a result of these researches, a future direction for advanced scenario analysis on performance assessment has been indicated, as well as associated issues to be discussed have been clarified. (author)

2002-01-01

77

Charged particle activation analysis of geological samples at the Rossendorf cyclotron  

International Nuclear Information System (INIS)

The capability of charged particle activation analysis of geological samples as a complement to instrumental neutron activation analysis was investigated. Different geological standard materials were activated at the Rossendorf cyclotron U-120 with 13.5 MeV deuterons. By means of ?-spectrometry the elements Mg, Ti, Co, Zn, Sr, and Y could be determined. The detection limits are in general favourable for the examination of geological samples. (author) 18 refs.; 3 tabs

1988-06-01

78

Analysis of integrated geologic data for uranium exploration in Egypt  

International Nuclear Information System (INIS)

Geologic information system (GIS) related to Nuclear Raw Materials is in current development in the Scient. Inform. Dept. (NMC). Processing of data follows developed criteria in U-exploration. Landsat image interpretation, photo lineaments, field measured joints, faults, folds, foliation, lineation, and deformed pebbles when properly integrated and computerized have pointed out a comprehensive tectonic model related to the CED of Egypt. The area seemed to be subjected to three deformative stages, in the first two; rocks undergone plastic deformation, while in the third one, rocks failed in brittle mode where the Red Sea Transverse Tectonic Trend (ENE-WSW) was developed intersecting the older plastically developed linear elements (NW-SE). Further rejuvenations permit opening the mentioned fractures and occupied by siliceous materials and jasperoid veins and lastly by U-type mineralization, best depicted in the plutons of El Missikat, El Erediya, Um Had and Kab Amiri. The Oligocene Qatrani Formation, north of Lake Qarun, NWD of Egypt is a typical example of fluviatile deposits. The middle clayey member is enclosed between two porous sandy members. The carbonaceous shale related to the clayey member shows abnormal U-concentrations. Statistical analysis of the distribution of uranium and other trace elements in the carbonaceous shale shows that U, Y, Mn and Ca obey the lognormal law while Sr, Rb, Zr, Cr and Ti obey the normal law. A geologic factor is derived that normally distributed elements are stationary, indigenous probably of detrital origin. Meanwhile, other lognormally distributed elements are active and mobile. Subsurface mapping shows that uranium tends to concentrate in the troughs of the flexured carbonaceous shale suggesting an epigenetic origin. 14 refs, 9 figs, 4 tabs

1988-09-01

79

A three-dimensional gravity model of the geologic structure of Long Valley caldera  

Energy Technology Data Exchange (ETDEWEB)

Several attempts to define and interpret this anomaly have been made in the past using 2-D and 3-D models. None of the previous interpretations have yielded definitive results, but in fairness, the interpretation here has benefited from a larger gravity data base and more subsurface control than available to previous workers. All published 3-D models simplistically assumed constant density of fill. All 2-D models suffered from the inherent three-dimensionality of the complicated density structure of Long Valley caldera. In addition, previous interpreters have lacked access to geological data, such as well lithologies and density logs, seismic refraction interpretations, suface geology, and structural geology interpretations. The purpose of this study is to use all available gravity data and geological information to constrain a multi-unit, 3-D density model based on the geology of Long Valley caldera and its vicinity. Insights on the geologic structure of the caldera fill can help other geophysical interpretations in determining near-surface effects so that deeper structure may be resolved. With adequate control on the structure of the caldera fill, we are able to examine the gravity data for the presence of deeper density anomalies in the crust. 20 refs., 7 figs.

Carle, S.F.; Goldstein, N.E.

1987-03-01

80

Seismic hazards: New trends in analysis using geologic data  

International Nuclear Information System (INIS)

In the late 1960s and early 1970s, largely in response to expansion of nuclear power plant siting and issuance of a code of federal regullations by the Nuclear Regulatory Commission referred to as Appendix A-10CFR100, the need to characterize the earthquake potential of individual faults for seismic design took on greater importance. Appendix A established deterministic procedures for assessing the seismic hazard at nuclear power plant sites. Bonilla and Buchanan, using data from historical suface-faulting earthquakes, developed a set of statistical correlations relating earthquake magnitude to surface rupture length and to surface displacement. These relationships have been refined and updated along with the relationship between fault area and magnitude and seismic moment and moment magnitude have served as the basis for selecting maximum earthquakes in a wide variety of design situations. In the paper presented, the authors discuss new trends in seismic hazard analysis using geologic data, with special emphasis on fault-zone segmentation and recurrence models and the way in which they provide a basis for evaluating long-term earthquake potential

1986-01-01

 
 
 
 
81

Carbonate pore systems: porosity/permeability relationships and geologic analysis  

Energy Technology Data Exchange (ETDEWEB)

The porosity/permeability relationships of the common carbonate rock types have been studied, with emphasis on the variety of pore types in upward-shoaling grainstone sequences including: Smackover, Lansing, Salem, and San Andres Formations. A result of these studies is an improved conceptual understanding of permeability gained from the cross-plotting of porosity and permeability data from plugs and whole cores accompanied by textural and fabric analyses of rock samples, thin sections, serial sections, and pore casts. Once the depositional texture and fabric of the rock are defined in terms of porosity and permeability, the evaluation of fractures and secondary porosity can be addressed. The secondary porosity is observed to be as high as 14% of the rock volume in the Smackover example and 21% of an oolitic sample from the Lansing Formation. Pore casts and serial sections reveal that the grain-moldic porosity is poorly connected to the intragranular pore system and contributes little to the permeability of the rock. This insight allows quantitative estimates of this type of secondary porosity using standard porosity and permeability data. The geologic and quantitative analysis of the various pore types and porosity/permeability relationships also aided in the interpretation of the log data from the reservoirs studied.

Nurmi, R.D.

1984-04-01

82

Investigation of structural geology and coal mine subsidence potential in Colorado Springs area using remote sensing and GIS technology  

International Nuclear Information System (INIS)

The purpose of this paper is to determine the extent to which remote structures which may affect the location and migration of subsidence over abandoned underground coal mines in the Colorado Springs area. Ultimately, these techniques could be useful for identifying such geologic structures at other abandoned mine land (AML) sites. Landsat satellite images and aerial photographs were used to interpret the geologic structure of the area. A geographic information system (GIS) was used to integrate the diverse data sets involved in the study and to allow reliable and reproducible spatial registration and analysis of the data. The specific study area used was the northern and northeastern Colorado Springs, Colorado, area where coal mining was active from the 1870s until 1957. The results of this study indicate that the subsidence hazard zones projected by Dames and Moore (1985) could be modified to take into account geologic structures as identified through remote sensing. Other AML sites should be investigated through remote sensing and lineament analysis to aid in fully evaluating subsidence potential of the sites. The GIS database also will provide a reasonably reliable source of spatial data for future land-use planning and tracking of subsidence hazards

1992-09-01

83

Geological assessment for the new road leading into Lanjarón (Granada, Spain): slope stability analysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Detailed geological study of the western part of a new road leading to Lanjarón (Betic Cordillera) has revealed the existence ofnatural instabilities in metapelitic rock masses ofthe Alpurrides Units. We have analysed the stability of the future slopes in the Cerro de la Escolta based on detailed geological mapping and measurement of structural data and mechanical discontinuities

2010-01-01

84

Structural geology of the North and Middle Caspian sea on the new geophysical data interpretation  

International Nuclear Information System (INIS)

Full text:A structural and tectonic map of the North and Middle Caspian Sea is made on the basis of seismic and other geological and geophysical data analysis. According to the plotting results the total amplitude range of the heterogeneous basement depths are in the North Caspian Sea (Ukatnensky depression-over 12 km and Prorva depression-over 16 km). In the middle Caspian Sea the deppest basement point is supposed in Sulak basin (over 12 km). The least basement depths are marked in Karpinsky ridge,Buzachinky and Karabogazsky arches (1-3 km). On the whole the morphology and structure of the basement confirms the conclusion previously made by many researches that the Caspian Sea is a heterogeneous depression superimposed on the junction of regional tectonic elements of various ages.The ancient East-European platform represented by Pricaspiisky depression (Donetsko-Astrakhanskaya fault system limits the latter in the south) is situated on the North. The middle Caspian Sea is occupied with the offshore continuation of Terek-Caspian foredeep is represented by Sulak basin clearly limited in the south by a system of upthrusts and thrusts falling under North Caucasus foreland.Geological interpretation of the Yuzhmorgeologiya Center new geophysical data allows making an assumption about the biohermexistence within TriassicSea sediments on Kuma-Manychsky depression offshore continuation. Seismic exploration works show strike-slip faults and thrust structure development within the sedimentary cover on the offshore continuation of Karpinsky ridge.Some strike-slipped blocks are separated by left-side shifts of the northeast stretch.The pool location at the left-side (east) blocks of the shift areas is marked.

2002-09-01

85

Geological characteristics and analysis on ore-controlling factors of Shihongtan uranium deposit, Turpan-Hami basin  

International Nuclear Information System (INIS)

On the basis of a brief introduction of regional geology of Turpan-Hami basin, geology and sand bodies characteristics for target stratum of Shihongtan uranium district, the author mainly expounds distributive law, zonation and relation between fronts and u-mineralization of interlayer oxidation zone for deposit district. The author states space arrangement, shape, size, material components of ores, exiting states of uranium as well as comparative study for north-ore belt and south-ore belt of Shihongtan uranium deposit. In final, the author points out ore-controlling factors are interlayer oxidation zone, nose uplift and faulted structure by systematic analysis

2002-12-01

86

The influence of geological loading on the structural integrity of an underground nuclear waste repository  

International Nuclear Information System (INIS)

Stresses are developed in underground nuclear waste repositories as a result of applied loads from geological movements caused by the encroachment of ice sheets or seismic activity for example. These stresses may induce fracturing of the waste matrix, repository vault and nearfield host geology. This fracturing will enhance the advective flow and allow more-rapid transfer of radionuclides from their encapsulation through the repository barriers and nearfield host rock. Geological loads may be applied either gradually as in crustal folding or encroachment of ice sheets, or rapidly as in the case of seismic movements. The analysis outlined in this report is conducted with a view to including the effects of geological loading in a probabilistic repository site assessment computer code such as SYVAC. (author)

1985-01-01

87

Linking geology and microbiology: inactive pockmarks affect sediment microbial community structure.  

Science.gov (United States)

Pockmarks are geological features that are found on the bottom of lakes and oceans all over the globe. Some are active, seeping oil or methane, while others are inactive. Active pockmarks are well studied since they harbor specialized microbial communities that proliferate on the seeping compounds. Such communities are not found in inactive pockmarks. Interestingly, inactive pockmarks are known to have different macrofaunal communities compared to the surrounding sediments. It is undetermined what the microbial composition of inactive pockmarks is and if it shows a similar pattern as the macrofauna. The Norwegian Oslofjord contains many inactive pockmarks and they are well suited to study the influence of these geological features on the microbial community in the sediment. Here we present a detailed analysis of the microbial communities found in three inactive pockmarks and two control samples at two core depth intervals. The communities were analyzed using high-throughput amplicon sequencing of the 16S rRNA V3 region. Microbial communities of surface pockmark sediments were indistinguishable from communities found in the surrounding seabed. In contrast, pockmark communities at 40 cm sediment depth had a significantly different community structure from normal sediments at the same depth. Statistical analysis of chemical variables indicated significant differences in the concentrations of total carbon and non-particulate organic carbon between 40 cm pockmarks and reference sample sediments. We discuss these results in comparison with the taxonomic classification of the OTUs identified in our samples. Our results indicate that microbial communities at the sediment surface are affected by the water column, while the deeper (40 cm) sediment communities are affected by local conditions within the sediment. PMID:24475066

Haverkamp, Thomas H A; Hammer, Øyvind; Jakobsen, Kjetill S

2014-01-01

88

Structural geology of Amazonian-aged layered sedimentary deposits in southwest Candor Chasma, Mars  

Science.gov (United States)

The structural geology of an outcropping of layered sedimentary deposits in southwest Candor Chasma is mapped using two adjacent high-resolution (1 m/pixel) HiRISE digital elevation models and orthoimagery. Analysis of these structural data yields new insight into the depositional and deformational history of these deposits. Bedding in non-deformed areas generally dips toward the center of west Candor Chasma, suggesting that these deposits are basin-filling sediments. Numerous kilometer-scale faults and folds characterize the deformation here. Normal faults of the requisite orientation and length for chasma-related faulting are not observed, indicating that the local sediments accumulated after chasma formation had largely ceased in this area. The cause of the observed deformation is attributed to landsliding within these sedimentary deposits. Observed crosscutting relationships indicate that a population of sub-vertical joints are the youngest deformational structures in the area. The distribution of strain amongst these joints, and an apparently youthful infill of sediment, suggests that these fractures have been active in the recent past. The source of the driving stress acting on these joints has yet to be fully constrained, but the joint orientations are consistent with minor subsidence within west Candor Chasma.

Okubo, C. H.

2010-01-01

89

A life cycle cost analysis framework for geologic storage of hydrogen : a scenario analysis.  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy has an interest in large scale hydrogen geostorage, which would offer substantial buffer capacity to meet possible disruptions in supply. Geostorage options being considered are salt caverns, depleted oil/gas reservoirs, aquifers and potentially hard rock cavrns. DOE has an interest in assessing the geological, geomechanical and economic viability for these types of hydrogen storage options. This study has developed an ecocomic analysis methodology to address costs entailed in developing and operating an underground geologic storage facility. This year the tool was updated specifically to (1) a version that is fully arrayed such that all four types of geologic storage options can be assessed at the same time, (2) incorporate specific scenarios illustrating the model's capability, and (3) incorporate more accurate model input assumptions for the wells and storage site modules. Drawing from the knowledge gained in the underground large scale geostorage options for natural gas and petroleum in the U.S. and from the potential to store relatively large volumes of CO{sub 2} in geological formations, the hydrogen storage assessment modeling will continue to build on these strengths while maintaining modeling transparency such that other modeling efforts may draw from this project.

Kobos, Peter Holmes; Lord, Anna Snider; Borns, David James

2010-10-01

90

An engineering geological appraisal of the Chamshir dam foundation using DMR classification and kinematic analysis, southwest of Iran  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the results of engineering geological  investigations and rock mechanics studies carried out at the proposed Chamshir dam site. It is proposed that a 155 m high solid concrete gravity-arc dam be built across the Zuhreh River to the southeast of the city of Gachsaran in south-western Iran. The dam and its associated structures are mainly located on the Mishan formation. Analysis consisted of rock mass classification and a kinematic
analysis of the dam foundation's rock masses. The studies were carried out in the field and the laboratory. The field studies included geological mapping, intensive discontinuity surveying, core drilling and sampling for laboratory testing. Rock mass classifications were made in line with RMR and DMR classification for the dam foundation. Dam foundation analysis regarding stability using DMR classification and kinematic analysis indicated that the left abutment's rock foundation (area 2 was unstable for planar, wedge and toppling failure modes.

Torabi Kaveh Mehdi

2011-12-01

91

Mass transport analysis in the near field of geologic repository  

Science.gov (United States)

A two-dimensional model for the groundwater flow and the contaminant transport has been developed. A water-saturated, deep geologic repository for high-level radioactive wastes (HLW) is considered. The region containing a waste canister, a backfill material around the canister, and the near-field rock (NFR) surrounding the backfill is considered. Discrete-Fracture Network (DFN) is generated in the NFR based on distribution functions of the fracture geometry parameters by random sampling. Flow-bearing fracture network is identified, and is transformed into an equivalent continuous porous medium in two different ways without calculating flow rates through individual fractures. The first transformation is applied locally, generating a heterogeneous porous medium. The second transformation is applied for the entire NFR, resulting in a homogeneous porous medium. While the heterogeneous porous medium is considered to represent characteristics of water flow in DFN better than the homogeneous porous medium, the homogeneous porous medium was often used in previous performance assessment studies for its simplicity. After these transformations, the spatial distribution of groundwater flow rate is calculated by a finite element method. The numerical results for the total discharge at the outer boundary of the homogenized NFR after the second transformation are benchmarked by analytical solutions with a relative difference smaller than 0.55%. The contaminant transport is simulated by a random-walk particle-tracking method, based on the obtained flow-rate distribution. Previous study for a step equation that determines the movement of contaminant particles has been critically reviewed. Numerical results obtained by the first and second transformations have been compared. The second transformation gives smaller mean values of the residence time of particles in the NFR and greater mean values of the mass absorption rate at the outer boundary of NFR than the first one does. Thus, if a contaminant transport analysis is to be made to obtain a conservative worst-case prediction, the second transformation is appropriate. However, because the second transformation yields nearly the same results for rocks with various kinds of heterogeneity, for site selection, in which performance of various kinds of host rocks needs to be differentiated, a transport model with the second transformation is not appropriate.

Lim, Doo-Hyun

92

Comparison between radar data and geophysical, geological and hydrological borehole paramenters by multivariate analysis of data  

International Nuclear Information System (INIS)

The object of the present work is to study the correlation between radar reflectors and geophysical, geological and hydraulical parameters from the boreholes. An additional objective is to show what information can be gained by the borehole radar with respect to waterflow and geological structures in crystalline rock. The tool for making the data modelling is Multivariate Data Analysis (SIMCA). For the data modelling there are two algorithms available in the SIMCA software. One for Principal Component analysis and one for Partial Least Squares regression analysis (PLS and PLS2). The PLS method gives the best result for the purpose of correlation between radar intensity and other variables. The result from the Principal Components, PLS, and PLS2 analysis shows that the strongest correlations results in a division between highly fractured rock and low fractured rock at all sites. Also, PLS and PLS2 analysis show that there is a good correlation between high radar intensity and highly fractured rock in the boreholes at all sites. The correlation between radar intensity and hydraulic condictivity is more ambiguous. Two of the investigated sites. Stripa and Finnsjoen, exhibit good correlation between radar intensity and hydraulic condictivity, while the correlation at Aevroe is lower and at Saltsjoetunnel it is poor. Hydraulic conductivity was not included in the analysis of the Klipperaas data. The best correlaiton in the data from Klipperaas was obtained between radar intensity and fractured lithological contracts. The degree of correlation between radar intensity and lithological contacts at the other four sites was lower than for Klipperaas. (24 figs., 37 tabs., 30 refs)

1989-01-01

93

Geologic Structure at the Curiosity Field Site from Stereo Topography (Invited)  

Science.gov (United States)

Over the initial months of its mission, the Curiosity rover has been exploring a number of rock units exposed around its landing site within Gale crater, Mars. A major scientific focus has been the development of a stratigraphic column to understand the depositional and age relationships of diverse outcrops studied by Curiosity. Many of the outcrops encountered by the rover are stratified, and likely sedimentary in origin, enabling the determination of depositional geometries and structural tilts. Curiosity routinely acquires stereo images with its engineering (Navcam, Hazcam) and science (Mastcam, MAHLI) cameras, from which topographic data can be derived. In particular, Mastcam stereo topography can achieve several millimeter-scale resolution for near-field observations, enabling analysis of individual laminations within layered rock targets. One particularly rich target encountered by Curiosity has been the Shaler outcrop, first observed at close range on sols 120 and 121. The layered sedimentary rocks of Shaler were exposed over a distance of 30 meters along the rover traverse, with an estimated stratigraphic thickness of 1-2 meters. At this location, a number of distinct sedimentary facies are observed, including abundant cross-stratification. Strongly differential erosion highlights the varying mechanical properties of the outcrop, likely resulting from changes in grain size and degree of cementation. In general, Shaler is composed of grains of coarse-sand size and finer, differing from the much coarser fluvial conglomerates observed at the rover's landing site. Structural measurements at Shaler and nearby outcrops demonstrate a variety of bedding orientations, consistent with the observed cross-bedded architecture. Strata at Shaler in particular exhibit an overall southeastern dip of 5-15 degrees. Interpretation of this trend as a primary depositional feature suggests a largely unidirectional transport vector during formation. Alternately, the southeastern trend of the outcrop may indicate local tilting as a result of impact or other post-depositional processes. Potential formation scenarios for Shaler and similar layered outcrops include aeolian and fluvial deposition. Ongoing analysis will attempt to discriminate between the multiple hypotheses for depositional origin and subsequent modification. These structural measurements better constrain the Shaler outcrop within the context of geologic units observed by Curiosity to date, both stratigraphically and through geologic process.

Lewis, K. W.; Edgar, L. A.; Gupta, S.; Rubin, D. M.; Kocurek, G.; Anderson, R. B.; Hayes, A. G.; Kah, L. C.

2013-12-01

94

A method of identifying social structures in siting regions for deep geological repositories in Switzerland  

Energy Technology Data Exchange (ETDEWEB)

Acceptance is a key element in the site selection process for deep geological repositories for high-level and low and intermediate-level radioactive waste in Switzerland. Participation requirements such as comprehensive negotiation issues and adequate resources have thus been defined by the Swiss Federal Office of Energy (SFOE). In 2008, on the basis of technical criteria Nagra (National Cooperative for the Disposal of Radioactive Waste) proposed several potential areas for deep geological repositories. The number of potential areas will be narrowed down within the next few years. All municipalities within the planning perimeter (the area in which surface facilities can be realised) are affected and form the siting region. In order to ensure that the local population have their say in the forthcoming discussions, regional participation bodies including all municipalities within a siting region are being set up by the SFOE. Regional participation ensures that local interests, needs and values are taken into account in the site selection process. Assembling the regional participation bodies is therefore of great importance. Before such bodies can be formed, however, the various interests, needs and values have to be identified, and special attention has to be paid to long-term interests of future generations, as well as to non-organised and under-represented interests. According to the concept of proportional representation, the interests, needs and values that are identified and weighted by the local population are to be represented in the regional participation procedure. The aim of this study is to share a method of mapping existing social structures in a defined geographical area. This involves a combination of an analysis of socio-economic statistical data and qualitative and quantitative social research methods

Brander, Simone (Swiss Federal Office of Energy SFOE, Bern (Switzerland))

2010-09-15

95

A method of identifying social structures in siting regions for deep geological repositories in Switzerland  

International Nuclear Information System (INIS)

Acceptance is a key element in the site selection process for deep geological repositories for high-level and low and intermediate-level radioactive waste in Switzerland. Participation requirements such as comprehensive negotiation issues and adequate resources have thus been defined by the Swiss Federal Office of Energy (SFOE). In 2008, on the basis of technical criteria Nagra (National Cooperative for the Disposal of Radioactive Waste) proposed several potential areas for deep geological repositories. The number of potential areas will be narrowed down within the next few years. All municipalities within the planning perimeter (the area in which surface facilities can be realised) are affected and form the siting region. In order to ensure that the local population have their say in the forthcoming discussions, regional participation bodies including all municipalities within a siting region are being set up by the SFOE. Regional participation ensures that local interests, needs and values are taken into account in the site selection process. Assembling the regional participation bodies is therefore of great importance. Before such bodies can be formed, however, the various interests, needs and values have to be identified, and special attention has to be paid to long-term interests of future generations, as well as to non-organised and under-represented interests. According to the concept of proportional representation, the interests, needs and values that are identified and weighted by the local population are to be represented in the regional participation procedure. The aim of this study is to share a method of mapping existing social structures in a defined geographical area. This involves a combination of an analysis of socio-economic statistical data and qualitative and quantitative social research methods

2009-12-15

96

The role of scenario analysis in radiological assessments of geologic disposal  

International Nuclear Information System (INIS)

This paper examines the role of scenario analysis in comprehensive radiological assessments of geologic disposal options. The objectives of these assessments are reviewed and assessment methodology is discussed, with emphasis on the scenario analysis aspects and the relationship between scenario analysis and consequence analysis. Suggestions are made for the development of assessment methodology and for future scenario research

1980-09-12

97

Geological Structures in the WaIls of Vestan Craters  

Science.gov (United States)

A compelling case can be made that Vesta is the parent asteroid for the howardite, eucrite and diogenite (HED) meteorites [1], although this interpretation has been questioned [2]. Generalized models for the structure of the crust of Vesta have been developed based on petrologic studies of basaltic eucrites, cumulate eucrites and diogenites. These models use inferred cooling rates for different types of HEDs and compositional variations within the clan to posit that the lower crust is dominantly diogenitic in character, cumulate eucrites occur deep in the upper crust, and basaltic eucrites dominate the higher levels of the upper crust [3-5]. These models lack fine-scale resolution and thus do not allow for detailed predictions of crustal structure. Geophysical models predict dike and sill intrusions ought to be present, but their widths may be quite small [6]. The northern hemisphere of Vesta is heavily cratered, and the southern hemisphere is dominated by two 400-500 km diameter basins that excavated deep into the crust [7-8]. Physical modeling of regolith formation on 300 km diameter asteroids predicts that debris layers would reach a few km in thickness, while on asteroids of Vesta's diameter regolith thicknesses would be less [9]. This agrees well with the estimated =1 km thickness of local debris excavated by a 45 km diameter vestan crater [10]. Large craters and basins may have punched through the regolith/megaregolith and exposed primary vestan crustal structures. We will use Dawn Framing Camera (FC) [11] images and color ratio maps from the High Altitude and Low Altitude Mapping Orbits (HAMO, 65 m/pixel; LAMO, 20 m/pixel) to evaluate structures exposed on the walls of craters: two examples are discussed here.

Mittlefehldt, David; Nathues, A.; Beck, A. W.; Hoffmann, M.; Schaefer, M.; Williams, D. A.

2014-01-01

98

Simulations of neutrino and muon interaction in matter for geological structures radiography  

International Nuclear Information System (INIS)

Neutrino and muon radiography seems to provide a method complementary to the more conventional seismic studies for getting information on the very deep geological structures. Here we describe the status of the simulations of neutrino and muon interaction in matter. (author)

2010-03-01

99

Structural geology practice and learning, from the perspective of cognitive science  

Science.gov (United States)

Spatial ability is required by practitioners and students of structural geology and so, considering spatial skills in the context of cognitive science has the potential to improve structural geology teaching and practice. Spatial thinking skills may be organized using three dichotomies, which can be linked to structural geology practice. First, a distinction is made between separating (attending to part of a whole) and combining (linking together aspects of the whole). While everyone has a basic ability to separate and combine, experts attend to differences guided by experiences of rock properties in context. Second, a distinction is made between seeing the relations among multiple objects as separate items or the relations within a single object with multiple parts. Experts can flexibly consider relations among or between objects to optimally reason about different types of spatial problems. Third, a distinction is made between reasoning about stationary and moving objects. Experts recognize static configurations that encode a movement history, and create mental models of the processes that led to the static state. The observations and inferences made by a geologist leading a field trip are compared with the corresponding observations and inferences made by a cognitive psychologist interested in spatial learning. The presented framework provides a vocabulary for discussing spatial skills both within and between the fields of structural geology and cognitive psychology.

Shipley, Thomas F.; Tikoff, Basil; Ormand, Carol; Manduca, Cathy

2013-09-01

100

THM coupling sensitivity analysis in geological nuclear waste storage  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A deep geological repository involving a multi-barrier system constitutes one of the most promising options to isolate high-level radioactive waste from the human environment. In order to certify the efficiency of waste isolation, it is essential to understand the behaviour of the confining geomaterials under a variety of environmental conditions. The efficiency of an Engineered Barrier System (EBS) is largely based on the complex behaviour of bentonite. To contribute to a better understandin...

2013-01-01

 
 
 
 
101

Geological and geophysical aspects of the Kurdashi structure, Azerbaijan  

International Nuclear Information System (INIS)

Full text:The paper is case history of the improved characterization of a complex structure in the Azerbaijan off shore achieved by application of advanced seismic tools such us 3D Pre-Stack Depth Migration and Continuity Depth Cube volumes. The investigation focuses on the Kurdashi Permit and adjacent areas of southern most Azerbaijan, neas its boundary with Iran. The Kurdashi Permit is operated by AGIP AZERBAIJAN, a subsidiary of the Italian ENI Agip Division. The South Caspian Basin in one of the worlds most unusual sedimentary basins. Three major river systems the Volga, Kura and AMU-Darya have converged to provide continuous sediment supply in the Neogene. Structures of the Kurdashi area demonstrate the strong involvement of faulted basement unlike structures in the central SCB. Basement is relatively shallow and the major basin wide detachment level, the thick and over-pressured Maykopian shale changes character, thins, on laps and eventually pinches out between the Kurdashi and Lenkoran areas. Several tectonic events can be observed to impact the Kurdashi geometry. The Pre-Stack Depth Migration was accomplished using the Paradigm Geophysical software Geodepth99. Te target oriented velocity model for migration of the volume was constructed using nine layers with each layer constructed from several iterations of velocity testing, 3D tomography, and migration. The combination of Pre-SDM and Continuity cube volumes used together permits a substantially improved resolution of faults and a clear indication of how they connect together. The combined observations made in the Continuity Cube volume and the Pre SDM volumes allow us to describe the fols as a classic buckle fold. With continuous tightening of the fold sice Lower Apsheronian time, the shallower surfaces undergo extension synchronous with compression at deeper levels.There is a mappable null surface. A mud volcano occurs where the main faults alternate their dip and tensile stress is greatest

2002-09-01

102

Method and apparatus for drilling horizontal holes in geological structures from a vertical bore  

Energy Technology Data Exchange (ETDEWEB)

This invention is directed to a method and apparatus for drilling horizontal holes in geological strata from a vertical position. The geological structures intended to be penetrated in this fashion are coal seams, as for in situ gasification or methane drainage, or in oil-bearing strata for increasing the flow rate from a pre-existing well. Other possible uses for this device might be for use in the leaching of uranium ore from underground deposits or for introducing horizontal channels for water and steam injections.

Summers, David A. (Rolla, MO); Barker, Clark R. (Rolla, MO); Keith, H. Dean (Rolla, MO)

1982-01-01

103

Commentary of Uruguay geological structure - Present status of its mining activity  

International Nuclear Information System (INIS)

This work is about the geological structure of Uruguay and its mining activity. The Rio de la Plata socket basin and the Rivera crystalline island are the oldest geochronological structures in Uruguay. This unit represents the 60% of the crystalline field and belongs to the Uruguay orogenetic Precambrian cycle. In the north there are sedimentary rocks and granites of the Upper Precambrian period.The mining and processing of marble, granite, agate, amethyst and metallic minerals are declared of national interest

1988-01-01

104

Structural geology of Shawneetown fault zone, Southeastern Illinois  

Energy Technology Data Exchange (ETDEWEB)

Vertical movements of crustal blocks along the narrow east-west-trending Shawneetown fault zone in southeastern Illinois occurred between Early Permian and Late Cretaceous. The main blocks moved vertically and retured to roughly their orignal positions so that strata now show little relative offset across the fault zone. However, individual faults with displacements up to 3,500 ft (1,070 m) bound narrow slices of steeply tilted or overturned strata resulting in a juxtaposition of Kinderhookian (Lower Mississippian) and Upper Devonian strata with Lower Pennsylvanina strata. The bedrock is intensely fractured, commonly brecciated, and cemented with either silica or calcite. Slickensides and mullion display various orientations within the zone and on individual outcrops. The dominant movement, however, appears to be vertical with no evidence for significant strike-slip movements. Pleistocene deposits do not exhibit offsets across the fault zone, indicating that no tectonic activity has occurred since the beginning of that epoch. The trend of the fault zone changes abruptly from east-west in southern Gallatin and easternmost Saline Counties to south-southwest in southern Saline and northeastern Pope Counties, where it joins the Fluorspar area fault complex. Here the zone widens and develops a braided pattern as the amount of displacement along individual faults decreases. The Shawneetown fault zone and Flourspar area fault complex in part are younger than the Cottage Grove fault system to the northwest and the Wabash Valley fault system to the north. The hope of finding structural traps near the junctions of the fuel systems has spurred recent oil exploration in the area.

Lumm, D.K.; Nelson, W.J.

1983-09-01

105

Study of gamma ray analysis software's. Application to activation analysis of geological samples  

International Nuclear Information System (INIS)

A comparative evaluation of the gamma-ray analysis software VISPECT, in relation to two commercial gamma-ray analysis software packages, OMNIGAM (EG and G Ortec) and SAMPO 90 (Canberra) was performed. For this evaluation, artificial gamma ray spectra were created, presenting peaks of different intensities and located at four different regions of the spectrum. Multiplet peaks with equal and different intensities, but with different channel separations, were also created. The results obtained showed a good performance of VISPECT in detecting and analysing single and multiplet peaks of different intensities in the gamma-ray spectrum. Neutron activation analysis of the geological reference material GS-N (IWG-GIT) and of the granite G-94, used in a Proficiency Testing Trial of Analytical Geochemistry Laboratories, was also performed , in order to evaluate the VISEPCT software in the analysis of real samples. The results obtained by using VISPECT were as good or better than the ones obtained using the other programs. (author)

1998-01-01

106

Investigations for the optimization of the analysis of geological samples by XRF  

International Nuclear Information System (INIS)

In the present work an attempt has been made to optimize conditions of sample of preparation and sample form for the analysis of some geological samples using X RF. The results obtained confirmed that pellet form is best in sample preparation for X RF analysis. It was also shown that the best pressure to apply in the pressing machine for obtaining such a pellet is 15 ton.The computer software used for analysis of the samples was QAES prepared by Kump. The calibration performed was based on the geological standard G 308. The results obtained for the analysis of some geological samples using the optimum sample preparation conditions and the performed calibration were in good agreement with results independently determined for the same samples using chemical methods. (Author)

1998-01-01

107

Geological evolution and analysis of confirmed or suspected gas hydrate localities: Volume 6, Basin analysis, formation and stability of gas hydrates in the Panama Basin  

Energy Technology Data Exchange (ETDEWEB)

This report presents a geological description of the Panama Basin, including regional and local structural settings, geomorphology, geological history, stratigraphy, and physical properties. It provides the necessary regional and geological background for more in-depth research of the area. Detailed discussion of bottom simulating acoustic reflectors, sediment acoustic properties, distribution of hydrates within the sediments, and the relation of hydrate distribution to other features such as salt diapirism are also included. The formation and stabilization of gas hydrates in sediments are considered in terms of phase relations, nucleation, and crystallization constraints, gas solubility, pore fluid chemistry, inorganic diagenesis, and sediment organic content. Together with a depositional analysis of the area, this report is a better understanding of the thermal evolution of the locality. It should lead to an assessment of the potential for both biogenic and thermogenic hydrocarbon generation. 63 refs., 38 figs., 7 tabs.

Krason, J.; Ciesnik, M.

1986-03-01

108

The growth of geological structures by repeated earthquakes, 1, conceptual framework  

Science.gov (United States)

In many places, earthquakes with similar characteristics have been shown to recur. If this is common, then relatively small deformations associated with individual earthquake cycles should accumulate over time to create geological structures. It is shown that existing models developed to describe leveling line changes associated with the seismic cycle can be adapted to explain geological features associated with a fault. In these models an elastic layer containing the fault overlies a viscous half-space with a different density. Fault motion associated with an earthquake results in immediate deformation followed by a long period of readjustment as stresses relax in the viscous layer and isostatic equilibrium is restored. The flexural rigidity of the crust (or the apparent elastic thickness) provides the main control of the width of a structure. The loading due to erosion and deposition of sediment determines the ratio of uplift to subsidence between the two sides of the fault. -Authors

King, G. C. P.; Stein, R. S.; Rundle, J. B.

1988-01-01

109

Determination of trace elements in geological SRM with the use of instrumental neutron activation analysis  

International Nuclear Information System (INIS)

The method of instrumental neutron activation analysis was applied for a multielemental trace analysis of six geological standard reference materials. 25 elements were determined using long-lived radionuclides. The relative error of the analyses ranged from 5 to 20%. 12 refs., 2 tabs. (author)

1988-01-01

110

Structural geology of wells of opportunity tested during 1980 and 1981  

Energy Technology Data Exchange (ETDEWEB)

Six geopressured-geothermal reservoirs have been tested. These reservoirs have been isolated in one or more directions by down-to-the-coast growth-type faulting. The two main types are those bounded updip by a single sealing fault and anticlinal traps bounded both up and down dip of the structure. Additional permeability barriers were encountered during testing. These barriers were not predicted in the original geologic evaluations and show the need to seek larger reservoirs in future tests.

Peterson, K.P.

1981-01-01

111

Engineering geological assessment and structural comparison of the Vollan and Ivasnasen rock slopes at Sunndal, Norway  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This master thesis has interest in analyzing the two unstable rock slopes Ivasnasen and Vollan. These rock slopes are located in a U-shaped valley in Sunndal municipally (Møre & Romsdal, western Norway). The analyses are based on a combined approach using detailed geomorphic, structural and geological field mapping. This along with interpretation of high-resolution digital elevation models (DEM) and orthophotos, LIDAR-scans from one of the sites (Ivasnasen 2010 and 2011), numerical a...

2012-01-01

112

Self-Discovery of Structural Geology Concepts using Interactive 3D Visualization  

Science.gov (United States)

Mastering structural geology concepts that depend on understanding three-dimensional (3D) geometries and imagining relationships among unseen subsurface structures are fundamental skills for geologists. Traditionally these skills are developed first, through use of 2D drawings of 3D structures that can be difficult to decipher or 3D physical block models that show only a limited set of relationships on the surfaces of the blocks, followed by application and testing of concepts in field settings. We hypothesize that this learning process can be improved by providing repeated opportunities to evaluate and explore synthetic 3D structures using interactive 3D visualization software. We present laboratory modules designed for undergraduate structural geology curriculum using a self-discovery approach to teach concepts such as: the Rule of V’s, structure separation versus fault slip, and the more general dependence of structural exposure on surface topography. The laboratory modules are structured to allow students to discover and articulate each concept from observations of synthetic data both on traditional maps and using the volume visualization software 3DVisualizer. Modules lead students through exploration of data (e.g., a dipping layered structure exposed in ridge-valley topography or obliquely offset across a fault) by allowing them to interactively view (rotate, pan, zoom) the exposure of structures on topographic surfaces and to toggle on/off the full 3D structure as a transparent colored volume. This tool allows student to easily visually understand the relationships between, for example a dipping structure and its exposure on valley walls, as well as how the structure extends beneath the surface. Using this method gives students more opportunities to build a mental library of previously-seen relationships from which to draw-on when applying concepts in the field setting. These laboratory modules, the data and software are freely available from KeckCAVES.

Billen, M. I.; Saunders, J.

2010-12-01

113

Applying geologic sensitivity analysis to environmental risk management: The financial implications  

Energy Technology Data Exchange (ETDEWEB)

The financial risks associated with environmental contamination can be staggering and are often difficult to identify and accurately assess. Geologic sensitivity analysis is gaining recognition as a significant and useful tool that can empower the user with crucial information concerning environmental risk management and brownfield redevelopment. It is particularly useful when (1) evaluating the potential risks associated with redevelopment of historical industrial facilities (brownfields) and (2) planning for future development, especially in areas of rapid development because the number of potential contaminating sources often increases with an increase in economic development. An examination of the financial implications relating to geologic sensitivity analysis in southeastern Michigan from numerous case studies indicate that the environmental cost of contamination may be 100 to 1,000 times greater at a geologically sensitive location compared to the least sensitive location. Geologic sensitivity analysis has demonstrated that near-surface geology may influence the environmental impact of a contaminated site to a greater extent than the amount and type of industrial development.

Rogers, D.T.

1999-07-01

114

Survey concerning geology and geological structure of sedimentary rock at Neogene in Horonobe-Cho, Hokkaido, Japan. Part 2  

International Nuclear Information System (INIS)

Survey was conducted for the following purpose: obtaining data on the planar variation in depth of the oxidized zone, understanding of the transition from oxidized zone through the dissolution zone to the fresh rock zone, and depicting of weathering history at near-surface in the area where the Laboratory is planned to be built and also establishing of stratigraphy and geological structure of the Neogene strata in the area around the Omagari Fault. During the survey, drilling was done at 23 sites. The standard penetration test was conducted at one drilling site (H16-1-01). Data of hardness and color degree were obtained for the cored samples at the all sites. Vinyl chloride pipes (VP50) for observation were set up after the drilling. The survey results show thicknesses of the fill(Bk), clay zone (Ac), mudstone of the oxidized zone (Ms-1), mudstone of the dissolution zone (Ms-2), and mudstone of the fresh rock zone (Ms-3) are 0.7 m, 0.1-3.3 m, 0.4-32.2 m, 1.0-12.5 m, 0.5-14.0 m, respectively. N-values in average of the Ms-1, Ms-2, and Ms-3 were 14, 19, and >50, respectively. Underground water levels confirmed by the survey were 1.1-15.46 m in depth (H=79.9-59.4 m). Average RQD of Ms-2 and Ms-3 were 8% and 45%, respectively. Hardness and color degree of the samples of Ms-3 from the fresh rock zone are: Ld-values=408, L* (brightness) = 32.4, a* (positive: red, negative: green)=0.01, and b* (positive: yellow, negative: blue)=6.7. Levels (above sea level) of the top of the fresh rock zone is higher at the higher-elevation sites compared to those at the lower-elevation sites, suggesting that the level of the top of the fresh rock zone is not very different in this area regardless of topography. There is no significant correlation between the hardness, Ld-values, of the samples and top depth of the fresh rock zone. The color degree of a fresh rock doesn't depend on the point and indicate a similar value. This work was performed by Ueyama-shisui Co., Ltd. under contract with Japan Nuclear Cycle Development Institute (JNC). (author)

2004-01-01

115

Neutron activation analysis of geological samples for gold and accessory elements power reactor  

International Nuclear Information System (INIS)

Possibility of using a power reactor for neutron activation analysis to detect gold and accompanying elements in geological samples of a region was investigated. Specimens (gold-containing samples and standards) were irradiated in a spare channel for ionization chambers located outside the core in graphite reflector. Spectrometry was conducted with the help of a semiconducting detector with LP 4900 multichannel analizer. Sensitivity threshold for gold was (1-3)10"-"6 % - (1-2)10"-"5 %. It is shown that this method can be used not only for gold detection but for high-sensitive multielement analysis of geological samples

1986-10-01

116

Geologic segregation of radioactive wastes: probabilistic analysis of scenari of 'Far Field' type for containment breakings  

International Nuclear Information System (INIS)

The range of events which could lead to a breaking of the geologic barrier is large and heterogeneous. Reliable evaluations on storage security can not be made using one methodology. The change of initial geologic conditions, due to the presence of deposit in the formation ask for carefull studies, mainly of experimental nature (in laboratory and in site). Although geologic events are variable, they can be treated in term of probability, once the starting hypotheses allow to consider them as stochastic. At this moment, the utilization of probabilistic techniques such as the Fault Tree Analysis (FTA) allows the identification of several breaking scenari which eventually may be used as a starting point for the consequences analysis

1980-09-12

117

A relation among geology, tectonics, and velocity structure, western to central Nevada Basin and Range  

Science.gov (United States)

In the northwestern to central Nevada Basin and Range, there are correlations between velocity and specific geologic structures of the crust. Mapped range-bounding faults at the surface can be traced to appreciable (10km) depths based on velocity variations and are consistent with subsurface projections of the faults based on seismic reflection images. Correlations between velocity and the surface geology show that in the upper crust the pre-Cenozoic rocks are underlain by high-velocity rocks, whereas the Tertiary ranges are underlain by lower-velocity rocks to depths as great as 10 km. The regional seismicity pattern is consistent with this interpretation, as earthquakes are largely confined within or near the base of the low-velocity rocks. These low-velocity, highly fractured rocks are laterally distributed in discrete zones, suggesting that extension is not uniformly distributed but occurs in discrete, highly extended zones. -from Author

Catchings, R. D.

1992-01-01

118

Method of magnetic susceptibility mapping of drilled cores. Experimental measurements for geologic structures determination  

International Nuclear Information System (INIS)

The evaluation of the safety of a deep geologic repository for dangerous materials requires the knowledge of the interstitial system of the surrounding host rock. A method is proposed for the determination of geologic structures (in particular fractures) from the magnetic susceptibility mapping of drilled cores. The feasibility of the method has been demonstrated using a SQUID magneto-gradient meter. A measurement tool using a new magnetic susceptibility captor and a testing bench have been developed. This tool allows the measurement of rocks with a magnetic susceptibility greater than 10-5 SI units and can generate magnetic susceptibility maps with 4 x 4 mm2 pixels. A magnetic visibility criterion has been defined which allows to foresee if a structure is visible or not. According to the measurements done, it is shown that any centimeter-scale structure with a sufficient magnetic contrast (20%) with respect to the matrix is visible. Therefore, the dip and the orientation of such structure can be determined with a 3 degree and a 5 degree precision, respectively. The position of the structure along the core axis is known with a 4 mm precision. On the other hand, about half of the magnetic contrasts observed do not correspond to the visual analyses and can be explained by very small variations of the mineralogic composition. This last point offers some interesting ways for future research using magnetic susceptibility mapping. (J.S.). 31 refs., 90 figs., 18 tabs., 2 photos., 6 appends

1993-01-01

119

Automated grid generation from models of complex geologic structure and stratigraphy  

Energy Technology Data Exchange (ETDEWEB)

The construction of computational grids which accurately reflect complex geologic structure and stratigraphy for flow and transport models poses a formidable task. With an understanding of stratigraphy, material properties and boundary and initial conditions, the task of incorporating this data into a numerical model can be difficult and time consuming. Most GIS tools for representing complex geologic volumes and surfaces are not designed for producing optimal grids for flow and transport computation. We have developed a tool, GEOMESH, for generating finite element grids that maintain the geometric integrity of input volumes, surfaces, and geologic data and produce an optimal (Delaunay) tetrahedral grid that can be used for flow and transport computations. GEOMESH also satisfies the constraint that the geometric coupling coefficients of the grid are positive for all elements. GEOMESH generates grids for two dimensional cross sections, three dimensional regional models, represents faults and fractures, and has the capability of including finer grids representing tunnels and well bores into grids. GEOMESH also permits adaptive grid refinement in three dimensions. The tools to glue, merge and insert grids together demonstrate how complex grids can be built from simpler pieces. The resulting grid can be utilized by unstructured finite element or integrated finite difference computational physics codes.

Gable, C.; Trease, H.; Cherry, T.

1996-04-01

120

Formational analysis in petroleum geology. Formatsionnyy analiz v neftyanoy geologii  

Energy Technology Data Exchange (ETDEWEB)

Factual material is generalized regarding the characteristics of specific formations in order to develop a classification of them and to clarify the laws governing oil and gas content of carbonaceous, carboniferous and certain other formations. The structural features and oil and gas content of specific formation and formational series of major oil and gas regions of Ciscuacasia, Mangyshlak, Central Asia, West and East Siberia, the Russian platform and the near-Ural region are covered.

1981-01-01

 
 
 
 
121

Geological evolution and analysis of confirmed or suspected gas hydrate localities  

Energy Technology Data Exchange (ETDEWEB)

Geological factors controlling the formation, stability, and distribution of gas hydrates of the Beaufort Sea region were investigated by basin analysis. Geological, geophysical, and geochemical data from the region were assembled and evaluated to determine the relationships of geological environments and gas hydrates. The Beaufort Sea is the southern part of the Arctic Ocean offshore of the North Slope of Alaska and the Yukon and Mackenzie districts of Canada. The Beaufort Sea study region extends northward from the Arctic coasts of Alaska and Canada between Point Barrow on the west to Cape Beaufort on the east. The northern boundary of the Beaufort Sea study region is 72.5{degrees}N. The study region comprises broad continental shelves, slopes, rises, and the Arctic abyssal plain. 84 refs., 76 figs., 9 tabs.

Finley, P.D.; Krason, J.

1988-10-01

122

Determination of hafnium and zirconium in geological materials by neutron activation analysis  

International Nuclear Information System (INIS)

In this paper, neutron activation analysis was developed for determining hafnium and zirconium in geological materials. The USGS geological standard rocks GSP-1 (granodiorite) and W-1 (di abase). The Brazilian geological standards GB-1 (granite) and BB-1 (basalt) from Instituto de Geociencias da Universidade da Bahia and P-1 a uraniferous rock from Pocos de Caldas, MG, Brazil were analyzed. Hafnium present in these rocks was analyzed by purely instrumental method by irradiating with both thermal and epithermal neutrons from IEA-R1 nuclear research reactor. In the case of zirconium depending on the sample a radiochemical separation was required. "1"5"4 Eu and "1"5"2 Eu radioisotopes emit gamma rays with energies too close to those emitted by "9"5 Zr and they cause interferences. (author)

1992-01-01

123

Summarized analysis on potential of uranium resources in China and strategy for uranium geologic exploration  

International Nuclear Information System (INIS)

Through the summarized analysis on the potential of uranium resources and the degree of uranium geologic work, the author proposes the strategy of uranium geologic exploration in China as follows: the Chinese government should make a long-term program for uranium geologic exploration and insist on the basic policy to be based on domestic resources, to meet the domestic demand, to increase of the storage (the increase of storage includes active utilization of uranium resources of foreign countries), and to do the uranium exploration properly in advance. Taking the ISL-amenable sandstone-hosted uranium deposit as the major prospecting target combined with actively exploring other types of economic uranium deposits should be taken as the basic exploration strategy. Guiding by new geologic-metallogenic theory system, using advanced exploration method and technique system, GIS prediction method system and digital geologic map series to do uranium exploration are regarded as basic technical idea to accelerate ascertaining potential uranium resources in China, and to provide powerful resources guarantee for the development of China's nuclear industry. (author)

2004-09-01

124

Geology and structure of the Malpaso caldera and El Ocote ignimbrite, Aguascalientes, Mexico  

International Nuclear Information System (INIS)

A new caldera, named Malpaso, is reported west of the city of Aguascalientes, Mexico. The Malpaso caldera is a volcano-tectonic depression, highly fractured and faulted, and was filled by voluminous pyroclastic products related to the caldera collapse. Due to these characteristics it as a graben caldera. It is truncated by younger normal faults of the Calvillo and Aguascalientes grabens. In this work we present a summary of the geologic and structural observations on this caldera, as well as a description of the main caldera product, the high-grade El Ocote ignimbrite.

2008-10-01

125

First Paleomagnetic Map of the Easternmost Mediterranean Derived from Combined Geophysical-Geological Analysis  

Science.gov (United States)

he easternmost Mediterranean is a tectonically complex region evolving in the long term and located in the midst of the progressive Afro-Eurasian collision (e.g., Ben-Avraham, 1978; Khain, 1984). Both rift-oceanic systems and terrane belts are known to have been formed in this collision zone (Stampfli et al., 2013). Despite years of investigation, the geological-geophysical structure of the easternmost Mediterranean is not completely known. The formation of its modern complex structure is associated with the evolution of the Neotethys Ocean and its margins (e.g., Ben-Avraham and Ginzburg, 1990; Robertson et al., 1991; Ben-Avraham et al., 2002). The easternmost Mediterranean was formed during the initial phase of the Neotethys in the Early and Late Permian (Golonka and Ford, 2000; Stampfli et al., 2013). At present this block of the ocean crust situated in the northern part of the Sinai plate (Ben-Avraham, 1978; Eppelbaum et al., 2012, 2014) is object of our investigation. The easternmost Mediterranean region has attracted increasing attention in connection with the recent discoveries of significant hydrocarbon deposits in this region (e.g., Montadert et al., 2010; Schenk et al., 2010; Eppelbaum et al., 2012). For example, Schenk et al. (2010) consider that more than 4 trillion m3 of recoverable gas is available in the Levant Basin (which located in the central part of the easternmost Mediterranean). Currently seismic prospecting is the main tool used in hydrocarbon deposit discovery. However, even sophisticated seismic data analysis (e.g., Hall et al., 2005; Roberts and Peace, 2007; Gardosh et al., 2010; Marlow et al., 2011; Lazar et al., 2012), fails to identify the full complex structural-tectonic mosaic of this region, and more importantly, is unable to clarify its baffling complex tectonic evolution. This highlights the need for combined analysis of geophysical data associated with the paleomagnetic and paleobiogeographic conditions that can yield deep paleotectonic criteria for oil and gas discovery in this region. Extensive geological-geophysical investigations have been carried out in this region, and a significant number of deep boreholes have been drilled. However integrated estimation of the deep structure of the hydrocarbon host deposits and their space-time evolution in terms of the modern geodynamics (first of all, plate tectonics: Ben-Avraham and Ginzburg, 1990; Robertson, 1998; Ben-Avraham et al., 2002, 2006; Jimenez-Munt et al., 2003; Le Pichon and Kreemer, 2010), are comparatively recent (Eppelbaum and Katz, 2011, 2012a; Eppelbaum et al., 2012, 2014). We elucidate this geodynamic relationship by examining the structural floors within the following tectonic-geophysical zones: (1) regions of development of continental crust of the Nubian, Arabian and Sinai plates, (2) remaining oceanic crust of the eastern Mediterranean, and (3) the thinned continental crust of the terrane belt. A series of new gravity and magnetic maps developed by employing satellite and airborne data (as well their transformations) accompanied by tectonic schemes were constructed (Eppelbaum and Katz, 2011; Eppelbaum et al., 2012a, 2012b, 2014). These new maps are crucial to a better understanding of the dynamics of hydrocarbon basin formation within the continental and shelf depressions, as well as the deep depressions of the easternmost Mediterranean where gas deposits in zones of oceanic crust evolution have only recently (April 2013) begun to be exploited. Careful attention should be paid to the blocks of oceanic (basaltic) crust with reverse magnetization that were discovered (Ben-Avraham et al., 2002; Eppelbaum, 2006). This issue was very briefly (Eppelbaum and Katz, 2012a) explained as paleomagnetic Kiama zone of inverse polarity and demands separate consideration. An integrated magnetic-gravity-seismic analysis conducted along three interpretation profiles unambiguously indicates the presence of blocks of the Earth's crust with reverse magnetization (Ben-Avraham et al., 2002). The results of 3D magnetic field modeling (advanced G

Eppelbaum, Lev; Katz, Youri

2014-05-01

126

Non-destructive neutron activation analysis of gold in geological samples  

International Nuclear Information System (INIS)

A method of gold determination in geological samples by means of neutron activation analysis is described. This method is based on the 197Au(n,?)198Au nuclear reaction. The 411.8 keV gamma-ray of 198Au is measured by high-resolution Ge/HP/detector. Under typical analytical condition the sensitivity of the analysis is 0.1 ppm. (author). 7 refs., 1 fig., 2 tabs

1992-01-01

127

Probabilistic Structural Analysis Program  

Science.gov (United States)

NASA/NESSUS 6.2c is a general-purpose, probabilistic analysis program that computes probability of failure and probabilistic sensitivity measures of engineered systems. Because NASA/NESSUS uses highly computationally efficient and accurate analysis techniques, probabilistic solutions can be obtained even for extremely large and complex models. Once the probabilistic response is quantified, the results can be used to support risk-informed decisions regarding reliability for safety-critical and one-of-a-kind systems, as well as for maintaining a level of quality while reducing manufacturing costs for larger-quantity products. NASA/NESSUS has been successfully applied to a diverse range of problems in aerospace, gas turbine engines, biomechanics, pipelines, defense, weaponry, and infrastructure. This program combines state-of-the-art probabilistic algorithms with general-purpose structural analysis and lifting methods to compute the probabilistic response and reliability of engineered structures. Uncertainties in load, material properties, geometry, boundary conditions, and initial conditions can be simulated. The structural analysis methods include non-linear finite-element methods, heat-transfer analysis, polymer/ceramic matrix composite analysis, monolithic (conventional metallic) materials life-prediction methodologies, boundary element methods, and user-written subroutines. Several probabilistic algorithms are available such as the advanced mean value method and the adaptive importance sampling method. NASA/NESSUS 6.2c is structured in a modular format with 15 elements.

Pai, Shantaram S.; Chamis, Christos C.; Murthy, Pappu L. N.; Stefko, George L.; Riha, David S.; Thacker, Ben H.; Nagpal, Vinod K.; Mital, Subodh K.

2010-01-01

128

Modified FILTERSIM Algorithm for Unconditional Simulation of Complex Spatial Geological Structures  

Directory of Open Access Journals (Sweden)

Full Text Available Facies and fracture network modeling need robust, realistic and multi scale methods that can extract and reproduce complex relations in geological structures. Multi Point Statistic (MPS algorithms can be used to model these high order relations from a visually and statistically explicit model, a training image. FILTERSIM as a pattern based MPS method attracts much attention. It decreases the complexity of computation, accelerates search process and increases CPU per-formance compare to other MPS methods by transferring training image patterns to a lower dimensional space. The results quality is not however as satisfactory. This work presents an improved version of FILTERSIM in which pattern extraction, persisting and pasting steps are modified to enhance visual quality and structures continuity in the realiza-tions. Examples shown in this paper give visual appealing results for the reconstruction of stationary complex struc-tures.

Mohammadreza Rasaei

2012-07-01

129

3D gravity imaging of deep geological structure of Huangling Anticline in Three Gorges area, China  

Science.gov (United States)

Three Gorges Dam is the largest hydraulic project in the world. Previous studies showed that Huangling Anticline is one of the main geological units in this area and has great influence on the safety of the dam, so it is important to investigate deep geological structure and evaluate stability of Huangling Anticline. Huangling Anticline locates in northern margin of Yangtze Block. It is surrounded by a few faults, and two of them are Xiannushan Fault and Yuan’an Fault, with NNW direction. There are also two main faults named Xinhua Fault and Yuyangguan-Tumen Fault with NNE and NE direction. These faults are regional faults with different sizes and cutting depth, and take charge of the development of geological structures in Three Gorges area with a long time. Two main arguments about the ability of inducing earthquakes of these faults were presented. One of the arguments suggested that these faults has weak or no enough activity to induce strong earthquakes, their key evidence is the thermoluminescence (TL) dating with some geological characteristics; the other was just opposite, in their opinion, Xiannushan Fault and Yuan’an Fault has deep cutting depth with great activity to induce strong earthquakes. However, they can not provide the evidences of deep geological structures and cutting depth of these faults. In our paper, 3D density structure of upper and middle crust beneath Three Gorges Dam and its adjacent regions is reconstructed by gravity imaging, using the Bouguer gravity anomaly and surface density constraints. Results of gravity imaging indicate that Huangling Anticline is a relatively high density zone. (1) Horizontally, Huangling Anticline is a huge U-shaped crystal rock controlled by Xiannushan Fault and Yuan’an Fault along NNW direction. In the southeast, Yuyangguan-Tumen Fault becomes the boundary of the anticline, and in the west, Xinhua Fault and Xiannushan Fault separate Huangling Anticline from Zigui basin; (2) From vertical profiles of gravity imaging, the relatively high density anomaly is located at the upper and middle crust, but in deeper region, the transition of the density distribution occurs, becoming relatively low gradually. This means that Huangling Anticline does not penetrate the whole crust while it is only attached on some rocks of low density. In other words, although Huangling Anticline itself is a rigid geological body, few earthquakes occur in it. However, Huangling Anticline’s bottom seems not stable enough because of its location just in the transitional zone of Southern Qinling and Northern Yangtze Block, the subduction of the Qinling oceanic crust and mutual extrusion between the various blocks may force the anticline to slide along the deep low density transitional zone, and this zone maybe an earthquake-prone area; (3) In addition, from density imaging, we can find that the faults around Huangling Anticline are all deep and nearly vertical. Due to the continuous uplifting of Huangling Anticline, the friction along these faults may be another source of earthquakes, which had been proved by some researches on the distribution of earthquakes in Three Gorges area.

Zhang, Y.; Chen, C.

2010-12-01

130

Comparison of the SKI, SKB, and SKN geological and structural models of the Aespoe area  

International Nuclear Information System (INIS)

Three sets of geological and structural models produced by three different groups are compared. The same set of basic data has been available to each of the groups. The models, all of which are 2 by 2 km by 1 km deep - or smaller, are based entirely on surface-based investigations. The modelled area is centered on the island of Aespoe, where SKB has built the Hard Rock Laboratory (HRL) in plutonic bedrock at a depth of 500 m. SKB (Swedish Nuclear Fuel and Waste Management Co) has recorded the basic data during the period 1986 to 1991, before starting the underground work. One of the main tasks in the SKB characterization of the HRL rock mass was to predict which of the geological structures will have the greatest rock-mechanical and hydraulic significance. The National Board for Spent Nuclear Fuel (SKN) constructed alternative models in 1992 to verify the SKB model. However, the SKN models were subsequently modified and converted into a hydrogeological model. The Swedish Nuclear Inspectorate (SKI) chose Aespoe as a hypothetical site for storage of nuclear waste in their SITE 94 project. The objective of the project is to assist SKI in their future review of SKB's application for a license to dispose of spent nuclear fuel underground. The agreement of the three models is found to be best where the density of information is greatest. The main difference between the two geological models is related to the inferred effects of block faulting on the rock type distribution. The correlation of moderately to gently inclined zones between the models is relatively poor at depth

1996-01-01

131

Integration of geological information in a structured approach to development of a safety case  

International Nuclear Information System (INIS)

The Specified Radioactive Waste Final Disposal Act, promulgated in June 2000, specifies that the siting process for a high-level radioactive waste (HLW) repository in Japan shall consist of the following three stages: - In the first stage, a literature survey is conducted on a nation-wide scale. Preliminary investigation areas (PIAs) for potential candidate sites are then nominated, based on area-specific literature surveys focusing on the long-term stability of the geological environment; - Detailed investigation areas (DIAs) for candidate sites are then selected from PIAs following surface-based investigations (including boreholes) carried out to evaluate the key characteristics of the geological environment; - In the final third stage, detailed site characterisation, including studies in underground experimental facilities, leads to selection of the site for repository construction. Following discussions with relevant Government and nuclear industry organisations, the Nuclear Waste Management Organization of Japan (NUMO) has decided to proceed with repository siting based entirely on an 'open solicitation procedure' (a call for volunteer host municipalities). NUMO promotes public involvement in decision making in the process of selecting sites, based on its basic policies, which consist of 'adopting of a stepwise approach', 'respecting voluntarism of municipalities' and 'ensuring transparency'. This volunteering process provides a unique challenge for ensuring transparency and traceability in development of conceptual site models which form a basis for repository concepts and associated safety cases in parallel with the step-wise siting process. A structured approach, therefore, is required to meet this target, which has been discussed partly in the light of development of Repository Concepts for given siting environments. The Siting Factors for selection of PIAs has also been developed. This paper illustrates a methodology for integrating geological information into the conceptual site models to be used in the structured approach. (author)

2004-01-01

132

Comparison of the SKI, SKB, and SKN geological and structural models of the Aespoe area  

Energy Technology Data Exchange (ETDEWEB)

Three sets of geological and structural models produced by three different groups are compared. The same set of basic data has been available to each of the groups. The models, all of which are 2 by 2 km by 1 km deep - or smaller, are based entirely on surface-based investigations. The modelled area is centered on the island of Aespoe, where SKB has built the Hard Rock Laboratory (HRL) in plutonic bedrock at a depth of 500 m. SKB (Swedish Nuclear Fuel and Waste Management Co) has recorded the basic data during the period 1986 to 1991, before starting the underground work. One of the main tasks in the SKB characterization of the HRL rock mass was to predict which of the geological structures will have the greatest rock-mechanical and hydraulic significance. The National Board for Spent Nuclear Fuel (SKN) constructed alternative models in 1992 to verify the SKB model. However, the SKN models were subsequently modified and converted into a hydrogeological model. The Swedish Nuclear Inspectorate (SKI) chose Aespoe as a hypothetical site for storage of nuclear waste in their SITE 94 project. The objective of the project is to assist SKI in their future review of SKB`s application for a license to dispose of spent nuclear fuel underground. The agreement of the three models is found to be best where the density of information is greatest. The main difference between the two geological models is related to the inferred effects of block faulting on the rock type distribution. The correlation of moderately to gently inclined zones between the models is relatively poor at depth. 46 refs, 30 figs, 18 tabs.

Tiren, S.A. [Geosigma AB, Uppsala (Sweden)

1996-06-01

133

The information content of high-frequency seismograms and the near-surface geologic structure of "hard rock" recording sites  

Science.gov (United States)

Due to hardware developments in the last decade, the high-frequency end of the frequency band of seismic waves analyzed for source mechanisms has been extended into the audio-frequency range (>20 Hz). In principle, the short wavelengths corresponding to these frequencies can provide information about the details of seismic sources, but in fact, much of the "signal" is the site response of the nearsurface. Several examples of waveform data recorded at "hard rock" sites, which are generally assumed to have a "flat" transfer function, are presented to demonstrate the severe signal distortions, including fmax, produced by near-surface structures. Analysis of the geology of a number of sites indicates that the overall attenuation of high-frequency (>1 Hz) seismic waves is controlled by the whole-path-Q between source and receiver but the presence of distinct fmax site resonance peaks is controlled by the nature of the surface layer and the underlying near-surface structure. Models of vertical decoupling of the surface and nearsurface and horizontal decoupling of adjacent sites on hard rock outcrops are proposed and their behaviour is compared to the observations of hard rock site response. The upper bound to the frequency band of the seismic waves that contain significant source information which can be deconvolved from a site response or an array response is discussed in terms of fmax and the correlation of waveform distortion with the outcrop-scale geologic structure of hard rock sites. It is concluded that although the velocity structures of hard rock sites, unlike those of alluvium sites, allow some audio-frequency seismic energy to propagate to the surface, the resulting signals are a highly distorted, limited subset of the source spectra. ?? 1988 Birkha??user Verlag.

Cranswick, E.

1988-01-01

134

Geological structures from televiewer logs of GT-2, Fenton Hill, New Mexico: Part 1, Feature extraction  

Energy Technology Data Exchange (ETDEWEB)

Patterns in reflected sonic intensity recognized during examination of televiewer logs of basement gneiss at the Hot Dry Rock Site, Fenton Hill, New Mexico, are due to geological fractures and foliations and to incipient breakouts. These features are obscured by artifacts caused by wellbore ellipticity, tool off-centering, and tool oscillations. An interactive method, developed for extraction of the structural features (fractures and foliations), uses human perception as a pattern detector and a chi-square test of harmonic form as a pattern discriminator. From imagery of GT-2, 733 structures were recovered. The acceptance rate of the discriminator was 54%. Despite these positive results, the general conclusion of this study is that intensity-mode imagery from Fenton Hill is not directly invertible for geological information because of the complexity of the televiewer imaging process. Developing a forward model of the intensity-imaging process, or converting to caliper-mode imagery, or doing both, will be necessary for high-fidelity feature extraction from televiewer data.

Burns, K.L.

1987-07-01

135

An Efficient Method to Recognize Geologic Structures by Analyzing the Pressure Data with Wavelet Transform  

Science.gov (United States)

Uncertainty in prediction of flow performance stems from the uncertainty in model parameters such as conductivity, porosity etc., to a large extent, while the characterization of the model parameters is demanding due to the inherent heterogeneity of geologic structures. Inverse modeling approaches attempt to identify the unknown model structures and corresponding parameters by integrating observation data. Several inverse methods have been proposed in the literature ranging from trial-and-error methods to advanced ensemble Kalman filter assimilation, including those that use multiple point statistics to characterize complex geologic structures. However, these methods are hindered by the huge amount of data accumulated with time, for instance, the pressure data are recorded at very fine time intervals from the very early stage of bore hole drilling to mature production period. Assimilation of such large amount of data can be a computational burden to the inverse methods. The object of this work is to propose a computationally efficient approach to analyze the long observation records in order to recognize the subsurface structures, especially flow connectivity which plays a critical role in transport prediction. Wavelet transform is found to be a powerful technique that transforms data into different components and analyzes each component at corresponding scale. By analyzing the components transformed we relate the characteristics of the heterogeneity to signature in the production/injection records. Combining components at different scales we are able to recognize connectivity between wells, and thereby identify complex structure in aquifers. The method is demonstrated in a synthetic example where CO2 is injected into a deep saline aquifer for sequestration. The method is computationally efficient since it involves no iterative forward simulation or sensitivity matrix computation. Once the important episodes have been identified in the dynamic data, inverse modeling with the reduced data set is supposed to lead to better models for conductivity variations in the aquifer.

Zhou, H.; Srinivasan, S.; Li, L.; Bryant, S. L.

2013-12-01

136

Methodologie for the use of neutron activation analysis of geological materials  

International Nuclear Information System (INIS)

A neutron-activation scheme for the determination of nine rare-earths and other trace elements in geological materials (feldspars, ilmenite, magnetite, pyroxenes, silicate rocks) is presented. The procedure is based on: epithermal neutron irradiation (2 days) followed by non-destructive analysis; thermal neutron irradiation (1 day) followed by instrumental analysis; thermal neutron irradiation (7 days) followed by radiochemical analysis; epithermal neutron irradiation (1 hour) followed by radiochemical analysis. The limits of detection are given for the elements of interest under the described operating conditions

1978-01-01

137

Structural geology of the Fuegian Andes and Magallanes fold-and-thrust belt - Tierra del Fuego Island  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A synthesis of the structural geology of the Tierra del Fuego Island, which integrates a new data set derived from field surveys and literature data of the last few years, is presented here. The main geological features of the region developed during the Mesozoic-Cenozoic Andean orogenic cycle that started in the Middle to Late Jurassic with a back-arc extension, crustal stretching and widespread volcanism, related to the break-up of Gondwanaland. An extensional fault system deriving from the...

2008-01-01

138

Basic feasibility study with overseas geological structure survey in FY 1999 - Kalewa area, Myanmar (Summary)  

Energy Technology Data Exchange (ETDEWEB)

For the purpose of evaluating coal resource in the Kalewa area southwest of Sagaing about 300km northwest of Mandalay city, Myanmar, survey was conducted on geology, test boring, specimen analysis, infrastructure, etc. The range of geological survey is approximately 5.5km{sup 2}, and test boring was carried out for 9 holes (total length: 2,046.74m). For the coal analysis, 8 specimens were used, and measurement was made of the combustion calorie, sulfur content, water content, density, ash, ash melting temperature, etc. Survey was also conducted on drilling conditions/methods for coal mines in the periphery, roads for coal transportation, barge loading ports, etc. The results of the survey are as follows. The thickness of the minable main coal seam is 2.1-2.9m, and the inclination angle is 40-42 degrees. Specimens from coal seams indicate low ash, low sulfur content and high combustion calorie. The estimated coal reserves are 7,730,000 tons, and they total 15,300,000 tons including those from other coal seams. In the development by the 100m-width longwall mining which was proposed, it is possible to produce 130,000 tons/year for more than 20 years. (NEDO)

NONE

2000-03-01

139

Determination of neodymium and gadolinium in geologic samples by neutron activation analysis  

International Nuclear Information System (INIS)

The determination of Nd and Gd present in rocks by neutron activation analysis is aimed at. A separation procedure for the rare earth group of elements is presented. The method is based on the retention of 233Pa, 182Ta and 46Sc by hydrated antimony pentoxide (HAP) in a 6M HClO4 medium. Those radioisotopes are interferences in the gamma-ray spectrum of 153Gd and 147Nd. The reliability of the method was tested by means of the geological standards BCR-1 and G-2 from the U.S. Geological Survey. The limitations of the instrumental neutron activation analysis and the advantages of the chemical separation are discussed for the special case of the Nd and Gd determinations. (Author)

1981-10-17

140

Error Analysis of Multi-Source Data for 3D Geological Modeling Using Entropy-based Weighting  

Science.gov (United States)

In each step of geological modeling, errors always have an impact on workflow processes and so have consequences that challenge 3D geological modeling. Methods such as geostatistics, fuzzy set theory and spatial error theory have been used to analyze errors that exist in the raw data behind geological models and these methods assume that a single error distribution exist in all kinds of data. However, different kinds of raw data, such as borehole, user-defined section and geological maps, even within a single kind of data, they may exist different types of positional error distributions. Consequently, analyzing errors of multi-source data for geological modeling remains a vital problem in geological modeling. In this study, we developed a novel approach to quantitatively analyze the distributions of errors in multi-source raw data used for constructing 3D geological structural models. Errors among raw data are usually discussed directly based on the error distributions of points, supposing that the positional error of geological boundaries is caused by spatial measurement rather than uncertainties in the geological attributes. In reality, geological boundaries are given by the distribution of geological attributes of related strata, which are themselves vaguely defined. Therefore, the spatial error in geological boundaries is mainly caused by the uncertainties of geological attributes. Here, we supposed that spatial position is fixed and geological attributes of each point in space vary. According to the spatial relationship between geological attributes and geological boundaries, the spatial error of geological boundaries is transferred into a specific probability of each geological attribute for each point, termed the ';Geological attribute probability'. The key problem in this research is to construct a function for transforming the 3D spatial problem into a 1-D probability distribution problem. We transferred several kinds of spatial error distributions into geological attribute probabilities, allowing different kinds of error distribution of spatial data to be summed directly after the transformation. When building a 3D geological model, several kinds of raw data may cross over one point or line. In this circumstance, an entropy-based weight was given for each kind of data when calculating the final probability. For any point of one data source in space, its geological attribute probability results in an entropy weight value. The larger the value, the smaller the entropy weight. The final geological attribute probability of each spatial point is calculated using a linear entropy-based weighted summation. A color scale is used to illustrate the distribution of geological attribute probability using the MapGIS K9. A concrete example illustrates that geological attribute probability is an effective way of describing multiple error distributions among the raw data used for geological modeling. Acknowledgement: This study is funded by NSFC (41102207) and the Fundamental Research Funds for the Central Universities (121gpy19).

Hou, W.; Yang, L.; Clarke, K.

2013-12-01

 
 
 
 
141

Geological storage of CO2: risks analysis, monitoring and measures. Final report  

International Nuclear Information System (INIS)

To use the CO2 geological storage as a coherent solution in the greenhouse gases reduction it needs to answer to safety and monitoring conditions. In this framework the BRGM presents this study in six chapters: risks analysis, the monitoring methods (geochemistry, geophysics, aerial monitoring, biochemistry, hydrogeology), the metrology, the corrosion problems, the thermal, hydrodynamical, geochemical and mechanical simulation and the today and future regulations. (A.L.B.)

2005-01-01

142

Geologic mapping of Indonesian rain forest with analysis of multiple SIR-B incidence angles  

Science.gov (United States)

The discrimination and mapping capabilities are to be evaluated for shuttle imaging radar-B (SIR-B) images of geologic features in Indonesia that are covered by equatorial rain forest canopy. The SIR-B backscatter from the rain forest at L-band is to be compared to backscatter acquired by the SEASAT scatterometer system at Ku-band ever corresponding areas. The approach for data acquisition, handling, and analysis and the expected results of the investigation are discussed.

Ford, J. P.; Sabins, F. F., Jr.; Asmoro, P., Jr.

1984-01-01

143

Uranium and thorium analysis in geological samples using SSTD - an application of F/? technique  

International Nuclear Information System (INIS)

The relation connecting concentrations of uranium and thorium atoms in geological samples with the alpha track rate in nuclear emulsions reported by R. Coppens, P. Richard and S. Bashir (1977) is modified for use in the plastic track detector, LR 115 type 2. Gamma ray spectrometric analysis of phosphorite samples from Mussorie syncline establishes the validity of the modified relation and hence will be of use in uranium and thorium estimation using solid state track detectors. 6 refs.. (author)

1986-01-01

144

Crustal structural survey for the state of Minas Gerais, Brazil, utilizing geophysical and geological information  

International Nuclear Information System (INIS)

Gravity, Magnetic (airborne, Magnet and Magsat), heat flow and seismicity available data for the state of Minas Gerais and adjacent regions is here analyzed, discussed and integrated with geologic information. The Late Archean crustal structure is defined as blocks of granite-greenstone separated by belts of high-grade terrains. The belts in eastern and southern Minas Gerais represent the lower parts of the Vitoria, Sao Paulo and Parana Blocks, which were up thrusted over the Brasilia Block through low-angle ductile simple shear Zones. That regional structure is cut and somewhat displaced by NW, ENE, NE and Ns fault sets. These faults are mostly related to the Transamazonian Event, and their geological expression appears to be as high-angle ductile simple shear zones. The development of the Middle/upper proterozoic folded sequences, the incidence of the Brasiliano/Uruacuano thermo tectonic events and the geometry of the Sao Francisco Craton were highly influenced by the preexistent weakness zones. The high-grade terrains, the borders of the Brasilia Block and the Transamazonian lineaments have been preferentially affected. The tectono-magmatic manifestations of the Wealdenian Reactivation, related to the opening of the Atlantic Ocean, occurred mostly among the uplifted zones (Alto Paranaiba Uplift) that developed partially until the rift stage (Mantiqueira Uplift). These processes clearly reveal the influence of the old structures of the state of Minas Gerais. The Mantiqueira Uplift presents a more accentuated seismic activity and thermal flow regime than the neighboring regions, so corresponding to the present less stable area of Minas Gerais. (DJM)

1985-01-01

145

Dynamic simulations of geologic materials using combined FEM/DEM/SPH analysis  

Energy Technology Data Exchange (ETDEWEB)

An overview of the Lawrence Discrete Element Code (LDEC) is presented, and results from a study investigating the effect of explosive and impact loading on geologic materials using the Livermore Distinct Element Code (LDEC) are detailed. LDEC was initially developed to simulate tunnels and other structures in jointed rock masses using large numbers of polyhedral blocks. Many geophysical applications, such as projectile penetration into rock, concrete targets, and boulder fields, require a combination of continuum and discrete methods in order to predict the formation and interaction of the fragments produced. In an effort to model this class of problems, LDEC now includes implementations of Cosserat point theory and cohesive elements. This approach directly simulates the transition from continuum to discontinuum behavior, thereby allowing for dynamic fracture within a combined finite element/discrete element framework. In addition, there are many application involving geologic materials where fluid-structure interaction is important. To facilitate solution of this class of problems a Smooth Particle Hydrodynamics (SPH) capability has been incorporated into LDEC to simulate fully coupled systems involving geologic materials and a saturating fluid. We will present results from a study of a broad range of geomechanical problems that exercise the various components of LDEC in isolation and in tandem.

Morris, J P; Johnson, S M

2008-03-26

146

Spatial Analysis of Correlation between Preliminary Geologic and Mineralogic Maps of Vesta  

Science.gov (United States)

The Dawn mission to Vesta has greatly improved the quality and resolution of data available to explore the asteroid. Prior to the Dawn mission the best data available was the one from Hubble Space Telescope with a maximum resolution of 50 km per pixel. The survey phase of the mission has pushed spatial resolution up to about 100 meters per pixel by the Framing Camera on-board Dawn, and 700 meters per pixel for the VIR spectrometer, spanning the spectral range from the visible to infrared at 0.25 - 1 ?m and 1 - 5 ?m. The frames of the FC and VIR have been processed and mosaicked. A preliminary Geologic map has been produced by mapping units and structures over the FC mosaic and the DTM derived from stereo processing of visible imagery[1]. Herein we will present first results of the quantitative correlation between the preliminary geologic and VIR-derived spectral parameters maps.

Frigeri, A.; De Sanctis, M. C.; Ammannito, E.; Yingst, R. A.; Mest, S.; Capaccioni, F.; Russell, C. T.

2012-09-01

147

Origin of anomalous subsidence due to coal underground mining and its relationship to geological structure  

Science.gov (United States)

Monitoring of the subsidence caused by mining lead to better understanding of the development of surface deformation and increase the reliability of the predictions models. Typical development of the subsidence in the subsurface Carboniferous is relatively quickly. Approximately 85% of the volume of the subsidence through can be observed in the period of one year after the end of the mining. For reliable surface risk assessment important is time of the deformation occurrence on the surface and critical dimension of the mining panels. However all those assumptions do not work when the structure of the rock mass is anomalous. The paper presents the case study of anomalies observed in surface deformation. The distinct subsidence anomaly may originate from a thick strata of Jurassic rocks in the overburden. The research presented focused on the surface deformation prediction capabilities in such specific geological conditions.

Malinowska, Agnieszka; Hejmanowski, Ryszard

2014-05-01

148

Geology of the ?oka structure in northern Banat (Central Paratethys, Serbia)  

Science.gov (United States)

The ?oka structure is a fault-bounded anticline in northern Banat, in the southern part of the Neogene Pannonian Basin. The structure and its vicinity were explored by 24 wells. In addition to well logs, paleontological, sedimentological and petrological analyses of cores and 27 seismic sections with different parameters of acquisition and processing were used for geological investigation of the area. The E-SE dipping pre-Neogene basement consists of Lower Triassic clastics and, in the NW part of the study area, Paleozoic greenschists. Thin Middle Miocene (Badenian) sediments unconformably overlie the basement and pinch out towards the elevated NW part of the study area. They are also missing in some wells on the apex of the ?oka structure, probably due to erosion. Badenian sediments were deposited in a shallow marine environment. The late Middle Miocene (Sarmatian) strata are missing and the Badenian is directly overlain by Upper Miocene (Pannonian) sediments. The latter also pinch out towards the NW but in contrast to Badenian sediments, they are present in all boreholes on the ?oka structure. Pannonian deposition took place in a caspibrackish environment of Lake Pannon, with predominance of marls and fine-grained clastics. Pannonian sediments are conformably overlain by latest Miocene (Pontian) and Pleistocene lacustrine, alluvial and terrestrial sediments.

Radivojevi?, Dejan; Rundi?, Ljupko; Kneževi?, Slobodan

2010-08-01

149

Geology of coronae and domal structures on Venus and models of their origin  

Energy Technology Data Exchange (ETDEWEB)

Coronae (160 to 670 km across) and domal structures (greater than 1000 km across) are complex topographic highs on Venus that were affected by volcanic and topographic processes. The geology of coronae and a major domal structure, Beta Regio, are documented using Pioneer Venus, Arecibo, and Venera 15/16 data. The evolution and possible models of origin of these features are also investigated. Beta Regio is a 2000 x 2300 km topographic high located in the equatorial region of Venus that rises over 5 km above the surrounding region. Within Beta Regio lie two large volcanic shields, Theia and Rhea Mons. Coronae are circular to elongate structures on Venus, characterized by an annulus of concentric compressional ridges and relatively raised topography surrounded by a peripheral trough. Volcanic domes, flows and edifices, as well as tectonic lineaments characterize the interiors of coronae. Thirty one coronae were detected on Venus. Two analytical models were developed that are consistent with the general characteristics and evolution of coronae: hotspot or rising mantle diapir model and sinking mantle diapir model. Coronae appear to be part of a continuum of thermally produced features on Venus, along with volcanic complexes and domal structures such as Beta Regio.

Stofan, E.R.

1989-01-01

150

North African petroleum geology: regional structure and stratigraphic overview of a hydrocarbon-rich cratonic area  

Energy Technology Data Exchange (ETDEWEB)

North Africa, including Sinai, contains some of the most important hydrocarbon-producing basins in the world. The North African Symposium is devoted to examining the exploration potential of the North African margin in light of the most recent and promising exploration discoveries. The geologic variety of the region is extraordinary and can challenge any exploration philosophy. Of primary interest are the Sirte basin of Libya, which has produced several billion barrels of oil, and the Gulf of Suez, a narrow, evaporite-capped trough with five fields that will produce more than 5 billion bbl. Both are extensional basins with minimal lateral movement and with good source rocks in direct proximity to reservoirs. Structural models of these basins give firm leads for future exploration. More difficult to evaluate are the Tethyan realm basins of the northern Sinai, and the Western Desert of Egypt, the Cyrenaican Platform of Libya, and the Tunisia-Sicily shelf area, where there are only limited subsurface data. These basins are extensional in origin also, but have been influenced by lateral tectonics. Favorable reservoirs exist, but source rocks have been a problem locally. Structural models with strong stratigraphic response offer several favorable play concepts. The Paleozoic Ghadames basin in Libya, Tunisia, and Algeria has the least complex structural history, and production appears to be limited to small structures. A series of stratigraphic models indicates additional areas with exploration potential. The Paleozoic megabasin of Morocco, with its downfaulted Triassic grabens, remains an untested but attractive area.

O' Connor, T.E.; Kanes, W.H.

1985-02-01

151

Determination of Iron and Nickel in Geological Samples by Activation Analysis with Reactor Fast Neutrons  

International Nuclear Information System (INIS)

Threshold reactions induced by reactor fast neutrons are well recognized. The concentration of Fe and Ni were determined in nine geological samples by activation analysis with reactor fast neutrons using the threshold reactions 54Fe( n,p)54Mn and 58Ni ( n, p )'58Co respectively. The fast neutron flux was determined using the reactions 92Mo(n, 2n)92mNb and 95Mo(n,p)95Nb. The determined concentration of Fe and Ni in the samples were checked by determining them in the GSJ JB-1 reference material using the same , ( p, n) reactions. There are a good agreement between the measured and recommended values. The concentrations of Fe were also determined by the ) , ( n, ?) capture reactions in the geological samples and the JB-1 reference material using the K?- NAA method. There are good agreements between the determined concentrations from the ) , ( p, n) and the ( ?, n) reactions.

2008-02-19

152

The analysis of geological samples using NAA methods in RSG-GAS  

International Nuclear Information System (INIS)

Because of irradiation facilities usage and development of NAA method in P2TRR, the geological samples was analyzed by NAA method. The aim of this research is to know the elements contain in geological samples. The samples were irradiated in the RSG-GAS's rabbit system. Samples pasca irradiation were measured by gamma spectrometer. The results of analysis showed that the stone samples contained different elements : Ce, Cr, Co, Fe, La, Lu, Na, Np, Pd, and Sm. The sand samples contained: Bi, Cd, Cs, Co, Fe, Eu, K, Pd, La, Lu, Na, Sc, Sm, Th, and Yb elements. There was a variation in elements concentration between 1.34 ppm Cr (lowest) and 179.06 ppm Sr (highest)

2002-10-01

153

Radiochemical neutron activation analysis of trace lanthanoids in geological and cosmochemical samples  

International Nuclear Information System (INIS)

In order to determine trace lanthanoids in geological and cosmochemical samples, an analytical procedure for radiochemical neutron activation analysis (RNAA) was developed, where lanthanoids are radiochemically purified through precipitations of hydroxides and fluorides, and cation exchange using HBr as an eluent. Chemical yields are determined by reactivation. The procedure was applied to the Allende meteorite and geological standard rocks. Our data for Allende are in excellent agreement with literature values, and those values for standard rocks, JP-1 (peridotite) and JF-2 (feldspar), in which lanthanoids are depleted by orders of 1 to 2 compared with those in Allende, seem to be reasonable, although not properly evaluated because of large scatterings in their literature data. This suggests that the present RNAA procedure is highly effective in determining trace lanthanoids (less than 1 ng) in rock samples. (orig.)

1995-03-01

154

14 MeV neutron activation analysis of geological and lunar samples  

Energy Technology Data Exchange (ETDEWEB)

14 MeV neutron activation analysis (NAA) is ideal for accurately determining Oxygen and Silicon contents in geological and lunar materials. It is fast, nondestructive, economical, and can be used on a routine basis in a laboratory. Although 14 MeV NAA is particularly suited to light elements, its use has been extended to measure other elements as well such as Aluminum, Magnesium, Iron, Calcium, Titanium, Strontium, Nickel, Yttrium, Zirconium, Niobium and Cerium. Thus, the use of 14 MeV neutrons is of considerable importance in NAA. The disadvantages of the method are that interference reactions are common because of high neutron energy; the flux is nonuniform in longer irradiation due to depletion of the target in the neutron generator. Overall, 14 MeV NAA is ideal for short irradiations and when supplemented with thermal NAA provides the maximum elemental information in small aliquants of geological and lunar materials.

Laul, J.C.; Wogman, N.A.

1981-04-01

155

Scientific Journals as Fossil Traces of Sweeping Change in the Structure and Practice of Modern Geology  

Directory of Open Access Journals (Sweden)

Full Text Available In our attempts to track changes in geological practice over time and to isolate the source of these changes, we have found that they are largely connected with the germination of new geologic subdisciplines. We use keyword and title data from articles in 68 geology journals to track the changes in influence of each subdiscipline on geology over all. Geological research has shifted emphasis over the study period, moving away from economic geology and petroleum geology, towards physics- and chemistry-based topics. The Apollo lunar landings had as much influence on the topics and practice of geological research as the much-cited plate-tectonics revolution. These results reflect the barely-tangible effects of the changes in vocabulary and habit of thought that have pervaded the substance of geology. Geological literature has increased in volume and specialization, resulting in a highly fragmentary literature. However, we infer that "big science," characterized by large amounts of funding, collaboration, and large logistical investments, makes use of this specialization and turns "twigging" into a phenomenon that enhances, rather than inhibits, the enterprise of research.

H. L. Vacher

2008-01-01

156

Structure and inferred geological history of Mid-Continent rift in Iowa  

Energy Technology Data Exchange (ETDEWEB)

Recent completion of a gravity and magnetic modeling project has provided new insight into the structure and geologic history of the central segment on the Mid-Continent rift (MCR) in Iowa. The rift zone is dominated by the Iowa horst, a mafic voclanics-dominated axial horst thrust horizontally, as much as 5 km or more, over postvolcanic rift clastics that fill basins on both its eastern and western flanks. The models indicate the volcanics-dominated sequence of the Iowa horst reaches thicknesses of at least 30 km and is composed of at least two structurally distinct packages. The lower package shows more structural complexity than the overlying package. Multiple parallel seismic reflectors in the upper volcanic package, interpreted as individual lava flows or sets of flows, are subhorizontal and commonly are continuous across most of the horst. The flanking clastic-filled basins reach a maximum depth of about 10 km, also are composed of two distinct packages that frequently can be discriminated in seismic data, and apparently are separated by an erosional unconformity. Keweenawan clastic rocks are present in several small basins that have been preserved on the Iowa horst. In cross section, the central segment of the MCR has approximate bilateral symmetry. This symmetry suggests that at least the upper volcanic package was deposited in what best can be described as a uniformly subsiding trough, not the half graben suggested for the MCR in the Lake Superior region.

Anderson, R.R.

1989-03-01

157

Gravity field of Kuwait and its relevance to major geological structures  

Energy Technology Data Exchange (ETDEWEB)

Regional gravity surveys were done in the state of Kuwait during 1986-1988. The new gravity maps show a good correlation with geomorphological features as well as with deeper geological structures. The free-air anomaly map clearly reflects the topography of the Jal Az Zor and Ahmadi ridges, and Wadi Al-Batin. The Bouguer anomaly map is dominated by two prominent gravity highs correlatable with subsurface structural arches. The north-trending gravity high in eastern Kuwait represents the effect of a major structure, the Kuwait arch, along which many important oil fields are located. A smaller northwest-trending high mapped in western Kuwait indicates the presence of a second subsurface arch, which in this paper is named the Dibdibba arch. The two gravity highs are separated by a wedge-shaped gravity low presumably caused by thicker sediments of the Dibdibba basin. Magnetic measurements along selected profiles show the two arches to be associated with 100-200-nT (nannotesla) anomalies apparently reflecting the positive subsurface relief of the crystalline basement. Along the length of the Kuwait arch, magnetic data also indicate lateral susceptibility variations possibly related to lithological variations within the basement.

Warsi, W.E.K. (Univ. of Kuwait, Safat (Kuwait))

1990-10-01

158

Analysis by neutronic activation of samples of a geologic formation of Cuba  

International Nuclear Information System (INIS)

The analysis by neutronic activation (AAN) is an analytical non destructive technique of high accuracy and sensibility. These advantages are very utilized in the determination of geological multielemental samples. In the job 22 elements are determined in 9 geological samples pertaining to the complex of dams of acid composition that includes the graphitic micaceous schist and the quartzites of the Canada Formation, developed fundamentally in the fasteners of the anticlinal Victoria (Yac. of Wolframio Lela, Island of the Youth, Cuba) The results obtained are of great importance for the evaluation of the potentiality of these rocks as fountains or of uranium adjusting and for the geologic prognostic of the region in study. The irradiation of the samples was carried out during three campaigns, in two occasions (October 1992 and November 1994) in the reactor of investigations of the ININ of Mexico, with a flow of thermic neutrons of 10a the 13 n.s-1 cm-2 and in an occasion in the nuclear reactor of the CAB (september 1994), with a flow of thermic neutrons of 6x 10 to the 12 n.s-1. The results were processed with the program ACTAM in the CEADEN. (S. Grainger)

1997-01-01

159

Structured Analysis - IDEF0  

DEFF Research Database (Denmark)

This note introduces the IDEF0 modelling language (semantics and syntax), and associated rules and techniques, for developing structured graphical representations of a system or enterprise. Use of this standard for IDEF0 permits the construction of models comprising system functions (activities, actions, processes, operations), functional relationships, and data (information or objects) that support systems integration. An IDEF0 model is domain specific in the sense that purpose, viewpoint and context must be identified in the model. The IDEF0 modelling language is recommended for projects that require a modelling technique for the analysis, development, re-engineering, integration, or acquisition of information systems; and incorporate a systems or enterprise modelling technique into a business process analysis or software engineering methodology.This note is a summary of the Standard for Integration Definition for Function Modelling (IDEF0). I.e. the Draft Federal Information Processing Standards Publication 183, 1993, December 21, Announcing the Standard for Integration Definition for Function Modelling (IDEF0).

Larsen, Michael Holm

1999-01-01

160

Thermo-mechanical sensitivity analysis of repository design parameters using Korean geological conditions  

International Nuclear Information System (INIS)

Extensive sensitivity analysis had been carried out for the seven design parameters, which can influence on the thermal-mechanical coupling behavior because of the stress in deep underground as well as the heat from the high-level radioactive waste. In this study, the three-dimensional commercial code, FLAC3D, was used for analyzing the sensitivity of the design parameters, which are related to disposal tunnel and deposition hole, on the temperature, stress, and displacement. The geological data measured at the two drilling sites, Yusung and Kosung, were used in the modelings. From the modelings, it was possible to investigate the thermal-mechanical coupling behavior of the deep underground repository under Korean geological conditions. Fractional factorial design was utilized for effective experimental design for the sensitivity analysis. Different techniques of sensitivity analysis were applied for the modeling results. From the analysis, it was possible to conclude that the deposition hole spacing is the most important parameter on the thermal-mechanical coupling behavior

2003-01-01

 
 
 
 
161

Structural geology of the Columbia Plateau and environs as related to the waste isolation safety assessment program  

International Nuclear Information System (INIS)

This report provides information on the structural geology of the Columbia Plateau in regard to selecting a site for radioactive waste disposal. This report describes the folding and faulting that has taken place during the past several million years, thus providing background for the general stress conditions of the area and giving clues to the mechanism of deformation

1979-11-01

162

Yucca Mountain thermal response: An evaluation of the effects of modeled geologic structure and thermal property descriptions  

International Nuclear Information System (INIS)

To assess the influence of mountain-scale thermal property model variations on predicted host-rock thermal response, a series of heat conduction calculations were run using a representative two-dimensional cross section of Yucca Mountain. The effects of modeled geologic structure were evaluated through comparisons of results from a single-material, homogeneous model with those from a uniformly layered model, a discontinuous sloping-layered model, and a geo-statistical realization of thermal properties. Comparisons indicate that assumed geologic structure can result in up to a 24 degrees C difference in predicted temperature response. Further, thermal simulations of the method used to analyze geostatistical realizations of thermal properties shows promise as an efficient means of capturing geologic structure without the complexities of intricate finite element meshing. The functional representation of two thermal property models were also investigated. The first examines the effect of using a weighting scheme to define properties for a single, homogenous material model. The second investigates the impact of thermal property temperature dependence on predicted response. As with the investigation of geologic structure, noticeable differences in predicted temperatures (up to 29 degrees C) were found to result

1995-01-01

163

Structure and permeability: geologic controls on induced seismicity at Nurek reservoir, Tadjikistan, USSR  

Energy Technology Data Exchange (ETDEWEB)

Induced seismicity at Nurek, Tadjik S.S.R., is occurring within the upper plate of the Ionakhsh thrust, which passes at depth directly beneath the reservoir. Within the immediate vicinity of the reservoir one can contrast two distinct areas, one seismic and the aseismic. Both consist of rocks that can be shown to have a highly anisotropic permeability due to alternating permeable and impermeable strata. Water flow is favored along bedding while essentially prohibited across bedding. However, because the two areas differ in structure, they also differ in their vertical component of permeability, as a direct result of the different attitudes of the bedding. In the aseismic area, vertical fluid flow is blocked by a syncline that cups the base of the reservoir. In the seismic area, a plunging anticline that crops out beneath the reservoir allows water to flow to depth in the high-permeability direction-along bedding. Because effective stress changes at depth are dependent on permeability characteristics, knowledge of subsurface permeability or permeability anisotropy can serve as a means by which to predict the distribution of induced seismic activity. Thus, while regional geologic studies may indicate the presence of lithologies that are conducive to the transmission of pore-water pressure, access of water to these units depends on the structural arrangement beneath the reservoir, on a very local scale.

Leith, W. (Lamont-Doherty Geological Observatory, Palisades, NY); Simpson, D.W.; Alvarez, W.

1981-10-01

164

Considerations on diversion analysis and the design of a safeguards approach. A case study of a geological repository for final disposal of spent fuel  

International Nuclear Information System (INIS)

Direct disposal of spent fuel has developed as an important option for the nuclear fuel cycle. The direct final disposal of spent nuclear fuel in a geological repository, as it is planned in Germany, makes new demands on international nuclear materials safeguards and requires the development of a new safeguards system, since no model procedures exist as yet. The development of an effective safeguards system and evaluation of alternative safeguards approaches calls for a comprehensive analysis of possible diversion paths together with an assessment as to what extent the relevant paths can be covered by safeguards measures. Since there are no prescribed and formalized procedures as to how to conduct the analysis, we try to apply the logical framework provided by material accountancy also as a basic structure for the diversion path analysis. This procedure can help to identify clearly the crucial points and novel safeguards issues raised by a geological disposal facility. (author). 1 fig

1994-12-01

165

Investigation on the geological structures obstructing the propagation of seismic waves - Based on physical modeling  

Energy Technology Data Exchange (ETDEWEB)

In petroleum exploration seismic reflection method is by far the most widely used. The resulting seismogram or seismic trace consists of many wavelets with different strengths and arrival times, due to the wavefront that have traveled different source-to receiver paths. In this sense, the seismic trace may be represented as a convolution of a wavelet with an impulse response denoting the various wavelet amplitudes and arrival times present in the trace. However, the wavelet suffers different attenuations while traveling through the earth layers. For example, the weathered layer (near-surface structure : e.g. valley) affect the propagating seismic wave in ways that cannot be simply modeled, but rather described in terms of an overall time delay and significant distortion of the source wavelet as it travels downward. Of course, the weathered layer will also affect the upgoing wave. Thus, the reflection method does not always lead to a desirable resolution in reflection section, because some specific constraints on the illumination of the deeper reflectors can be often imposed by the near-surface effect. Among other things, the mechanism for attenuation in many types of rocks is not very well understood. The present work is then mostly focussed on studying problems of wave propagation especially dealing with the near-surface structure problem by using physical modeling. An attempt was made to compare the measured data in detail with those from numerical method (ray theory). Besides, various kinds of physical models were additionally built to simulate the complex geological structures comprising wavy layer, coal seam structure, absorbing inhomogeneities, gradient layer that are not simply amenable to theory. Hereby, an attention was given on the reflection and transmission responses. The results illustrated in this work will provide a basis for the future oil exploration in Korea and demonstrate the potential of physical modeling as well. (author). 7 refs., 4 tabs., 62 figs.

Kim, Jung Yul; Hyun, Hye ja; Kim, Yoo Sung [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

1997-12-01

166

Nondestructive analysis of individual fluid inclusion based on SRXRF and its application in oil geology  

International Nuclear Information System (INIS)

The experimental device and methods of nondestructive analysis on individual fluid inclusion by synchrotron radiation X-ray fluorescence microprobe are described. With the standard sample NIST612 as reference, the detection limits of some elements are calculated and the typical organic inclusion taken from the western basin of China which contain oil gas are analyzed nondestructively. The semi-quantitative detection results of K, Ti, V, Cr, Mn, Ge, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Ba, Pb etc. are given, and the application of the results on oil geology is discussed

2002-10-01

167

Study of the determination of molybdenum in geological materials by neutron activation analysis  

International Nuclear Information System (INIS)

The determination of molybdenum in geological materiais by instrumental neutron activation analysis frequently does not present results due to spectral interferences of radioisotopes and due to 99Mo produced by fission of uranium. In order to eliminate interfering elements such as Na, Fe, U and lanthanides a chemical separation procedure was studied using and anionic exchange resin. In this separation, a recovery of (93+-3%) of Mo was obtained and pratically all the uranium was found in the effluent. Activation with epithermal neutrons reduced the interferences mainly those originating from uranium. Interference factors of 0.84 ?g Mo/?g U and 0.038?g Mo/?g U, respectively for thermal and epithermal irradiations, were determined experimentally. The separation method applied to the analysis of synthetic samples containing 141Ce and 59Fe interferents presented results with a precision of 6.9% and relative error of 2.6%. Analysis of Mo was also carried out in two international geological samples (AGV-1 and BCR-1) and in a sample of volcanic rock from Pocos de Caldas, MG Brazil. A sensitivity of 0.014? of Mo was attained by this method in the absence of interferering elements. (author)

1987-01-01

168

The relations between geological structure in the western Jincheng diggings and coal-bed methane wells arrangement  

Energy Technology Data Exchange (ETDEWEB)

At present, in Qinshui basin the coal-bed methane wells networks arrangement mainly used is an equidistant diamond layout. This method does not consider the influences between the geological character and controlling area of coal-bed methane wells. In light of this, an area was chosen where groundwater activities were weak, favored for the enrichment and preservation of coal-bed methane. The area is in the western Jincheng diggings in the southern Qinshui basin. The article discusses systematically for different geological positions, the differences of time for gas production, water production and cumulative gas production of coal-bed methane wells and the reasons for the disparity, and points out the relationship between the geological structure and well arrangement. 9 refs., 3 figs., 2 tabs.

Ni, X.; Wang, Y.; Jie, M.; Wu, J. [China University of Mining and Technology, Beijing (China)

2007-02-15

169

Study on systemizing the technology on the investigation and analysis of deep underground geological environment, 2005  

International Nuclear Information System (INIS)

The following study was done in this year with the aim of systemizing the technology on the investigation and analysis to grasp deep underground geological environment in relation to the radioactive waste disposal. (1) The study to extract the research and development (R and D) subjects turned to the practical investigation and analysis of deep underground geological environment. (2) The study on the advanced technical basis of the investigation and analysis of deep underground geological environment. It continued in the former year and got the following results. Concerning (1), the concrete investigation, measurement, numerical analyses and chemical analyses were enforced about the following item and extracted some subjects with the viewpoint of radioactive waste disposal. More over, the way to make the co-operative program among each field of the following 1), 2), and 3) was discussed. 1) The subjects extracted with the viewpoint of the repository design and engineering technology: The evaluation technique of the excavation disturbed zone (EDZ) of hard fractured rock using acoustic emission (AE) or micro seismicity measurement and so on. The evaluation was enlarged to the soft sedimentary rock in this year. The fracture sealing technique such as vibration grouting toward low permeable rock mass. 2) The subject extracted with the viewpoint of the safety assessment: The precipitation of the metal hydroxide (non-crystallized) through migration process in rock mass and change to the crystallized oxide. The examination of Fe-hydroxide was the target study in this year. The evaluation of corrosion affected by high-Eh ground water and/or oxidized substances. 3) The subjects extracted with the viewpoint of the geological environment: The fracture distribution characteristics around the fault that is thought to meet in the underground facilities and the prediction of long term activities of the fault. Natural sealing process by the secondary filling materials (iron oxide and carbonate and so on) in the fracture of rock mass, and that influence which may be given to the long-term migration and release of nuclides. (author)

2005-01-01

170

Geological structure of the offshore Sumatra forearc region estimated from high-resolution MCS reflection survey  

Science.gov (United States)

To investigate detailed fault distributions and shallow geological structure offshore northwestern Sumatra, we obtained high-resolution Multi-Channel Seismic (MCS) reflection data around the Sunda Trench, trench slope, and forearc high regions offshore northwestern Sumatra. In general, trench-parallel anticlinal ridges are distributed from trench slope region to forearc high region. Two kinds of different vergence systems are characterized in the Sumatra forearc region; landward vergence is dominant in the lower trench slope region, and seaward vergence is dominant in the forearc high region. Moreover, piggyback or slope basins are recognized between anticlinal ridges. Deformation in the uppermost part of these basins, that is referred to 'recent' deformation in this paper, can be identified not only along major thrusts but also between major thrusts and the lower trench slope, suggesting these are related to recently active faulting. Several but the largest number of such deformation are distributed along a major thrust located in the middle of the forearc high region, whereas few are done along other major thrusts.

Misawa, Ayanori; Hirata, Kenji; Seeber, Leonard; Arai, Kohsaku; Nakamura, Yasuyuki; Rahardiawan, Riza; Udrekh; Fujiwara, Toshiya; Kinoshita, Masataka; Baba, Hisatoshi; Kameo, Katsura; Adachi, Keita; Sarukawa, Hiroshi; Tokuyama, Hidekazu; Permana, Haryadi; Djajadihardja, Yusuf S.; Ashi, Juichiro

2014-01-01

171

Geological structures from televiewer logs of GT-2, Fenton Hill, New Mexico: Part 3, Quality control  

Energy Technology Data Exchange (ETDEWEB)

A procedure has been developed for extracting geological structures from paper prints of intensity-mode televiewer logs. It was applied to old logs of drill hole GT-2 at the Fenton Hill, New Mexico, Hot Dry Rock Site. A series of tests have also been developed for measuring the resultant data quality, and this report describes these tests and applies them to evaluate the procedure. A test for measurement accuracy shows that locations were measured to better than 0.1 ft and orientations to within 1/sup 0/. The root-mean-square error in fitting a trace rarely exceeded 0.2 ft. The second set of tests, for reproducibility, measures the amount of association between two different runs of the same length of hole, in this case a distance of 275 ft. Two new measures of association are defined, termed coplanarity and collinearity. The lack of any recurrences requires explanation and leads to a third set of tests, for repetition rate. The low repetition rate is explained by random errors in location and orientation, which are different on each run. A fourth set of tests consists of fitting a model of the feature-extraction process to the data and estimating data reliability from quality parameters of the model. A perception model yielded an estimate of data quality at 91.5%.

Burns, K.L.

1987-12-01

172

Release consequence analysis for a hypothetical geologic radioactive waste repository in salt  

International Nuclear Information System (INIS)

One subtask conducted under the INFCE program is to evaluate and compare the health and safety impacts of different fuel cycles in which all radioactive wastes (except those from mining and milling) are placed in a geologic repository in salt. To achieve this objective, INFCE Working Group 7 examined the radiologic dose to humans from geologic repositories containing waste arisings as defined for seven reference fuel cycles. This report examines the release consequences for a generic waste repository in bedded salt. The top of the salt formation and the top of the repository are assumed to be 250 and 600 m, respectively, below the surface. The hydrogeologic structure above the salt consists of two aquifers and two aquitards. The aquifers connect to a river 6.2 km from the repository. The regional gradient to the river is 1 m/km in all aquifers. Hydrologic, transport, and dose models were used to model two release scenarios for each fuel cycle, one without a major disturbance and one in which a major geologic perturbation breached the repository immediately after it was sealed. The purpose of the modeling was to predict the rate of transport of radioactive contaminants from the repository through the geosphere to the biosphere, and to determine the potential dose to humans. Of the many radionuclides in the waste, only 129I and 226Ra arrived at the river in sufficient concentrations for a measurable dose calculation. Radionuclide concentrations in the ground water pose no threat to man because the ground water is a concentrated brine and it is diluted by a factor of 106 to 107 upon entering the river

1979-01-01

173

Local ground parameters of blasting vibration models for different geological structures at Mae Moh lignite mine, Thailand  

Directory of Open Access Journals (Sweden)

Full Text Available This study was carried out at Mae Moh lignite mine, Lampang Province, Thailand. Vibration data were recorded in different directions: SE-pit to Huai King Village, SE-pit to Hang Hung Village, SE-pit to PR building and C-pit to SE-pit. More than hundred data points were collected and used for the formulation of ground parameters equations according to scale distance model for each direction. It was observed that geological structures might affect the propagation of the vibration wave. The formulated equations according to scale distance model are different for different geological structures. Three different structures of ground involved in this study were overburden (shale and claystone, lignite seam and combination of overburden and lignite seam. Formulated equations for vibration model in these media were given and discussed.

Vishnu Rachpech

2014-02-01

174

Geology of Kentucky  

Science.gov (United States)

This website contains geologic maps of Kentucky, with a discussion of geologic time in regards to the rocks, minerals, fossils, and economic deposits found there. There are also sections that describe strata and geologic structures beneath the surface (faults, basins, and arches), the structural processes (folding and faulting) that create stratigraphic units, the geomorphology of the state, geologic information by county, a general description of geologic time, fossil, rocks, and minerals of Kentucky, and a virtual field trip through Natural Bridges State Park. Links are provided for further information.

175

Uranium and thorium analysis in geological samples using plastic track detectors  

International Nuclear Information System (INIS)

A formula is proposed for a LR-115 type 2 plastic track detector relating the alpha track rate and concentrations of U and Th in geological samples. Uranium was estimated using a fission track technique and Th was calculated from alpha autoradiography. The proposed formula was applied for Th analysis in phophorite samples from Mussourie Syncline, U.P. (India). Gamma ray spectrometric analysis of phosphorite samples established the validity of the formula for U and Th estimation. Quartizite samples collected from the Kula area of Himachal Pradesh (India) were analysed using the formula. U and Th contents were found to vary from 2.63 to 18.73 ppm and 0.92 to 95.92 ppm, respectively. (author)

1986-01-01

176

Characterization of multiple prompt gamma-ray analysis (MPGA) system at JAEA for elemental analysis of geological and cosmochemical samples  

International Nuclear Information System (INIS)

The newly installed multiple prompt gamma-ray analysis (MPGA) system at the Japan Atomic Energy Agency (JAEA) was characterized for nondestructive multi-element analysis of geological and cosmochemical samples. Analysis of the hydrogenous meteorite Orgueil by both MPGA and PGA implies that MPGA can be used for elemental determination with sufficient accuracy. For some elements which cannot be determined by conventional PGA due to the spectral interference or lower sensitivity, it was shown that they could be determined by MPGA. - Highlights: ? Offline sorting modes of the coincidence data in MPGA were evaluated for elemental analyses. ? MPGA detection limits for some studied elements were improved around one order of magnitude than those obtained by other PGA facilities. ? For some elements, which cannot be determined by conventional PGA, it was observed that they could be determined by MPGA. ? Analysis of the hydrogenous meteorite Orgueil by MPGA implies that it can be used for elemental analysis with sufficient accuracy.

2012-08-01

177

2005 dossier: granite. Tome: safety analysis of the geologic disposal; Dossier 2005: granite. Tome analyse de surete du stockage geologique  

Energy Technology Data Exchange (ETDEWEB)

This document makes a status of the researches carried out by the French national agency of radioactive wastes (ANDRA) about the safety aspects of the geologic disposal of high-level and long-lived (HLLL) radioactive wastes in granite formations. Content: 1 - safety approach: context and general goal, references, design approach by safety functions, safety approach during the construction-exploitation-observation-closure phase, safety analysis during the post-closure phase; 2 - general description: HLLL wastes, granitic environment, general structure of the architecture of a disposal facility; 3 - safety functions and disposal design: general context, safety functions of the long-term disposal, design dispositions retained to answer the functions; 4 - operational safety: people's protection, radiological risks during exploitation, risk analysis in accident situation; 5 - qualitative safety analysis: methodology, main results of the analysis of the features, events and processes (FEP) database; 6 - disposal efficiency evaluation during post-closure phase: calculation models, calculation tools used for the modeling of radionuclides transport, calculation results and main lessons. (J.S.)

NONE

2005-07-01

178

Monitoring systems and geological structure assessment leading to improved management of mining conditions  

Energy Technology Data Exchange (ETDEWEB)

This main aim of the project was to investigate issues associated with longwalling in weak mining conditions and in particular, ground response when mining through faults. The objectives of the project were: By combined longwall support and microseismic monitoring, devise a means to readily understand changes in the interaction between strata and supports in faulted zones and regions of weak conditions more generally. Assess actual mining experiences from mines that have mined through fault zones to understand the need for grouting and other actions given the geological context of these faults. A review of past fault consolidation projects from various mines in the Bowen Basin was also undertaken. The aim of the review was to devise a means to assess faulted areas to determine the need for consolidation and their likely impact on mining performance. A measurement trial and program of microseismic monitoring of mining through a fault was carried out in LW105, Moranbah North mine. Analysis of the fault pre-consolidation program including comment on grout takes, pressures and penetration was undertaken. Longwall support monitoring and face stability analysis was used to examine overall strata-support interaction processes. The objective of the CSIRO microseismic monitoring study was to investigate the feasibility of using geophones installed on the ground surface to detect ground response characteristics associated with mining through the fault. It was found that locations of significant rock fracturing could be determined with high accuracy in plan view but poorly in depth. In general, the number of seismic events recorded on the ground surface was about 1/3 of those recorded in the deep boreholes, due to considerable seismic attenuation near the ground surface.

Terry Medhurst [AMC Consultants (Australia)

2006-10-15

179

Neural network analysis for geological interpretation of tomographic images beneath the Japan Islands  

Science.gov (United States)

Recent advances in methodologies of geophysical observations, such as seismic tomography, seismic reflection method and geomagnetic method, provide us a large amount and a wide variety of data for physical properties of a crust and upper mantle (e.g. Matsubara et al. (2008)). However, it has still been difficult to specify a rock type and its physical conditions, mainly because (1) available data usually have a lot of error and uncertainty, and (2) physical properties of rocks are greatly affected by fluid and microstructures. The objective interpretation and quantitative evaluation for lithology and fluid-related structure require the statistical analyses of integrated geophysical and geological data. Self-Organizing Maps (SOMs) are unsupervised artificial neural networks that map the input space into clusters in a topological form whose organization is related to trends in the input data (Kohonen 2001). SOMs are powerful neural network techniques to classify and interpret multiattribute data sets. Results of SOM classifications can be represented as 2D images, called feature maps which illustrate the complexity and interrelationships among input data sets. Recently, some works have used SOM in order to interpret multidimensional, non-linear, and highly noised geophysical data for purposes of geological prediction (e.g. Klose 2006; Tselentis et al. 2007; Bauer et al. 2008). This paper describes the application of SOM to the 3D velocity structure beneath the whole Japan islands (e.g. Matsubara et al. 2008). From the obtained feature maps, we can specify the lithology and qualitatively evaluate the effect of fluid-related structures. Moreover, re-projection of feature maps onto the 3D velocity structures resulted in detailed images of the structures within the plates. The Pacific plate and the Philippine Sea plate subducting beneath the Eurasian plate can be imaged more clearly than the original P- and S-wave velocity structures. In order to understand more precise prediction of lithology and its structure, we will use the additional input data sets, such as tomographic images of random velocity fluctuation (Takahashi et al. 2009) and b-value mapping data. Additionally, different kinds of data sets, including the experimental and petrological results (e.g. Christensen 1991; Hacker et al. 2003) can be applied to our analyses.

Kuwatani, T.; Toriumi, M.

2009-12-01

180

Present and future geologic applications of petrographic and other image analysis  

Energy Technology Data Exchange (ETDEWEB)

Relatively simple and inexpensive imaging hardware has provided the potential for the capture and analysis of great quantities of useful rock information. A common petrographic imaging system can be trained to identify the holes in rocks; from this collection of pores, variables such as permeability, recovery potential, and diagenetic history can be calculated for many rocks. Relationships between rock properties and petrophysical logs can also be ascertained and quantified in many instances. For many companies, petrographic image analysis has become a commonplace procedure. The techniques involved with geologic image analysis derive directly from cancer research and other pattern-recognition-based studies. As these studies have advanced, so do the potential applications for the petroleum geologist. Intelligent software can be used to determine the volume of clay in a thin section and further subdivide the volume into framework clay, clay lining the pore network, and isolated particles. Techniques that quantify textures can be used to determine mineralogy, classify depositional environment, and sort out diagenetic history. Essentially, anything the eye can see in a rock, image analysis can capture. Furthermore, newer statistical approaches can extract meaningful and useful information from the captured data. On the macro scale, image analysis can be used to describe larger scale core properties. Many of the macro techniques are based on satellite imaging techniques in conjunction with map comparison algorithms. On both the macro and micro scales, fractures can be identified and subsequently quantified similar to lineation analysis, thus offering access to information quite useful to the petroleum geologist.

Full, W.E. (Wichita State Univ., KS (United States))

1991-08-01

 
 
 
 
181

Parametric uncertainty analysis using Latin Hypercube Sampling in risk assessment of deep geological HLW repository  

International Nuclear Information System (INIS)

With regard to the safety assessment of deep geological HLW repository, there may be many parameters subject to uncertainty. Dilution factor is considered as a parameter that has large uncertainty in this study. Under the assumption that PWR spent fuels are disposed of into deep geological repository, uncertainty analysis on dilution factor has performed. Deterministic calculation of radionuclides transport through geosphere is performed preliminarily. To analyze the uncertainty of dilution factor, lognormal distribution is assumed with range from 4 to 100,000 and Latin Hypercube Sampling (LHS) is used for sampling. Finally, annual individual dose calculated with sampled dilution factor and the histogram of peaks of annual individual doses is proved to have lognormal distribution by chi-square test. Lower and upper limits of annual individual dose are shown with 95% confidence level. Uncertainty of dose resulted from wide range of dilution factor may cause large difference between lower and upper limit up to four order of magnitude. In the condition of low dilution in geosphere, the annual individual dose is even up to 10-4 mSv/yr. (author)

2000-12-01

182

Coda-wave interferometry analysis of time-lapse VSP data for monitoring geological carbon sequestration  

Energy Technology Data Exchange (ETDEWEB)

Injection and movement/saturation of carbon dioxide (CO2) in a geological formation will cause changes in seismic velocities. We investigate the capability of coda-wave interferometry technique for estimating CO2-induced seismic velocity changes using time-lapse synthetic vertical seismic profiling (VSP) data and the field VSP datasets acquired for monitoring injected CO2 in a brine aquifer in Texas, USA. Synthetic VSP data are calculated using a finite-difference elastic-wave equation scheme and a layered model based on the elastic Marmousi model. A possible leakage scenario is simulated by introducing seismic velocity changes in a layer above the CO2 injection layer. We find that the leakage can be detected by the detection of a difference in seismograms recorded after the injection compared to those recorded before the injection at an earlier time in the seismogram than would be expected if there was no leakage. The absolute values of estimated mean velocity changes, from both synthetic and field VSP data, increase significantly for receiver positions approaching the top of a CO2 reservoir. Our results from field data suggest that the velocity changes caused by CO2 injection could be more than 10% and are consistent with results from a crosswell tomogram study. This study demonstrates that time-lapse VSP with coda-wave interferometry analysis can reliably and effectively monitor geological carbon sequestration.

Zhou, R.; Huang, L.; Rutledge, J.T.; Fehler, M.; Daley, T.M.; Majer, E.L.

2009-11-01

183

MI-1320 Mass spectrometer and its analytical parameters for isotope analysis in geology  

International Nuclear Information System (INIS)

Presented are the technical characteristic of a new serial MI-1320 mass spectrometer and the value of its analytical parameters obtained in the laboratory tests when analysing the isotope standards of plumbum, strontium and uranium. Isotope sensitivity of the device constitutes 3x10-6, 6 the probe use factor (according to uranium) is 0.5-1.5x10-3 ion/atom. The reproduction of results of measurements of isotopic ratios in independent experiments constitutes 0.04-0.015% rel. These and other characteristics of the device exceed by 1-2 orders the corresponding characteristics of the domestic mass spectrometers of the preceeding generation used in geology. Mass spectrometer permits to carry out studies requiring high sensitivity and accuracy of measurements and to achieve isotope data of a qualitatively new level at variations of isochronous dating of geologic samples, cosmic bodies at studying natural variations of isotopic composition of chemical elements permitting isotopic analysis in solid phase. The ways of further development of the device are considered

1979-10-01

184

Marine Geological Structure and Active Faults in Kii Strait and off the Southern Coast of Kii Peninsula  

Science.gov (United States)

Submarine geological and geophysical surveys in and around the Kii Strait were carried out by two different methods. A single channel watergun method was executed to clarify the fault structures on the shelf in the northern part of the Kii Strait, and a multichannel airgun method was performed to reveal the basement structures of the shelf slope, the Muroto Trough, the outer ridge, the inner trench slope, the Nankai Trough and the Shikoku Basin. The results show that the single channel watergun system is available for the geophysical survey on the shelf in the open sea and the multichannel airgun system is effective for the investigation of deep sea geological structure. Many small faults were detected on the shelf off Tanabe city. They are distributed widely in the shelf area, cannot be recognized as strike-slip faults and are not active in the latest Pleistocene and Recent. Upheaval and subsidence axes trending N-S direction and other upheaval axis trending ENE-WSW direction were recognized in the surveyed area. The last axis was generated later than those trending N-S direction. The provident scarps observed in the northern margin of the Muroto Trough and at the submarine canyons' sides have been proved to be caused not by faulting but by submarine landslides. The outline of the geological structure in the southernmost part of the outer zone of southwest Japan across the outer ridge, the Nankai Trough and the Shikoku Basin has been revealed by this survey.

Mitsuhashi, Akira; Kadosawa, Hiroshi; Yoshikawa, Soji; Iwasaki, Yoshinori; Huzita, Kazuo

185

Inference of the structure of karst conduits using quantitative tracer tests and geological information: example of the Swiss Jura  

Science.gov (United States)

Karst aquifers are known for being particularly heterogeneous with highly transmissive conduits embedded in low permeability volumes of rock matrix. Artificial tracer experiments have been carried out in a complex karst aquifer of the folded Jura Mountains in Switzerland with the aim of deciphering the conduit organisation. It is shown that tracer experiments with multiple injection points under different flow conditions can lead to useful information on the conduits’ structure. This information has been combined with data from structural geology, spring hydrology, and speleological observations. A conceptual model of the conduit network shows that a detailed inference of the conduit organisation can be reached: geology controls conduit location and orientation; spring hydrology, including temporary springs, constrains conduit elevations and relative hydraulic heads in the aquifer subsystems; and tracer tests identify major flow paths and outlets of the system and dilution caused by non-traced tributaries, as well as the presence of secondary flow routes. This understanding of the Aubonne aquifer structure has important implications for the future management of the groundwater resource. Similar approaches coupling geological information, spring hydrology, and multi-tracer tests under various flow conditions may help to characterise the structure of the conduit network in karst aquifers.

Perrin, Jérôme; Luetscher, Marc

2008-08-01

186

Geological structure of the Tatric and Fatric units among the Belianska and Vrátna dolina valleys (the Krivánska Fatra Mts.  

Directory of Open Access Journals (Sweden)

Full Text Available This paper deals with the geological setting of the area between Belianska and Vrátna dolina valley in the Krivánska Fatra Mts. In the study area can be recognised numerous north-vergent structures considered as a result of the palaeo-Alpine (Cretaceous tectonic evolution related to the nappe stacking of the Fatric and Hronic units. Another dominant structures, south-verging folds and reverse faults confirm the neo-Alpine (Early Miocene backthrusting recorded in the surrounding regions. This event is considered as a result of the sinistral transpression regime operated between the Central and Outer Western Carpathians and could be responsible also for the development of the straight open macro folds with the generally N–S oriented axes. A revised geological map is presented as well.

Michal Sentpetery

2012-06-01

187

SG2PS (structural geology to postscript converter) – A graphical solution for brittle structural data evaluation and paleostress calculation  

Science.gov (United States)

The aim of this work was to create an open source cross platform application to process brittle structural geological data with seven paleostress inversion algorithms published by different authors and formerly not available within a single desktop application. The tool facilitates separate processing and plotting of different localities, data types and user made groups, using the same single input file. Simplified data input is supported, requiring as small amount of data as possible. Data rotation to correct for bedding tilting, rotation with paleomagnetic declination and k-means clustering are available. RUP and ANG stress estimators calculation and visualization, resolved shear direction display and Mohr circle stress visualization are available. RGB-colored vector graphical outputs are automatically generated in Encapsulated PostScript and Portable Document Format. Stereographical displays on great circle or pole point plot, equal area or equal angle net and upper or lower hemisphere projections are implemented. Rose plots displaying dip direction or strike, with dip angle distribution of the input data set are available. This tool is ideal for preliminary data interpretation on the field (quick processing and visualization in seconds); the implemented methods can be regularly used in the daily academic and industrial work as well.

Sasvári, Ágoston; Baharev, Ali

2014-05-01

188

Determination of hydrogen in geological standard samples by neutron induced Prompt Gamma-ray Analysis (PGA)  

International Nuclear Information System (INIS)

Hydrogen contents in geological standard rock samples were determined by neutron-induced Prompt Gamma-ray Analysis (PGA) using thermal neutron beam line installed at the JRR-3 reactor of Japan Atomic Energy Research Institute. Samples were made constant in weight by drying them in an oven before assaying to PGA so that moisture (denoted as H2O-) adsorbed on samples was desorbed. Helium gas was introduced into the sample box to purge the vapor in the air during the measurement. Repeated analyses of peridotite and basaltic samples yielded reproducible values of hydrogen after blank correction, implying that the PGA procedure applied in this study is reliable to measure hydrogen contents present in igneous rock samples. The procedure was also applied to meteorite samples and reasonable values of hydrogen were obtained

2005-04-11

189

The use of the MCNP code for the quantitative analysis of elements in geological formations  

Energy Technology Data Exchange (ETDEWEB)

The Monte Carlo modelling calculations using the MCNP code have been performed, which support the spectrometric neutron-gamma (SNGL) borehole logging. The SNGL enables the lithology identification through the quantitative analysis of the elements in geological formations and thus can be very useful for the oil and gas industry as well as for prospecting of the potential host rocks for radioactive waste disposal. In the SNGL experiment, gamma-rays induced by the neutron interactions with the nuclei of the rock elements are detected using the gamma-ray probe of complex mechanical and electronic construction. The probe has to be calibrated for a wide range of the elemental concentrations, to assure the proper quantitative analysis. The Polish Calibration Station in Zielona Gora is equipped with a limited number of calibration standards. An extension of the experimental calibration and the evaluation of the effect of the so-called side effects (for example the borehole and formation salinity variation) on the accuracy of the SNGL method can be done by the use of the MCNP code. The preliminary MCNP results showing the effect of the borehole and formation fluids salinity variations on the accuracy of silicon (Si), calcium (Ca) and iron (Fe) content determination are presented in the paper. The main effort has been focused on a modelling of the complex SNGL probe situated in a fluid filled borehole, surrounded by a geological formation. Track length estimate of the photon flux from the (n,gamma) interactions as a function of gamma-rays energy was used. Calculations were run on the PC computer with AMD Athlon 1.33 GHz processor. Neutron and photon cross-sections libraries were taken from the MCNP4c package and based mainly on the ENDF/B-6, ENDF/B-5 and MCPLIB02 data. The results of simulated experiment are in conformity with results of the real experiment performed with the use of the main lithology models (sandstones, limestones and dolomite). (authors)

Cywicka-Jakiel, T.; Woynicka, U. [The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Zorski, T. [University of Mining and Metallurgy, Faculty of Geology, Geophysics and Environmental Protection, Krakow (Poland)

2003-07-01

190

An evaluation of the suitability of ERTS data for the purposes of petroleum exploration. [lithology and geological structure of Anadarko Basin of Oklahoma and Texas  

Science.gov (United States)

The author has identified the following significant results. ERTS-1 data give exploration geologists a new perspective for looking at the earth. The data are excellent for interpreting regional lithologic and structural relationships and quickly directing attention to areas of greatest exploration interest. Information derived from ERTS data useful for petroleum exploration include: linear features, general lithologic distribution, identification of various anomalous features, some details of structures controlling hydrocarbon accumulation, overall structural relationships, and the regional context of the exploration province. Many anomalies (particularly geomorphic anomalies) correlate with known features of petroleum exploration interest. Linears interpreted from the imagery that were checked in the field correlate with fractures. Bands 5 and 7 and color composite imagery acquired during the periods of maximum and minimum vegetation vigor are best for geologic interpretation. Preliminary analysis indicates that use of ERTS imagery can substantially reduce the cost of petroleum exploration in relatively unexplored areas.

Collins, R. J. (principal investigator); Mccown, F. P.; Stonis, L. P.; Petzel, G. J.; Everett, J. R.

1974-01-01

191

Overview of the structural geology and tectonics of the Central Basin Platform, Delaware Basin, and Midland Basin, West Texas and New Mexico  

Energy Technology Data Exchange (ETDEWEB)

The structural geology and tectonics of the Permian Basin were investigated using an integrated approach incorporating satellite imagery, aeromagnetics, gravity, seismic, regional subsurface mapping and published literature. The two primary emphases were on: (1) delineating the temporal and spatial evolution of the regional stress state; and (2) calculating the amount of regional shortening or contraction. Secondary objectives included delineation of basement and shallower fault zones, identification of structural style, characterization of fractured zones, analysis of surficial linear features on satellite imagery and their correlation to deeper structures. Gandu Unit, also known as Andector Field at the Ellenburger level and Goldsmith Field at Permian and younger reservoir horizons, is the primary area of interest and lies in the northern part of Ector county. The field trends northwest across the county line into Andrews County. The field(s) are located along an Ellenburger thrust anticline trap on the eastern margin of the Central Basin Platform.

Hoak, T. [Kestrel Geoscience, Littleton, CO (United States); Sundberg, K. [Phillips Petroleum Co., Bartlesville, OK (United States); Ortoleva, P. [Indiana Univ., Bloomington, IN (United States)

1998-12-31

192

High-precision EA-IRMS analysis of S and C isotopes in geological materials  

International Nuclear Information System (INIS)

The continuous flow elemental analyzer-isotopic ratio mass spectrometer (EA-IRMS) technique provides a significant improvement over conventional extraction methods for the determination of C- and S-isotope ratios in geological materials. It is faster and requires much smaller quantities of material for analysis. Sample preparation is simple, with little or no need for chemical or complete mechanical mineral phase separation, and EA-IRMS sample introduction is rapid. However, because of its simplicity and the fact that data quality depends on the control of a variety of factors, the technique requires rigid adherence to a careful sample analysis protocol. The matching of sample and reference peak heights by sample weight adjustment minimizes non-linearity effects. An accurate calibration should be determined by using standards having a wide range of isotopic compositions, ideally bracketing the samples analysed to both low and high isotopic ratios, and a regular analysis of standards undertaken to maintain the accuracy of the calibration. The calibration equation must be monitored throughout the run by regular analysis of standards, and performance of the Cu-reduction reactor regularly checked to avoid O2 saturation. With this level of attention to analytical detail, measured precision on replicates of isotopic standards is in the order of ±0.1 per mille for both C and S isotopic analyses. For S this is a significant improvement over conventional techniques, with 53% of natural samples analysed replicating to better than ±0.1 per mille

2006-05-01

193

Comparison of mainframe and minicomputer spectral analysis codes in the activation analysis of geological samples  

International Nuclear Information System (INIS)

This paper presents a comparison study of one of the most widely used mainframe codes, GAMANL, and the applications software supplied with the nuclear data 6620 gamma-ray spectroscopy system. The study was conducted by performing analyses on U.S. Geological Survey (USGS) standard rocks. The spectral details studied were those frequently found in complex samples and which may not be readily duplicated using pulsers. Five replicate samples of approximately 30 mg each of USGS rocks G-1, G-2, W-1 and BCR-1 were irradiated in a reactor for 10 hours at a flux of 6 x 1013 n cm-2 sec-1. A Ge(Li) detector was used for counting. Decay corrections were made for Ce-141, Cr-51, Nd-147, Sc-46, Rb-86, Fe-59, and Ta-182. The gamma ray spectra for G-1, G-2, W-1 and BCR-1 are shown

1982-01-01

194

Geological and Structural evolution of the Eurasia Africa plate boundary in the Gulf of Cadiz Central Eastern Atlantic Sea.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Iberia Africa plate boundary, cross, roughly W-E, connecting the eastern Atlantic Ocean from Azores triple junction to the Continental margin of Morocco. Relative movement between the two plate change along the boundary, from transtensive near the Azores archipelago, through trascurrent movement in the middle at the Gloria Fracture Zone, to transpressive in the Gulf of Cadiz area. This study presents the results of geophysical and geological analysis on the plate boundary area offshore Gibral...

2010-01-01

195

Neutron-activation analysis of several US Geological Survey and National Bureau of Standards reference materials  

International Nuclear Information System (INIS)

In this work, several US Geological Survey (U.S.G.S.) and National Bureau of Standards (N.B.S.) reference samples have been analyzed in an effort to improve the quality of elemental concentration data available on these materials, so they can be used in a program of verification of factor analysis source resolution procedures. The analyses of these samples were performed by instrumental neutron activation analysis (INAA). The samples analyzed were: U.S.G.S. Green River Shale, N.B.S. 45b Homogeneous River Sediment, U.S.G.S. Analyzed Peridotite N.B.S. 1579 Powdered Lead-based Paint, U.S.G.S. Hawaian Basalt U.S.G.S. Marine Mud, U.S.G.S. Analyzed Cody Shale U.S.G.S. Glass Mountain Rhyolite, N.B.S. Argillaceous Limestone No. 1, and a sample of Spex ultrapure graphite. Neutron activation analysis was employed because of the high sensitivity that can be attained in determining elemental concentrations. Although INAA is a relatively simple method and the reproducibility of the data is good, the method shows some inaccuracies. The basic theory and technique are reviewed in an attempt to show where problems can arise and how they can be dealt with

1981-01-01

196

Assessing the impacts of geopressure on exploration using integrated geological log analysis  

Energy Technology Data Exchange (ETDEWEB)

The occurrence of geopressure anomalies in the El Furrial, Chaguaramal and Boqueron oil fields in the Maturin subbasin of the Eastern Venezuela Basin, and their heterogeneous evolution through geological time has caused significant drilling problems. Identification of these anomalies and isolation of the adjacent subcompacted formations has cost much time and money. There are two main abnormal pressure zones in the Eastern Venezuela Basin. The lower occurs in a thick homogenous marine shale sequence of the Carapita Formation, deposited during late Oligocene-early Miocene times, which was followed by a late Miocene period of uplift and erosion. The upper occurs in marine shales and sandstones of the La Pica Formation, which was transgressively deposited on the eroded Carapita Formation. Using an integrated analysis of lithology and wireline logs, tectonically-influenced sections have been identified within the lower geopressure which have modified its original conditions. Furthermore, the late Miocene unconformity between the two zones controls the occurrence, style and dimension of the upper geopressure. Detailed differential compaction analysis from low to high hydraulic potential intervals through the lithostratigraphic sequence and their association to the unconformity explain the evolution and the current state of geopressure distribution throughout the oil fields. These conclusions are supported by direct and indirect quantitative pore and fracture pressure gradient analysis. The study identifies areas within these fields (e.g., Central and Eastern Boqueron) which show alterations of the occurrence and behavior of the geopressure. Such knowledge permits rapid modifications to drilling programs, allowing successful exploration and development.

Betancour, I.R. (Lagoven, Monagas (Venezuela)); Vellez, F.; Gonzales, A. (Exlog de Venezuela, Monagas (Venezuela))

1993-02-01

197

Summary report of the advanced scenario analysis for performance assessment of geological disposal  

International Nuclear Information System (INIS)

First of all, with regard to the FEP information data on the Engineered Barrier System (EBS) developed by JNC, description level and content of the FEPs have been examined from various angles on the basis of the latest research information. Each content of the FEP data has been classified and modified by means of integrating descriptive items, checking detail levels and correlations with other FEPs, collating with the H12 report, and adding technical information after H12 report. Secondly, scenario-modeling process has been studied. The study has been conducted by evaluating representation of the repository system, definition of FEP properties, and process interactions based on the concept of the interaction matrix (RES format) which represents influences between physicochemical characteristics of the repository, followed by an experimental development of the actual RES interaction matrix based on the H12 report as the examination to improve the transparency, traceability and comprehensibility of the scenario analysis process. Lastly, in relation to the geological disposal system, assessment techniques have been examined for more practical scenario analysis on particularly strong perturbations. Possible conceptual models have been proposed for each of these scenarios; seismic, faulting, and dike intrusion. As a result of these researches, a future direction for advanced scenario analysis on performance assessment has been indicated, as well as associated issues to be discussed have been clarified. (author)

2002-01-01

198

The advanced scenario analysis for performance assessment of geological disposal. 2  

International Nuclear Information System (INIS)

As the first step of this study, description level and content of the FEPs (Feature, Event, Process) with regard to the FEP information data on the Natural Barrier System developed by JNC have been examined from various angles on the basis of the latest research information. Each content of the FEP data has been classified and modified by means of integrating descriptive items, checking detail levels and correlations with other FEPs, collating with the H12 report, and adding technical information after H12 report. Secondly, scenario analysis method has been studied. As an illustrated example, a procedure for deriving a calculation case by using Connectivity Matrix and PPM (Parameters, Processes, Models) database was applied for buffer in base scenario and then volcanism scenario. Also, another approach based on Correlation Matrix has been comparatively discussed to list up future subjects. Lastly, in relation to the geological disposal system, assessment techniques have been examined for more practical scenario analysis on variant scenario. Possible conceptual models have been proposed for uplift and erosion scenario. As a result of these researches, a future direction for advanced scenario analysis on performance assessment has been indicated, as well as associated issues to be discussed have been clarified. (author)

2003-01-01

199

Experience of use of digital gravimagnetic data for specification of a geological structure of the North Ural region  

Science.gov (United States)

Study of magnetic heterogeneities of the lithosphere is very important for the prediction of minerals. Results of developing a geophysical basis for specifying the geological map in sheet Q-42 (Polar Urals) are considered. Geophysical basis is a set of digital geophysical data prepared at the stage that preceded compilation of the geological map. The main geophysical materials in the set are magnetic anomalies map, gravimetric, and radiometric maps at 1:1 000 000 scale. Geophysical maps are compiled based on medium and large-scale field measurements and structured in the database in three information levels. Final digital materials are represented in the database by 500x500m grids. Investigations of digital cartographic materials result in a scheme of integrated interpretation of geophysical data and geological-geophysical section. The following conclusions were obtained for the study region using digital gravimetric data: - anomalous areas corresponding to large synclinoria or anticlinoria of the Ural fold system were revealed within the North Urals region overlapped by platform cover; - significant peculiarity of material complexes of the Kharbey Anticlinorium characterized by intense positive anomaly of the gravity field is shown; - the presence of bodies of mafic composition within the overlapped by platform cover Gortsky, Yarsalinsky synclinoria and Uvat-Khanty-Mansiysk median massif is confirmed and new development areas of intrusive rocks of mafic composition are revealed; - assumed Triassic rift structures filled with volcanic formations of mafic composition and intruded by small gabbroid bodies, usually prospective for hydrocarbons, are revealed.

Litvinova, Tamara; Erinchek, Yury; Krasinsky, Egor; Kudryavtsev, Ivan

2014-05-01

200

Hypogeal geological survey in the "Grotta del Re Tiberio" natural cave (Apennines, Italy): a valid tool for reconstructing the structural setting  

Science.gov (United States)

As karst systems are natural windows to the underground, speleology, combined with geological surveys, can be useful tools for helping understand the geological evolution of karst areas. In order to enhance the reconstruction of the structural setting in a gypsum karst area (Vena del Gesso, Romagna Apennines), a detailed analysis has been carried out on hypogeal data. Structural features (faults, fractures, tectonic foliations, bedding) have been mapped in the "Grotta del Re Tiberio" cave, in the nearby gypsum quarry tunnels and open pit benches. Five fracture systems and six fault systems have been identified. The fault systems have been further analyzed through stereographic projections and geometric-kinematic evaluations in order to reconstruct the relative chronology of these structures. This analysis led to the detection of two deformation phases. The results permitted linking of the hypogeal data with the surface data both at a local and regional scale. At the local scale, fracture data collected in the underground have been compared with previous authors' surface data coming from the quarry area. The two data sets show a very good correspondence, as every underground fracture system matches with one of the surface fracture system. Moreover, in the cave, a larger number of fractures belonging to each system could be mapped. At the regional scale, the two deformation phases detected can be integrated in the structural setting of the study area, thereby enhancing the tectonic interpretation of the area ( e.g., structures belonging to a new deformation phase, not reported before, have been identified underground). The structural detailed hypogeal survey has, thus, provided very useful data, both by integrating the existing information and revealing new data not detected at the surface. In particular, some small structures ( e.g., displacement markers and short fractures) are better preserved in the hypogeal environment than on the surface where the outcropping gypsum is more exposed to dissolution and recrystallization. The hypogeal geological survey, therefore, can be considered a powerful tool for integrating the surface and log data in order to enhance the reconstruction of the deformational history and to get a three-dimensional model of the bedrock in karst areas.

Ghiselli, Alice; Merazzi, Marzio; Strini, Andrea; Margutti, Roberto; Mercuriali, Michele

2011-06-01

 
 
 
 
201

On risk analysis for repositories in northern Switzerland: extent and probability of geological processes and events  

International Nuclear Information System (INIS)

The literature study assesses, in the form of expert analysis, geological processes and events for a 1200 km"2-area of northern Switzerland, with regard to repositories for medium- and high-active waste (depth 100 to 600 m and 600 to 2500 m, respectively) over the next 10"6 years. The area, which comprises parts of the Tabular Jura, the folded Jura and the Molasse Basin, the latter two being parts of the Alpine Orogene, has undergone a non-uniform geologic development since the Oligocene. Within the next 10"4 to 10"5 years a maximum earthquake intensity of VIII-IX (MSK-scale) has been predicted. After this period, particularly in the southern and eastern parts of the area, glaciations will probably occur, with associated erosion of possibly 200 to 300 m. Fluvial erosion as a reponse to an uplift could reach similar values after 10"5 to 10"6 years; however, there are no data on the recent relative vertical crustal movements of the area. The risk of a meteorite impact is considered small as compared to that of these factors. Seismic activity and the position and extent of faults are so poorly known within the area that the faulting probability cannot be derived at present. Flooding by the sea, intrusion of magma, diapirism, metamorphism and volcanic eruptions are not considered to be risk factors for final repositories in northern Switzerland. For the shallow-type repositories, the risk of denudation and landslides have to be judged when locality-bound projects have been proposed. (Auth.)

1981-01-01

202

Geological structure characteristics of high spatial resolution remote sensing data and the discovery of geological tiny-structure in Zhuguang uranium ore concentrated area  

International Nuclear Information System (INIS)

Uranium prospecting is a complex system project. New ways and new technologies' support and service can supply more precise prospecting information. Zhuguang Uranium Ore Concentrated Area is one of the largest granite-type uranium ore concentrated areas in China. Through structural interpretating to its high spatial resolution remote sensing data, much small to tiny type structural information is interpretated which can not be interpretated on lower spatial resolution remote sensing data. This information may have some relation with uranium mineralization. The work can supply more precise structural information and some revelations for this area's mineralization regularity research. (authors)

2011-06-01

203

A study of shallow groundwater flow based on groundwater level and geological structures in the Horonobe area, Hokkaido  

Science.gov (United States)

For assessing the safety of geological disposal of high-level radioactive waste, it is important to understand groundwater flow as a driving force of mass transport. Authors have been carrying out the surface hydrological investigation in the Horonobe area, Hokkaido. Results of groundwater-level observations, and relationship between distributions of groundwater-level and geological structures suggest that constructions of underground facilities have no effect on shallow groundwater-level fluctuations, and that water infiltrate from ground surface into shallow underground in the snow covered season, and that water infiltrate into deeper underground along faults. In the future, it is necessary to be modeling and quantitatively assess the water infiltration and recharge based on directly and/or indirectly observed data of evapotranspiration and soil moisture content by weighing lysimeter and soil moisture meter, and tensiometer.

Yokota, Hideharu; Yamamoto, Yoichi; Maekawa, Keisuke

204

An engineering geological appraisal of the Chamshir dam foundation using DMR classification and kinematic analysis, southwest of Iran  

Scientific Electronic Library Online (English)

Full Text Available SciELO Colombia | Language: English Abstract in spanish Este articulo describe los resultados de una investigación de ingeniería geológica y estudios de mecánica de roca que se llevo a cabo en el lugar propuesto para le represa Chamshir. Se propone una presa de 155m de altura, de arco gravitacional en concreto de solido, la cua debe ser construida a trav [...] és del rio Zuhreh al sureste de la ciudad de Gachsaran en el suroeste de Irán. La presa y su estructura asociada son localizadas principalmente sobre la formación Mishan. El análisis consistió en la clasificación del macizo rocoso y un análisis cinemático de la fundación de la masa rocosa de la presa. Los estudios se llevaron a cabo en campo y laboratorio. Los estudios de campo incluyeron cartografía geológica, un estudio intensivo de discontinuidad, perforación de núcleo y toma de muestras para pruebas de laboratorio. La clasificación de la masa rocosa se realizo de acuerdo con la clasificación RMR y DMR para la fundación de la presa. El análisis de basamento rocoso de la presa en relación a la estabilidad usando la clasificación DMR y el análisis cinemático indico que el estribo izquierdo del basamento (área 2) es inestable para tipos de fallo planares y de cuña. Abstract in english This paper describes the results of engineering geological investigations and rock mechanics studies carried out at the proposed Chamshir dam site. It is proposed that a 155 m high solid concrete gravity-arc dam be built across the Zuhreh River to the southeast of the city of Gachsaran in south-west [...] ern Iran. The dam and its associated structures are mainly located on the Mishan formation. Analysis consisted of rock mass classification and a kinematic analysis of the dam foundation's rock masses. The studies were carried out in the field and the laboratory. The field studies included geological mapping, intensive discontinuity surveying, core drilling and sampling for laboratory testing. Rock mass classifications were made in line with RMR and DMR classification for the dam foundation. Dam foundation analysis regarding stability using DMR classification and kinematic analysis indicated that the left abutment's rock foundation (area 2) was unstable for planar, wedge and toppling failure modes.

Mehdi, Torabi Kaveh; Mojtaba, Heidari.

205

Mathematical and geological approaches to minimizing the data requirements for statistical analysis of hydraulic conductivity. Technical completion report  

Energy Technology Data Exchange (ETDEWEB)

Field scale heterogeneity has been recognized as a dominant control on solute dispersion in groundwater. Numerous random field models exist for quantifying heterogeneity and its influence on solute transport. Minimizing data requirements in model selection and subsequent parameterization will be necessary for efficient application of quantitative models in contaminated subsurface environments. In this study, a detailed quantitative sedimentological study is performed to address the issue of incorporating geologic information into the geostatistical characterization process. A field air-minipermeameter is developed for rapid in-situ measurements. The field study conducted on an outcrop of fluvial/interfluvial deposits of the Pliocene- Pleistocene Sierra Ladrones Formation in the Albuquerque Basin of central New Mexico. Architectural element analysis is adopted for mapping and analysis of depositional environment. Geostatistical analysis is performed at two scales. At the architectural element scale, geostatistical analysis of assigned mean log-permeabilities of a 0.16 km{sup 2} peninsular region indicates that the directions of maximum and minimum correlation correspond to the directions of the large-scale depositional processes. At the facies scale, permeability is found to be adequately represented as a log-normal process. Log-permeability within individual lithofacies appears uncorrelated. The overall correlation structure at the facies scale is found to be a function of the mean log-permeability and spatial distribution of the individual lithofacies. Based on field observations of abrupt spatial changes in lithology and hydrologic properties, an algorithm for simulating multi-dimensional discrete Markov random fields. Finally, a conceptual model is constructed relating the information inferred from dimensional environment analysis to the various random fields of heterogeneity.

Phillips, F.M.; Wilson, J.L.; Gutjahr, A.L.; Love, D.W.; Davis, J.M.; Lohmann, R.C.; Colarullo, S.J.; Gotkowitz, M.B.

1992-12-01

206

Radioactive and geological analysis of airborne gamma spectrometric data for locating favorable traps for uranium prospecting in the Syrian desert (Area-1), Syria  

International Nuclear Information System (INIS)

Statistical analysis has been applied to the airborne spectrometric data for the Syrian desert (Area-1), Syria in order to characterize and isolate the anomalous uranium radioactive zones. Equivalent uranium eU values vary between a minimum of 0.01 and a maximum of 32.74 ppm. Uranium prospecting methodology recently proposed is successfully applied in order to explain the origin of the radioactive anomalies related to Area-1. The dominant geological conditions effectively contributing to the uranium radioactive anomalies in the study area have been determined through the analysis of five radioactive-geological profiles. Different favorable traps have been identified and localized for uranium prospecting. Those uranium traps merit further detailed exploration for determining their uranium potential with depth. - Highlights: ? Determine the radioactive characteristics of Area-1. ? Apply a uranium prospecting methodology for guiding uranium exploration activities in Area-1. ? Explain the origin of the radioactive anomalies in Area-1. ? Relate the structural and geological conditions with the anomalous radioactive occurrences.

2012-10-01

207

Two-dimensional spectral analysis of the distribution of terrestrial gamma-ray dose rate evaluated from geological map  

International Nuclear Information System (INIS)

Terrestrial gamma-ray dose-rate maps were derived from the geological maps of Hokkaido and Central Honshu. Two-dimensional Fourier analysis of the two dose-rate maps yielded power spectra, which are nearly isotropic for the most part of the wave number space. The validity of the dose-rate distribution estimated from the geological map was discussed on the basis of magmatic differentiation, and was tested by comparing the estimated values with the observed one-dimensional data. (author)

1993-03-01

208

Structural Analysis of Biodiversity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Large, recently-available genomic databases cover a wide range of life forms, suggesting opportunity for insights into genetic structure of biodiversity. In this study we refine our recently-described technique using indicator vectors to analyze and visualize nucleotide sequences. The indicator vector approach generates correlation matrices, dubbed Klee diagrams, which represent a novel way of assembling and viewing large genomic datasets. To explore its potential utility, here we apply the i...

Sirovich, Lawrence; Stoeckle, Mark Y.; Zhang, Yu

2010-01-01

209

Geology and structure of Beta Regio, Venus: Results from Arecibo radar imaging  

Energy Technology Data Exchange (ETDEWEB)

Arecibo radar images of a portion of the equatorial region of Venus provide the first high resolution (1.5- to 2.0-km) synoptic coverage of Beta Regio. Within this area, tessera, a complex deformed terrain, is identified as a major geologic unit with the largest region corresponding to a plateau on the east flank of the highland. Three models are proposed to explain the origin and evolution of Beta Regio and are identified as Mantle Plume/Passive Crust, Mantle Plume/Active Crust, and Mantle Plume/Crustal Spreading. The Mantle Plume/Passive Crust model appears to be the most consistent with the geology in this region and suggests that a plume disrupts a preexisting region of tessera.

Senske, D.A.; Head, J.W. (Brown Univ., Providence, RI (USA)); Stofan, E.R. (Jet Propulsion Lab., Pasadena, CA (USA)); Campbell, D.B. (Cornell Univ., Ithaca, NY (USA))

1991-06-01

210

Geology and structure of Beta Regio, Venus - Results from Arecibo radar imaging  

Science.gov (United States)

Arecibo radar images of a portion of the equatorial region of Venus provide the first high resolution (1.5- to 2.0-km) synoptic coverage of Beta Regio. Within this area, tessera, a complex deformed terrain, is identified as a major geologic unit with the largest region corresponding to a plateau on the east flank of the highland. Three models are proposed to explain the origin and evolution of Beta Regio and are identified as Mantle Plume/Passive Crust, Mantle Plume/Active Crust, and Mantle Plume/Crustal Spreading. The Mantle Plume/Passive Crust model appears to be the most consistent with the geology in this region and suggests that a plume disrupts a preexisting region of tessera.

Senske, D. A.; Head, J. W.; Stofan, E. R.; Campbell, D. B.

1991-01-01

211

Study on systemizing technology on investigation and analysis of deep underground geological environment. Japanese fiscal year, 2007 (Contract research)  

International Nuclear Information System (INIS)

In this year, the following studies were carried out with the aim of systemizing the technology on the investigation and analysis to understand the deep underground geological environment in relation to the radioactive waste disposal. (1) The study on the research and development (R and D) subjects which turned to the practical investigation and analysis of deep underground geological environment. (2) The study on the advanced technical basis for the investigation and analysis of deep underground geological environment. The results obtained from the studies are as follows: Regarding (1), the specific investigations, measurements and numerical and chemical analyses were performed particularly for research subjects: 1) engineering technology and 2) geological environment. Based on the results on (1), 3) tasks of collaboration research on intermediate area between the research fields, including the safety assessment field, were selected. Also redefinition of the NFC (Near Field Concept) were discussed. Regarding (2), based on the extracted tasks of JAEA (Japan Atomic Energy Agency) research project, the study was implemented considering previous R and D results and detailed research at the research field was carried out. This study contributed to the R and D development for its practical application. Concurrently, information exchange and discussion on the 2nd phase (the Construction Phase) of the MIU (Mizunami Underground Research Laboratory) research program were often held. (author)

2009-01-01

212

Integrated geophysical survey for the geological structural and hydrogeothermal study of the North-western Gargano promontory (Southern Italy  

Directory of Open Access Journals (Sweden)

Full Text Available A multimethodological geophysical survey was performed in the north-western part of the Gargano promontory to study the geological structural setting and the underground fluid flow characteristics. The area has a complex tectonics with some magmatic outcrops and shallow low-enthalpy waters. Electrical, seismic reflection, gravimetric and magnetic surveys were carried out to reconstruct the geological structures; and in order to delineate the hydrogeothermal characteristics of the area, the self-potential survey was mainly used. Moreover magnetic and self-potential measurements were also performed in the Lesina lake. The joint three-dimensional interpretation of the geophysical data disclosed a large horst and graben structure covering a large part of the area. In the central part of the horst a large ramified volcanic body was modelled. The models show some intrusions rising from it to or near to the surface. The main structures are well deep-seated in the Crust and along them deep warm fluids rise as the SP data interpretation indicates.

D. Schiavone

1996-06-01

213

3D acoustic and microseismic location of collapse events in complex, 3D geological structures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Passive microseismics is a well developed technique that has gained importance in petroleum exploration operations as well as in geohazard assessment. When applied in complex geological environments, it requires advanced processing capabilities to ensure useful accuracy in the source location and characterization. Here we investigate a fast marching method to determine the travel-time field, rays and ray take-off angles in complex 3D media, for application with a direct-search event location ...

Klein, Emmanuelle; Lomax, Anthony; Lizeur, Armand; Klingelhoefer, Frauke; Contrucci, Isabelle; Bigarre, Pascal

2011-01-01

214

Study on the detection of geological structure in coal mine using radon-measuring method  

International Nuclear Information System (INIS)

The presented radon-measuring method is a new technique in nuclear geophysics. By using this technique, hidden fracture, hidden depressed column, empty-hollow of old coal pit and growth region of water-containing fracture or crevice in bottom of coal seam can be detected in coal mine. The test results have proved that the technique is a fast, flexible and economical radioactive geophysical method, which can play a crucial role in coal mine geology

1993-09-01

215

Safety analysis of geologic containment of long life radioactive wastes. Critical assessment of existing methods and proposition of prospective approach  

International Nuclear Information System (INIS)

Existing methods of risk analysis applied to disposal of long-lived radioactive waste in geologic formations are rewieved. A prospective analysis method for containment performances is proposed, deduced in the burial system from the combination of interaction between wastes, repository, host rock, surrounding geosphere, of natural evolution of each component of the system, sudden or chance events that could break waste containment. The method is based on the elaboration of four basic schemes graded in difficulties to facilitate comparisons

1983-01-01

216

The analysis of cracked structures  

International Nuclear Information System (INIS)

A brief review of the general problem of stable crack systems in many classes of structures, notably reinforced concrete structures, is made. Very simple methods of analysis are derived and some elaboration is described, as well as methods of optimising the calculations. Analytical methods are compared with experiments

1974-05-01

217

Study on the development of geological environmental model  

International Nuclear Information System (INIS)

The safety performance assessment was carried out in potential geological environment in the conventional research and development of geological disposal, but the importance of safety assessment based on the repository design and scenario considering the concrete geological environment will increase in the future. The research considering the link of the major three fields of geological disposal, investigation of geological environment, repository design, and safety performance assessment, is the contemporary worldwide research theme. Hence it is important to organize information flow that contains the series of information process form the data production to analysis in the three fields, and to systemize the knowledge base that unifies the information flow hierarchically. The purpose of the research is to support the development of the unified analysis system for geological disposal. The development technology for geological environmental model studied for the second progress report by JNC are organized and examined for the purpose of developing database system with considering the suitability for the deep underground research facility. The geological environmental investigation technology and building methodology for geological structure and hydro geological structure models are organized and systemized. Furthermore, the quality assurance methods in building geological environment models are examined. Information which is used and stored in the unified analysis system are examined to design database structure of the system based on the organized methodology for building geological environmental model. The graphic processing function for data stored in the unified database are examined. furthermore, future research subjects for the development of detail models for geological disposal are surveyed to organize safety performance system. (author)

2002-01-01

218

A modern regional geological analysis of Venezuela - lessons from a major new world oil province on exploration in mature areas  

Energy Technology Data Exchange (ETDEWEB)

Venezuela has produced some 44 billion bbl of oil since the early part of the century. As such, it represents one of the world's major oil producers and a mature petroleum province. However, major tracts of Venezuela's sedimentary basins remain underexplored and large discoveries are still being made in new and old reservoir systems. A regional geological analysis of Venezuela, focusing on basin evolution and sequence stratigraphy and incorporating data from the three national oil companies, is presented. The analysis presents a regionally consistent tectonostratigraphic model capable of explaining the evolution of the Mesozoic and Cenozoic basins of Venezuela and placing the major reservoir facies in their regional tectonic and sequence stratigraphic context. Four regional cross sections describe the stratigraphic and structural model. The model recognizes a Jurassic rifting event and inversion, succeeded by an Early Cretaceous passive margin. In western Venezuela, the Early Cretaceous passive subsidence is enhanced locally by extension related to the Colombian active margin. Venezuela experienced a major change in the Campanian with the initial collision of the Caribbean arc, recorded by foreland structuring and widespread stratigraphic changes. From the Campanian onward, the tectonostratigraphic evolution can be modeled in terms of a progressive southeast-directed arc-continent collision and the migration of the associated foredeep and rift basins. Within the tectonic framework, the major sequence stratigraphic units are identified and the reservoir distribution interpreted. This model provides a strong predictive tool to extrapolate reservoir systems into Venezuela's underexplored areas and to readdress its traditional areas.

Daly, M. (BP Exploracion de Venezuela, Stockley Park, Middlesex (United Kingdom)); Audemard, F. (Intevep, Miranda (Venezuela)); Valdes, G. (Petroleos de Venezuela, Caracas (Venezuela))

1993-09-01

219

Mine-Tunnel Design & Monitoring Analysis for Major Faults and Complex Geological Conditions  

Directory of Open Access Journals (Sweden)

Full Text Available Mining operations at Nanyang-Slope Coal Mine are considerably challenging. The Nanyang- Slope Coal Field has a complex tectonic structure; having major faults, large fissures and fracture- zones, and great changes in coal-seam thickness. Mine tunnel-way 301 traverses multiple complex faults with developed fractures, broken surrounding rock, and high tectonic stresses. The original rectangular-section tunnel design using anchor-bolt-mesh retainment was prone to rib-spalling, and the problem could not be controlled by use of additional encryption anchors on the tunnel sides. The mud-rock above the tunnel-ceiling is soft and argillized, which expands and softens on contact with water. This caused problems with the epoxy bonding agent failing to effectively secure bolt-anchors to the rock, resulting in anchor-bolt-mesh failure. In consideration of the complex geological conditions, a tunnel construction utilizing a curved wall arch-section and anchor-bolt- mesh-concrete spray was proposed. MJ-40 anchor-rod dynamometers were used to measure the forces in the tunnel rock-anchor bolts; and tunnel-rock deformation and surface displacement was monitored over the course of several weeks using a measuring station. Results show that the construction design effectively lowers the effects of the tectonic stresses on any one part of the tunnel, and demonstrates the safety and reliability of the tunnel-retainment and support design.

Xiang-dong ZHANG

2013-01-01

220

Structural Analysis of Combustion Models  

CERN Document Server

Using ReactionKinetics, a Mathematica based package a few dozen detailed models for combustion of hydrogen, carbon monoxide and methanol are investigated. Essential structural characteristics are pulled out, and similarities and differences of the mechanisms are highlighted. These investigations can be used before or parallel with usual numerical investigations, such as pathway analysis, sensitivity analysis, parameter estimation, or simulation.

Tóth, J; Zsély, I

2013-01-01

 
 
 
 
221

Analysis of geological samples by the micro-PIXE facility at KFUPM  

International Nuclear Information System (INIS)

The scanning microprobe facility of the 3 MV Tandetron accelerator at King Fahd University of Petroleum and Minerals (KFUPM) has been applied extensively in various fields, including geology. A number of geological investigations carried out on samples of gold-bearing rocks, phosphorite ores and volcanic sediments is reviewed. Elemental composition and distribution maps across single mineral grains, fluid inclusions, grain boundaries and matrices were measured. The microscopic data obtained are discussed to understand fundamental geological processes and ore genesis, and the provenance of economically important trace minerals contained in these samples. (author)

2005-07-01

222

Risk analysis and prospective geology in matters of underground storage of the nuclear industrial wastes  

Energy Technology Data Exchange (ETDEWEB)

The principal choice concerning the radioactive waste management is to bury it in geological formations. To substantiate the validity of this choice and to persuade the public opinion of it, we must assess the risks the future populations may run. It is, therefore, necessary to foresee the behaviour and the interactions of three types of surroundings: 1. the wastes, their packaging and wrappings; 2. the geological system of confinements; 3. the external environment. A review is given of the hypothesis and methods of forecasting used or considered in this field, with a special emphasis on the prospective geology and the probabilistic approaches. 26 references.

Marsily, G. de; Ledoux, E.; Masure, P.

1983-01-01

223

Simultaneous determination of the noble metals in geological material by radiochemical neutron-activation analysis  

International Nuclear Information System (INIS)

A simple procedure is described for determining the noble metals in geological samples rich in chromium and copper. Powdered rock samples (0.1 to 0.3 g) are irradiated in an epithermal neutron flux, under a cadmium filter, to reduce interference from 51Cr and 64Cu. After digestion with a peroxide fusion, the noble metals are separated on Srafion NMRR ion-exchange resin. Activity from chromium(VI), retained on the resin, is eliminated by reduction to chromium(III) with iron(II) sulphate before separation. The gamma-ray activity is measured with a lithium-drifted germanium detector for palladium (109Pd), platinum (199Au), iridium (194Ir) and gold (198Au). The separation yield (iridium 40%, palladium 80%, gold 90%) is determined for each sample by irradiating the resin to activate a stable noble metal carrier. Multi-element noble metal standards (0.1 to 8 ?g) are prepared from dilute solutions (100 ?l) evaporated on resin (1 ml). The practical detection limits are 2.5 ng of palladium and platinum, 0.1 ng of iridium and 0.01 ng of gold. The reliability of the procedure was confirmed by analysing sulphide standards (PTM, PTC) and standard rocks (PCC-1, DTS-1). The method has been applied to the analysis of chrome-spinels. (author)

1980-01-01

224

Microtremor Measurements in Borg El Arab city, Alexandria, Egypt: Analysis of the Correlation with local Geology  

Science.gov (United States)

Seventy-eight microtremor measurements have been done in Burg Elarab city, Alexandria, Egypt. The dataset has been processed using the horizontal to vertical spectral analysis (H/V). In most sites, H/V curve for amplitude spectra display a clear peak suggesting the presence of a soil-bedrock impedance contrast. Other sites, however, show more than one peak indicating the presence of more than one impedance contrast through sedimentary cover. Two groups of fundamental frequencies range can be discriminated; the majority group varies from 1.0 Hz to 1.36 and the minority group from 3.9 to 4.35 Hz. The presence of the two groups of frequencies range is interpreted based on the geology of study area. As the majority group is corresponding to Quaternary deposit and the minority one is overly on the Calcarinate bars. Additionally, the estimated values for the fundamental frequency from microtremor data are compared with that from data estimated from SPT-N values of a few boreholes within the area of interest where it is shown a good agreement.

Ezz Elarab, Mohamed; Mohamed, Abouela. A.; Elshat, Adel; Helal, Abdelnasser; Skokry, Mohamed

2014-05-01

225

Satellite geological and geophysical remote sensing of Iceland: Preliminary results from analysis of MSS imagery  

Science.gov (United States)

A binational, multidisciplinary research effort in Iceland is directed at an analysis of MSS imagery from ERTS-1 to study a variety of geologic, hydrologic, oceanographic, and agricultural phenomena. A preliminary evaluation of available MSS imagery of Iceland has yielded several significant results - some of which may have direct importance to the Icelandic economy. Initial findings can be summarized as follows: (1) recent lava flows can be delineated from older flows at Askja and Hekla; (2) MSS imagery from ERTS-1 and VHRR visible and infrared imagery from NOAA-2 recorded the vocanic eruption on Heimaey, Vestmann Islands; (3) coastline changes, particularly changes in the position of bars and beaches along the south coast are mappable; and (4) areas covered with new and residual snow can be mapped, and the appearance of newly fallen snow on ERTS-1, MSS band 7 appears dark where it is melting. ERTS-1 imagery provides a means of updating various types of maps of Iceland and will permit the compilation of special maps specifically aimed at those dynamic environmental phenomena which impact on the Icelandic economy.

Williams, R. S., Jr.; Boedvarsson, A.; Fridriksson, S.; Palmason, G.; Rist, S.; Sigtryggsson, H.; Thorarinsson, S.; Thorsteinsson, I.

1973-01-01

226

Pure shear deformation of square objects, and applications to geological strain analysis  

Science.gov (United States)

Geological objects that deform differently from the rock matrix, such as pebbles or other clasts, are unlikely to have been originally circular or elliptical in section, and must therefore be expected to deform heterogeneously and change shape irregularly. We investigate this process with finite element models of pure shear deformation of square objects in three orientations, square, skew and diagonal, in a matrix with different viscosity. Modelling shows that 'squares' deform irregularly, with competent objects becoming barrel shaped and 'fish mouthed' (cf. boudins), whereas incompetent objects become bone shaped or elongate lobes. The object aspect ratios ( RO) are less different from the bulk strain ratio ( RS) than for equivalent circular objects. In contrast, diagonal squares deform almost homogeneously into 'rhombs', with aspect ratios closer to those for circles. Asymmetrically oriented 'skew squares' behave intermediately, developing skew flag and hooked shapes according to competence contrasts, that might be misdiagnosed as shear criteria. All these square objects (and circles in theory), show almost linear strain paths of object versus bulk ( R-1), with slope related to viscosity ratio, object shape and orientation. Linear relationships are also found for concavity/convexity shape factors for 'squares'. The results have implications for strain analysis and competence contrasts in rocks.

Treagus, Susan H.; Lan, Labao

2000-01-01

227

Identification of significant parameters through sensitivity analysis in biosphere assessment of geological disposal  

International Nuclear Information System (INIS)

Radiation doses to human beings are calculated by modeling the radionuclide migration processes and the exposure pathways at surface environment in the biosphere assessment of geological disposal. A great effort is necessary when all of the biosphere parameters need to be collected at the actual surface environment of any proposed repository, because a great number of biosphere parameters, such as element-specific parameters, parameters specific to the surface environment or human behavior, are used in the biosphere assessment. Therefore, it is helpful to identify the biosphere parameters that should be collected at the actual environment in advance. For this purpose, the following approaches were developed in this study: (1) Extraction of the significant biosphere parameters through sensitivity analysis including estimation of the influences of variation of element-specific parameters (e.g. soil-to-plant transfer factors, concentration coefficients to animal products) on flux-to-dose conversion factors. (2) Checking the data sources of the significant biosphere parameters on the present dataset. (3) Making the priority list in future data acquisition. So far, steps (1) and (2) have been done, therefore this report summarizes the results obtained from these steps. (author)

2008-01-01

228

Processing and geologic analysis of conventional cores from well ER-20-6 No. 1, Nevada Test Site  

International Nuclear Information System (INIS)

In 1996, Well Cluster ER-20-6 was drilled on Pahute Mesa in Area 20, in the northwestern corner of the Nevada Test Site (NTS). The three wells of the cluster are located from 166 to 296 meters (m) (544 to 971 feet [ft]) southwest of the site of the underground nuclear test code-named BULLION, conducted in 1990 in Emplacement Hole U-20bd. The well cluster was planned to be the site of a forced-gradient experiment designed to investigate radionuclide transport in groundwater. To obtain additional information on the occurrence of radionuclides, nature of fractures, and lithology, a portion of Well ER-20-6 No. 1, the hole closest to the explosion cavity, was cored for later analysis. Bechtel Nevada (BN) geologists originally prepared the geologic interpretation of the Well Cluster ER-20-6 site and documented the geology of each well in the cluster. However, the cores from Well ER-20-6 No. 1 were not accessible at the time of that work. As the forced-gradient experiment and other radio nuclide migration studies associated with the well cluster progressed, it was deemed appropriate to open the cores, describe the geology, and re-package the core for long-term air-tight storage. This report documents and describes the processing, geologic analysis, and preservation of the conventional cores from Well ER20-6 No. 1

1997-01-01

229

Processing and geologic analysis of conventional cores from well ER-20-6 No. 1, Nevada Test Site  

Energy Technology Data Exchange (ETDEWEB)

In 1996, Well Cluster ER-20-6 was drilled on Pahute Mesa in Area 20, in the northwestern corner of the Nevada Test Site (NTS). The three wells of the cluster are located from 166 to 296 meters (m) (544 to 971 feet [ft]) southwest of the site of the underground nuclear test code-named BULLION, conducted in 1990 in Emplacement Hole U-20bd. The well cluster was planned to be the site of a forced-gradient experiment designed to investigate radionuclide transport in groundwater. To obtain additional information on the occurrence of radionuclides, nature of fractures, and lithology, a portion of Well ER-20-6 No. 1, the hole closest to the explosion cavity, was cored for later analysis. Bechtel Nevada (BN) geologists originally prepared the geologic interpretation of the Well Cluster ER-20-6 site and documented the geology of each well in the cluster. However, the cores from Well ER-20-6 No. 1 were not accessible at the time of that work. As the forced-gradient experiment and other radio nuclide migration studies associated with the well cluster progressed, it was deemed appropriate to open the cores, describe the geology, and re-package the core for long-term air-tight storage. This report documents and describes the processing, geologic analysis, and preservation of the conventional cores from Well ER20-6 No. 1.

Prothro, L.B., Townsend, M.J.; Drellack, S.L. Jr. [and others

1997-09-01

230

A simple analysis of potential radiological exposure from geological disposal of Canada's nuclear fuel waste  

International Nuclear Information System (INIS)

AECL has submitted an environmental impact statement (EIS) describing its proposal for geological disposal of Canada's nuclear fuel waste. The EIS presents a detailed analysis of potential radiation exposure of an individual of a critical group of people in a hypothetical case. In this report, we provide a simpler analysis of potential exposure in the hope that the inherent safety of the disposal will be more readily evident from the analysis. A key to the simplification is the elimination from the analysis of the complex transport processes through disposal vault sealing materials and the geosphere. We also eliminate the relatively complex function describing the failure of the thin-walled titanium containers in the case study presented in the EIS. We therefore conceptually replace the thin-walled titanium containers with thicker-walled copper containers, are expected to remain intact much longer than 10,000 a, the period for which a quantitative estimate of individual exposure is made. However, about 1 in 5000 containers could have small defects that were undetected during manufacture. Our analysis applies only to the case of an undisrupted vault. We assume that the vault and geosphere barriers remain intact and prevent immobile radionuclides from reaching the biosphere. However, we also assume that the three most important mobile radionuclides can escape through an undected manufacturing defect in the container wall, and that the flux of these radionuclides is diluted by well water being used by people. We have focused on 129I, 36Cl and 14C, because these nuclides are found to be the dominant source of exposure in more complex analyses. If a single container released radionuclides to well water, we estimate dose rates of about 1 ?Sv.a-1 from drinking water and 29 ?Sv.a-1, which the Atomic Eenrgy Control Board has adopted as a de minimis dose rate, i.e., a dose rate so small as to not warrant institutional control. We believe that the dose rates are greatly overestimated because of the many conservative assumptions and simplifications used in the analysis. (author) 51 refs., 4 tabs., 2 figs

1996-01-01

231

Platinum stable isotope analysis of geological standard reference materials by double-spike MC-ICPMS  

DEFF Research Database (Denmark)

We report a method for the chemical purification of Pt from geological materials by ion-exchange chromatography for subsequent Pt stable isotope analysis by multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS) using a Pt-Pt double-spike to correct for instrumental mass bias. Double-spiking of samples was carried out prior to digestion and chemical separation to correct for any mass-dependent fractionation that may occur due to incomplete recovery of Pt. Samples were digested using a NiS fire assay method, which pre-concentrates Pt into a metallic bead that is readily dissolved in acid in preparation for anion-exchange chemistry. Pt was recovered from anion-exchange resin in concentrated HNO acid after elution of matrix elements, including the other platinum group elements (PGE), in dilute HCl and HNO acids. The separation method has been calibrated using a precious metal standard solution doped with a range of synthetic matrices and results in Pt yields of �90% with purity of �95%. Usingthis chemical separation technique, we have separated Pt from 11 international geological standard reference materials comprising of PGE ores, mantle rocks, igneous rocks and one sample from the Cretaceous-Paleogene boundary layer. Pt concentrations in these samples range from ca. 5ngg to 4μgg. This analytical method has been shown to have an external reproducibility on δPt (permil difference in the Pt/Pt ratio from the IRMM-010 standard) of ±0.040 (2sd) on Pt solution standards (Creech et al., 2013, J. Anal. At. Spectrom. 28, 853-865). The reproducibility in natural samples is evaluated by processing multiple replicates of four standard reference materials, and is conservatively taken to be ca. ±0.088 (2sd). Pt stable isotope data for the full set of reference materials have a range of δPt values with offsets of up to 0.4� from the IRMM-010 standard, which are readily resolved with this technique. These results demonstrate the potential of the Pt isotope system as a tracer in geochemical systems. © 2013 Elsevier B.V.

Creech, J.B.; Baker, J.A.

2014-01-01

232

Geological characteristicsand analysis of the zinc-fluorite ore deposit prospecting in Naoyangping-Damogou mine at Pingli County, southeastern Shaanxi, China .  

Directory of Open Access Journals (Sweden)

Full Text Available The Naoyangping-Damogou zinc-fluoritemining area is located in the Caledonian fold belt of the east wing of Pingli Anticlinorium in the North Dabashan Mountains. The region is located within the Qinling fold belt, which was formed during intense activity in the late Paleozoic.The belt has a north-north-west orientation and consists of a system of anticlines, synclines, thrust faults, shear strike slip faults and ductile shear zone. Two dominant fault structures and other small faults sets appear closely associated with zinc-fluorite mineralization within the region, with several depositscommonly occurring along these faults.Based on analysis of geological background and geological characteristics of the zinc-fluorite mineralization in the region, the ore-controlling factors and the genesis of the zinc-fluorite ore deposit have indicated that the geological conditions for prospecting a large-scale deposit are existing in the Naoyangping-Damogou mining area. It also establish the metallogenic favorable locations prediction of the zinc-fluorite deposit in this area.

MoussoundaKounga Claude

2013-05-01

233

Study on systematizing technology on the investigation and analysis of deep underground geological environment. Japanese Fiscal Year, 2006 (Contract research)  

International Nuclear Information System (INIS)

In this year the following studies were carried out with the aim of systematizing the technology on the investigation and analysis to understand deep underground geological environment in relation to the radioactive waste disposal. (1) The study on the research and development (R and D) subjects which turned to the practical investigation and analysis of deep underground geological environment. (2) The study on the advanced technical basis for the investigation and analysis of deep underground geological environment. From the studies, the following results were obtained. Regarding (1), the concrete investigation, measurements, numerical analyses and chemical analyses were performed with respect to research subjects 1) the repository design and engineering technology, 2) the safety assessment and 3) the geological environment. And from the viewpoint of radioactive waste disposal, specific subjects were selected. More over the discussion on the collaborative research program for niche area between each fields 1), 2) and 3) was given. One of the important subjects was 'redefinition of the near field concept (NFC)'. Consequently the specific study on the NFC redefinition was carried out as well as the element research on niche area between the research fields. On 2), the evaluation of research results and its practical use for the R and D activities were considered based on the fundamental and elemental technology which the study group performed. The practical research programs to characterize the geological environment and engineering technologies, which were applied to the Tono Geoscience Center, were also discussed. Concurrently opportunities to exchange information and opinions on the 2nd phase (the Shaft Construction Phase) of the MIU (Mizunami Underground Research Laboratory) research program were often opened up in the JAEA. (author)

2008-01-01

234

Structural geology and sedimentology of the Heiligenhafen till section, Northern Germany  

Science.gov (United States)

Three Pleistocene tills can be distinguished in a coastal cliff section near Heiligenhafen, northern Germany, on the basis of structural and petrographic characteristics. The Lower and Middle Tills had previously been ascribed to the Saalian, and the Upper Till to the Late Weichselian. The former two tills are folded, and unconformably overlain by the Upper Till. In this paper, structural and sedimentological observations are used to investigate whether the Lower and Middle Tills belong to one glacial advance, or two separate (Saalian) advances, as was suggested in earlier studies based on fine gravel stratigraphy. From the contact with local rocks to the top of the MT there is a steady increase in allochtonous components (Scandinavian rocks) and decrease in parautochtonous (chalk and flint) and autochtonous components (local Eocene siltstone and meltwater sediments). This is paralleled by a trend towards increasing deformation (finite strain) from the bedrock to the top of the section. The most obvious aspect of this latter trend is the massive appearance of the MT which can be interpreted as the result of homogenization by repeated folding and attenuation of sediment lenses which have been incorporated into the till. This interpretation is supported by macroscopic and microscopic observations of structures in both tills. The structural analysis of the tills is based on the marked contrast in symmetry between sections parallel and perpendicular to the shear direction. Structures on all scales in the LT as well as in the MT indicate E-W (dextral) shearing, except in the western part of the section, where this is overprinted by W-E (sinistral) shearing. The sediment inclusions in the chalk-rich LT are mainly fragments of one or more strongly extended glaciofluvial delta bodies with a depositional direction towards WSW. Locally these delta sediments rest on Eocene siltstone and contain numerous angular fragments of this local bedrock. Boudins and lenses of sorted sediments are incorporated into the till and occur as "islands of low strain" in a high strain homogeneous matrix. It is concluded that the LT and MT do not belong to two stratigraphically separate Saalian advances. The section is alternatively interpreted as one subglacial shear zone (deformation till) with upward increasing strain and allochtonous component content. It probably formed during the Younger Saalian (Warthe) westward advance from the Baltic region. Folding of the two diamicts occurred due to lateral compression near the Late Saalian ice margin. The section was finally overridden by the Late Weichselian Young Baltic advance, eroding the folded LT and MT and depositing the UT.

Van der Wateren, Frederik M.

1999-12-01

235

Modified chromatographic separation scheme for Sr and Nd isotope analysis in geological silicate samples  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A novel chromatographic separation technique for Sr and Nd separation from geological silicate samples was established and successfully tested for routine use in Laboratory of Radiogenic Isotopes of the Czech Geological Survey. The separation scheme is based on combination and modification of methods published in papers by Christian Pin and his co-workers. This triple column arrangement enables the isolation of pure Sr and Nd fractions (also Sm if required) from bulk-rock solution in a single...

2008-01-01

236

Neutronic and thermal hydraulic analysis of the Geological Survey TRIGA Reactor  

Science.gov (United States)

The United States Geological Survey TRIGA Reactor (GSTR) is a 1 MW reactor located in Lakewood, Colorado. In support of the GSTR's relicensing efforts, this project developed and validated a Monte Carlo N-Particle Version 5 (MCNP5) model of the GSTR reactor. The model provided estimates of the excess reactivity, power distribution and the fuel temperature, water temperature, void, and power reactivity coefficients for the current and limiting core. The MCNP5 model predicts a limiting core excess reactivity of 6.48 with a peak rod power of 22.2 kW. The fuel and void reactivity coefficients for the limiting core are strongly negative, and the core water reactivity coefficient is slightly positive, consistent with other TRIGA analyses. The average fuel temperature reactivity coefficient of the full power limiting core is -0.0135 /K while the average core void coefficient is -0.069 /K from 0-20 % void. The core water temperature reactivity coefficient is +0.012 /K. Following the neutronics analysis, the project developed RELAP5 and PARET-ANL models of the GSTR hot-rod fuel channel under steady state and transient conditions. The GSTR limiting core, determined as part of this analysis, provides a worst case operating scenario for the reactor. During steady state operations, the hot rod of the limiting core has a peak fuel temperature of 829 K and a minimum departure from nucleate boiling ratio of 2.16. After a $3.00 pulse reactivity insertion the fuel reaches a peak temperature is 1070 K. Examining the model results several seconds after a pulse reveals flow instabilities that result from weaknesses in the current two-channel model.

Shugart, Nicolas

237

Geological structure of oil and gas provinces in East Siberia from geophysical data. Geologicheskoye stroyeniye neftegazonosynkh provintsiy vostochnoy Sibiri po geofizicheskim dannym  

Energy Technology Data Exchange (ETDEWEB)

Material is generalized and analyzed for the use of geophysical methods (electrical exploration, seismic exploration etc.) for studying the geological structure of oil and gas provinces in East Siberia. An examination is made of the structure of the consolidated earth's crust, structure of the surface of foundation and sedimentary mantle, and main stages of its formation. Recommendations are made for the direction of geophysical work in order to prospect for oil and gas. It is designed for geophysicists and geologists involved in the questions of the geological structure of east Siberia and prospecting for oil and gas in this region.

Savinskiy, K.A.; Lopatin, S.S.; Volkhonin, V.S.; Yakovlev, I.A.; Zolotov, A.N.

1983-01-01

238

Geologic Mapping Exercise  

Science.gov (United States)

This exercise is designed to simulate how a basic geological investigation of a site takes place. A basic geological investigation includes familiarizing yourself with the unconsolidated sediments, rocks, structural geology, and groundwater present at your site. As part of this exercise you will have to properly identify a variety of rock types and sediments, create maps that represent data you collected at each location, and complete a basic report of your findings (optional). Once completed, this exercise should give students a basic understanding of how the various concepts used throughout the semester are applied in the real world in the form of a geological investigation.

Smith, Andrew

239

Marine Geological Discoveries  

Science.gov (United States)

This site by a Norwegian researcher features descriptions of marine geological formations: pockmarks, mud volcanoes, deep-water coral reefs, and gas hydrates. Using ROV technology, he has taken photos of these deep seafloor features, and compares them to geological structures seen on land, and even on the moon.

240

Preliminary analysis on the disposal of high-level radioactive wastes in geological formations of Sao Paulo state, Brazil  

International Nuclear Information System (INIS)

Several studies show that deep geological formations are the most promising solution - technical and economical - for the safe disposal of the high-level radioactive wastes produced by the nuclear industry. In order to obtain the necessary information to assess on the use of geological sites in Brazil - for the disposal of high-level radioactive waste generated by the brazilian nuclear industry - a careful survey on the basalt and granite rocks of Sao Paulo State was made. The data obtained were evaluated according to guidelines established by the International Atomic Energy Agency. The favourable and unfavourable characteristics of the basalts, granites and their respective occurrence areas in the Sao Paulo state territory - as potential waste disposal sites - were analysed. This preliminary and regional characterization is not a conclusive study whether these two rocks types are definitively the most suitable geological formations for use as nuclear waste repository or not. It is the subsidy for a more detailed analysis. Other factors such as social, political and economical aspects, ecological effects, engineering geology, heat generation rate of the waste, type of radiation emitted and corrosive nature of the waste must also be taken into account. (author)

1981-01-01

 
 
 
 
241

Methodology for the biosphere analysis in the evaluation of deep geological repositories for high radioactive waste  

International Nuclear Information System (INIS)

This report summarizes the work done and the achievements reached within the R and D Project that IMA/CIEMAT has had with ENRESA during 1993-1995. The overal R and D Project has a wide radiological protection context, but the work reported here relates only to the development of a Methodology for considering the Biosphere sub-system in the assessments of deep geological repositories for high radioactive wastes (HLW). The main areas concerned within the Methodology have to do with Biosphere structure and morphology in the long-term relevant to deep disposal of HLW: in the contexts of the assessment of these systems, and appropiate modelling of the behaviour of radionuclides released to the biosphere system and with the associated human exposure. This document first provides a review of the past and present international and national concerns about the biosphere modelling and its importance in relation to the definition of safety criteria. A joint ENRESA/ANDRA/IPSN/CIEMAT study about the definition and proactical descriptions of the biosphere systems under different climatic states is then summarized. The Methodology developed by IMA/CIEMAT is outlined with an illustration of the way it works. Different steps and procedures are included for a better proactical understanding of the software tools developed within the project to support the application of the Methologoy. This Methodology is widely based on an international working group on Reference Biospheres part national work for ENRESA has been supported under a collaborative agreement with QuantiSci Ltd. Specific software development have been carried out in collaboration with QuantiSci Ltd and with the Polytechnical University of Madrid. Most of the items included within the Methodology and moreover the Methodology as a whole, follows a continuos progressive development. It is increasinaly recognized that assessment capabilities, establisment of safety criteria and regulatory framework and the steps in a regulatory development programme should all proceed in parallel. (Author)

1997-01-01

242

Structural analysis of NPP components and structures  

International Nuclear Information System (INIS)

Capabilities for effective structural integrity assessment have been created and extended in several important cases. In the paper presented applications deal with pressurised thermal shock loading, PTS, and severe dynamic loading cases of containment, reinforced concrete structures and piping components. Hydrogen combustion within the containment is considered in some severe accident scenarios. Can a steel containment withstand the postulated hydrogen detonation loads and still maintain its integrity? This is the topic of Chapter 2. The following Chapter 3 deals with a reinforced concrete floor subjected to jet impingement caused by a postulated rupture of a near-by high-energy pipe and Chapter 4 deals with dynamic loading resistance of the pipe lines under postulated pressure transients due to water hammer. The reliability of the structural integrity analysing methods and capabilities which have been developed for application in NPP component assessment, shall be evaluated and verified. The resources available within the RATU2 programme alone cannot allow performing of the large scale experiments needed for that purpose. Thus, the verification of the PTS analysis capabilities has been conducted by participation in international co-operative programmes. Participation to the European Network for Evaluating Steel Components (NESC) is the topic of a parallel paper in this symposium. The results obtained in two other international programmes are summarised in Chapters 5 and 6 of this paper, where PTS tests with a model vessel and benchmark assessment of a RPV nozzle integrity are described. (author)

1998-12-07

243

A life cycle cost analysis framework for geologic storage of hydrogen : a user's tool.  

Energy Technology Data Exchange (ETDEWEB)

The U.S. Department of Energy (DOE) has an interest in large scale hydrogen geostorage, which could offer substantial buffer capacity to meet possible disruptions in supply or changing seasonal demands. The geostorage site options being considered are salt caverns, depleted oil/gas reservoirs, aquifers and hard rock caverns. The DOE has an interest in assessing the geological, geomechanical and economic viability for these types of geologic hydrogen storage options. This study has developed an economic analysis methodology and subsequent spreadsheet analysis to address costs entailed in developing and operating an underground geologic storage facility. This year the tool was updated specifically to (1) incorporate more site-specific model input assumptions for the wells and storage site modules, (2) develop a version that matches the general format of the HDSAM model developed and maintained by Argonne National Laboratory, and (3) incorporate specific demand scenarios illustrating the model's capability. Four general types of underground storage were analyzed: salt caverns, depleted oil/gas reservoirs, aquifers, and hard rock caverns/other custom sites. Due to the substantial lessons learned from the geological storage of natural gas already employed, these options present a potentially sizable storage option. Understanding and including these various geologic storage types in the analysis physical and economic framework will help identify what geologic option would be best suited for the storage of hydrogen. It is important to note, however, that existing natural gas options may not translate to a hydrogen system where substantial engineering obstacles may be encountered. There are only three locations worldwide that currently store hydrogen underground and they are all in salt caverns. Two locations are in the U.S. (Texas), and are managed by ConocoPhillips and Praxair (Leighty, 2007). The third is in Teeside, U.K., managed by Sabic Petrochemicals (Crotogino et al., 2008; Panfilov et al., 2006). These existing H{sub 2} facilities are quite small by natural gas storage standards. The second stage of the analysis involved providing ANL with estimated geostorage costs of hydrogen within salt caverns for various market penetrations for four representative cities (Houston, Detroit, Pittsburgh and Los Angeles). Using these demand levels, the scale and cost of hydrogen storage necessary to meet 10%, 25% and 100% of vehicle summer demands was calculated.

Kobos, Peter Holmes; Lord, Anna Snider; Borns, David James; Klise, Geoffrey T.

2011-09-01

244

Elemental analysis of geological samples by means of spectrometry of proton-induced gamma- and X-rays  

International Nuclear Information System (INIS)

The application of spectrometry of ion-induced X-rays and gamma rays (PIXE and PIGE), and backscattered particles (RBS) for elemental analysis of geological samples is described. The sample preparation and the experimental arrangement are outlined, also the evaluation of concentrations and the detection limits. As an example for the application of these methods, the results are quoted of a measurement of the lateral distributions of elements across a ferromanganese encrustation from the Baltic Sea. (author)

1990-01-01

245

High resolution seismic stratigraphic analysis: An integrated approach to the subsurface geology of the SE Persian Gulf  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Papers included in this dissertation: Paper 1: Farzadi, P. 2006a. The development of Middle Cretaceous carbonate platforms, Persian Gulf, Iran: Constraints from seismic stratigraphy, well and biostratigraphy. Petroleum Geoscience, 12, 59-68. Paper 2: Farzadi, P. 2006b. Seismic facies analysis based on 3D multi-attribute volume classification, Dariyan Formation, SE Persian Gulf. Journal of Petroleum Geology,29/2, 159-174. Paper 3: Farzadi, P. & Hesthammer, J. (Submitted 2006)...

Farzadi, Pourdad

2006-01-01

246

3D imaging of geological structures by R-VSP utilizing vibrations caused by shaft excavations at the Mizunami Underground Research Laboratory in Japan  

Science.gov (United States)

Japan Atomic Energy Agency is now conducting the Mizunami Underground Research Laboratory (MIU) project. The MIU consists of two shafts (main shaft: 6.5m, ventilation shaft: 4.5m diameter) and horizontal research galleries, in sedimentary and granitic rocks at Mizunami City, Central Japan. The MIU project is a broad scientific study of the deep geological environment providing the basis for research and development for geological disposal of high level radioactive waste. One of the main goals is to establish techniques for investigation, analysis and assessment of the deep geological environment in fractured crystalline rock. As a part of the MIU project, we carried out the Reverse-Vertical Seismic Profile (R-VSP) using vibrations from the blasting for the shaft excavations and drilling of boreholes in the horizontal research galleries and examined the applicability of this method to imaging of geological structures around underground facilities, such as the unconformity between the sedimentary rocks and the basal granite, and faults and fracture zones in the granite. R-VSP method is a seismic method utilizing the receiver arrays on surface and seismic sources underground (e.g. in boreholes). This method is advantageous in that planning of 3-dimensional surveys is easy compared with reflection seismic surveying and conventional VSP because seismic source arrays that are major constraint for conducting surveys on surface are unnecessary. The receiver arrays consist of six radial lines on surface with a central focus on the main shaft. Seven blast rounds for the main shaft excavation from GL-52.8m to GL-250m and the borehole drilling in the GL-200m horizontal research gallery were observed. Three types of data processing, conventional VSP data processing (VSP-CDP transform and VSP migration), Reflection data processing utilizing Seismic interferometry method (“Seismic interferometry”) and Reflection mapping utilizing Image Point transform method (“IP transform”), were performed to obtain reflection images from heterogeneous geological structure. As the results, the reflective events that seemed to correspond with sedimentary layers, the unconformity between sedimentary rocks and granite, and fracture zones in granite could be detected by reflection profiles using “conventional VSP data processing” and “Seismic interferometry”. However, it is difficult to identify the faults around the MIU because they are generally at a high-angle. “IP transform” is one type of Radon transform which change common shot gather to IP domain. Image Points are defined through geometries of sources and reflectors. Reflection signals in time domain can be accumulated and enhanced in IP domain by “IP transform” on the condition of the right angle to a fault. So, by a search of the direction that reflection signals are enhanced using “IP transform”, the locations of faults can be inferred. By this method, the distribution of faults that correspond with faults in the current geological model constructed from investigation data in the MIU project could be detected.

Matsuoka, T.; Hodotsuka, Y.; Ishigaki, K.; Lee, C.

2009-12-01

247

Deep structure of the Danilovskii graben in Western Siberia: A geological interpretation of the density models  

Science.gov (United States)

Gravimetric modeling is conducted for the Triassic Danilovskii graben. The model region may be an etalon for all of Western Siberia because of the nearby Danilovskoe and Severo-Danilovskoe oil deposits and representative geophysical and drilling data. The correctness of the gravitation model was checked by the magnetic model of the graben constructed on the basis of the gravitation model; the difference between the measured and model anomalous magnetic fields is less than 5%. The density models of the graben have shown that rocks with a significantly excess density of 0.3 g/cm3 and higher, which probably represent the Triassic mantle diapir, should be located under the axial part of the graben. Rhyolites, forming small irregular bodies on the geological map of the basement, are combined into the common lopolith-like subvolcanic body at depths. The graben is flattened toward the north, which explains the previously unclear presence of Carboniferous shales among the Triassic rocks.

Ivanov, K. S.; Kostrov, N. P.; Manushko, E. A.

2013-08-01

248

Evaluation of LANDSAT-2 (ERTS) images applied to geologic structures and mineral resources of South America  

Science.gov (United States)

The author has identified the following significant results. Work with the Image 100 clearly demonstrates that radiance values of LANDSAT data can be used for correlation of geologic formations across international boundaries. The Totora Formation of the Corocoro Group of Tertiary age was traced from known outcrops near Tiahuanaco, Bolivia, along the south side of Lake Titicaca westward into Peru where the same rocks are considered to be Cretaceous in age. This inconsistency suggests: (1) that a review of this formation is needed by joint geological surveys of both countries to determine similarities, differences, and the true age; (2) that recognition of the extension of the copper-bearing Totora Formation of Bolivia into Peru may provide Peru with a new target for exploration. Equal radiance maps made by use of the Image 100 system show as many as eight different units within salar deposits (salt flats) of the Bolivian Altiplano. Standard film processed images show them as nearly uniform areas of white because of lack of dynamic range in film products. The Image 100 system, therefore, appears to be of great assistance in subdividing the salt flats on the basis of moisture distribution, surface roughness, and distribution of windblown materials. Field work is needed to determine these relationships to mineral composition and distribution. Images representing seasonal changes should also improve the accuracy of such maps. Radiance values of alteration zones related to the occurrence of porphyry copper ores were measured at the San Juan del Abra deposit of northern Chile using the Image 100 system. The extent to which these same values may be used to detect similar alteration zones in other areas has not yet been tested.

Carter, W. D. (principal investigator)

1975-01-01

249

Sodium loop framework structural analysis  

Energy Technology Data Exchange (ETDEWEB)

This document provides the structural analysis of the Sodium Loop framework in a drop condition. The drop is similar to the US Department of Transportation non-bulk, performance-oriented packaging (Packaging Group I) drop test. The drop height evaluated for the Sodium Loop framework is 5.9 ft.

Nguyen, P.M.

1995-06-06

250

Sodium loop framework structural analysis  

International Nuclear Information System (INIS)

This document provides the structural analysis of the Sodium Loop framework in a drop condition. The drop is similar to the US Department of Transportation non-bulk, performance-oriented packaging (Packaging Group I) drop test. The drop height evaluated for the Sodium Loop framework is 5.9 ft

1995-01-01

251

High Resolution/High Fidelity Seismic Imaging and Parameter Estimation for Geological Structure and Material Characterization  

Energy Technology Data Exchange (ETDEWEB)

In this project, we develop new theories and methods for multi-domain one-way wave-equation based propagators, and apply these techniques to seismic modeling, seismic imaging, seismic illumination and model parameter estimation in 3D complex environments. The major progress of this project includes: (1) The development of the dual-domain wave propagators. We continue to improve the one-way wave-equation based propagators. Our target is making propagators capable of handling more realistic velocity models. A wide-angle propagator for transversely isotropic media with vertically symmetric axis (VTI) has been developed for P-wave modeling and imaging. The resulting propagator is accurate for large velocity perturbations and wide propagation angles. The thin-slab propagator for one-way elastic-wave propagation is further improved. With the introduction of complex velocities, the quality factors Qp and Qs have been incorporated into the thin-slab propagator. The resulting viscoelastic thin-slab propagator can handle elastic-wave propagation in models with intrinsic attenuations. We apply this method to complex models for AVO modeling, random media characterization and frequency-dependent reflectivity simulation. (2) Exploring the Information in the Local Angle Domain. Traditionally, the local angle information can only be extracted using the ray-based method. We develop a wave-equation based technique to process the local angle domain information. The approach can avoid the singularity problem usually linked to the high-frequency asymptotic method. We successfully apply this technique to seismic illumination and the resulting method provides a practical tool for three-dimensional full-volume illumination analysis in complex structures. The directional illumination also provides information for angle-domain imaging corrections. (3) Elastic-Wave Imaging. We develop a multicomponent elastic migration method. The application of the multicomponent one-way elastic propagator and the wide-angle correction preserve more dynamic information carried by the elastic waves. The vector imaging condition solves the polarization problem of converted wave imaging. Both P-P and P-S images can be calculated. We also use converted waves to improve the image of steep sub-salt structures. The synthetic data for the SEG/EAGE salt model are migrated with a generalized screen algorithm and for the converted PSS-wave path. All the sub-salt faults are properly imaged.

Ru-Shan Wu, Xiao-Bi Xie, Thorne Lay

2005-06-06

252

Structure and geological evolution of the bedrock at southern Satakunta, SW Finland  

Energy Technology Data Exchange (ETDEWEB)

The southern Satakunta area lies on the west coast of Finland, mainly covering the mainland (with main towns Pori and Rauma), but also including the coastal archipelago and part of the Bothnian Sea. Near the centre of the area lies the island of Olkiluoto, on which Finland's site for a deep repository for spent nuclear fuel is located. The purpose of the present report is to compile and interpret all available geological and geophysical data relevant to understanding the regional geological setting of the Olkiluoto site. The area described is covered by four 1:100 000 scale geological map sheets, published by the Geological Survey of Finland, which, together with low-altitude aeromagnetic maps, provide the basis for a new 1:250 000 geological map compilation. This shows that the bedrock of southern Satakunta can be subdivided into three main zones: a pelitic migmatite belt in the southwest, a central, NW-SE trending area of sandstone, and a psammitic migmatite belt in the northeast. The migmatite belts formed during the Svecofennian orogeny, 1900-1800 Ma ago (Palaeoproterozoic). The sandstone area is the remnant of an alluvial basin, preserved now in a NW-SE trending graben, bounded on both sides by normal fault zones. The sandstones are thought to be at least 1400-1300 Ma old (Mesoproterozoic), and they are cut by Postjotnian olivine diabase dykes, 1270-1250 Ma in age. The Svecofennian migmatite belts show a complex history of formation, with various phases of anatexis/metamorphism, deformation and intrusion. In the pelitic migmatite belt, in which the Olkiluoto site is situated, four phases of ductile deformation (D-D4) and two phases of regional highT/lowP metamorphism and migmatite formation can be recognised, together with synorogenic (tonalite, granodiotite) and late orogenic ( potassium granite) intrusions. Subsequently, this very heterogeneous complex was intruded by anorogenic rapakivi granites, with ages 1580-1550 Ma. One pluton, the Eurajoki stock, approaches to within 5 km of the Olkiluoto site. The results of gravimetric surveys have indicated that the margin of the Eurajoki stock slopes westward underneath the site, but to depths in excess of 3000 m. Plate tectonic reconstructions of the Precambrian of Finland, partly based on the results of major deep seismic sounding experiments, such as the international GGT/SVEKA project (along a NE-SW transect through the Satakunta area), indicate the pelitic and psammitic migmatite belts in Satakunta represent parts of the early Proterozoic Southern Finland and Central Finland continental arcs, respectively. Collision of these arc complexes took place 1890 - 1880 Ma ago, when the rocks were deformed and metamorphosed for the first time. The highT/lowP metamorphism was caused by mafic underplating, which led to a strong increase in temperature, and recrystallisation and partial remelting of the rocks in the upper crust. The collision of the arc complexes is characterised by an intense magmatic activity, which appears as synorogenic granitoids. In the next stage, 1860 - 1810 Ma ago, mafic underplating caused a second high-temperature metamorphic event and partial melting of the sedimentary rocks in southern Finland, producing the late-orogenic potassium. granites, dated at 1840 - 1830 Ma. The Subjotnian rapakivi granites associated with mafic rocks, the Jotnian Satakunta sandstone formation and the Postjotnian diabase dykes and sills represent the cratonisation stages of the Svecofennides. Rapakivi granites and related mafic rocks were generated in an anorogenic extensional regime by partial melting of the upper mantle and lower crust. The Jotnian Satakunta sandstone is a fluvial sediment formation deposited in a deltaic environment. The development of the graben or rift valley, where the sandstone was deposited, may have begun already during the Subjotnian, ca. 1650 Ma ago. The olivine diabase dykes represent the feeding channels of Postjotnian flood basalts. However, no such volcanic rocks have preserved in the area. The intrusion of the diabase dykes caused the

Paulamaeki, S.; Paananen, M.; Elo, S. [Geological Survey of Finland (Finland)

2002-02-01

253

Structure and geological evolution of the bedrock at southern Satakunta, SW Finland  

International Nuclear Information System (INIS)

The southern Satakunta area lies on the west coast of Finland, mainly covering the mainland (with main towns Pori and Rauma), but also including the coastal archipelago and part of the Bothnian Sea. Near the centre of the area lies the island of Olkiluoto, on which Finland's site for a deep repository for spent nuclear fuel is located. The purpose of the present report is to compile and interpret all available geological and geophysical data relevant to understanding the regional geological setting of the Olkiluoto site. The area described is covered by four 1:100 000 scale geological map sheets, published by the Geological Survey of Finland, which, together with low-altitude aeromagnetic maps, provide the basis for a new 1:250 000 geological map compilation. This shows that the bedrock of southern Satakunta can be subdivided into three main zones: a pelitic migmatite belt in the southwest, a central, NW-SE trending area of sandstone, and a psammitic migmatite belt in the northeast. The migmatite belts formed during the Svecofennian orogeny, 1900-1800 Ma ago (Palaeoproterozoic). The sandstone area is the remnant of an alluvial basin, preserved now in a NW-SE trending graben, bounded on both sides by normal fault zones. The sandstones are thought to be at least 1400-1300 Ma old (Mesoproterozoic), and they are cut by Postjotnian olivine diabase dykes, 1270-1250 Ma in age. The Svecofennian migmatite belts show a complex history of formation, with various phases of anatexis/metamorphism, deformation and intrusion. In the pelitic migmatite belt, in which the Olkiluoto site is situated, four phases of ductile deformation (D-D4) and two phases of regional highT/lowP metamorphism and migmatite formation can be recognised, together with synorogenic (tonalite, granodiotite) and late orogenic ( potassium granite) intrusions. Subsequently, this very heterogeneous complex was intruded by anorogenic rapakivi granites, with ages 1580-1550 Ma. One pluton, the Eurajoki stock, approaches to within 5 km of the Olkiluoto site. The results of gravimetric surveys have indicated that the margin of the Eurajoki stock slopes westward underneath the site, but to depths in excess of 3000 m. Plate tectonic reconstructions of the Precambrian of Finland, partly based on the results of major deep seismic sounding experiments, such as the international GGT/SVEKA project (along a NE-SW transect through the Satakunta area), indicate the pelitic and psammitic migmatite belts in Satakunta represent parts of the early Proterozoic Southern Finland and Central Finland continental arcs, respectively. Collision of these arc complexes took place 1890 - 1880 Ma ago, when the rocks were deformed and metamorphosed for the first time. The highT/lowP metamorphism was caused by mafic underplating, which led to a strong increase in temperature, and recrystallisation and partial remelting of the rocks in the upper crust. The collision of the arc complexes is characterised by an intense magmatic activity, which appears as synorogenic granitoids. In the next stage, 1860 - 1810 Ma ago, mafic underplating caused a second high-temperature metamorphic event and partial melting of the sedimentary rocks in southern Finland, producing the late-orogenic potassium. granites, dated at 1840 - 1830 Ma. The Subjotnian rapakivi granites associated with mafic rocks, the Jotnian Satakunta sandstone formation and the Postjotnian diabase dykes and sills represent the cratonisation stages of the Svecofennides. Rapakivi granites and related mafic rocks were generated in an anorogenic extensional regime by partial melting of the upper mantle and lower crust. The Jotnian Satakunta sandstone is a fluvial sediment formation deposited in a deltaic environment. The development of the graben or rift valley, where the sandstone was deposited, may have begun already during the Subjotnian, ca. 1650 Ma ago. The olivine diabase dykes represent the feeding channels of Postjotnian flood basalts. However, no such volcanic rocks have preserved in the area. The intrusion of the diabase dykes caused the sinki

2002-01-01

254

The seabed geomorphology and geological structure of the Firth of Lorn, western Scotland, UK  

Science.gov (United States)

We present recently collected swath bathymetry from the Firth of Lorn. 553km2 of data were collected during 2012-2013 as part of the INIS Hydro project (Ireland, Northern Ireland and Scotland Hydrographic Survey). The inshore waters covered by this survey represent a priority area for the renewable industry, shipping and tourism and encompass a number of Special Areas of Conservation (SAC) including for rocky reef habitat. Surprisingly, given this interest, this project is the first comprehensive bathymetric survey of the area. This region of near shore continental shelf is revealed as a predominantly bedrock-dominated seabed, characterised by a series of narrow, stratigraphically constrained basins eroded into the Proterozoic and Palaeozoic-age bedrock. The principal basement of the region is composed of deformed Dalradian-age metasediments overlain unconformably by ?Silurian-age Old Red Sandstones and lavas. The resistant, uneroded igneous extrusives have formed raised rock platforms. Most strikingly the central region of the Firth of Lorn is dominated by an up to 150m high vertical cliff extending for approximately 20km. The origin of this prominent feature, here termed the Insh Fault, is not well understood however it may have resulted from a combination of Dalradian-age faulting and erosion of exposed softer metasediments in the central basin. Extensive seabed faulting also occurs; possibly as Dalradian-age syn-sedimentary faults. Carboniferous and Tertiary-age minor intrusives are common throughout the region in particular the Tertiary-age dolerite dyke swarms can be traced for many kilometres, exposed on the sediment-free bedrock surfaces. The survey region includes the Corryvreckan Whirlpool and Great Race, beneath the tidal flows of which there are active submarine sand dunes. Evidence for past glaciation is widespread and well preserved in the Firth of Lorn with preserved moraines and over-deepened basins common across the area. Initial geological and geomorphological mapping shows that our understanding of the offshore outcrop geology can be greatly improved by the collection of these new high-resolution bathymetric datasets.

Howe, John; Arosio, Riccardo; Dove, Dayton; Anderton, Roger; Bradwell, Tom

2014-05-01

255

Use of the GIS (Geographic Information Systems in Determining Realtionship between Geology, Structures and Mineral Prospects, Southern Part of the Arabian Shield, Saudi Arabia  

Directory of Open Access Journals (Sweden)

Full Text Available GIS can be utilized in geology in different fields among them; mineral and petroleum exploration, geological mapping and reconnaissance, environmental studies, and in hydrogeological modeling. In mineral exploration the GIS is used to define a set of characteristics of specific mineral deposit that might be used as a guide to similar deposits in the region. An example is being the spatial relation of igneous intrusions and / or geological structures to the mineral prospect locations. This study aimed at using the GIS to find out the relationship of the different geological features through the layers (coverages. These features include faults, intrusions and mineral locations in the Southern Arabian Shield. Coverages (layers for the digitized material were created using ARC INFO and consequently edited, cleaned and built. Coverages were also imported and exported in order to be read by ARC VIEW. Results of study indicated an excellent association of the faults and other structures to the known mineral locations. Positive correlation can also be concluded from the spatial distribution of the mineral locations and igneous intrusions. These results may imply that igneous intrusions and structural features control mineralizations. The conclusion can help in discorving mineralizaiton in similar geological and structural setting within the Arabian Shield area.

Mustafa M. Hariri

2003-01-01

256

Comparative investigation of schemes of geological sample preparation for flame atomic absorption analysis  

International Nuclear Information System (INIS)

Comparative investigation of 6 schemes of decomposition of geological materials (rocks, concentrates and minerals) is carried out. The samples were attacked by inorganic acids to partial or complete dissolution. With the sample complete decomposition Cd, V, Mo, Be, Cs, Sr et al. elements may be quantitatively analysed using atomic absorption and atomic emission spectrometry methods

1987-02-01

257

Analysis of Cuban geological samples with the use of a cyclical electron accelerator: microtron  

Energy Technology Data Exchange (ETDEWEB)

The sphere of utilization of nuclear physical methods in geology is very wide, ranging from seeking and exploration of useful mineral beds, the control of the elaboration of the numeral material and of the depths and about the depth of the element composition for geochemical purposes.

Leonard, M. (Comision de Energia Atomica, La Habana (Cuba)); Tsipenyuk, Yu.M. (AN SSSR, Moscow. Inst. Fizicheskikh Problem)

1981-01-01

258

Geologic structure and volcanic history of the Yanaizu-Nishiyama (Okuaizu) geothermal field, Northeast Japan  

Energy Technology Data Exchange (ETDEWEB)

The Yanaizu-Nishiyama geothermal field, also known as Okuaizu, supports a 65 MWe geothermal power station. It is located in the western part of Fukushima Prefecture, northeast Japan. This field is characterised by rhyolitic volcanism of about 0.3-0.2 Ma that formed Sunagohara volcano. Drillcore geology indicates that volcanism began with a caldera-forming eruption in the center of this field, creating a 2-km-diameter funnel-shaped caldera. Subsequently, a fault-bounded block including this caldera subsided to form a 5-km-wide lake that accumulated lake sediments. Post-caldera volcanism formed lava domes and intrusions within the lake, and deposited ash-flow tuffs in and around the lake. The hydrothermal system of this field is strongly controlled by subvertical faults that have no relation to the volcanism. The principal production zone occurs at a depth of 1.0-2.6 km within fractured Neogene formations along two northwest-trending faults to the southeast of the caldera. These faults also formed fracture zones in the lake sediments, but there was no apparent offset of the sediments. Stratigraphic studies suggest that post-caldera activities of Sunagohara volcano have migrated southeastward to the present high-temperature zone. The source magma of Sunagohara volcano may contribute to the thermal potential of this field. (Author)

Mizugaki, Keiko [Geological Survey of Japan, Geothermal Research Dept., Higashi Tsukuba (Japan)

2000-04-01

259

Comparison of seismic sources for imaging geologic structures on the Oak Ridge Reservation, Tennessee  

International Nuclear Information System (INIS)

In this study, five non-invasive swept sources, three non-invasive impulsive sources and one invasive impulsive source were compared. Previous shallow seismic source tests (Miller and others, 1986, 1992, 1994) have established that site characteristics should be considered in determining the optimal source. These studies evaluated a number of invasive sources along with a few non-invasive impulsive sources. Several sources (particularly the high frequency vibrators) that were included in the ORR test were not available or not practical during previous tests, cited above. This study differs from previous source comparisons in that it (1) includes many swept sources, (2) is designed for a greater target depth, (3) was conducted in a very different geologic environment, and (4) generated a larger and more diverse data set (including high fold CMP sections and walkaway vertical seismic profiles) for each source. The test site is centered around test injection well HF-2, between the southern end of Waste Area Grouping 5 (WAG 5) and the High Flux Isotope Reactor (HFIR)

1997-01-01

260

Development of an Integrated Numerical Simulation System for Geologic Carbon Dioxide Storage into a Prospective Storage Site in the Gyeongsang Basin, Korea: from Geologic Modeling to Risk Analysis Modeling  

Science.gov (United States)

An integrated numerical simulation system (package) was developed to predict and analyze geologic carbon dioxide storage. The integrated numerical simulation system consists of the four units such as three-dimensional geologic modeling of target geologic formation systems, prediction modeling of behavior (trapping mechanisms, leakage mechanisms) of carbon dioxide, evaluation modeling of three major performances (storage capacity, seal capacity, injection capacity) of target geologic formation systems, and analysis modeling of leakage risk of deep groundwater and carbon dioxide. This integrated numerical simulation system was then applied to a prospective storage site in the northern part of the Gyeongsang Basin, Korea. A series of three-dimensional geologic modeling of the target geologic formation system at the site was performed first using GOCAD (Paradigm, 2012). The geologic modeling results reveal that the site is composed of the five sedimentary geologic formations such as the Nakdong Formation, Hasandong Formation, Jinju Formation, Iljik Formation, and Hupyungdong Formation in ascending order, and a thick sandstone layer in the Hasandong Formation can be a target formation for geologic carbon dioxide storage. Above the target formation, three more sandstone layers (aquifers) exist, and carbon dioxide can leak into these aquifers. A series of prediction modeling of behavior of carbon dioxide injected into the target formation under various carbon dioxide injection amounts was then performed using TOUGH2 (Pruess et al., 1999). The prediction modeling results show that injected carbon dioxide can not only be stored as a free fluid phase by hydrodynamic trapping but can also be stored as an aqueous phase by solubility trapping. As a result, the carbon dioxide plume (free fluid phase of carbon dioxide) moves upward by buoyancy, whereas the carbon dioxide dissolved groundwater (aqueous phase of carbon dioxide) moves slowly downward by gravity. Finally, a series of analysis modeling of leakage risk of deep groundwater and carbon dioxide through abandoned wells under various locations was performed using CO2-LEAK (Kim, 2012). The analysis modeling results show that carbon dioxide injection can cause deep groundwater (brine) and carbon dioxide (both free fluid and aqueous phases) leakage into the overlying aquifers through the abandoned wells. In that case, brine leaks first, aqueous phase of carbon dioxide then leaks, and free fluid phase of carbon dioxide leaks finally. This work was supported by the Korea CCS 2020 Program funded by the National Research Foundation (NRF), Ministry of Science, ICT and Future Planning, Republic of Korea.

Kim, J.; Park, S.; Kihm, J.

2013-12-01

 
 
 
 
261

Stress analysis in multilayer structures  

Science.gov (United States)

The magnitude and distribution of thermal stresses in multilayer thin film structures have been modeled using a analytical solution method (ASM) and a newly developed hybrid finite element method (HFEM). This combined approach treats stress singularity as well as nonsingularity with equal ease. The use of hybrid elements based on an analytical solution of the stress singularity at the free edge has been found to provide accurate thermal stress solutions with fast convergence. Modeling of stress behavior in multilayer structures has been extended to include solutions for non-90sp° wedges (so called sharp edges) and solutions for multimaterial wedges. The dependence of the order of the stress singularity as well as the intensity of the stress singularity on the specific free edge geometry has been worked out as well. The results of theoretical analysis and calculations have made feasible the development of a software program, titled "Multilayer Structures" (MLS). The program is Windows-based. It is user friendly, allowing efficient and rapid thermal stress analysis of virtually any multilayer structure. It is seen as a valuable tool in design and for manufacturing and quality control functions in areas in which multilayer structures play a vital role. With a specially designed automesh engine and a simplified procedure for residual stress calculations, tedious preprocessing procedures need not be of concern. The program still provides the opportunity to use conventional finite element analysis. The MLS program has been applied and evaluated in various areas, such as in the optimization of substrate and film thicknesses in Multi Chip Modules (MCM's), the design of functionally gradient transition layers required in the bonding of dissimilar materials, and the identification of suitable substrates or buffer layers in diamond film deposition. The work reported in this dissertation constitutes a first step towards a full understanding of the mechanical behavior of multilayer structures and the development of a complete and comprehensive tool to predict performance.

White, Dongming Yuan

1997-12-01

262

Sea-level variability in tide-gauge and geological records: An empirical Bayesian analysis (Invited)  

Science.gov (United States)

Sea level varies at a range of temporal and spatial scales, and understanding all its significant sources of variability is crucial to building sea-level rise projections relevant to local decision-making. In the twentieth-century record, sites along the U.S. east coast have exhibited typical year-to-year variability of several centimeters. A faster-than-global increase in sea-level rise in the northeastern United States since about 1990 has led some to hypothesize a 'sea-level rise hot spot' in this region, perhaps driven by a trend in the Atlantic Meridional Overturning Circulation related to anthropogenic climate change [1]. However, such hypotheses must be evaluated in the context of natural variability, as revealed by observational and paleo-records. Bayesian and empirical Bayesian statistical approaches are well suited for assimilating data from diverse sources, such as tide-gauges and peats, with differing data availability and uncertainties, and for identifying regionally covarying patterns within these data. We present empirical Bayesian analyses of twentieth-century tide gauge data [2]. We find that the mid-Atlantic region of the United States has experienced a clear acceleration of sea level relative to the global average since about 1990, but this acceleration does not appear to be unprecedented in the twentieth-century record. The rate and extent of this acceleration instead appears comparable to an acceleration observed in the 1930s and 1940s. Both during the earlier episode of acceleration and today, the effect appears to be significantly positively correlated with the Atlantic Multidecadal Oscillation and likely negatively correlated with the North Atlantic Oscillation [2]. The Holocene and Common Era database of geological sea-level rise proxies [3,4] may allow these relationships to be assessed beyond the span of the direct observational record. At a global scale, similar approaches can be employed to look for the spatial fingerprints of land ice melt [5]. We end by presenting preliminary results from such an analysis. [1] Sallenger et al. (2012), Nat. Clim. Change 2: 884-888. [2] Kopp (in press),Geophys. Res. Lett. [3] Engelhart and Horton (2011), Quat. Sci. Rev. 54: 12-25. [4] Kemp et al. (2011), Proc. Natl. Acad. Sci. 108: 11017-11022. [5] Hay et al. (2013). Proc. Natl. Acad. Sci. 110: 3692-3699.

Kopp, R. E.; Hay, C.; Morrow, E.; Mitrovica, J. X.; Horton, B.; Kemp, A.

2013-12-01

263

Cluster analysis of track structure  

International Nuclear Information System (INIS)

One of the possibilities of classifying track structures is application of conventional partition techniques of analysis of multidimensional data to the track structure. Using these cluster algorithms this paper attempts to find characteristics of radiation reflecting the spatial distribution of ionizations in the primary particle track. An absolute frequency distribution of clusters of ionizations giving the mean number of clusters produced by radiation per unit of deposited energy can serve as this characteristic. General computation techniques used as well as methods of calculations of distributions of clusters for different radiations are discussed. 8 refs.; 5 figs

1991-01-01

264

Structural Analysis of Complex Networks  

CERN Multimedia

Filling a gap in literature, this self-contained book presents theoretical and application-oriented results that allow for a structural exploration of complex networks. The work focuses not only on classical graph-theoretic methods, but also demonstrates the usefulness of structural graph theory as a tool for solving interdisciplinary problems. Applications to biology, chemistry, linguistics, and data analysis are emphasized. The book is suitable for a broad, interdisciplinary readership of researchers, practitioners, and graduate students in discrete mathematics, statistics, computer science,

Dehmer, Matthias

2011-01-01

265

Effects of Karst and geological structure on groundwater flow: The case of Yarqon-Taninim Aquifer, Israel  

Science.gov (United States)

SummaryThis study demonstrates the significant influences of the geological structure (especially folding and lithology) and the karst system on groundwater flow regime. Folds divert groundwater flow from the general hydraulic gradient; marly layers sustain several perched sub-aquifers above the regional aquifer; and karstification increases the hydraulic conductivity by several orders of magnitude. These phenomena are quantitatively demonstrated within the Yarqon-Taninim (YT) basin, Israel, which is a complex groundwater system, combining several (extremely) opposite characteristics: humid and arid recharge zones, phreatic and confined parts, shallow and deep sub-aquifers, stratified and relatively-homogeneous sub-basins, saline and fresh water bodies, as well as stagnant and fast-flowing groundwater regions. We have introduced a 3D geological-based grid for the basin (for the first time). It was implemented into a numerical code (FEFLOW), which was used thereafter to analyze quantitatively the flow regime, the groundwater mass balance, and the aquifer hydraulic properties. We present up to date conceptual understanding and numerical modeling of the YT flow field, especially at its mountainous parts. Based on the calibration procedure and the sensitivity analyses, we obtained the best-fitted hydraulic conductivity values for the aquifer mesh. The general phenomenon observed is that as groundwater flow quantity increases, the hydraulic conductivity also increases. We interpret this result by the karstification mechanism (including paleo-karst). Thus, where groundwater flow-lines converge and where groundwater discharge amount increases, the karstification process intensifies and permeability increases. Consequently, at the mountainous region, along the syncline axes, where groundwater flow-lines converge, higher conductivities are found. Modeling results also exhibit that at the lowland confined area, the geological structure does not play a major role in directing groundwater flow. Rather, the flow field is controlled by the well-developed karst system and the relatively homogenous carbonate section. It is hypothesizes that the extensive karstification took place at the Messinian Salinity Crises, ˜5.5 Ma, during which groundwater heads as well as sea level were lowered by several 100 m.

Dafny, Elad; Burg, Avi; Gvirtzman, Haim

2010-08-01

266

Assessment of natural radioactivity levels in rocks and their relationships with the geological structure of Johor state, Malaysia  

International Nuclear Information System (INIS)

The distribution of natural radionuclides (238U, 232Th and 40K) and their radiological hazard effect in rocks collected from the state of Johor, Malaysia were determined by gamma spectroscopy using a high-purity germanium detector. The highest values of 238U, 232Th and 40K activity concentrations (67±6, 85±7 and 722±18 Bg kg-1, respectively) were observed in the granite rock. The lowest concentrations of 238U, 232Th (2±0.1 Bq kg-1 for 238U and 2±0.1 Bq kg-1 for 232Th) were observed in gabbro rock. The lowest concentration of 40K (45±2 Bq kg-1) was detected in sandstone. The radium equivalent activity concentrations for all rock samples investigated were lower than the internationally accepted value of 370 Bq kg-1. The highest value of radium equivalent in the present study (239±17 Bq kg-1) was recorded in the area of granite belonging to an acid intrusive rock geological structure. The absorbed dose rate was found to range from 4 to 112 nGy h-1. The effective dose ranged from 5 to 138 ?Sv h-1. The internal and external hazard index values were given in results lower than unity. The purpose of this study is to provide information related to radioactivity background levels and the effects of radiation on residents in the study area under investigation. Moreover, the relationships between the radioactivity levels in the rocks within the geological structure of the studied area are discussed. (authors)

2014-01-01

267

Evaluation of geologic structure guiding ground water flow south and west of Frenchman Flat, Nevada Test Site  

International Nuclear Information System (INIS)

Ground water flow through the region south and west of Frenchman Flat, in the Ash Meadows subbasin of the Death Valley ground water flow system, is controlled mostly by the distribution of permeable and impermeable rocks. Geologic structures such as faults are instrumental in arranging the distribution of the aquifer and aquitard rock units. Most permeability is in fractures caused by faulting in carbonate rocks. Large faults are more likely to reach the potentiometric surface about 325 meters below the ground surface and are more likely to effect the flow path than small faults. Thus field work concentrated on identifying large faults, especially where they cut carbonate rocks. Small faults, however, may develop as much permeability as large faults. Faults that are penetrative and are part of an anastomosing fault zone are particularly important. The overall pattern of faults and joints at the ground surface in the Spotted and Specter Ranges is an indication of the fracture system at the depth of the water table. Most of the faults in these ranges are west-southwest-striking, high-angle faults, 100 to 3500 meters long, with 10 to 300 /meters of displacement. Many of them, such as those in the Spotted Range and Rock Valley are left-lateral strike-slip faults that are conjugate to the NW-striking right-lateral faults of the Las Vegas Valley shear zone. These faults control the ground water flow path, which runs west-southwest beneath the Spotted Range, Mercury Valley and the Specter Range. The Specter Range thrust is a significant geologic structure with respect to ground water flow. This regional thrust fault emplaces siliceous clastic strata into the north central and western parts of the Specter Range

1998-01-01

268

Assessment of natural radioactivity levels in rocks and their relationships with the geological structure of Johor state, Malaysia.  

Science.gov (United States)

The distribution of natural radionuclides ((238)U, (232)Th and (40)K) and their radiological hazard effect in rocks collected from the state of Johor, Malaysia were determined by gamma spectroscopy using a high-purity germanium detector. The highest values of (238)U, (232)Th and (40)K activity concentrations (67±6, 85±7 and 722±18 Bg kg(-1), respectively) were observed in the granite rock. The lowest concentrations of (238)U and (232)Th (2±0.1 Bq kg(-1) for (238)U and 2±0.1 Bq kg(-1) for (232)Th) were observed in gabbro rock. The lowest concentration of (40)K (45±2 Bq kg(-1)) was detected in sandstone. The radium equivalent activity concentrations for all rock samples investigated were lower than the internationally accepted value of 370 Bq kg(-1). The highest value of radium equivalent in the present study (239±17 Bq kg(-1)) was recorded in the area of granite belonging to an acid intrusive rock geological structure. The absorbed dose rate was found to range from 4 to 112 nGy h(-1). The effective dose ranged from 5 to 138 ?Sv h(-1). The internal and external hazard index values were given in results lower than unity. The purpose of this study is to provide information related to radioactivity background levels and the effects of radiation on residents in the study area under investigation. Moreover, the relationships between the radioactivity levels in the rocks within the geological structure of the studied area are discussed. PMID:23965286

Alnour, I A; Wagiran, H; Ibrahim, N; Hamzah, S; Elias, M S; Laili, Z; Omar, M

2014-01-01

269

EFFECT OF GEOLOGICAL STRUCTURES ON THE HYDROGEOLOGICAL CHARACTERISTICS OF QUATERNARY DEPOSITS IN BARANJA  

Directory of Open Access Journals (Sweden)

Full Text Available Shifts of structural units, which started in Pliocene are specifically expressed during the Quaternary. They last still today and affected the hydrogeological relations in the region of Baranja. Lithological development is dominated by one or maximum two layers of uniform midium grained sand which in places exceeds to fine grained sand, and in some places in the sand with gravel. Mentioned structures have impacted the natural quality of groundwater. Considering individual episodes of uplift and lowering of sediments, caused by movements along a particular structures, led to changes in oxidative and reductive conditions of deposition. Consequently, different quality of water occurs in wellfields of Baranja

Maja Briški

2010-12-01

270

Structure and properties of fluid-filled grain boundaries under stress in geological materials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two of the three processes making up the deformation mechanism of intergranular pressure solution, being dissolution and diffusion, take place in the grain boundary fluid phase. Hence, the structure and physical properties of wet grain boundaries under stress can be expected to influence the kinetics of both dissolution and diffusion, as a result of effects such as molecular structuring of the fluid film, the grain boundary surface area available for dissolution, the dissipation of energy oth...

Noort, R.

2008-01-01

271

Comparative study of procedures for preparation of geological samples for flame atomic absorption analysis  

Energy Technology Data Exchange (ETDEWEB)

An experimental comparison has been made of six procedures for dissolving geological materials (rocks of different composition, concentrates, and minerals). Treating the samples with acids by procedures 3, 4, and 5, which produce complete decomposition of the sample, provides for the quantitative determination of the elements: Fe, Al, Mg, Ca, Na, K, Mn, Cr, Ni, Co, Zn, Cu, Ti, Sb, Pb, Bi, Cd, V, Mo, Be, Li, Rb, Cs, Ba, and Sr by atomic absorption and atomic emission spectrometry. If procedure 4 is used, the alkali metals are determined from a different sample of the material. Procedure 5 is the optimum method for dissolving different geological materials for determining a large number of elements from a single sample. Decomposition of the samples by procedure 6 enables the elements of interest to be separated from sodium, sulfur, phosphorus and other elements that are transferred to the solution when the melted material is leached with water.

Simonova, V.I.; Ivanova, L.D.; Smertina, L.N.

1987-07-20

272

Determination of niobium in geological materials by activation analysis with pre-irradiation separation  

International Nuclear Information System (INIS)

The solvent extraction of Nb from geological materials in the presence of carrier-free 95Nb tracer prior to neutron irradiation is described. The possibilities of contamination and interferences are discussed. Dissolution of samples and the solvent extraction of Nb are relatively simple and can be made simultaneously on a large number of samples and the subsequent activation procedure allows more efficient use of the reactor. For the measurement of 10-6 g of Nb, the uncertainty due to counting statistics is +-2 percent and the limit of detection or of contamination is of the order of 5 x 10-9 g. This technique was used to measure the Nb content in 15 U.S. Geological Survey standard rocks

1978-01-01

273

Information on prospecting and analysis of the geological uraniferous favourability of Peru  

International Nuclear Information System (INIS)

The activities carried out in Peru from 1958 until 1975 in search of uranium deposits are described. In 1976 the 'Peruvian Nuclear Plan' was approved, and the Peruvian Institute of Nuclear Energy/Instituto Peruano de Energia Nuclear (IPEN) was given the responsibility of organizing and carrying out all activities related to uranium exploration and production in the country. The programme is under implementation and comprises organization of infrastructural support, training of technical personnel, selection of favourable areas, and exploration and adoption of the most favourable national policy to permit development of the national uranium resources. The criteria applied for definition of the 'uranium favourability' of the main Peruvian geological environments are described, taking into account geological composition and concepts relating to the matallogenesis and control of uranium deposits. The results of this area selection are reported. (author)

1978-12-08

274

THE SIGNIFICANCE OF STRUCTURAL AND GEOLOGICAL RELATIONSHIP ASSESSMENT IN THE CONSTRUCTION OF THE OMBLA UNDERGROUND HYDROELECTRIC POWER PLANT  

Directory of Open Access Journals (Sweden)

Full Text Available The construction design of the underground hydroelectric plant Ombla required geological and structural investigations to he carried out. Due to past earthquakes in the area permanent tectonic movements were inferred. Therefore, in the wider and adjacent surroundings of the Ombla spring it was necessary to analyze the structural fabric and the geodynamic characteristics of the area. The most active zone encountered is the front part of a thrust fault belonging to the Dinaricum regional structural unit. The compressive regime is maintained as a response to the regional stress of an approximately S-N orientation. Different displacements of various parts of the Dinaricum unit are present. Along the rim of the structural blocks, the Hum-Om-bla fault zone extends, accompanied by left transcurrent faults, Through this zone the main groundwater drainage occurs supplying the Ombla spring. In the local Ombla spring area this zone is characterized by three sub-blocks and three major faults. The most important fault for the vital facilities of the Ombla hydroelectric power plant is the Plo?ice fault which divides the structural sub-blocks. Along this fault zone there are four mutually connected. The lowest two arc active groundwater draining systems supplying the Ombla spring. The data on local stress implies the following deformation of sub-blocks: sub-blocks 2c and 2f are displaced along normal faults from 20° to 30° to the left, downwards, while the sub-block 2 d is displaced along the Plo?ice thrust fault of 100° to 130° to the left, upwards. The structural data confirmed that the building of an underground dam with a height from 100 to 130 m was feasible. The connection between the caverns and the fault zone was determined. The unfavorable position of the active Plo?ice fault zone imposes the construction of vital Ombla power plant facilities underground.

Eduard Prelogovi?

1997-12-01

275

Determination of the noble metals in chromites and other geological materials by radiochemical neutron activation analysis  

International Nuclear Information System (INIS)

A procedure is described for determining the noble metals in geological samples of varied composition (Si enriched or Cr enriched). This rapid separation procedure allows very low detection limits for all platinum group elements (except Rh) and Ag. It uses the coprecipitation of Pd, Pt, Au, Ag and Ru with Se and Te, and the fixation of Os on an ion-exchange resin. Ir is systematically determined by epithermal NAA using multiparameter coincidence spectrometry. (author)

1987-06-01

276

Determination of the noble metals in chromites and other geological materials by radiochemical neutron activation analysis  

International Nuclear Information System (INIS)

A procedure is described for determining the noble metals in geological samples of varied composition (Si enriched or Cr enriched). This rapid separation procedure allows very low detection limits for all PGE (except Rh) and Ag. It uses the coprecipitation of Pd, Pt, Au, Ag and Ru with Se and Te, and the fixation of Os on an ion-exchange resin. Ir is systematically determined by epithermal NAA using multiparameter coincidence spectrometry. (author)

1986-06-23

277

3D Geological Modeling under Extremely Complex Geological Conditions  

Directory of Open Access Journals (Sweden)

Full Text Available 3D modeling method is divided into geospatial modeling and 3D geological modeling. 3D geological modeling technique has become a favorable tool for people to observe and analyze the geological body enriched in mineral resources. Unlike geospatial modeling, 3D geological modeling must consider various geological conditions affecting spatial shape and petrophysical distribution of geological body for its complexity. This article analyzes the uncertainty, complexity and diversity of geological body, and lists complex geological conditions controlling spatial shape and petrophysical distributions of geological body. And then 3D geological modeling method under the control of complex geological conditions is proposed, and corresponding modeling workflow is set up. Finally, taking 3D geological modeling of petroleum exploration and development for example, 3D geological model of Shu II district in the Liaohe oil-field is built. Based on this model, some applications are realized, such as 3D visualization of structural model and petrophysical model, reserves calculation and drilling design, etc.

Yanlin Shao

2012-03-01

278

Analysis of possible geological storage of CO{sub 2} and nuclear waste in Lithuania  

Energy Technology Data Exchange (ETDEWEB)

Lithuania is currently dealing with two major problems in energy sector: final closure of Ignalina Nuclear Power plant (Ignalina NPP) in the end of 2009 and nuclear waste disposal and climate change mitigation issues having in mind replacement of nuclear capacities with fossil one and anticipated increase in GHG emissions. Lithuania has two options: to construct new nuclear power plant also taking into account nuclear waste disposal issue or to burn fossil fuel and to apply carbon capture and storage (CCS) for GHG emission reduction. These two options need to be investigated in Lithuania based on various studies conducted in Lithuania and abroad dealing with geological carbon storage and nuclear waste disposal potentials. There are no long-lived nuclear waste geological storage capacities in Lithuania and there is no pilot project on CCS developed in Lithuania. The aim of the article is to analyse and compare geological carbon and nuclear waste storage opportunities in Lithuania and to assess nuclear and carbon capture and storage technologies in terms of costs. (author)

Streimikiene, Dalia; Mikalauskiene, Asta [Lithuanian Energy Institute, Breslaujos 3, LT-44403, Kaunas (Lithuania)

2010-08-15

279

Application of remote sensor data to geologic analysis of the Bonanza test site, Colorado  

Science.gov (United States)

The author has identified the following significant results. The Hayden Pass (Orient mine area) includes 60 sq miles of the northern Sangre de Cristo Mountains and San Luis Valley in south-central Colorado. Based on interpretation of the remote sensor data, a geologic map was prepared and compared with a second geologic map, prepared from interpretation of both remote sensor data and field data. Comparison of the two maps gives an indication of the usefulness and reliability of the remote sensor data. The relative utility of color and color infrared photography was tested. The photography was used successfully to locate 75% of all faults in a portion of the geologically complex Bonanza volcanic center and to map and correctly identify 93% of all quaternary deposits and 62% of all areas of tertiary volcanic outcrop. Using a filter wheel photometer, more than 8,600 measurements of band reflectance of several sedimentary rocks were performed. The following conclusions were drawn: (1) the typical spectral reflectance curve shows a gradual increase with increasing wavelength; (2) the average band reflectance is about 0.20; and (3) within a formation, the minimum natural variation is about 0.04, or about 20% of the mean band reflectance.

Lee, K. (principal investigator)

1976-01-01

280

Implementation of the k0-standardization method for analysis of geological samples at the Neutron Activation Analysis Laboratory, Sao Paulo, Brazil  

International Nuclear Information System (INIS)

The Neutron Activation Analysis Laboratory (LAN-IPEN) has been analysing geological samples for many years with the INAA comparative method, for geochemical and environmental research. This study presents the results obtained in the implementation of the k-0-standardization method at LAN-IPEN, for geological samples analysis, by using the program k0-IAEA, provided by the International Atomic Energy Agency (IAEA). The thermal to epithermal flux ratio f and the shape factor ? of the epithermal flux distribution of the IEA-R1 nuclear reactor of IPEN were determined for the pneumatic irradiation facility and one selected irradiation position, for short and long irradiations, respectively. To obtain these factors, the 'bare triple-monitor' method with 197Au-96Zr-94Zr was used. In order to validate the methodology, the geological reference materials basalts JB-1 (GSJ) and BE-N (IWG-GIT), andesite AGV-1 (USGS), granite GS-N (ANRT), SOIL-7 (IAEA) and sediment Buffalo River Sediment (NIST-BRS-8704), which represent different geological matrices, were analysed. The concentration results obtained agreed with assigned, with bias <10 % except for Zn in AGV-1. The U-score test showed that all results, except Mg in JB-1, are within 95 % confidence interval. These results indicate excellent possibilities of using this parametric method at the LAN-IPEN for geochemical and environmental studies. (author)

2014-01-01

 
 
 
 
281

Assessment of DInSAR Potential in Simulating Geological Subsurface Structure  

Science.gov (United States)

High resolution geophysical surveys, including seismic, gravity, magnetic, etc., provide valuable information about subsurface structuring but they are very costly and time consuming with non-unique and sometimes conflicting interpretations. Several recent studies have examined the application of DInSAR to estimate surface deformation, monitor possible fault reactivation and constrain reservoir dynamic behaviour in geothermal and groundwater fields. The main focus of these studies was to generate an elevation map, which represents the reservoir extraction induced deformation. This research study, however, will focus on developing methods to simulate subsurface structuring and identify hidden faults/hydraulic barriers using DInSAR surface observations, as an innovative and cost-effective reconnaissance exploration tool for planning of seismic acquisition surveys in geothermal and Carbon Capture and Sequestration regions. By direct integration of various DInSAR datasets with overlapping temporal and spatial coverage we produce multi-temporal ground deformation maps with high resolution and precision to evaluate the potential of a new multidimensional MSBAS technique (Samsonov & d'Oreye, 2012). The technique is based on the Small Baseline Subset Algorithm (SBAS) that is modified to account for variation in sensor parameters. It allows integration of data from sensors with different wave-band, azimuth and incidence angles, different spatial and temporal sampling and resolutions. These deformation maps then will be used as an input for inverse modelling to simulate strain history and shallow depth structure. To achieve the main objective of our research, i.e. developing a method for coupled InSAR and geophysical observations and better understanding of subsurface structuring, comparing DInSAR inverse modelling results with previously provided static structural model will result in iteratively modified DInSAR structural model for adequate match with in situ observations. The newly developed and modified algorithm will then be applied in another part of the region where subsurface information is limited.

Fouladi Moghaddam, N.; Rudiger, C.; Samsonov, S. V.; Hall, M.; Walker, J. P.; Camporese, M.

2013-12-01

282

Computer-assisted geometric and kinematic analysis of subsurface faulting in the vicinity of Yucca Mountain, Nevada, using balanced geologic cross sections  

International Nuclear Information System (INIS)

Computer-assisted geological cross section balancing methods are used in the geometric and kinematic analysis of subsurface structures in the vicinity of Yucca Mountain, Nevada, including underlying listric normal fault and detachment fault geometries and their relationships in a linked fault system. Dips of hanging wall fault blocks are directly related to the shapes of underlying curved normal and detachment faults. Arrays of small faults that are pervasively distributed through the hanging wall blocks are interpreted to be the bulk deformation mechanism of the block. As the hanging wall slides over the underlying fault surface, the fault block deforms to accommodate itself to the shape of the fault. Distributed slip on the small fault array is assumed to accomplish this shape change. The deformation is modeled as general simple shear, such that changes in shape of the model fault blocks take place by distributed slip on uniformly oriented slip surfaces that are evenly spaced through the area of the block, replicating the behavior of a deck of cards. Computed listric normal fault trajectories and surface geologic data constrain the range of compatible depths to potential detachment fault zones below Yucca Mountain to between about 3.5 and 6 kilometers. This is at least 1 to 2 kilometers deeper than the contact between the base of the Tertiary volcanics and the Paleozoic section. Preliminary balanced versions of sections A-A' and B-B' of Scott and Bonk show that assumption of a vertical simple shear deformation mechanism for fault block distortion will produce geologically reasonable subsurface models of faulting

1991-05-03

283

The geologic structures observed in drillhole DOE-2 and their possible origins: Waste Isolation Pilot Plant  

International Nuclear Information System (INIS)

Questions remain as the origins of evaporite deformation within the Salado and Castile formations. Two miles north of the WIPP site, a stacked sequence of depressions was indicated by shallow boreholes. Such structures raise questions regarding the role of dissolution and gravity tectonics at the WIPP site. To investigate these structures, DOE drilled hole DOE-2 north of the WIPP site. At DOE-2, the downward displacement of stratigraphic markers in the Salado confirmed the presence of stacked depressions, which were the primary target of the drilling program. The halitic units between the marker beds were thickened compared to the average section determined from basin-wide drilling. The remaining question is whether dissolution occurred in the underlying Castile and resulted in the deformation of the Salado. Markers in the anhydrite units indicate recumbent structures and thickening of the anhydrite units by folding. As a consequence, the Castile Formation is nearly its average thickness, with the folded thickness of anhydrite compensating for the missing halite. The nearby thickening of halite within the Castile, the absence of relic anhydrite laminae in the attenuated halite units, and the high strain fabric of the remaining halite suggest that dissolution was not the dominant process in the Castile. The favored hypothesis for the Castile structures is salt flow in response to gravity inversion of the anhydrite and halite units of the Castile. 21 refs., 18 figs

1987-01-01

284

Engineering Geology  

Science.gov (United States)

Engineering geology remains a potpourri of applied classical geology, and 1977 witnessed an upswing in demand for these services. Traditional foundation-related work was slight, but construction related to national needs increased briskly. Major cities turned to concerns of transit waste-water treatment and solid-waste disposal. (Author/MA)

Hatheway, Allen W.

1978-01-01

285

Physical geology  

Energy Technology Data Exchange (ETDEWEB)

The book integrates current thinking on processes (plate techtonics, chemical cycles, changes throughout geologic time). It is an introduction to investigations into the way the earth works, how mountains are formed, how the atmosphere, hydrosphere, crust and mantle interact with each other. Treatments on climate, paleoclimatology and landscape evolution are included, as is a discussion on how human activity affects geological interactions.

Skinner, B.; Porter, S.

1987-01-01

286

3-D FEM modelling of geological structures caused by geometrical instabilities and contrasts in rock strength  

Science.gov (United States)

Many three-dimensional (3-D) structures in rock, which formed during the deformation of the Earth's crust and lithosphere, are controlled by a difference in mechanical strength between rock units and are often the result of a geometrical instability. Such structures are, for example, folds, pinch-and-swell structures (due to necking) or cuspate-lobate structures (mullions). These structures occur from the centimeter to the kilometer scale and the related deformation processes control the formation of, for example, fold-and-thrust belts and extensional sedimentary basins or the deformation of the basement-cover interface. The 2-D deformation processes causing these structures are relatively well studied, however, several processes during large-strain 3-D deformation are still incompletely understood. One of these 3-D processes is the lateral propagation of these structures, such as cusp propagation in a direction orthogonal to the shortening direction or neck propagation in direction orthogonal to the extension direction. We study the 3-D evolution of geometrical instabilities with numerical simulations based on the finite element method (FEM). Simulating geometrical instabilities caused by sharp variations of mechanical strength between rock units requires a numerical algorithm that can accurately resolve material interfaces for large differences in material properties (e.g. between limestone and shale) and for large deformations. Therefore, our FEM code combines a numerical contour-line technique and a deformable Lagrangian mesh with re-meshing. With this combined method it is possible to accurately follow the initial material contours with the FEM mesh and to accurately resolve the geometrical instabilities. The algorithm can simulate 3-D deformation for a visco-elasto-plastic rheology. Stresses are limited by a yield stress using a visco-plastic formulation and the viscous rheology is described by a power-law flow law. The 3-D FEM code is applied to model 3-D power-law folding and power-law Rayleigh-Taylor instabilities (diapirs) with different re-meshing scenarios. The results are tested with the analytical solution for small amplitudes and with 2-D numerical results for large amplitudes. Thereby,the small initial geometrical perturbations for folding and necking are exactly followed by the FEM mesh. In order to test and measure the numerical properties for an Eulerian mesh we use the analytical solution for a two-dimensional viscous inclusion in pure shear. The FEM code is further applied to study the evolution of lithospheric-scale 3-D slab detachment and its lateral propagation.

von Tscharner, Marina; Schmalholz, Stefan

2014-05-01

287

Structural geology of the Sunset Lake slice, Taconic fold thrust belt, western Vermont  

Energy Technology Data Exchange (ETDEWEB)

The Sunset Lake slice is purported to be the lowest thrust sheet in the Taconics. Only a small area is underlain by this thrust sheet and the region has remained unmapped since the regional compilation by Zen. Apparently most (if not all) of the early mapping of this area was done by John Rodgers who comments on it in his comment to Rowley and Kidd. Since the time of that early mapping, significant new aspects of Taconic stratigraphy have come to light which alter the structures mapped. The authors have remapped the greater portion of the Sunset Lake slice with several questions in mind: Is the stratigraphy in this slice the same as in the Giddings Brook slice immediately above Are there differences in the structural history of the two slices The Sunset lake slice contains the same stratigraphy defined in the Fairhaven, Vt. area by Rowley, Kidd and Delano from the Bomoseen Fm. up to the Hatch Hill Fm. The upper part of the stratigraphy, however, is not present. The structures displayed by the new mapping indicate that the rocks experienced two episodes of folding prior to their final thrust emplacement. The early folds are isoclinal, with N-S striking axial planes and shallowly plunging axes. These folds are responsible for repetition of the stratigraphy. The later folds are more open and have an axial plane crenulation cleavage. Thus, the structural history of the Sunset Lake slice is identical to the Giddings Brook slice and, if it truly is a separate thrust slice, it probably is not much less further traveled than the larger slice above it. The surrounding middle Ordovician flysch is both cleaved and uncleaved. On the eastern side of the thrust sheet cleaved flysch lies structurally above the taconic rocks in fault contact. Thus, the margins of the sheet, at least in part, are flysch-on-flysch and, thus, difficult to map with accuracy.

Carpenter, D.; Day, K. (Colgate Univ., Hamilton, NY (United States))

1993-03-01

288

Glossary of Geology  

Science.gov (United States)

The Glossary has expanded coverage particularly in such active fields as carbonate sedimentology, environmental geology and geophysics, GIS, GPS, hydrology and hydraulics, marine and coastal geology, organic geochemistry, paleoecology, seismology, stratigraphic nomenclature, speleology and karst, and structural geology and tectonics. Many definitions provide a syllabification guide and background information. Thus a reader will learn the difference between look-alike pairs, such as sylvanite (a mineral) and sylvinite (a rock); the origin of terms; the meaning of abbreviations and acronyms common in the geosciences vocabulary; the dates many terms were first used; the meaning of certain prefixes; and the preferred term of two or more synonyms.

Jackson, Julia A.

289

Epithermal neutron activation analysis and detection limit calculation for trace amounts of thorium at nanogram level, in Israeli geological samples  

International Nuclear Information System (INIS)

Trace amounts of thorium in Israeli geological samples were determined by epithermal neutron activation analysis followed by high resolution gamma-ray spectrometry. Epithermal neutron irradiation has the advantage of enhancing the production of 233Th via the 232Th?233Th reaction over that of interfering nuclides which have a lower Isub(0)/sigmasub(0) ratio. The delay time between the end of irradiation and the start of measurements was shortened to 1-2 days. Under the experimental conditions described, the detection limit of Th was 3.3+-0.7 ng. The method is nondestructive, accurate and highly sensitive. (author)

1983-01-01

290

Structural Analysis of Fungal Cerebrosides  

Directory of Open Access Journals (Sweden)

Full Text Available Of the ceramide monohexosides (CMHs, gluco- and galactosylceramides are the main neutral glycosphingolipids expressed in fungal cells. Their structural determination is greatly dependent on the use of mass spectrometric techniques, including fast atom bombardment-mass spectrometry (FAB-MS, electrospray ionization (ESI-MS, and energy collision-induced dissociation mass spectrometry (ESI-MS/CID-MS. Nuclear magnetic resonance (NMR has also been used successfully. Such a combination of techniques, combined with classical analytical separation, such as HPTLC and column chromatography, has led to the structural elucidation of a great number of fungal CMHs. The structure of fungal CMH is conserved among fungal species and consists of a glucose or galactose residue attached to a ceramide moiety containing 9-methyl-4,8-sphingadienine with an amidic linkage to hydroxylated fatty acids, most commonly having 16 or 18 carbon atoms and unsaturation between C-3 and C-4. Along with their unique structural characteristics, fungal CMHs have a peculiar subcellular distribution and striking biological properties. Fungal cerebrosides were also characterized as antigenic molecules directly or indirectly involved in cell growth or differentiation in Schizophyllum commune, Cryptococcus neoformans, Pseudallescheria boydii, Candida albicans, Aspergillus nidulans, A.fumigatus and Colletotrichum gloeosporioides. Besides classical techniques for cerebroside (CMH analysis, we now describe new approaches, combining conventional TLC and mass spectrometry, as well as emerging technologies for subcellular localization and distribution of glycosphingolipids by SIMS and imaging MALDI TOF .

ElianaBarreto-Bergter

2011-12-01

291

The reconstruction of palaeodrainage and regional geologic structures in Australia's canning and officer basins using NOAA-AVHRR satellite imagery  

Science.gov (United States)

NOAA-AVHRR, LAC-imagery is a synoptic tool that has proven applications to the identification and mapping of palaeolandforms and geologic structures within the vast and relatively inaccessible arid and semi-arid regions of the Australian continent. The reconstruction of previously unmapped surface and sub-surface features, in regions nominated as prime exploration zones, aids the definition of tectonic environments which may be conducive to the location of groundwater, hydrocarbon resources and mineral deposits. The interpretation of enhanced NOAA-AVHRR imagery from the NOAA satellite series provides a rapid means of assessing the potential of partially explored regions for a low financial outlay per unit area covered. The multidate, multitemporal availability and multispectral nature of NOAA-AVHRR imagery permits a diurnal and seasonal investigation of a region using reflected and thermal wavebands of the electromagnetic spectrum. This paper discusses the enhancements, procedures and benefits of using NOAA-AVHRR imagery to identify sub-surface structures in the desert regions of the Canning and Officer basins.

Tapley, Ian J.

1988-12-01

292

Strength analysis of net structures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main goal of this PhD project was to develop a method for non-linear strength analysis of net structures applied in the aquaculture and fishing industries, e.g. net cages and trawls. The work focused on the aquaculture net cage, which was applied in experiments and analyses, and included research to establish knowledge within material properties and failure modes of traditional netting materials for aquaculture. It was chosen to focus on tensile properties and to study...

Moe, Heidi

2009-01-01

293

Strength analysis of net structures  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main goal of this PhD project was to develop a method for non-linear strength analysis of net structures applied in the aquaculture and fishing industries, e.g. net cages and trawls. The work focused on the aquaculture net cage, which was applied in experiments and analyses, and included research to establish knowledge within material properties and failure modes of traditional netting materials for aquaculture. It was chosen to focus on tensile properties and to study elastic and plastic...

2009-01-01

294

Criticality analysis of aggregations of actinides from commerical nuclear waste in geological storage  

International Nuclear Information System (INIS)

An underground nuclear-waste terminal-storage facility for either spent fuel elements or high level waste from a reprocessing plant will contain large amounts of fissionable actinides. Such a facility must be designed to preclude the concentration of these isotopes into a critical mass. Information on the critical masses of the various isotopes present in spent fuel or high level waste is required as part of such a design effort. This study provides this information. The results of this study will be used, in conjunction with geologic transport rates of the actinide compounds, to estimate mass formation probabilities in waste repositories. A computational model was developed as part of the study to perform criticality calculations rapidly and efficiently and to produce tables and plots of actinide concentration in geologic material versus critical mass. The criticality model uses a discrete ordinates approximation to neutron transport theory and treats six energy groups and spherical geometry. Neutron cross sections were obtained from ENDF/B-IV or ENDF/B-V cross section libraries. Critical masses calculated with the computational model were checked against experimental values and against more detailed calculational values and were found to be from 30 percent less to 10 percent greater. Critical mass calculations were made for five waste types, five waste ages, five actinide elements, and four geologic compositions. Minimum critical masses were calculated for over 400 combinations of the above variables. The relative importance for criticality of the various actinides and waste types is presented in terms of the number of possible critical masses per waste container

1978-01-01

295

Fractional diffusion analysis of the electromagnetic fields generated by a transient straight current source over a porous geological media  

Science.gov (United States)

An interpretation based on the Continuous Time Random Walk theory (CTRW) to the diffusion of electromagnetic fields generated by a transient straight current source over a porous geological media is presented here. The CTRW theory is demonstrated to be a powerful tool to concisely and more accurately model a transport process in a fractal medium with complex structures, comparing to the classical transport theory. In the controlled-source electromagnetic (EM) induction setting, the time dependent evolution of the EM field of some sources over a rough medium are governed by the fractional diffusion EM equation in a CTRW sense. The master equation can be solved for a uniform conducting half-space in the Laplace domain semi-analytically. We use 2D finite difference method to calculate the solution numerically for the assigned space and transform to time domain with Gaver-Stehfest algorithm. Here we adopt a spatially uniform roughness parameter ? in the solution to characterize the complexity of the geoelectrical structure of the geological medium. To introduce the heterogeneity to our model, we set up the space as several 2 D blocks with different conductivities and ?s. Then we compare our results with the synthetic data we got from the high resolution numerical simulations. We are able to show that by introducing the heterogeneity to the fractional diffusion perspective, our approach is competent for tracing the diffusion process with less model parameters.

Ge, J.; Everett, M. E.; Weiss, C. J.

2010-12-01

296

Assessment of methods of geological basin analysis for application to the Uinta and Piceance Basins  

Energy Technology Data Exchange (ETDEWEB)

Various methods of characterizing the physical (pressure-temperature) history of stratigraphic units in a subsiding basin are examined. Methods are divided into two groups: practical and computational. Practical methods involve interpretation of compaction and subsidence history from geophysical logs and other geologic data. The method is applied, as an example, from data for the Uinta Basin in northeastern Utah. Computational methods involve calculations simulating physical conditions for a given stratigraphy throughout the time of subsidence. The relative merits of the two methods are discussed and proposals made for initial study of the temperature-pressure history of kerogen-bearing rocks of the Uinta or Piceance Basins of northeastern Utah.

Sweeney, J.J.

1984-05-01

297

Environmental geologic analysis of Rio de las Taguas basin Departmento Iglesia San Juan Argentina  

International Nuclear Information System (INIS)

A mineral environmental research project results where it has been located in Rio de las Taguas basin, Departamento Iglesia, Provincia de San Juan, Argentina. It has been placed in frontal Andean mountain in San Juan. In this geographic framework has been developed Au and Ag mineral project in order the world scale. The aim of this article is has been related the mineral and geological units bet wen the basin chemistry as well as to carry out future measurements mines impacts in this area. (author)

2007-10-10

298

Structural geology controls on groundwater flow: Lembang Fault case study, West Java, Indonesia  

Science.gov (United States)

Field evidence has shown that Lembang Fault (West Java, Indonesia) can act as a groundwater flow barrier. There are outcrops along the footwall comprising consolidated brecciated rock with very low permeability, springs and hot springs occurring along down-thrown hanging-wall rock adjacent to the fault, and a high permeability layer of old and young Tangkuban Parahu eruptive materials (hanging wall) juxtaposed against the low permeability of the older volcanic layer of Bukit Tunggul unit (footwall). Two different environmental tracers were utilized in the study: electrical conductivity measurement and stable isotope analysis. Hydraulic head was measured at some wells along the fault and water electrical conductivity measurements were carried out in a small catchment, the upper part of Cikapundung River basin, which is located just north of Bandung City. Water samples for stable isotope composition analysis were taken from 19 observation wells distributed randomly inside the basin. All analysis data lead to the recognition that Lembang Fault blocks the groundwater flow. No indication was found for water being recharged at higher elevation in the northern part of Bandung Basin, which means the recharged water in Mount Tangkuban Parahu area does not reach Bandung Plain.

Delinom, Robert M.

2009-06-01

299

Shakedown analysis of frame structure  

International Nuclear Information System (INIS)

In many fields of advanced technology, such as nuclear, space and aeronautic activities or off-shore exploration oil, very high requirements are imposed on structural safety and reliability. Because of the complexity of the practical loading, the response of structure to variable loading is quite different from that to the proportional load, and the failure forms are not the same. Generally there exist local failure due to plastic fatigue (alternating plasticity) and a gradual divergence of the deformed configuration (incremental collapse of ratchetting). Prager once gave the word of shakedown to a safety structure and he pointed out that an elasto-plastic structure subjected to cyclic histories of loads and/or temperature distributions is said to shake down if its plastic work is bounded. This means that the structure attains at a finite time or approaches asymptotically a situation of purely clastic cycling. When this is not the case, nonadaptation will occur. Since Melan and Koiter produced the upper and lower shakedown theorems respectively, a great achievements have been obtained in the area of theoretical and practical shakedown analysis, especially since Maier pointed out the linear program method, a lot of unsolved problems have been analyzed on the basis of shakedown theorems. In this paper, we studied the linear program formula of upper and lower bound theorem, on the basis of comparison of these two formula, a conclusion was obtained that the shakedown parameter solved by lower bound theorem is a complete solution when surplus variables arc not basic ones. Therefore it is unnecessary to solve a problem using upper bound theorem if surplus variables arc zeros when it is solved by lower bound theorem, and this easilizes somewhat what is considered

1993-08-15

300

Modified chromatographic separation scheme for Sr and Nd isotope analysis in geological silicate samples  

Directory of Open Access Journals (Sweden)

Full Text Available A novel chromatographic separation technique for Sr and Nd separation from geological silicate samples was established and successfully tested for routine use in Laboratory of Radiogenic Isotopes of the Czech Geological Survey. The separation scheme is based on combination and modification of methods published in papers by Christian Pin and his co-workers. This triple column arrangement enables the isolation of pure Sr and Nd fractions (also Sm if required from bulk-rock solution in a single step during one working day. The Sr and Nd yields are high, while blank levels remain low. This procedure minimizes the acid consumption and time needed for the separation by more than half compared to the traditional ion exchange separation techniques. The calibration of the Ln.Spec columns should be periodically monitored because the elution of REEs shifts after a period of extensive use of the resin. Suitability of this technique for Sr and Nd separation from silicate rock samples was confirmed by repeated measurements of 87Sr/86Sr and 143Nd/144Nd isotopic ratios in three international reference materials BCR-1, JA-1 and JB-3.

Denkova P

2008-01-01

 
 
 
 
301

The relationship of structures and geological-building of Rudòany ore field to geotechnics features  

Directory of Open Access Journals (Sweden)

Full Text Available The geostructural and geotechnical analysis was aimed at the concrete conditions of the Rudòany ore field at the Spi? region, the part of the Slovak Republic. Our research results make it possible to minimalize the negative influence of moisture liquidation of the mine field from the ecological point of view. The paper is devided into followings parts: present and future moisture liquidations and their influences on surface subsidences, the theoretical principles for the geotechnical evaluation of the subsidences and application of the principles.

Vavrek Pavol

1999-12-01

302

Rare earth elements content in geological samples from eastern desert, Egypt, determined by instrumental neutron activation analysis  

Energy Technology Data Exchange (ETDEWEB)

Twenty representative geological samples (tonalite, granodiorite, adamellite, syenogranite, rapakivi syenogranite, alkali feldspar granite and monzogranite) were collected from G. Kattar area in Eastern Desert, Egypt, for analysis by instrumental neutron activation as a sensitive nondestructive analytical tool for the determination of 14 rare earth elements (REEs) and to find out the following: (1) what information could be obtained about the REEs and distribution patterns of REEs in geological samples under investigation, (2) to estimate the accuracy, reproducibility and detection limit of the INAA method in case of the given samples. The samples were properly prepared together with standard reference material and simultaneously irradiated in a neutron flux of 7x10{sup 11} n/cm{sup 2} s in the TRIGA Mainz research reactor facilities. The gamma spectra were collected by an HPGe detector and the analysis was done by means of a computerized multichannel analyzer. The choice of the nuclear reaction, irradiation and decay times, and of the proper gamma radiation in counting are presented and discussed. The results are found to be in good agreement with certified values.

El-Taher, A., E-mail: Atef_Eltaher@hotmail.co [Physics Department, Faculty of Science, Al-Azher University, Assuit Branch 71542 Assuit (Egypt)

2010-09-15

303

Rare earth elements content in geological samples from eastern desert, Egypt, determined by instrumental neutron activation analysis  

International Nuclear Information System (INIS)

Twenty representative geological samples (tonalite, granodiorite, adamellite, syenogranite, rapakivi syenogranite, alkali feldspar granite and monzogranite) were collected from G. Kattar area in Eastern Desert, Egypt, for analysis by instrumental neutron activation as a sensitive nondestructive analytical tool for the determination of 14 rare earth elements (REEs) and to find out the following: (1) what information could be obtained about the REEs and distribution patterns of REEs in geological samples under investigation, (2) to estimate the accuracy, reproducibility and detection limit of the INAA method in case of the given samples. The samples were properly prepared together with standard reference material and simultaneously irradiated in a neutron flux of 7x1011 n/cm2 s in the TRIGA Mainz research reactor facilities. The gamma spectra were collected by an HPGe detector and the analysis was done by means of a computerized multichannel analyzer. The choice of the nuclear reaction, irradiation and decay times, and of the proper gamma radiation in counting are presented and discussed. The results are found to be in good agreement with certified values.

2010-09-01

304

Geological and structural characterization and microtectonic study of shear zones Colonia  

International Nuclear Information System (INIS)

The “Colonia Shear Zone System”, characterized by a transcurrent system of predominant sinistral shear sense, is defined by two approximately parallel shear zones, denominated Isla San Gabriel-Juan Lacaze Shear Zone (ISG-JL S.Z.) and Islas de Hornos-Arroyo Riachuelo Shear Zone (IH-AºR S. Z.). Represented by rocks with ductile and brittle deformation, are defined as a strike slip fault system, with dominant subvertical foliation orientations: 090-100º (dip-direction 190º) and 090-100º (dip-direction 005º). The K/Ar geochronology realized, considering the estimates temperatures conditions for shear zones (450-550º), indicate that 1780-1812 Ma should be considered a cooling age and therefore a minimum deformation age. The observed microstructures suggest deformation conditions with temperatures between 450-550º overprinted by cataclastic flow structures (reactivation at lower temperature)

2010-05-01

305

Geological heritage of Morocco  

International Nuclear Information System (INIS)

Full text: The soil and subsoil of Morocco are rich in geological phenomena that bear the imprint of a history that goes back in time more than 2000 million years. Very many sites geologically remarkable exposed in accessible outcrops, with good quality remain unknown to the general public and therefore deserve to be vulgarized. It is a memory to acquaint to the present generations but also to preserve for future generations. In total, a rich geological heritage in many ways: Varied landscapes, international stratotypes, various geological structures, varied rocks, mineral associations, a huge procession of fossiles, remnants of oceanic crust (ophiolites) among oldests ones in the world (800my), etc... For this geological heritage, an approach of an overall inventory is needed, both regionally and nationally, taking into account all the skills of the earth sciences. This will put the item on the natural (geological) potentialities as a lever for sustainable regional development. For this, it is necessary to implement a strategy of ''geoconservation'' for the preservation and assessment of the geological heritage.

2012-10-22

306

Geology and structure of major uranium-bearing zones in India and their exploration  

International Nuclear Information System (INIS)

Radiogeologic, lithostratigraphic, tectonic, and crustal evolutionary considerations have enabled the recognition of three major uranium provinces in India: the Singhbhum Province in the north-east; the Rajasthan Province in the north-west; and the Madhya Pradesh Province in central India. The paper describes the salient features of the three uranium provinces, with particular emphasis on their structural set-up, magmatectonics, and the controls of uranium mineralization, and presents a few recent case histories of individual deposits (Bagjata and Turamdih in Singhbhum, and Dhabi-Dumhat in Madhya Pradesh) discovered by integrated exploration techniques. The three uranium provinces are related to major deep-seated faults: the Singhbhum Province lies at the arcuate north-east end of the deep fault of the Eastern Ghats; the Rajasthan Province parallels the great boundary fault; and the Madhya Pradesh Province aligns with the Mahanadi-Son rift system. Some of the plausible explanations for these remarkable features are: localization of uranium ore during episodes of crustal fracturing in Precambrian times; reactivation and rejuvenation of favourable basement structures; and the role of local 'hot spots' (aided by compressional and vertical tectonics) in crustal zones anomalously enriched in the heat-producing elements. Uranium exploration strategy in India during the last three decades reveals two significant trends - the application of conventional radiometric techniques during the period 1950-65; and introduction of sophisticated methodology comprising non-radiometric geophysical techniques, emanometry, aerial and car-borne gamma-ray spectrometry, geochemical surveys, and photogeological techniques as supplements to conventional radiometry, during the period 1965-75. It is concluded that extension of such integrated exploration techniques to favourable virgin terrains in India would lead to newer and richer uranium ore discoveries. (author)

1976-04-02

307

Dynamic analysis of embedded structures  

International Nuclear Information System (INIS)

The paper presents simplified rules to account for embeddment and soil layering in the soil-structure interaction problem, to be used in dynamic analysis. The relationship between the spring method, and a direct solution (in which both soil and structure are modeled with finite elements and linear members) is first presented. It is shown that for consistency of the results with the two solution methods the spring method should be performed in the following three steps: 1. Determination of the motion of the massless foundation (having the same shape as the actual one) when subjected to the same input motion as the direct solution. 2. Determination of the frequency dependent subgrade stiffness for the relevant degrees of freedom. 3. Computations of the response of the real structure supported on frequency dependent soil springs and subjected at the base of these springs to the motion computed in step 1. The first two steps require, in general, finite element methods, which would make the procedure not attractive. It is shown in the paper, however, that excellent approximations can be obtained, on the basis of 1-dimensional wave propagation theory for the solution of step 1, and correction factors modifying for embeddment the corresponding springs of a surface footing on a layered stratum, for the solution of step 2. (Auth.)

1977-08-19

308

Geological structure of the deep eastern Mediterranean Sea (east of 25 Degrees E)  

Energy Technology Data Exchange (ETDEWEB)

The deformation fronts of the Cyprus arc and the Mediterranean ridge, extending from the Turkey-Syria boundary to north Cyrenacia, are the southernmost superficial expression of the convergence between the Eurasian and African plates. They separate the Eastern Mediterranean deep basin into two different structural units: (1) A thrust belt, northward, with the presence of Cenozoic sedimentary basins which could be considered piggy-back basins (Iskenderun, Adana, Cilicia, and Antalya basins). These basins, filled by 4,000 to 6,000 m of Cenozoic sediments, lie on a substratum composed of south-vergent nappes emplaced between the Late Cretaceous and the late Miocene. (2) A foreland area, southward, where the thick Herodotus and Levantine sedimentary basins, relatively undeformed, lie on the passive and subsident African continental margin initiated during Late Triassic or early Liassic time. Due to the still-active collision between the thrust belt and the Erathosthenes seamount, Cyprus was uplifted and today represents the emerged part of the deformation front. During the Messinian, with the isolation of the Mediterranean Sea, evaporitic deposits including a salt layer (sometimes more than 2,000 m thick) were widely distributed into the Iskenderun, Cilicia, Antalya, Levantine, and Herodotus basins. In these basins, the Messinian sedimentation was directly controlled by basin topography.

Montadert, L.; Sage, L.; Letouzey, J. (Institut Francais du Petrole, Rueil-Malmaison (France))

1988-08-01

309

Geological structure impact on the exchange between fractures and matrix for the fractured porous media  

International Nuclear Information System (INIS)

Fractured porous media are characterized by the presence of fractures at several scales with heterogeneous properties implying areas highly permeable by comparison with the rock. Hydraulically, these media are characterized by short reaction times, due to the fractures, and long reaction times, due to the rock. These media are important for several topics as contaminated sites, element storage and resources exploitation. The main challenge of fracture porous media modeling is the representation of the geometrical and physical heterogeneities. As an exact representation of the medium is not possible, it is necessary to determine the key properties of the medium. This study aims at determining the impact of the geometrical and physical properties of the fractures and the matrix from the local to the global scales. A first part consists in creating methods to evaluate structure effects on the exchange between the fractures and the matrix and a second part consists in using these methods on several media. Finally, we describe a new discrete dual-porosity model taking into account the properties of the media characterizing its behavior. (author)

2010-01-01

310

Structural and Tectonic Geology of the Namche Barwa-Gyala Peri Antiform, Southeastern Tibet  

Science.gov (United States)

The Namche Barwa-Gyala Peri antiform is shown by our field mapping and lab results to have two parts, separated by a major north-dipping crustal-scale shear zone and fault, the Nam-la thrust zone. The oldest detected parts of this thrust zone are amphibolite-grade ductile shear involved with abundant dioritic migmatites; it later progressed through s/c mylonites, and into brittle faulting localised on the northern side of the zone. Cooling ages show that the northern part of the NB-GP antiform was very recently and rapidly exhumed, suggesting that the thrust is linked to this exhumation and still active. South and southwest of the Nam-la thrust and migmatite zone, biotite cooling ages of 4-10Ma show that growth of this extension of the Namche Barwa antiformal structure was minimal after the latest Miocene. The Nam-la thrust crosses the Tsangpo at the first major knickpoint and passes northwest into the marginal thrust fault and shear zone bounding the Gyala Peri massif. Older ductile shear is expressed in the steeply-dipping bordering zones of both sides of the NB-GP antiform and we interpret this largely to be from the original Himalayan underthrusting fabrics, reoriented by the antiform. Most ductile shear indicators seen in Lhasa block gneisses and the Himalayan Tethyan metasediments near the attenuated Indus-Tsangpo ophiolitic suture southwest of the NB- GP massif are thrust sense, either related to the early-Miocene Gangdese thrust, or to earlier Himalayan thrusting. The hypothesis of an extensional detachment fault within the Lhasa block between basement gneisses and amphibolite-grade metasediments is rejected on the basis of our observations in the field. Evidence for north-down normal sense shear associated with amphibolite-greenschist facies rocks along the attenuated Indus-Tsangpo ophiolitic suture has been seen in a few places, possibly evidence of mid-Miocene STDS-related extension. Within the western side of the overall Namche Barwa antiform, a belt of variably retrograded high-pressure gneisses forms the upper part of the apparent Indian basement. This belt has a narrow thrust-sense mylonite zone along its southeastern (lower) contact, with amphibolite facies clastic metasediments below. Its northwestern contact with Tethyan quartzose, pelitic and calcsilicate amphibolite facies schists is a normal-sense ductile shear zone. We interpret this belt as a crustal slice deeply-subducted and returned quickly to within the crust during the earliest stages of the Himalyan collision, its shear zone contacts probably related to this upward return. The northern end of the NB-GP antiform plunges steeply north, producing a large-scale monoclinal fold in the Lhasa block basement and metasedimentary cover schists and gneisses; the steep part of this fold is within the Jiali Fault Zone, and here right-lateral strike-slip brittle faulting is locally prominent. Surface structural constraints require detachment of the NB-GP rocks from at least mid- crustal depths, but by themselves do not necessarily require that the Nam-la shear zone extend to the base of the present double-thickness crust.

Kidd, W. S.; Lim, C.; Zeitler, P. K.; Enkelmann, E.; Booth, A. L.; Chamberlain, C. P.; Tang, W.; Liu, Y.; Craw, D.

2006-12-01

311

Geology of drill hole USW VH-2, and structure of Crater Flat, southwestern Nevada  

International Nuclear Information System (INIS)

A 1219 meter (4000 ft) drill hole in Crater Flat shows the absence of buried Pliocene or Quaternary volcanic rocks, and penetrates a section of Timber Mountain, Paintbrush, and the upper part of the Crater Flat Tuffs, similar to that exposed adjacent to Crater Flat. A prominent negative aeromagnetic anomaly between the drill hole and Bare Mountain is attributed to a westward thickening section of a reversely magnetized Miocene basalt. The relatively shallow depth of this basalt in the west-central part of Crater Flat indicates that no large amount of tectonic movement has occurred in approximately the last 10 m.y. Massive brecciated wedges of Paleozoic rocks are penetrated in two stratigraphic intervals in the drill hole; the older one, between the Tiva Canyon Member of the Paintbrush Tuff and the Rainier Mesa Member of the Timber Mountain Tuff, correlates with the time of maximum faulting east of Crater Flat in the Yucca Mountain area. The younger slide masses are correlated with a large slide block of probable late Miocene age exposed along the southwestern rim of Crater Flat. The structural pattern and style buried beneath central and western Crater Flat is deduced to be similar to that exposed at Yucca Mountain, but less developed. The major fault system controlling the steep east face of Bare Mountain, though probably still active, is believed to have developed mainly as a result of caldera collapse between 13 and 14 m.y. ago. Relations between faulting and four episodes of basalt eruption in the Crater Flat area strongly suggest contemporaneity of the two processes. 17 refs., 2 figs., 3 tabs

1985-01-01

312

Multi-elemental analysis of aqueous geological samples by inductively coupled plasma-optical emission spectrometry  

Science.gov (United States)

Typically, 27 major, minor, and trace elements are determined in natural waters, acid mine drainage, extraction fluids, and leachates of geological and environmental samples by inductively coupled plasma-optical emission spectrometry (ICP-OES). At the discretion of the analyst, additional elements may be determined after suitable method modifications and performance data are established. Samples are preserved in 1–2 percent nitric acid (HNO3) at sample collection or as soon as possible after collection. The aqueous samples are aspirated into the ICP-OES discharge, where the elemental emission signals are measured simultaneously for 27 elements. Calibration is performed with a series of matrix-matched, multi-element solution standards.

Todorov, Todor I.; Wolf, Ruth E.; Adams, Monique

2014-01-01

313

Groundwater Flow Systems at the Nevada Test Site, Nevada: A Synthesis of Potentiometric Contours, Hydrostratigraphy, and Geologic Structures  

Energy Technology Data Exchange (ETDEWEB)

Contaminants introduced into the subsurface of the Nevada Test Site by underground nuclear testing are of concern to the U.S. Department of Energy and regulators responsible for protecting human health and safety. The potential for contaminant movement away from the underground test areas and into the accessible environment is greatest by groundwater transport. The primary hydrologic control on this transport is evaluated and examined through a series of contour maps developed to represent the hydraulic-head distribution within each of the major aquifers underlying the area. Aquifers were identified and their extents delineated by merging and analyzing multiple hydrostratigraphic framework models developed by other investigators from existing geologic information. A map of the hydraulic-head distribution in each major aquifer was developed from a detailed evaluation and assessment of available water-level measurements. Multiple spreadsheets that accompany this report provide pertinent water-level and geologic data by well or drill hole. Aquifers are mapped and discussed in general terms as being one of two types: alluvial-volcanic, or carbonate. Both aquifer types are subdivided and mapped as independent regional and local aquifers, based on the continuity of their component rock. Groundwater-flow directions, approximated from potentiometric contours that were developed from the hydraulic-head distribution, are indicated on the maps and discussed for each of the regional aquifers and for selected local aquifers. Hydraulic heads vary across the study area and are interpreted to range in altitude from greater than 5,000 feet in a regional alluvial-volcanic aquifer beneath a recharge area in the northern part of the study area to less than 2,300 feet in regional alluvial-volcanic and carbonate aquifers in the southwestern part of the study area. Flow directions throughout the study area are dominantly south-southwest with some local deviations. Vertical hydraulic gradients between aquifer types are downward throughout most of the study area; however, flow from the alluvial-volcanic aquifer into the underlying carbonate aquifer, where both aquifers are present, is believed to be minor because of an intervening confining unit. Limited exchange of water between aquifer types occurs by diffuse flow through the confining unit, by focused flow along fault planes, or by direct flow where the confining unit is locally absent. Interflow between regional aquifers is evaluated and mapped to define major flow paths. These flow paths delineate tributary flow systems, which converge to form intermediate and regional flow systems. The implications of these flow systems in controlling transport of radionuclides away from the underground test areas at the Nevada Test Site are briefly discussed. Additionally, uncertainties in the delineation of aquifers, the development of potentiometric contours, and the identification of flow systems are identified and evaluated. Eleven tributary flow systems and three larger flow systems are mapped in the Nevada Test Site area. Flow systems within the alluvial-volcanic aquifer dominate the western half of the study area, whereas flow systems within the carbonate aquifer are most prevalent in the southeastern half of the study area. Most of the flow in the regional alluvial-volcanic aquifer that moves through the underground testing area on Pahute Mesa is discharged to the land surface at springs and seeps in Oasis Valley. Flow in the regional carbonate aquifer is internally compartmentalized by major geologic structures, primarily thrust faults, which constrain flow into separate corridors. Contaminants that reach the regional carbonate aquifer from testing areas in Yucca and Frenchman Flats flow toward downgradient discharge areas through the Alkali Flat-Furnace Creek Ranch or Ash Meadows flow systems and their tributaries.

Fenelon, Joseph M.; Sweetkind, Donald S.; Laczniak, Randell J.

2010-01-25

314

Dynamic analysis of embedded structures  

International Nuclear Information System (INIS)

The paper presents simplified rules to account for embedment and soil layering in the soil-structure interaction problem, to be used in dynamic analyses. The relationship between the spring method, and a direct solution (in which both soil and structure are modele with finite elements and linear members) is first presented. It is shown that for consistency of the results with the two solution methods the spring method should be performed in the following three steps: 1. Determination of the motion of the massless foundation (having the same shape as the actual one) when subjected to the same input motion as the direct solution. For an embedded foundation it will yield, in general, both translations and rotations. 2. Determination of the frequency dependent subgrade stiffness for the relevant degrees of freedom. This step yields the so-called 'soil springs'. 3. Computations of the response of the real structure supported on frequency dependent soil springs and subjected at the base of these springs to the motion computed in step 1. The first two steps require, in general, finite element methods, which would make the procedure not attractive. It is shown in the paper, however, that excellent approximations can be obtained, on the basis of 1-dimensional wave propagation theory for the solution of step 1, and correction factors modifying for embedment the corresponding springs of a surface footing on a layered stratum, for the solution of step 2. Use of these rules not only provides remarkable agreement with the results obtained from a full finite element analysis, but results in substantial savings of computer execution and storage requirements

1977-08-19

315

Self-attenuation correction in gamma-ray spectrometry analysis of geological samples using the transmission method  

Energy Technology Data Exchange (ETDEWEB)

Laboratory gamma spectrometric analyses require correction for self-attenuation effect due to the interactions of the photons emitted by the sample and its own matrix. This issue becomes more important when samples of distinct densities and matrixes have to be measured. In this study, self-attenuation factors for efficiency correction of an HPGe detector, used for rock and soil radionuclide analyses, were calculated through gamma transmission measurements. These factors were calculated for 17 geological samples arranged in cylindrical recipients. For each sample, transmission measurements were accomplished for 17 energies ranging from 59 to 1409 keV, using three punctual sources, {sup 152}Eu, {sup 133}Ba and {sup 241}Am. The samples include several lithotypes (sandstone, siltstone, rhyolite and basalt), saprolite, soil, pure silica, pure calcium carbonate, a blend of carbonate and silica, and three IAEA reference materials for natural occurring radionuclide analysis, RG-K-1, IAEA-326 and IAEA-385. The densities varied from 0.5 to 2.2 g.cm{sup -3}. These data permitted a good fit with a theoretically deduced function that models the self-attenuation correction factor dependence on samples densities. The dependence on energy was empirically modeled. This function can be further used to correct the self-attenuation effect on gamma spectrometric analyses of other geological samples in the studied energy range. Some limitations of the model are discussed. (author)

Bastos, Rodrigo O.; Ferreira, Ademar de O.; Appoloni, Carlos R. [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Fisica. Lab. de Fisica Nuclear Aplicada]. E-mails: rbastos@uel.br; ofademar@hotmail.com; appoloni@uel.br

2007-07-01

316

Self-attenuation correction in gamma-ray spectrometry analysis of geological samples using the transmission method  

International Nuclear Information System (INIS)

Laboratory gamma spectrometric analyses require correction for self-attenuation effect due to the interactions of the photons emitted by the sample and its own matrix. This issue becomes more important when samples of distinct densities and matrixes have to be measured. In this study, self-attenuation factors for efficiency correction of an HPGe detector, used for rock and soil radionuclide analyses, were calculated through gamma transmission measurements. These factors were calculated for 17 geological samples arranged in cylindrical recipients. For each sample, transmission measurements were accomplished for 17 energies ranging from 59 to 1409 keV, using three punctual sources, 152Eu, 133Ba and 241Am. The samples include several lithotypes (sandstone, siltstone, rhyolite and basalt), saprolite, soil, pure silica, pure calcium carbonate, a blend of carbonate and silica, and three IAEA reference materials for natural occurring radionuclide analysis, RG-K-1, IAEA-326 and IAEA-385. The densities varied from 0.5 to 2.2 g.cm-3. These data permitted a good fit with a theoretically deduced function that models the self-attenuation correction factor dependence on samples densities. The dependence on energy was empirically modeled. This function can be further used to correct the self-attenuation effect on gamma spectrometric analyses of other geological samples in the studied energy range. Some limitations of the model are discussed. (author)

2007-10-05

317

Investigation of corrosion and analysis of passive films concerning some nickel alloys and stainless steels in reconstructed geological environments  

International Nuclear Information System (INIS)

This research thesis addresses the corrosion behaviour of materials which might be used for the fabrication of radioactive waste containers. After a bibliographical study on films formed on Fe-Cr-Ni alloys, this research concentrates on passivation and de-passivation phenomena of three nickel-base alloys among the most resistant to corrosion and which also meet processing and economic criteria: Hastelloy C4, Inconel 625 and ZICNDU 25-20. Titanium and Ti-Pd alloy are also studied. Parameters governing pitting corrosion are notably studied. After a recall of knowledge on passive films formed on Fe-Cr-Ni alloys, and a presentation of experimental and technical conditions, the author reports and discussed the results obtained by electrochemical studies, reports the determination of factors governing alloy passivation in geological waters. The influence of some soluble impurities is notably studied. The author reports the analysis by glow discharge optical emission spectrometry to determine the composition of passive films with respect to geological water nature, the immersion duration and the electrode potential. Additional surface analyses are performed by X-ray photoelectron spectrometry (XPS or ESCA) and secondary ion mass spectrometry (SIMS). Finally, the author uses a dosing method by neutron radio-activation of alloy elements to determine dissolution mechanisms

1984-01-01

318

Study on the remote sensing geological information of uranium mineralization in Western Liaoning and Northern Hebei  

International Nuclear Information System (INIS)

Based on the whole areal geological map joint application rd exploitation, composite forming map, generalization analysis and field examination in detail of key region that mainly depend on remote sensing information and generalize the data of geology, geophysical and geochemical prospecting, and geohydrology, this paper reveals the structure framework, regional geological background, uranium metallogenic condition and space time distribution rule of orustal evolution and its result, and set up the interpretation marks of arc-shaped structure in different of rock area and discusses its geological genesis. The author also interprets volcanic apparatus, small type closed sedimentary basin, magmatic rock body which relate closely to uranium deposit, ore control structure and occurrence and type of mineralization alteration envelope. The thermal halo point of satellite image is emphatically interpreted and its geological meaning and its relation to uranium deposit is discussed. Remote sensing geological prospecting ore model and synthetic provision model is determined lastly

1996-12-01

319

Reconstructing the geological and structural history of an active geothermal field: A case study from New Zealand  

Science.gov (United States)

The utilisation of geothermal systems benefits from an understanding of the host-rock geology, locations and controls of permeability pathways, and the nature and timing of magmatic sources providing thermal energy. Kawerau Geothermal Field in the central Taupo Volcanic Zone (TVZ) of New Zealand is currently developed for electricity generation and direct uses of high-temperature steam to ~ 200 MW electrical output. The Kawerau geothermal system is hosted in a sequence of volcanic lithologies (tuffs, lavas and intrusive bodies) and sediments that overlie faulted Mesozoic metasedimentary (greywacke) basement. Identification of lithologies in the volcanic/sedimentary sequence is challenging due to the levels of hydrothermal alteration and lithological similarities. A combination of detailed petrological investigations, consideration of the emplacement processes and greater certainty of crystallisation or eruption ages through U-Pb age determinations on zircons is used to reconstruct the depositional and faulting evolution of the rocks hosting the currently active hydrothermal system. The oldest event inferred is faulting of the greywacke along northwest-southeast orientated, dominantly strike-slip structures to generate half-grabens that were filled with sediments, incorporating two dated ignimbrites (2.38 ± 0.05 and 2.17 ± 0.05 Ma). A 1.46 ± 0.01 Ma ignimbrite was deposited relatively evenly across the field, implying that any topographic relief was subdued at that time. Subsequent deposition of ignimbrites occurred in episodes around 1.0, 0.55-0.6, and 0.32 Ma, interspersed with thin sedimentary sequences that accumulated at average rates of 0.06 mm yr- 1. Andesite lavas from a buried composite cone occur as a conformable package between units dated at 1.0 and 0.6 Ma. Bodies of coherent rhyolite occur at multiple stratigraphic levels: two magma types with associated tuffs were emplaced as domes and sills at 0.36 ± 0.03 Ma, and a third type at 0.138 ± 0.007 Ma as dikes, and domes that are exposed at surface. The andesitic Putauaki composite cone southwest of the field first erupted around 8 ka, but earlier hydrothermal eruption breccias imply that magma was intruded to shallow depths as early as ~ 16 ka. Age data and associated correlations show that post-1.5 Ma normal faulting has accompanied episodic subsidence of the Kawerau area, with fault movement focused between northeast-southwest structures (associated with the geometry of the modern TVZ) and the reactivated northwest-southeast structures associated with most displacement in the area prior to 1.5 Ma. Contrasts between emplacement of coherent rhyolite as sills at 0.36 Ma and a dike at 0.138 Ma reflect a shift in orientation of the principal stress axes in response to initiation of the modern TVZ rifting regime. Most volcanic rocks at Kawerau are distally sourced from elsewhere in the TVZ but form local marker horizons that delineate topographic relief within the field, and additionally constrain past subsidence rates. Current rates of subsidence and thermal output at Kawerau are geologically recent features associated with latest Quaternary rifting processes (< ~ 50 ka) and emplacement of the magmatic system for Putauaki volcano (~ 16 ka) respectively.

Milicich, S. D.; Wilson, C. J. N.; Bignall, G.; Pezaro, B.; Bardsley, C.

2013-07-01

320

Geologic Framework and Description of Coalbed Gas Plays  

Science.gov (United States)

Coalbed gas currently accounts for about 6 percent of all US natural gas reserves. This 85-page US Geological Survey report describes the geology of these coalbed gas plays, discusses potential for future prospects and provides a brief history of coalbed gas exploration in the US. Copious information about many sedimentary basins, Cretaceous and Tertiary strata, and Laramide structures is included as part of the coalbed methane play analysis.

Rice, Dudley; Survey, Us G.

 
 
 
 
321

Analysis of Water Flow Paths: Methodology and Example Calculations for a Potential Geological Repository in Sweden  

International Nuclear Information System (INIS)

Safety assessment related to the siting of a geological repository for spent nuclear fuel deep in the bedrock requires identification of potential flow paths and the associated travel times for radionuclides originating at repository depth. Using the Laxemar candidate site in Sweden as a case study, this paper describes modeling methodology, data integration, and the resulting water flow models, focusing on the Quaternary deposits and the upper 150 m of the bedrock. Example simulations identify flow paths to groundwater discharge areas and flow paths in the surface system. The majority of the simulated groundwater flow paths end up in the main surface waters and along the coastline, even though the particles used to trace the flow paths are introduced with a uniform spatial distribution at a relatively shallow depth. The calculated groundwater travel time, determining the time available for decay and retention of radionuclides, is on average longer to the coastal bays than to other biosphere objects at the site. Further, it is demonstrated how GIS-based modeling can be used to limit the number of surface flow paths that need to be characterized for safety assessment. Based on the results, the paper discusses an approach for coupling the present models to a model for groundwater flow in the deep bedrock

2006-12-01

322

Parametric analysis of mined geologic disposal of high-level radioactive waste  

International Nuclear Information System (INIS)

A simplified mathematical model has been developed to screen potential mined geological repository sites taking into account the uncertainty in the input data. Initial input data that was assumed constant was inventory of radioactive wastes, number and size of cannisters, size of repository, and the ground water flow area. Though there is some uncertainty in these data, by far the greatest uncertainty pertained to leach rate of the waste form and cannister, ground water velocity, retardation rates of nuclides relative to ground water, distance to the biosphere and flow rate in the receiving waters in the biosphere. These were varied over realistic ranges from 1 to 4 orders of magnitude. The results showed that there are a wide variety of combinations of these parameters that allow a waste repository to be sited without exceeding the maximum permissible concentrations of isotopes in drinking water. It is concluded that for the artificially-created nuclides it is the intermediate time period, greater than 1000 years and less than 1 million years, that poses the greatest problem

1982-03-01

323

Scenarios of geological long-term safety: Risk analysis for a final repository for high-level radioactive wastes in Northern Switzerland  

International Nuclear Information System (INIS)

A synopsis is presented of the geological risk factors for a high level radioactive waste repository in Northern Switzerland. The study is based on results available so far of the ongoing regional geological and neotectonic investigations. Scenarios of possible future geological situations have been derived by combining data of observed and/or measured ongoing neotectonic processes with those of reconstructed trends of past geological history. These scenarios have been used to predict the impact of possible future geological developments and events on a repository for a time horizon of approx. one million years. Two regional scenarios provide the framework for the megatectonic development: In scenario A the alpine orogenic cycle is assumed to have come to an end, tectonic movements would gradually die out. In such a scenario the safety of a repository within the Basement at a depth of some 1200 m is not considered to be at risk. For scenario B the alpine orogeny is assumed to be actively continuing now and for the next 10 million years. Therefore, tectonic deformation in the Jura-mountains and the Black Forest would also continue. However, the results of the risk analysis indicate that plausible future geological developments within the timeframe of one million years would not adversely affect the safety of a repository

1985-01-01

324

Methodological aspects and development of techniques for neutron activation analysis of microcomponents in materials of geologic origin  

International Nuclear Information System (INIS)

Some aspects of the activation analysis methodology applied to geological samples activated in nuclear reactors were studied, and techniques were developed for the determination of various elements in different types of matrixes, using gamma spectrometry for the measurement of the products. The consideration of the methodological aspects includes the study of the working conditions, the preparation of samples and standards, irradiations, treatment of the irradiated material, radiochemical separation and measurement. Experiments were carried out on reproducibility and errors in relation to the behaviour of the measurement equipment and that of the methods of area calculation (total area, Covell and Wasson), as well as on the effects of geometry variations on the results of the measurements, the RA-3 reactors's flux variations, and the homogeneity of the samples and standards. Also studied were: the selection of the conditions of determination, including the irradiation and decay times; the irradiation with thermal and epithermal neutrons; the measurement with the use of absorbers, and the resolution of complex peaks. Both non-destructive and radiochemical separation techniques were developed for the analysis of 5 types of geological materials. These methods were applied to the following determinations: a) In, Cd, Mn, Ga and Co in blende; b) La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in fluorites; c) La, Ca, Eu, Tb, Yb, Se and Th in barites and celestites; d) Cu and Zn in soils. The spectral interferences or those due to nuclear reactions were studied and evaluated by mathematical calculation. (M.E.L.)

1982-01-01

325

Road-map to plan and structure the preliminary site investigation program for a geological repository in Japan  

International Nuclear Information System (INIS)

Available in abstract form only. Full text of publication follows: A stepwise site selection process has been adopted for geological disposal of HLW in Japan. Literature surveys (LS), followed by preliminary investigations (PI) and, finally, detailed investigations (DI) in underground facilities will be carried out in the successive selection stages. In the PI stage, surface-based investigations such as borehole surveys and geophysical prospecting will be implemented with two main objectives. The first is to obtain information relating to legal requirements on siting, such as the occurrence of igneous or fault activity, and to confirm the extremely low likelihood of adverse impacts on the candidate site resulting from such phenomena. The second is to obtain the information required for the design and performance assessment of the engineered barrier system and the repository. In order to implement these preliminary investigations rigorously and efficiently within the constraints of a limited time period, budget and resources, PI planning before commencing investigations and on-site PI management during the investigation phase are very important issues. The planning and management of PI have to be performed by NUMO staff, but not all staff have sufficient experience in the range of disciplines involved. NUMO therefore decided to compile existing knowledge and experience in the planning and management of investigations in the form of manuals to be used to improve and maintain internal expertise. Experts with experience in overseas investigation programs were requested to prepare these manuals. This paper outlines the structure and scope of the upper level manual (road-map) and discusses NUMO's experience in applying it in 'dry-runs' to model sites. (authors)

2007-09-02

326

Geology and Geomorphology of the Manipur Valley Using Digitally Enhanced Satellite Image and SRTM DEM in the Eastern Himalaya, India  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Landsat ETM+ data and SRTM DEM data were used to delineate the geological, structural and geomorphological features in the intermontane Imphal Valley in Manipur, India. This area has simple geology, structural features and there- fore provides an ideal site to test the utility of remote sensing and GIS techniques in geological studies. The various techniques such as band ratioing, Principal Component Analysis (PCA) and generation of FCC (False Colour Composite) were employed on ETM+ data. The...

Abdullah Khan; Sarfaraz Ahmad; Shadab Khurshid

2012-01-01

327

Finite element analysis of stresses and deformations occurring in the spent nuclear fuel (SNF) disposal canister deposited in a deep geological repository  

International Nuclear Information System (INIS)

Highlights: • The weight reduction design of the PWR SNF disposal canister is presented. • The optimal SNF basket rotation angle to minimize canister weight is sought. • Conventional structural analysis and Kriging method are developed for this purpose. • The optimal SNF basket rotation angle is determined to be 45°. • The canister weight is correspondingly reduced by 16% from 25 tons to 21 tons. -- Abstract: Numerical computer experimental methodologies are investigated for the weight reduction of a spent nuclear fuel (SNF) disposal canister designed to be deposited in a Korean deep geological repository from a pressurized water reactor (PWR). Finite element analyses of stresses and deformations occurring inside the cylindrical canister under the deposited conditions are performed to assess its structural strength at various rotation angles (?) of the SNF basket. Specifically, the cross sections of four square tube shaped SNF baskets (assemblies) contained in the canister are rotated. Using a conventional structural analysis and a Kriging method, an optimal rotation angle is determined in relation to canister diameter and weight. Both sets of results are in agreement. It was also determined that the computed deformation changes slightly in relation to variances in rotation angle, while the stress incurred inside the cast iron insert of the canister noticeably changes reaching its highest value at ? = 45° while still maintaining safe structural integrity. It is concluded that the diameter of the canister can be reduced from its original design value (102 cm) to 95.8463 cm resulting in a ?16.0% reduction in canister weight for an optimal rotation angle of 45°

2014-01-01

328

Finite element analysis of stresses and deformations occurring in the spent nuclear fuel (SNF) disposal canister deposited in a deep geological repository  

Energy Technology Data Exchange (ETDEWEB)

Highlights: • The weight reduction design of the PWR SNF disposal canister is presented. • The optimal SNF basket rotation angle to minimize canister weight is sought. • Conventional structural analysis and Kriging method are developed for this purpose. • The optimal SNF basket rotation angle is determined to be 45°. • The canister weight is correspondingly reduced by 16% from 25 tons to 21 tons. -- Abstract: Numerical computer experimental methodologies are investigated for the weight reduction of a spent nuclear fuel (SNF) disposal canister designed to be deposited in a Korean deep geological repository from a pressurized water reactor (PWR). Finite element analyses of stresses and deformations occurring inside the cylindrical canister under the deposited conditions are performed to assess its structural strength at various rotation angles (?) of the SNF basket. Specifically, the cross sections of four square tube shaped SNF baskets (assemblies) contained in the canister are rotated. Using a conventional structural analysis and a Kriging method, an optimal rotation angle is determined in relation to canister diameter and weight. Both sets of results are in agreement. It was also determined that the computed deformation changes slightly in relation to variances in rotation angle, while the stress incurred inside the cast iron insert of the canister noticeably changes reaching its highest value at ? = 45° while still maintaining safe structural integrity. It is concluded that the diameter of the canister can be reduced from its original design value (102 cm) to 95.8463 cm resulting in a ?16.0% reduction in canister weight for an optimal rotation angle of 45°.

Wang, Bo [Department of Mechanical and Aerospace Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854-8058 (United States); School of Aeronautics, Northwestern Polytechnical University of China, Xi’an 710072 (China); Gea, Hae Chang [Department of Mechanical and Aerospace Engineering, Rutgers, The State University of New Jersey, 98 Brett Road, Piscataway, NJ 08854-8058 (United States); Kwon, Young Joo, E-mail: yjkwon@hongik.ac.kr [Department of Mechanical and Design Engineering, Hongik University, 2639 Sejong-ro, Jochiwon, Sejong 339-701 (Korea, Republic of)

2014-01-15

329

Geology of Venus planet  

International Nuclear Information System (INIS)

Nowadays data of geological-morphological analysis of the Venus surface obtained as a result of the analysis of ''Venus-15 and -16'' space probes images are presented. The specific features of the Venus relief - plains, mountains, craters are considered and geological-morphological map of the Venus survey zone by ''Venus-15 and -16'' space probes is presented. Data on potassium, uranium, torium and main rockforming elements in the Venus surface rocks by the data of ''Venus-8;-9;-10;-13 and -14'' and ''Vega-1 and -2'' space probes are given

1986-01-01

330

Nuclear Dynamics Consequence Analysis (NDCA) for the Disposal of Spent Nuclear Fuel in an Underground Geologic Repository - Volume 3: Appendices  

International Nuclear Information System (INIS)

The United States Department of Energy Office of Environmental Management's (DOE/EM's) National Spent Nuclear Fuel Program (NSNFP), through a collaboration between Sandia National Laboratories (SNL) and Idaho National Engineering and Environmental Laboratory (INEEL), is conducting a systematic Nuclear Dynamics Consequence Analysis (NDCA) of the disposal of SNFs in an underground geologic repository sited in unsaturated tuff. This analysis is intended to provide interim guidance to the DOE for the management of the SNF while they prepare for final compliance evaluation. This report presents results from a Nuclear Dynamics Consequence Analysis (NDCA) that examined the potential consequences and risks of criticality during the long-term disposal of spent nuclear fuel owned by DOE-EM. This analysis investigated the potential of post-closure criticality, the consequences of a criticality excursion, and the probability frequency for post-closure criticality. The results of the NDCA are intended to provide the DOE-EM with a technical basis for measuring risk which can be used for screening arguments to eliminate post-closure criticality FEPs (features, events and processes) from consideration in the compliance assessment because of either low probability or low consequences. This report is composed of an executive summary (Volume 1), the methodology and results of the NDCA (Volume 2), and the applicable appendices (Volume 3)

1998-01-01

331

Nuclear Dynamics Consequence Analysis (NDCA) for the Disposal of Spent Nuclear Fuel in an Underground Geologic Repository - Volume 3: Appendices  

Energy Technology Data Exchange (ETDEWEB)

The United States Department of Energy Office of Environmental Management's (DOE/EM's) National Spent Nuclear Fuel Program (NSNFP), through a collaboration between Sandia National Laboratories (SNL) and Idaho National Engineering and Environmental Laboratory (INEEL), is conducting a systematic Nuclear Dynamics Consequence Analysis (NDCA) of the disposal of SNFs in an underground geologic repository sited in unsaturated tuff. This analysis is intended to provide interim guidance to the DOE for the management of the SNF while they prepare for final compliance evaluation. This report presents results from a Nuclear Dynamics Consequence Analysis (NDCA) that examined the potential consequences and risks of criticality during the long-term disposal of spent nuclear fuel owned by DOE-EM. This analysis investigated the potential of post-closure criticality, the consequences of a criticality excursion, and the probability frequency for post-closure criticality. The results of the NDCA are intended to provide the DOE-EM with a technical basis for measuring risk which can be used for screening arguments to eliminate post-closure criticality FEPs (features, events and processes) from consideration in the compliance assessment because of either low probability or low consequences. This report is composed of an executive summary (Volume 1), the methodology and results of the NDCA (Volume 2), and the applicable appendices (Volume 3).

Taylor, L.L.; Wilson, J.R. (INEEL); Sanchez, L.C.; Aguilar, R.; Trellue, H.R.; Cochrane, K. (SNL); Rath, J.S. (New Mexico Engineering Research Institute)

1998-10-01

332

A 3D visualization of spatial relationship between geological structure and groundwater chemical profile around Iwate volcano, Japan: based on the ARCGIS 3D Analyst  

Science.gov (United States)

We established 3D geological and hydrological model around Iwate volcano to visualize 3D relationships between subsurface structure and groundwater profile. Iwate volcano is a typical polygenetic volcano located in NE Japan, and its body is composed of two stratovolcanoes which have experienced sector collapses several times. Because of this complex structure, groundwater flow around Iwate volcano is strongly restricted by subsurface construction. For example, Kazahaya and Yasuhara (1999) clarified that shallow groundwater in north and east flanks of Iwate volcano are recharged at the mountaintop, and these flow systems are restricted in north and east area because of the structure of younger volcanic body collapse. In addition, Ohwada et al. (2006) found that these shallow groundwater in north and east flanks have relatively high concentration of major chemical components and high 3He/4He ratios. In this study, we succeeded to visualize the spatial relationship between subsurface structure and chemical profile of shallow and deep groundwater system using 3D model on the GIS. In the study region, a number of geological and hydrological datasets, such as boring log data and groundwater chemical profile, were reported. All these paper data are digitized and converted to meshed data on the GIS, and plotted in the three dimensional space to visualize spatial distribution. We also inputted digital elevation model (DEM) around Iwate volcano issued by the Geographical Survey Institute of Japan, and digital geological maps issued by Geological Survey of Japan, AIST. All 3D models are converted into VRML format, and can be used as a versatile dataset on personal computer.

Shibahara, A.; Ohwada, M.; Itoh, J.; Kazahaya, K.; Tsukamoto, H.; Takahashi, M.; Morikawa, N.; Takahashi, H.; Yasuhara, M.; Inamura, A.; Oyama, Y.

2009-12-01

333

The growth of the continent through geological time studied by Nd isotope analysis of shales  

International Nuclear Information System (INIS)

We determined the Nd isotopic composition and the Sm/Nd ratios in a series of Australian shales ranging from 0.2 Gy to 3.3 Gy. The first result of this study is the constancy of the Sm/Nd ratio in these shales, as in granitoids. Secondly, the initial (143Nd/144Nd) ratio gives a regular curve decreasing through geological time. Both results confirm that shales are representative samples of the continental crust, when insoluble elements, like REE, are studied. We calculated their Nd model ages of crustal differentiation. The model ages regularly decrease with the stratigraphic ages and after 2 Gy, the curve flattens and tends to an asymptotic value at around 1.8 Gy. The significance of the shales is that they represent a mixture of continental materials and we consider the model age of such a mixture directly linked with the mean age of the continental portion feeding the sedimentary basin. From these results, we deduce a quantitative model of the growth curve of the continental source of the shales taking into account the effects of erosion which selectively sample recent mountains relative to shield areas. We propose that the results obtained here are representative of the whole Gondwana continent. Having studied the case of the Australian shales, we try to extend our study. First we applied our quantitative approach to the recent results obtained by O'Nions et al. on North Atlantic provinces. The continental growth curves obtained by our inversion procedure are quite distinct from the Australian shales showing the regional character of shales. (orig./WB)

1984-01-01

334

Appendix P: analysis of geological and geophysical data in selected areas of the North Pacific  

International Nuclear Information System (INIS)

During 1979 we initiated a comprehensive assessment of existing marine geological and geophysical data for the northwest Pacific (PAC 1; 200 to 500N; 1450 to 1800E). The purpose of these studies is to locate, if possible, several 10 x 10 (latitude x longitude) areas which may qualify as candidate waste-disposal sites. Some of these 10 x 10 sites will then be surveyed in detail on future cruises. We have examined all 3.5 and 12 kHz echogram data through the PAC 1 area contained in the Lamont-Doherty, Scripps, and Univ. of Hawaii echogram libraries. These data comprise the vast majority of data that exist for the northwest Pacific. Using these data we were able to classify and map the distribution of various types of microtopography and acoustic reflectivity (echo character) throughout the PAC 1 area. These studies revealed (1) the nature of stratification in the upper 25 to 100 m of the sea floor; (2) nature of the microtopography of the sea floor and areal distribution of basement outcrops; (3) locations of areas affected by bottom currents and mass-wasting process. We have also compiled and evaluated all D.S.D.P. drilling information and L-DGO piston core, bottom camera, heat-flow, sonobuoy, and low frequency seismic-reflection data for the PAC 1 area. We are continuing to compile additional acoustic and station data from other sources including US Navy, NOAA, Japan, and N.G.S.D.C., DMA. Our studies in the PAC 1 area to date have enabled us to locate at least 10 10 x 10 areas which appear to be potentially suitable sites for further waste disposal studies. Three of these potential sites will be surveyed in detail on an upcoming VEMA cruise in spring 1980. Remaining areas will be surveyed during future cruises

1981-04-01

335

Design and analysis of heliostat support structure  

Energy Technology Data Exchange (ETDEWEB)

The design method of the heliostat support structure with the aim of reducing the cost maximally is described in this paper. In order to guarantee the strength, stiffness and stability of the structure, dynamic performance and static performance including internal stress and distortion are analyzed by means of VSAP (Visual Structural Analysis Program) finite element computational software. Then the support structure is optimized on the basis of the analysis. (orig.)

Zang Chuncheng; Wang Zhifeng [Inst. of Electrical Engineering, CAS, BJ (China); Liu Xiaobing; Zhang Xiliang [Himin Solar Energy Group Co. Ltd, Dezhou, SD (China); Wang Yanzhong [Beijing Univ. of Aeronautics and Astronautics, BJ (China)

2008-07-01

336

Integrated Temporal and Spatial Studies of Biological Community Structure, Fluid Geochemistry, and Geological Perturbations on the East Pacific Rise  

Science.gov (United States)

Over the past 19 years, temporal and spatial changes in vent faunal community structure, fluid chemistry, and geological features have been tracked on the East Pacific Rise. Specifically, co-located studies of temporal and spatial changes within the Integrated Study Site region of the EPR have included the: 1) photographic documentation of more than 30 diffuse-flow habitats; 2) characterization of in situ fluid chemistry, temperature, and pH in these habitats; 3) characterization of basalts influenced by venting to enumerate microbial, meiofaunal, and metazoan colonists; 4) characterization of low-temperature hydrothermal fluids for microbial and chemical analyses; and 5) characterization of colonization substrates along with time-lapse camera systems and autonomous chemical and temperature sensors; and 6) characterization of seismic activity spatially targeted at these experimental locations. The goal of this work has been to address first order questions and the existence of correlative patterns among microbial communities, metazoan colonization, and fluid chemical composition- an essential prerequisite for further detailed studies of biological interactions and community dynamics at hydrothermal vents. These co-located activities, which now span a volcanic eruption, have yielded individual and interdependent datasets, which are currently at different stages of analyses and synthesis toward the examination of the interactions of subseafloor perturbations, fluid chemistry and microbes on faunal colonization. Ongoing analytical activities for integration and modeling include: 1) characterizing the composition of microbial colonizers; 2) assigning physiological and functional attributes of microbial colonizers; 3) comparing microbial community composition and physiology with patterns of metazoan colonization; 4) correlating relationships between microbial and metazoan colonization to relationships between fluid chemistry, pH, temperature; 5) relating results of strategic sampling to the observed changes in hydrothermal fluid flux and biological community structure (e.g., succession) at pre- and post-eruptive hydrothermal vents. Our integrative goals include providing input and continuity to long-term, time-series data sets to yield models and insights into temporal and spatial scales over which ecological processes occur on fast-spreading mid-ocean ridges.

Shank, T. M.; Govenar, B.; Luther, G.; Lutz, R.; Vetriani, C.; Tolstoy, M.; Moore, T.; Nuzzio, D.

2008-12-01

337

Antarctica Geology  

Science.gov (United States)

This site contains information about the continent of Antarctica. There is a classroom practice and instructional module. The students will be able to describe the general geology of the land under the Antarctic ice and to explain from where the rocks may have come.

338

Structure of the San Andreas Fault Zone and SAFOD Drill Site as Revealed by Surface Geologic Mapping and Seismic Profiling Near Parkfield, California  

Science.gov (United States)

New geologic mapping, combined with high-resolution seismic reflection and refraction profiling, in the vicinity of the San Andreas Fault Observatory at Depth (SAFOD) deep bore hole near Parkfield, California indicates a wide and structurally complex San Andreas fault zone. The geologic and geophysical techniques both indicate the location and orientation of previously unmapped faults. The San Andreas fault zone near the SAFOD site is at least 5 km wide and is dominated by faults oriented subparallel to the surface trace of the San Andreas fault. Subsurface orientation of faults indicate that the San Andreas fault zone is composed of at least two flower structures in the upper 3 km, with the main trace approximately centered on the more easterly of these structures. The SAFOD drill site is located near the center of the other flower structure. A third flower structure may lie farther to the southwest of our studies. The flower structures likely merge at depth, but at least in the upper 3 to 4 km (the target depth of the SAFOD main hole), they are distinct features. Based on inferred ages of rock types juxtaposed across faults and geomorphic evidence along faults, it appears that the plate boundary (San Andreas fault zone) near the SAFOD site has migrated eastward during the past approximately 20 million years by forming new flower structures.

Rymer, M. J.; Catchings, R. D.; Thayer, M.; Arrowsmith, J. R.

2004-12-01

339

Project Geological Map to the Millionth Scale.  

Science.gov (United States)

Methodologies for the systematic use of remote sensing techniques for regional geological mapping are reported. A large amount of new geological information was obtained permitting a better understanding of structural, tectonic and stratigraphical problem...

A. R. Dossantos L. C. Chiang P. R. Meneses P. Veneziani U. P. Dossantos

1977-01-01

340

Uranium geology and geochemistry, Copper Mountain, Wyoming  

International Nuclear Information System (INIS)

This paper reviews the geology of the major rock units, characterizes the geology, structure, and alteration of the North Canning deposit, discusses the results of geochmemical exploration research and presents alternatives for the genesis of the deposit. 17 refs

1980-01-01

 
 
 
 
341

Structural integrity analysis of thermocouple column assembly and support structure  

International Nuclear Information System (INIS)

The thermocouple column assembly and support structure designed by AREVA is a new structure that has not been used in other nuclear power plants in the world. Structural integrity of the assembly and support is an important factor to the long-term safe operation of the plant. In this work, static analysis under dead weight, FIV influence analysis, modal analysis, seismic analysis, and LOCA analysis were performed. The results indicate that the bolts of initial design cannot bear the load of Service Level D with LOCA. Reasonable improvement measures and its reasons were proposed and assessed. The improved structure was installed in the reactor vessel closure head in the period of NPP shut-down and refueling. (authors)

2010-02-01

342

Geological assessment techniques  

Energy Technology Data Exchange (ETDEWEB)

What are the best geologic methods of assessing undiscovered petroleum potentials For prospects, these methods are estimating probable trap-reservoir volume, if possible, with hydrocarbon fill fraction from analysis of oil and gas generated, migrated, and trapped; for plays (geologically coherent prospect groups), these methods are summing prospect assessment or evaluating future field numbers and sizes for the group; and for basins or regions, the best methods are summing play assessments. Methods such as delphi, subjective, probability, arbitrary analogy ratings, and basin volumes and yields are obsolete. Play analysis is the key to any assessment. Play maps of the source, reservoir, and trap controls of oil and gas provide the best perspectives on prospect risking and main basin potentials. The most practical play approach, under the usual limits of time and data, is by grouped geologic field numbers and sizes. Play assessment at its best uses a prospect count and success ratio for estimating future fields, a field-size distribution tied to the largest undrilled prospect, and an evaluation of geologic risk. Geologic play assessment has powerful advantages over purely statistical approaches. It spatially locates perceived areas of greatest success, it can provide estimates for subareas of special economic or environmental interest, and it is fully compatible with prospect summation. It applies to all exploration stages and knowledge levels, readily handles oil vs. gas, and is documentable, flexible, reproducible, and updatable.

White D.A.

1989-03-01

343

Analysis of piezoelectric structures and devices  

CERN Document Server

This edited work covers piezoelectric materials in the form of beams, plates, shells, and other structural components in modern devices and structures. Applications are frequency control and detection functions in resonators, sensors, actuators, oscillations, and other smart and intelligent structures. The contributions cover novel methods for the analysis of piezoelectric structures including wave propagation, high frequency vibration, material characterization, and optimization of structures. Understanding of these methods is increasingly important in the design and modelling of next generat

Chen, Weiqiu; Wang, Ji

2013-01-01

344

Geological model neural network method  

Energy Technology Data Exchange (ETDEWEB)

The deficiency of traditional estimating method which is used to build coal bed geological model is analysed. The theory and method of neural network, and the feasibility and superiority of using it to build coal bed geological model are discussed with reference to the geological variable characteristics such as the space territory, the continuity, the anisotropism and high degree of non-liner relation. The basic structure of neural network model which is used to estimate the geological variables is built, and the non-liner mapping relation between the geological variables and their influencing factors is described also. Thereby the estimating method of geological model based on neural network is brought forward. 2 refs., 4 figs., 1 tab.

Bai, R.; Guo, S.; Song, Z.; Shen, Y. [Liaoning Technical University, Fuxin (China)

2000-06-01

345

Mathematical Statistics in the Geology  

Directory of Open Access Journals (Sweden)

Full Text Available During the last period is modern geology oriented toward intensive utilisation of mathematical methods. Utilisation of these methods was conditioned by complicated structure of geological bodies, which resulted from interaction of a couple of factors. In the period of projection, realisation and evaluation of geological works one meet many problems of description of a character of geological data. These problems ? very often trivial ? arise from the poor knowledge of the principles of statistical methods. Transformation of real geological object into the form of abstract mathematical model is the basic and usually also the most complicated step of mathematical solution. There is also to be mentioned that there is no unitary approach to the modelling or uniform direction for a method of data processing selection. Complicacy of geological objects needs rational simplification of the model, otherwise the solution would be too complicated or even impossible.

Bliš?an Peter

1999-06-01

346

Dynamic analysis program for frame structure  

International Nuclear Information System (INIS)

A general purpose computer program named ISTRAN/FD (Isub(HI) STRucture ANalysis/Frame structure, Dynamic analysis) has been developed for dynamic analysis of three-dimensional frame structures. This program has functions of free vibration analysis, seismic response analysis, graphic display by plotter and CRT, etc. This paper introduces ISTRAN/FD; examples of its application are shown with various problems : idealization of the cantilever, dynamic analysis of the main tower of the suspension bridge, three-dimensional vibration in the plate girder bridge, seismic response in the boiler steel structure, and dynamic properties of the underground LNG tank. In this last example, solid elements, in addition to beam elements, are especially used for the analysis. (auth.)

1975-01-01

347

Petroleum geology in China  

Energy Technology Data Exchange (ETDEWEB)

Lectures on the petroleum geology of China are presented. The contents include: hydrocarbon accumulation in sedimentary basins of China; exploration of buried-hill oil fields in north China; fault-block tectonics and oil resources of China; alluvial sand clastic reservoirs in Karamay; geological structure and hydrocarbon occurrence of the Bohai Gulf oil and gas basin; and habitat of hydrocarbons in and adjacent to the South China Sea. Each of the lectures presented has been abstracted separately for the U.S. Department of Energy's Energy Data Base. (JMT)

Mason, J.F. (ed.)

1981-01-01

348

Neutron activation analysis of gold, silver, tungsten and antimony at the scheelite deposit of Felbertal (Austria) and their geological-genetical interpretation  

International Nuclear Information System (INIS)

The authors discuss the neutron activation analysis of gold, silver, tungsten and antimony in geologic deposits in Austria. In particular, they discuss the method of investigation and sample preparation. They compare ore types and rock types and also the eastern and western ore zone. The influence of stratigraphy and palaeogeographical position is also considered. (G.T.H.)

1979-01-01

349

Geologic mapping using integrated AIRSAR, AVIRIS, and TIMS data  

Science.gov (United States)

The multi-sensor aircraft campaign called the 'Geologic Remote Sensing Field Experiment' (GRSFE), conducted during 1989 in the southwestern United States, collected multiple airborne remote sensing data sets and associated field and laboratory measurements. The GRSFE airborne data sets used in this study include the airborne Synthetic Aperture Radar (AIRSAR), the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), and the Thermal Infrared Multispectral Scanner (TIMS). Each sensor's unique characteristics were used for this study in a combined analysis scheme for geologic mapping. AIRSAR was used to map structures and landforms, AVIRIS was used to map mineralogy, and TIMS was used to map lithology. Visual data integration using IHS transforms and combined numerical analysis using derived geophysical and geologic parameters with 'multispectral' techniques resulted in improved geologic mapping over that possible using each data set individually.

Kruse, Fred A.

1993-01-01

350

Nuclear methods applied to environmental and geological studies: instrumental neutron activation analysis  

International Nuclear Information System (INIS)

Full text: Both thermal and epithermal neutron instrumental activation analysis as well as prompt gamma ray activation analysis were used to investigate the vertical distribution of some major and 30 trace elements in several cores collected from various locations of Danube delta as well as from the anoxic zone of the Black Sea Continental Platform. The major elements were Na, Al, Ca, K, Ti, Fe and Cl while the trace elements were Sc, V, Cr, Ni, Co, Zn, Cu, As, Sr, Rb, Zr, Mo, Sn, In, Sb, Ba, Cs, La, Ce, Nd, Eu, Sm, Tb, Dy, Yb, Hf, Ta, W, Th, U. At the same time the vertical distribution of anthropogenic 137Cs (from atmospheric nuclear tests and 1986 Chernobyl accident) was used to determine the sediments age, sedimentation rate as well as to evidence any sediment redistribution. Principal Component Analysis together with the Cluster Analysis were the main statistic methods used to interpret experimental data in connection with two model rocks: Upper Continental Core (UCC) and Mid Ocean Ridge Basalt (MORB). Final results concerning this kind of analysis are presented and discussed by taking into account the decline of industrial activity in the former Communist States abutting Danube River. (authors)

2008-10-29

351

Fourier Analysis and Structure Determination--Part III: X-ray Crystal Structure Analysis.  

Science.gov (United States)

Discussed is single crystal X-ray crystal structure analysis. A common link between the NMR imaging and the traditional X-ray crystal structure analysis is reported. Claims that comparisons aid in the understanding of both techniques. (MVL)

Chesick, John P.

1989-01-01

352

Some geological structural features of the South Mangyshlak oil and gas region according to data of interpreting space photographs  

Energy Technology Data Exchange (ETDEWEB)

The boundaries of the oil and gas region, its inner tectonic zoning, and the links between local elevations and regional faults are examined. The convergence of inter- pretation data and geological-geophysical materials are analyzed, and sections are recommended for setting up oil and gas searches.

Bogorodskiy, S.M.; Lion, Yu.A.

1981-01-01

353

Robustness Analysis of Kinetic Structures  

DEFF Research Database (Denmark)

Kinetic structures in architecture follows a new trend which is emerging in responsive architecture coined by Nicholas Negroponte when he proposed that architecture may benefit from the integration of computing power into built spaces and structures, and that better performing, more rational buildings would be the.

Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

2009-01-01

354

Vibration characteristics analysis for HANARO reactor structures  

International Nuclear Information System (INIS)

The first objective of this study is to investigate the vibration characteristic of the HANARO reactor structure. The second one is to generate the dynamic correlation between the fuel assembly and the reactor structure. For these purposes, the in-air and in-water finite element models of the reactor structure were developed and their modal analyses were carried out. The fundamental natural frequency of the in-water reactor structure was obtained as 17.7Hz that is approximately the half of the natural frequency of the in-air reactor structure, 34.9Hz. This natural frequency agree well with the analysis result(17.46Hz) of the AECL. The modal analysis of the reactor model including the piping of the primary cooling system(PCS) show that the effect of the PCS piping on the dynamic characteristics of the reactor structure is negligible. For generating the dynamic correlation between the fuel assembly and the reactor structure, the in-water reactor model including the fuel assemblies was developed, and its modal analysis was performed. The analysis results demonstrate that there are no resonance between the fuel assemblies and the reactor structures. The developed 3-D model of the in-water reactor structure will be used as a base model for the dynamic characteristic and stress analysis when it is necessary to modify the design of the reactor structure or to install additional structures for the irradiation test

2001-01-01

355

Vibration characteristics analysis for HANARO reactor structures  

Energy Technology Data Exchange (ETDEWEB)

The first objective of this study is to investigate the vibration characteristic of the HANARO reactor structure. The second one is to generate the dynamic correlation between the fuel assembly and the reactor structure. For these purposes, the in-air and in-water finite element models of the reactor structure were developed and their modal analyses were carried out. The fundamental natural frequency of the in-water reactor structure was obtained as 17.7Hz that is approximately the half of the natural frequency of the in-air reactor structure, 34.9Hz. This natural frequency agree well with the analysis result(17.46Hz) of the AECL. The modal analysis of the reactor model including the piping of the primary cooling system(PCS) show that the effect of the PCS piping on the dynamic characteristics of the reactor structure is negligible. For generating the dynamic correlation between the fuel assembly and the reactor structure, the in-water reactor model including the fuel assemblies was developed, and its modal analysis was performed. The analysis results demonstrate that there are no resonance between the fuel assemblies and the reactor structures. The developed 3-D model of the in-water reactor structure will be used as a base model for the dynamic characteristic and stress analysis when it is necessary to modify the design of the reactor structure or to install additional structures for the irradiation test.

Ryu, Jeong Soo; Yoon, Doo Byung

2001-06-01

356

Archaeological elements of Mt. Lykaion Sanctuary of Zeus (southern Peloponnesus) in relation to tectonics and structural geology  

International Nuclear Information System (INIS)

The Sanctuary of Zeus is the focus of the Mt. Lykaion Excavation/Survey (University of Pennsylvania, University of Arizona, and 39th Ephorate of Prehistoric and Classical Antiquities). It was described by Pausanias as a sacred place of pan-Hellenic significance, with stadium and hippodrome in which athletic games were held, a sanctuary of Pan, and a formidable temenos and altar of Lykaion Zeus. In picturing human activity on this mountain during ancient times, it is not adequate to treat the mountain as if it were simply a tall, symmetrical, and handy edifice within which rock contents are irrelevant, for the geology within Mt. Lykaion significantly influenced what was built on it, and where! There are contemporary reminders of the 'power' of the site, including the devastating April, 1965, Megalopolis earthquake, the epicenter of which was merely 4 km away. In fact, there are active normal faults within the sanctuary. However the primary geoarchitecture is that of the Pindos fold and thrust belt, fashioned largely in Cretaceous through Eocene. Mt. Lykaion's dome-like summit is a thrust klippe separated from underlying nappes by a major thrust fault (Lykaion thrust), the subhorizontal trace of which encircles the mountain creating a subtle bench in the landscape coinciding closely with archaeological and natural elements important to the sanctuary (e.g., stoa, seatwall, fountains, trails). Late Jurassic through Eocene 'Pindos Group' formations are stacked and repeated by the thrusting. Inter-relationships between bedrock, structure, and archaeology are revealed in a 'geoarchaeological column,' which displays positioning of elements in relation to the thrust, and orientations of rock formations in relation to flat patches in otherwise steep, rocky country, which became sites suitable for placement of hippodrome, baths, temenos, horse pasturing areas, etc. Worked limestone blocks are locally derived and can be matched with formations. The compelling high elevation of the ash altar is testimony to residual crustal buoyancy achieved through 'Pindos' crustal shortening, and the steep processional ascent to the altar speaks to regional active normal faulting and rapid erosion

2008-07-01

357

Neutron diffraction analysis of crystal magnetic structures  

International Nuclear Information System (INIS)

An investigation of the state-of-the art of the neutron diffraction analysis of magnetic structures from the point of view of the theory of crystal symmetry is given. Various and numerous structures determined from the neutron diffraction analysis investigations can be classified and described with the theory of space group representations of crystals. The analysis of quite a number of various magnetic structures shows that they arise according to Landau hypothesis. The foundations of a symmetry analysis of magnetic structures and the methods for their determination are given. A physical explanation is given for the existence of magnetic structures. The experimental investigations of the crystal lattice distortions accompanying a magnetic ordering are reviewed. In this review is given a symmetry approach to the description of the magnetic structures of crystals; and a possibility to analyze them by a scattering of nonpolarized and polarized neutrons

1980-01-01

358

Computer applications for engineering/structural analysis  

Energy Technology Data Exchange (ETDEWEB)

Analysts and organizations have a tendency to lock themselves into specific codes with the obvious consequences of not addressing the real problem and thus reaching the wrong conclusion. This paper discusses the role of the analyst in selecting computer codes. The participation and support of a computation division in modifying the source program, configuration management, and pre- and post-processing of codes are among the subjects discussed. Specific examples illustrating the computer code selection process are described in the following problem areas: soil structure interaction, structural analysis of nuclear reactors, analysis of waste tanks where fluid structure interaction is important, analysis of equipment, structure-structure interaction, analysis of the operation of the superconductor supercollider which includes friction and transient temperature, and 3D analysis of the 10-meter telescope being built in Hawaii. Validation and verification of computer codes and their impact on the selection process are also discussed.

Zaslawsky, M.; Samaddar, S.K.

1991-01-01

359

Mine-Tunnel Design & Monitoring Analysis for Major Faults and Complex Geological Conditions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Mining operations at Nanyang-Slope Coal Mine are considerably challenging. The Nanyang- Slope Coal Field has a complex tectonic structure; having major faults, large fissures and fracture- zones, and great changes in coal-seam thickness. Mine tunnel-way 301 traverses multiple complex faults with developed fractures, broken surrounding rock, and high tectonic stresses. The original rectangular-section tunnel design using anchor-bolt-mesh retainment was prone to rib-sp...

Zhang, Xiang-dong; Fan, Shi-xing; Zhang, Hu-wei; Zhang, Yu

2013-01-01

360

Assessment of ERTS-1 imagery as a tool for regional geological analysis in New York State. [Lake Ontario  

Science.gov (United States)

The author has identified the following significant results. Linear anomalies dominate the new geological information derived from ERTS-1 imagery, total lengths now exceeding 26,500 km. Maxima on rose diagrams for ERTS-1 anomalies correspond well with those for mapped faults and topographic lineaments. Multi-scale analysis of linears shows that single topographic linears at 1:2,500,000 may become dashed linears at 1:1,000,000 aligned zones of shorter parallel, en echelon, or conjugate linears at 1:5000,000, and shorter linears lacking any conspicuous zonal alignment at 1:250,000. Field work in the Catskills suggests that the prominent new NNE lineaments may be surface manifestations of dip slip faulting in the basement, and that it may become possible to map major joint sets over extensive plateau regions directly on the imagery. Most circular features found were explained away by U-2 airfoto analysis but several remain as anomalies. Visible glacial features include individual drumlins, drumlinoids, eskers, ice-marginal drainage channels, glacial lake shorelines, sand plains, and end moraines.

Isachsen, Y. W. (principal investigator); Fakundiny, R. H.; Forster, S. W.

1974-01-01

 
 
 
 
361

Petrofacies analysis - the petrophysical tool for geologic/engineering reservoir characterization  

Energy Technology Data Exchange (ETDEWEB)

Petrofacies analysis is defined as the characterization and classification of pore types and fluid saturations as revealed by petrophysical measures of a reservoir. The word {open_quotes}petrofacies{close_quotes} makes an explicit link between petroleum engineers concerns with pore characteristics as arbiters of production performance, and the facies paradigm of geologists as a methodology for genetic understanding and prediction. In petrofacies analysis, the porosity and resistivity axes of the classical Pickett plot are used to map water saturation, bulk volume water, and estimated permeability, as well as capillary pressure information, where it is available. When data points are connected in order of depth within a reservoir, the characteristic patterns reflect reservoir rock character and its interplay with the hydrocarbon column. A third variable can be presented at each point on the crossplot by assigning a color scale that is based on other well logs, often gamma ray or photoelectric effect, or other derived variables. Contrasts between reservoir pore types and fluid saturations will be reflected in changing patterns on the crossplot and can help discriminate and characterize reservoir heterogeneity. Many hundreds of analyses of well logs facilitated by spreadsheet and object-oriented programming have provided the means to distinguish patterns typical of certain complex pore types for sandstones and carbonate reservoirs, occurrences of irreducible water saturation, and presence of transition zones. The result has been an improved means to evaluate potential production such as bypassed pay behind pipe and in old exploration holes, or to assess zonation and continuity of the reservoir. Petrofacies analysis is applied in this example to distinguishing flow units including discrimination of pore type as assessment of reservoir conformance and continuity. The analysis is facilitated through the use of color cross sections and cluster analysis.

Watney, W.L.; Guy, W.J.; Gerlach, P.M. [Kansas Geological Survey, Lawrence, KS (United States)] [and others

1997-08-01