WorldWideScience
1

Remote geologic structural analysis of Yucca Flat  

Energy Technology Data Exchange (ETDEWEB)

The Remote Geologic Analysis (RGA) system was developed by Pacific Northwest Laboratory (PNL) to identify crustal structures that may affect seismic wave propagation from nuclear tests. Using automated methods, the RGA system identifies all valleys in a digital elevation model (DEM), fits three-dimensional vectors to valley bottoms, and catalogs all potential fracture or fault planes defined by coplanar pairs of valley vectors. The system generates a cluster hierarchy of planar features having greater-than-random density that may represent areas of anomalous topography manifesting structural control of erosional drainage development. Because RGA uses computer methods to identify zones of hypothesized control of topography, ground truth using a well-characterized test site was critical in our evaluation of RGA's characterization of inaccessible test sites for seismic verification studies. Therefore, we applied RGA to a study area centered on Yucca Flat at the Nevada Test Site (NTS) and compared our results with both mapped geology and geologic structures and with seismic yield-magnitude models. This is the final report of PNL's RGA development project for peer review within the US Department of Energy Office of Arms Control (OAC) seismic-verification community. In this report, we discuss the Yucca Flat study area, the analytical basis of the RGA system and its application to Yucca Flat, the results of the analysis, and the relation of the analytical results to known topography, geology, and geologic structures. 41 refs., 39 figs., 2 tabs.

Foley, M.G.; Heasler, P.G.; Hoover, K.A. (Pacific Northwest Lab., Richland, WA (United States)); Rynes, N.J. (Northern Illinois Univ., De Kalb, IL (United States)); Thiessen, R.L.; Alfaro, J.L. (Washington State Univ., Pullman, WA (United States))

1991-12-01

2

Remote geologic structural analysis of Yucca Flat  

Energy Technology Data Exchange (ETDEWEB)

The Remote Geologic Analysis (RGA) system was developed by Pacific Northwest Laboratory (PNL) to identify crustal structures that may affect seismic wave propagation from nuclear tests. Using automated methods, the RGA system identifies all valleys in a digital elevation model (DEM), fits three-dimensional vectors to valley bottoms, and catalogs all potential fracture or fault planes defined by coplanar pairs of valley vectors. The system generates a cluster hierarchy of planar features having greater-than-random density that may represent areas of anomalous topography manifesting structural control of erosional drainage development. Because RGA uses computer methods to identify zones of hypothesized control of topography, ground truth using a well-characterized test site was critical in our evaluation of RGA`s characterization of inaccessible test sites for seismic verification studies. Therefore, we applied RGA to a study area centered on Yucca Flat at the Nevada Test Site (NTS) and compared our results with both mapped geology and geologic structures and with seismic yield-magnitude models. This is the final report of PNL`s RGA development project for peer review within the US Department of Energy Office of Arms Control (OAC) seismic-verification community. In this report, we discuss the Yucca Flat study area, the analytical basis of the RGA system and its application to Yucca Flat, the results of the analysis, and the relation of the analytical results to known topography, geology, and geologic structures. 41 refs., 39 figs., 2 tabs.

Foley, M.G.; Heasler, P.G.; Hoover, K.A. [Pacific Northwest Lab., Richland, WA (United States); Rynes, N.J. [Northern Illinois Univ., De Kalb, IL (United States); Thiessen, R.L.; Alfaro, J.L. [Washington State Univ., Pullman, WA (United States)

1991-12-01

3

Structural Geology  

Science.gov (United States)

This site contains a variety of resources for faculty members who teach undergraduate structural geology. You will find links to activities and assignments, internet and computer resources, useful articles and maps, presentations from the summer 2004 workshop on teaching structural geology, working groups and a discussion forum, and lots of creative ideas for teaching structural geology.

4

Process for structural geologic analysis of topography and point data  

Science.gov (United States)

A quantitative method of geologic structural analysis of digital terrain data is described for implementation on a computer. Assuming selected valley segments are controlled by the underlying geologic structure, topographic lows in the terrain data, defining valley bottoms, are detected, filtered and accumulated into a series line segments defining contiguous valleys. The line segments are then vectorized to produce vector segments, defining valley segments, which may be indicative of the underlying geologic structure. Coplanar analysis is performed on vector segment pairs to determine which vectors produce planes which represent underlying geologic structure. Point data such as fracture phenomena which can be related to fracture planes in 3-dimensional space can be analyzed to define common plane orientation and locations. The vectors, points, and planes are displayed in various formats for interpretation.

Eliason, Jay R. (Richland, WA); Eliason, Valerie L. C. (Richland, WA)

1987-01-01

5

Structural Geology Techniques  

Science.gov (United States)

The University of Wisconsin - Green Bay has created this collection of material and instructions on how to analyze and plot structural geology data. Topics covered includes planes, lines, relations between lines and planes, geologic structures, intersection of structures with topography, stereonet techniques, stress and strain, and analysis of complex structures.

Dutch, Steven

2009-05-21

6

Geological-structural models used in SR 97. Uncertainty analysis  

Energy Technology Data Exchange (ETDEWEB)

The uncertainty of geological-structural models was studied for the three sites in SR 97, called Aberg, Beberg and Ceberg. The evaluation covered both regional and site scale models, the emphasis being placed on fracture zones in the site scale. Uncertainty is a natural feature of all geoscientific investigations. It originates from measurements (errors in data, sampling limitations, scale variation) and conceptualisation (structural geometries and properties, ambiguous geometric or parametric solutions) to name the major ones. The structures of A-, B- and Ceberg are fracture zones of varying types. No major differences in the conceptualisation between the sites were noted. One source of uncertainty in the site models is the non-existence of fracture and zone information in the scale from 10 to 300 - 1000 m. At Aberg the development of the regional model has been performed very thoroughly. At the site scale one major source of uncertainty is that a clear definition of the target area is missing. Structures encountered in the boreholes are well explained and an interdisciplinary approach in interpretation have taken place. Beberg and Ceberg regional models contain relatively large uncertainties due to the investigation methodology and experience available at that time. In site scale six additional structures were proposed both to Beberg and Ceberg to variant analysis of these sites. Both sites include uncertainty in the form of many non-interpreted fractured sections along the boreholes. Statistical analysis gives high occurrences of structures for all three sites: typically 20 - 30 structures/km{sup 3}. Aberg has highest structural frequency, Beberg comes next and Ceberg has the lowest. The borehole configuration, orientations and surveying goals were inspected to find whether preferences or factors causing bias were present. Data from Aberg supports the conclusion that Aespoe sub volume would be an anomalously fractured, tectonised unit of its own. This means that the borehole investigations may not represent the site outside the covered volume. Finally five different uncertainty indices were calculated for regional and site scale, borehole data, representativity and structural knowledge. High uncertainty exists for all site volumes in terms of structural knowledge. Uncertainty in representativity is rather high at Aberg. Beberg and Ceberg has high uncertainty indices when regional scale models are concerned 30 refs, 36 figs, 8 tabs

Saksa, P.; Nummela, J. [FINTACT Oy (Finland)

1998-10-01

7

Geological-structural models used in SR 97. Uncertainty analysis  

International Nuclear Information System (INIS)

The uncertainty of geological-structural models was studied for the three sites in SR 97, called Aberg, Beberg and Ceberg. The evaluation covered both regional and site scale models, the emphasis being placed on fracture zones in the site scale. Uncertainty is a natural feature of all geoscientific investigations. It originates from measurements (errors in data, sampling limitations, scale variation) and conceptualisation (structural geometries and properties, ambiguous geometric or parametric solutions) to name the major ones. The structures of A-, B- and Ceberg are fracture zones of varying types. No major differences in the conceptualisation between the sites were noted. One source of uncertainty in the site models is the non-existence of fracture and zone information in the scale from 10 to 300 - 1000 m. At Aberg the development of the regional model has been performed very thoroughly. At the site scale one major source of uncertainty is that a clear definition of the target area is missing. Structures encountered in the boreholes are well explained and an interdisciplinary approach in interpretation have taken place. Beberg and Ceberg regional models contain relatively large uncertainties due to the investigation methodology and experience available at that time. In site scale six additional structures were proposed both to Beberg and Ceberg to variant analysis of these sites. Both sites include uncertainty in the form of many non-interpreted fractured sections along the boreholes. Statistical analysis gives high occurrences of structures for all three sites: typically 20 - 30 structures/km3. Aberg has highest structural frequency, Beberg comes next and Ceberg has the lowest. The borehole configuration, orientations and surveying goals were inspected to find whether preferences or factors causing bias were present. Data from Aberg supports the conclusion that Aespoe sub volume would be an anomalously fractured, tectonised unit of its own. This means that the borehole investigations may not represent the site outside the covered volume. Finally five different uncertainty indices were calculated for regional and site scale, borehole data, representativity and structural knowledge. High uncertainty exists for all site volumes in terms of structural knowledge. Uncertainty in representativity is rather high at Aberg. Beberg and Ceberg has high uncertainty indices when regional scale models are concerned

8

Texture analysis for automated classification of geologic structures  

Science.gov (United States)

Texture present in aeromagnetic anomaly images offers an abundance of useful geological information for discriminating between rock types, but current analysis of such images still relies on tedious, human interpretation. This study is believed to be the first effort to quantitatively assess the performance of texture-based digital image analysis for this geophysical exploration application. We computed several texture measures and determined the best subset using automated feature selection techniques. Pattern classification experiments measured the ability of various texture measures to automatically predict rock types. The classification accuracy was significantly better than a priori probability and prior weights-of-evidence results. The accuracy rates and choice of texture measures that minimize the error rate are reported. ?? 2006 IEEE.

Shankar, V.; Rodriguez, J.J.; Gettings, M.E.

2006-01-01

9

Fundamentals of Structural Geology  

Science.gov (United States)

Fundamentals of Structural Geology is a textbook that emphasizes modern techniques of field data acquisition and analysis, the principles of continuum mechanics, and the mathematical and computational skills necessary to quantitatively describe, model, and explain the deformation of rock in Earth's lithosphere. This site provides an online interface for the book with supplementary materials for readers, instructors, and students. Resources include color photographs of outcrops, textbook figures, and supplementary illustrations for classroom presentations; student exercises to develop Matlab skills; Matlab scripts to make textbook figures dynamic, introduction to the concepts of differential geometry, mechanical models, and the evolution of geologic structures; and research quality data sets and solutions for instructors. The site also includes book information and links to additional resources.

Pollard, David; Fletcher, Raymond; University, Stanford

10

Photos of structural geology  

Science.gov (United States)

This page contains four categories of structural geology photos: brittle structures, ductile structures, active tectonics, and unconformities. All photos are freely downloadable and are at resolutions sufficient for power point.

Miller, Marli

11

Structural Geology 'Research' Conference  

Science.gov (United States)

In this assignment students read and discuss a peer-reviewed journal article and prepare for and attend our class 'research' conference. In the conference they present on an area of current research as discussed in the journal article they read, and they practice formulating questions about other's research. Outcomes: 1. Read and discuss a structural geology peer-reviewed journal article. 2. Prepare a presentation that demonstrates your understanding of a current research topic in structural geology. 3. View and understand several diverse areas within geology and geophysics that use structural geology in research. 4. Ask questions relevant to a research presentation.

Willis, Julie

12

Growth structures : examples of integrated sedimentological and structural-geological basin analysis  

OpenAIRE

This thesis is based on research in the interface oftwo geological disciplines, sedimentology (the study of sediments, like sandstone and limestone) and structural geology (the study of rock deformation). Sedimentation is influenced by cosmic and climatological processes, sea-level change, and deformation of the earth's crust. Prerequisites for the generation of sediments are uplift and erosion in source areas, and subsidence and deposition in basins. Contrary to these vertical...

Nijman, W.

1999-01-01

13

Stratigraphy and structural geology  

Science.gov (United States)

The immediate goal of stratigraphy and structural geology is to reduce the enormous complexity of a planetary surface to comprehensible proportions by dividing the near-surface rocks into units and mapping their distribution and attitude.

Carr, M. H.; Wilhelms, D. E.; Greeley, R.; Guest, J. E.

1976-01-01

14

Experiencing Structural Geology  

Science.gov (United States)

Describes an undergraduate structural geology course that incorporates field lab time and research. Lectures, outside readings, and in-class experimentation are coordinated with the field work to prepare a scientific report. (MA)

Davis, George H.

1978-01-01

15

Java Structural Geology Software  

Science.gov (United States)

This website features Java programs that illustrate basic structural geology concepts. This suite of animations includes topics such as shear, stress versus strain, three dimensional strain, flow lines, rotating clasts and others. The animations are downloadable for Mac, PC and Linux.

Primm, Skylar L.; Department Of Geology And Geophysics, University O.

16

Structural Geology and Geomechanics  

Science.gov (United States)

The teaching and research program, Structural Geology and Geomechanics at Stanford University, concentrates on brittle deformation in the earth's crust as well as fracturing and faulting of rocks under ductile conditions. Researchers can learn about the group's research which effectively unites field observations, laboratory experiments, and theoretical modeling. Scientists can learn about the program's software such as the Poly3Dinv which uses triangular dislocations to solve linear inverse problems. The site also publicizes the Stanford Rock Fracture Project, which researches rock fractures, crustal deformation, and fluid flow.

17

Teaching Resources in Structural Geology  

Science.gov (United States)

This portal provides access to an extensive selection of web-based teaching resources in structural geology. It features basic information on rock types, faults, folds, and other structures; virtual maps and field trips; and on strain and rheology. There is also a page of links to external sites on structural geology.

18

Semi-automatic mapping of geological Structures using UAV-based photogrammetric data: An image analysis approach  

Science.gov (United States)

Recent advances in data acquisition technologies, such as Unmanned Aerial Vehicles (UAVs), have led to a growing interest in capturing high-resolution rock surface images. However, due to the large volumes of data that can be captured in a short flight, efficient analysis of this data brings new challenges, especially the time it takes to digitise maps and extract orientation data. We outline a semi-automated method that allows efficient mapping of geological faults using photogrammetric data of rock surfaces, which was generated from aerial photographs collected by a UAV. Our method harnesses advanced automated image analysis techniques and human data interaction to rapidly map structures and then calculate their dip and dip directions. Geological structures (faults, joints and fractures) are first detected from the primary photographic dataset and the equivalent three dimensional (3D) structures are then identified within a 3D surface model generated by structure from motion (SfM). From this information the location, dip and dip direction of the geological structures are calculated. A structure map generated by our semi-automated method obtained a recall rate of 79.8% when compared against a fault map produced using expert manual digitising and interpretation methods. The semi-automated structure map was produced in 10 min whereas the manual method took approximately 7 h. In addition, the dip and dip direction calculation, using our automated method, shows a mean±standard error of 1.9°±2.2° and 4.4°±2.6° respectively with field measurements. This shows the potential of using our semi-automated method for accurate and efficient mapping of geological structures, particularly from remote, inaccessible or hazardous sites.

Vasuki, Yathunanthan; Holden, Eun-Jung; Kovesi, Peter; Micklethwaite, Steven

2014-08-01

19

Applications of multifractal analysis of dipmeter microresistivity curves for characterisation of geological structures  

Energy Technology Data Exchange (ETDEWEB)

We use multifractal analysis as a geostatistical tool to characterise microresistivity signals produced by dipmeter well-logging tolls. A sliding window of a fixed length is placed along the signals. For each window, the irregularity of the microresistivity signals is quantified in terms of what we refer to as texture indices. These indices are calculated using multifractal statistics. Texture indices are plotted as a function of depth to form texture logs. In this manner, the rich information contained in microresistivity logs is synthesised in texture logs which are compared to sedimentological logs and to depositional environment interpretations. Texture logs are calculated for five wells from the North Sea and we show that the texture logs relate to the geological interpretations and that in certain cases they can be used as an useful additional tool assisting geological interpretations of log data.

Huseby, Olaf; Muller, Jiri [Institutt for Energiteknikk, Kjeller (Norway)

1996-07-01

20

Geological structure; 1 : 500 000  

International Nuclear Information System (INIS)

This map represents the topical status of the knowledge on the basic structural dissection and geological building of the territory of Slovakia. Eighty per cent of it relies on the basic geological maps at scale 1 : 25 000 and regional geological maps at scale 1 : 50 000 compiled in the years 1963 - 1992. The rest is based in other published geological maps and re-interpretation of the geological map at scale 1 : 200 000 from 1963. The map is compiled in disclosed manner, it does not represent the Quaternary deposits. Apart from higher precision it differs from the preceding geological map of Czechoslovakia at scale 1 : 500 000 by the fact that it is consequently lithographic, as the legend does not display appurtenance to the tectonic units putting emphasis on the lithological and stratigraphic characteristics. Tectonic units are represented in a separate scheme. In the framework of the crystalline basement along with the rock complexes with unknown age also the complexes of undoubtedly the Palaeozoic, scarcely metamorphosed rocks are defined. In the broader region of the Slovak karst a new view of the Meliatic, Turnaic, and Silicic is presented. (authors)

21

A geological structural analysis of the southeastern Zagros (Iran) ranges based on metric camera photos  

Science.gov (United States)

Spacelab metric photography was used to make a tetonic inventory of the southeastern Zagros Ranges on the Persian Gulf. Photogeological structural analysis shows that the fold mountains are cut by overthrust faults and by major faults. The latter strike at a right or an acute angle to the folds. They are inferred to be associated with the rigid competent basement and punch through the sedimentary cover. Active and inactive salt plugs together with collapse structures occur along these overthrust faults and along major faults, which represent intricate plate tectonic movement planes. The salt plugs are confined to the intersections of areas of pressure maximum and salt concentration with these tectonic elements.

Fuerst, M.

1985-04-01

22

SoftStructure: Structural Geology on a PC  

Science.gov (United States)

SoftStructure is a package of more than 20 programs (most under DOS) for Quantitative Analysis in Structural Geology, including: MOHR, SHEAR, STRAIN, FRY, CALCITE_TWINS, STRESS_INVERSION, FOLTING, CRACK, ESHELBY, FAULT_GROWTH, and more. These programs are available for free for research and teaching purposes.

Others, Ze'Ev R.

23

Metrological parameters for the delayed neutron method of analysis of geological structures for uranium  

International Nuclear Information System (INIS)

The ''direct'' delayed neutron method is shown to be a useful method to analyze standard rock and ore samples over a wide range of uranium concentrations. Comparison of the metrological parameters known at present with the method of determining uranium in geological objects suggests that the delayed neutron method meets the requirements of applied geochemistry much more satisfactorily and opens up for it new prospects

24

A Graphical Approach to Quantitative Structural Geology.  

Science.gov (United States)

Describes how computer graphic methods can be used in teaching structural geology. Describes the design of a graphics workstation for the Apple microcomputer. Includes a listing of commands used with software to plot structures in a digitized form. Argues for the establishment of computer laboratories for structural geology classes. (TW)

De Paor, Declan G.

1986-01-01

25

Structural Geology Mapping/GIS Software  

Science.gov (United States)

This site contains Stereographic Projection and Rose Diagram plotting packages (GEOrient); a structural and drillhole calculator (GeoCalculator); strain, and shear zone calculators; geological field database information; and Geographic Information Systems (Mapinfo) software for plotting structural symbols on maps (GeoMapSymbol; previously GeoSymbol]. There are also several animations for teaching structural geology.

Holcombe, Rod

2008-01-14

26

Structural mapping of potential rockslide sites in the Storfjorden area, western Norway:the influence of bedrock geology on hazard analysis  

OpenAIRE

Forkortet: The western coast of Norway is particularly vulnerable to active rockslide development due to the recent post-glacial uplift and the deep incision of the fjords created by glacial activity, leading to extremely steep fjord sides. The purpose of this work was to determine the influence of structural geology on the hazard analysis related to large rock avalanches in the Storfjorden area. This is an area were several historical rock avalanches and related tsunamies have to disaste...

Henderson, I. H. C.; Saintot, A.; Derron, M. H.

2006-01-01

27

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

28

Gravimetric Study of Geological Structures of Teboursouk Area, Northern Tunisia  

Directory of Open Access Journals (Sweden)

Full Text Available Gravity data associated with surface geology in the Northern Tunisian Atlas offer better understand to the underlying structures in Teboursouk area and to highlight other deep or unknown structures in surface. The gravity study was based on qualitative and quantitative analysis including the construction of the gravity Bouguer anomaly, upward continuations, residual anomaly, and Horizontal gradient maxima maps. The main results display many positive and negative anomalies as the response of geological structures (J. Cheid Triassic structure, Khalled plain, El Aroussa plain. In addition, the horizontal gradient maxima integrated with geological and structural maps let the identification of major directions of gravimetric lineaments in the study area us NE-SW trending features at the boundaries of J. Cheid structure, NW-SE direction that limit Gaafour plain and Tabet Ech Cherif syncline, and N-S trending that bordered El Aroussa basin. Major results allowed the construction of a new structural map of the study zone.

Amira Ayed-Khaled

2012-09-01

29

Development of multiple source data processing for structural analysis at a regional scale. [digital remote sensing in geology  

Science.gov (United States)

Various image processing techniques developed for enhancement and extraction of linear features, of interest to the structural geologist, from digital remote sensing, geologic, and gravity data, are presented. These techniques include: (1) automatic detection of linear features and construction of rose diagrams from Landsat MSS data; (2) enhancement of principal structural directions using selective filters on Landsat MSS, Spacelab panchromatic, and HCMM NIR data; (3) directional filtering of Spacelab panchromatic data using Fast Fourier Transform; (4) detection of linear/elongated zones of high thermal gradient from thermal infrared data; and (5) extraction of strong gravimetric gradients from digitized Bouguer anomaly maps. Processing results can be compared to each other through the use of a geocoded database to evaluate the structural importance of each lineament according to its depth: superficial structures in the sedimentary cover, or deeper ones affecting the basement. These image processing techniques were successfully applied to achieve a better understanding of the transition between Provence and the Pyrenees structural blocks, in southeastern France, for an improved structural interpretation of the Mediterranean region.

Carrere, Veronique

1990-01-01

30

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

31

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

32

Geological variation in S-wave velocity structures in Northern Taiwan and implications for seismic hazards based on ambient noise analysis  

Science.gov (United States)

Ambient noise analysis in Northern Taiwan revealed obvious lateral variations related to major geological units. The empirical Green's functions extracted from interstation ambient noise were regarded as Rayleigh waves, from which we analyzed the group velocities for period from 3 to 6 s. According to geological features, we divided Northern Taiwan into seven subregions, for which regionalized group velocities were derived by using the pure-path method. On average, the group velocities in mountain areas were higher than those in the plain areas. We subsequently inverted the S-wave velocity structure for each subregion down to 6 km in depth. Following the analysis, we proposed the first models of geology-dependent shallow S-wave structures in Northern Taiwan. Overall, the velocity increased substantially from west to east; specifically, the mountain areas, composed of metamorphic rocks, exhibited higher velocities than did the coastal plain and basin, which consist of soft sediment. At a shallow depth, the Western Coastal Plain, Taipei Basin, and Ilan Plain displayed a larger velocity gradient than did other regions. At the top 3 km of the model, the average velocity gradient was 0.39 km/s per km for the Western Coastal Plain and 0.15 km/s per km for the Central Range. These S-wave velocity models with large velocity gradients caused the seismic waves to become trapped easily in strata and, thus, the ground motion was amplified. The regionalized S-wave velocity models derived from ambient noises can provide useful information regarding seismic wave propagation and for assessing seismic hazards in Northern Taiwan.

Lai, Ya-Chuan; Huang, Bor-Shouh; Huang, Yu-Chih; Yao, Huajian; Hwang, Ruey-Der; Huang, Yi-Ling; Chang, Wen-Yen

2014-12-01

33

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

34

Interpreting geological structure using kriging  

International Nuclear Information System (INIS)

The authors applied kriging (geostatistics) to interpret the structure of basement rock in Yucca Flat, NTS from borehole data. The estimation error for 118 data is 81 m comparable with those based on both gravity and borehole data. Using digitized topographic data, they tested the kriging results and found that the model validation process (Thomas option) on data gave a fair representation of the overall uncertainty of the kriged values

35

Gravimetric Study of Geological Structures of Teboursouk Area, Northern Tunisia  

OpenAIRE

Gravity data associated with surface geology in the Northern Tunisian Atlas offer better understand to the underlying structures in Teboursouk area and to highlight other deep or unknown structures in surface. The gravity study was based on qualitative and quantitative analysis including the construction of the gravity Bouguer anomaly, upward continuations, residual anomaly, and Horizontal gradient maxima maps. The main results display many positive and negative anomalies as the response of g...

Amira Ayed-Khaled; Taher Zouaghi; Mohamed Ghanmi; Fouad Zargouni

2012-01-01

36

Earth Structure: An Introduction to Structural Geology and Tectonics  

Science.gov (United States)

This is the home page for Ben van der Pluijm's and Steve Marshak's structural geology textbook. This page contains a brief synopsis of each of the chapters in their text. The chapter summaries in total provide an overview of the basic principles of structural geology and tectonics. Section A. covers Fundamentals such as force, stress, deformation, strain and rheology; Section B. covers Brittle Structures (faults, veins and joints); Section C covers Ductile Structures (folds, fabrics, shear zones etc); and Section D. covers Tectonics and Regional Deformation. The page also contains structural and tectonic animations and links to numerous related web sites and professional organizations.

Van Der Pluijm, Ben

37

Inner thermal resonance in thermoelastic geological structures  

Science.gov (United States)

When investigating heterogeneous media such as composite materials or geological structures, it is convenient to replace them by macroscopic equivalent media, which simplifies computations a lot. In the paper, we look for the equivalent macroscopic model for describing seismic wave propagation and transient heat transfers in thermoelastic periodic geological structures made of rock or soil. We follow the route described in Auriault (2012), to investigating thermoelastic composite media. We use the method of multi-scale asymptotic expansions. By estimating the dimensionless numbers in the momentum and energy balances, we show that an equivalent macroscopic model exists for describing seismic waves at very low frequencies only. The model then shows a damping which is due to thermal resonance at the heterogeneity scale. At higher frequencies, such an equivalent macroscopic model does not exist. Macroscopic models for describing transient heat transfers do not exist.

Auriault, Jean-Louis

2014-10-01

38

Applied Structural Geology – Case Studies of Underground Constructions and Rockslides  

OpenAIRE

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 pro...

Ganerød, Guri Venvik

2008-01-01

39

Modelling of Geological Structures Using Emergence  

Science.gov (United States)

A complex system based approach is used to model geological structures. Preliminary work is presented to show how mutually interacting agents can be used to probe local regions and obtain emergent behaviour of its geometrical properties. Models are built bottom up from the smaller components to simulate regions from camp scales to regional scales. In nature, very complex structures exhibiting discontinuous and heterogeneous features are common. Modelling such regions using conventional methods is cumbersome and influences between close proximity zones are generally not considered. Agents are able to detect local and global features in the entire model space, as detailed as the data set allows. These features are incorporated into the interpolation of a modeled zone if those features are coupled to that location. We attempt to see if opportunities exist for exploiting complex systems approaches in what is a classical knowledge driven modelling domain with high emphasis on expert interpretive methods. Geological maps (2D, 3D or 4D) are fundamentally an emergent result of an iterative mental process which focuses on reconciling disparate data. The end goal of our research is to point a way forward in which complexity can support the simulation of maps and thus support the interpretive workflow.

Hillier, M.; de Kemp, E. A.; Sprague, K.

2009-05-01

40

Structural effects of C60+ bombardment on various natural mineral samples-Application to analysis of organic phases in geological samples  

International Nuclear Information System (INIS)

Organic phases trapped inside natural mineral samples are of considerable interest in astrobiology, geochemistry and geobiology. Examples of such organic phases are microfossils, kerogen and oil. Information about these phases is usually retrieved through bulk crushing of the rock which means both a risk of contamination and that the composition and spatial distribution of the organics to its host mineral is lost. An attractive of way to retrieve information about the organics in the rock is depth profiling using a focused ion beam. Recently, it was shown that it is possible to obtain detailed mass spectrometric information from oil-bearing fluid inclusions, i.e. small amounts of oil trapped inside a mineral matrix, using ToF-SIMS. Using a 10 keV C60+ sputter beam and a 25 keV Bi3+ analysis beam, oil-bearing inclusions in different minerals were opened and analysed individually. However, sputtering with a C60+ beam also induced other changes to the mineral surface, such as formation of topographic features and carbon deposition. In this paper, the cause of these changes is explored and the consequences of the sputter-induced features on the analysis of organic phases in natural mineral samples (quartz, calcite and fluorite) in general and fluid inclusions in particular are discussed. The dominating topographical features that were observed when a several micrometers deep crater is sputtered with 10 keV ters deep crater is sputtered with 10 keV C60+ ions on a natural mineral surface are conical-shaped and ridge-like structures that may rise several micrometers, pointing in the direction of the incident C60+ ion beam, on an otherwise flat crater bottom. The sputter-induced structures were found to appear at places with different chemistry than the host mineral, including other minerals phases and fluid inclusions, while structural defects in the host material, such as polishing marks or scratches, did not necessarily result in sputter-induced structures. The ridge-like structures were often covered by a thick layer of deposited carbon. Despite the appearance of the sputter-induced structures and carbon deposition, most oil-bearing inclusions could successfully be opened and analysed. However, smaller inclusion (60, carbon deposition, topography, mineral, fluid inclusions, geological samples, depth profiling.

41

Geological Update of the Santa Marta Impact Structure, Brazil  

Science.gov (United States)

We present here the results of geological mapping carried out in the Santa Marta structure. It is a complex impact structure located in Piauí State, northeastern Brazil, and it is the countrýs sixth impact structure to be recognized identified.

de Oliveira, G. J. G.; Vasconcelos, M. A. R.; Crósta, A. P.; Góes, A. M.; Reimold, W. U.; Chamani, M.

2014-09-01

42

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

43

Structural geological controls on the flow and occurrence of groundwater in the basement lithologies of the Limpopo Province, South Africa  

OpenAIRE

The work for this thesis was conducted on the basement lithologies of the Limpopo Province in South Africa. An investigation into the correlation between structural geology and the flow/occurrence of groundwater was conducted on these lithologies. Field measurements of geological structures were recorded and compared graphically and statistically to existing groundwater borehole data. Data analysis revealed that the structural geology in the basement lithologies of the Limpopo Province of Sou...

Petzer, Konstant Johannes

2009-01-01

44

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

45

Geological structure and mineral resources of Algeria  

International Nuclear Information System (INIS)

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 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 descr the stratigraphic column.This paper describe the main geological structure and mineral resources of Algeria. (authors)

46

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

47

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

48

MONITORED GEOLOGIC REPOSITORY INTERNAL HAZARDS ANALYSIS  

International Nuclear Information System (INIS)

This analysis was performed by the Management and Operating Contractor (M andO) Safety Assurance Department to identify and document the internal hazards and preliminary events associated with preclosure operations of the Monitored Geologic Repository (MGR). Internal hazards are those hazards presented by operation of the facility and associated processes. These are in contrast to external hazards which involve natural phenomena and external man-made hazards. The hazard analysis methodology used in this analysis provides a systematic means to identify facility hazards and associated events that may result in radiological consequences to the public and facility worker during the MGR preclosure period. The events are documented in a preliminary events list and are intended to be used as input to the MGR Design Basis Event (DBE) selection process. It is expected that the results from this analysis will undergo further screening and analysis based on the criteria that apply to the performance of DBE analyses for the preclosure period of repository operation. As the MGR design progresses, this analysis will be reviewed to ensure no new hazards are introduced and that previously evaluated hazards have not increased in severity

49

Precise rare earth analysis of geological materials  

International Nuclear Information System (INIS)

Rare earth element (REE) concentrations are very informative in revealing chemical fractionation processs in geological systems. The REE's (La-Lu) behavior is characteristic of various primary and secondary minerals which comprise a rock. The REE's contents and their patterns provide a strong fingerprint in distinguishing among various rock types and in understanding the partial melting and/or fractional crystallization of the source region. The REE contents in geological materials are usually at trace levels. To measure all the REE at such levels, radiochemical neutron activation analysis (RNAA) has been used with a REE group separation scheme. To maximize detection sensitivites for individual REE, selective ?-ray/x-ray measurements have been made using normal Ge(Li) and low-energy photon detectors (LEPD), and Ge(Li)-NaI(Tl) coincidence-noncoincidence spectrometer systems. Using these detection methods an individual REE can be measured at or below the ppB levels; chemical yields of the REE are determined by reactivation

50

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

51

Developing Successful Learning Strategies in Structural Geology.  

Science.gov (United States)

Makes the case that geologic fieldwork requires more than knowledge of basic skills learned in the standard undergraduate curriculum. Argues that synthesis of the skills into a schema must be done before one can address the kinds of problems that arise when doing field investigations. Argues for the use of descriptive geometry and trigonometry in…

De Caprariis, Pascal P.

2002-01-01

52

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.

Dave Barnes

53

Geological Storage of CO2:Sensitivity and Risk Analysis  

OpenAIRE

Geological CO2 storage has the potential to be a key technology for prevention of industrial CO2 emission into the atmosphere. A successful storage operation requires safe geological structures with large storage capacity. The practicality of the technology is challenged by various operational concerns, ranging from site selection to long-term monitoring of the injected CO2. The research in this report addresses the value of using sophisticated geological modeling to help in predict...

Ashraf, Meisam

2014-01-01

54

An analysis of fracture trace patterns in areas of flat-lying sedimentary rocks for the detection of buried geologic structure. [Kansas and Texas  

Science.gov (United States)

Two study areas in a cratonic platform underlain by flat-lying sedimentary rocks were analyzed to determine if a quantitative relationship exists between fracture trace patterns and their frequency distributions and subsurface structural closures which might contain petroleum. Fracture trace lengths and frequency (number of fracture traces per unit area) were analyzed by trend surface analysis and length frequency distributions also were compared to a standard Gaussian distribution. Composite rose diagrams of fracture traces were analyzed using a multivariate analysis method which grouped or clustered the rose diagrams and their respective areas on the basis of the behavior of the rays of the rose diagram. Analysis indicates that the lengths of fracture traces are log-normally distributed according to the mapping technique used. Fracture trace frequency appeared higher on the flanks of active structures and lower around passive reef structures. Fracture trace log-mean lengths were shorter over several types of structures, perhaps due to increased fracturing and subsequent erosion. Analysis of rose diagrams using a multivariate technique indicated lithology as the primary control for the lower grouping levels. Groupings at higher levels indicated that areas overlying active structures may be isolated from their neighbors by this technique while passive structures showed no differences which could be isolated.

Podwysocki, M. H.

1974-01-01

55

Integrated Field Project in Structural Geology and Sedimentology/Stratigraphy  

Science.gov (United States)

The field project described in the Big Horn Basin is a capstone experience for our innovative full-year course sequence that combines two geologic disciplines traditionally taught separately (in "silos") sedimentology/stratigraphy and structural geology. We feel that a holistic approach that combines an understanding of the processes involved in both disciplines allows students to more easily develop the geologic history of an area from collected field data. The result is a two-semester course sequence that integrates the concepts of the two disciplines through a full year of study. While we have more than ten different field projects during the year, these are simply "snapshots" that allow the student to only see a piece of the geologic puzzle. These exercises do develop skills that the student will use in the capstone experience the geologic synthesis of a specific region currently the Sheep Mountain region of the Big Horn Basin. The field-mapping project in the Big Horn Basin is followed by five weeks of sequenced work that allows each student to synthesize a complete geologic (sedimetologic and structural) history of the region. This includes the construction of a geologic map and cross-sections, understanding the depositional history (including environments of deposition), the syn- or post-depositional deformation of the region and an attempt to put the local geologic history into the context of regional deformation and tectonics. We believe that by integrating the disciplines into the two-semester sequence capped with the field mapping and synthesis better prepares students to "think like a geologist".

Malinconico, Lawrence

56

Geological structure and geochemistry controlling radon in soil gas  

International Nuclear Information System (INIS)

Geological factors causing radon anomalies are either geochemical/petrophysical (controlling the diffusive 222Rn and 220Rn potential), or structural (controlling the advective 222Rn component), or both. While geochemical anomalies normally are easily explained and rather stable in time, structural anomalies often show fluctuations and interpretation of their origin can be very intricate. Geology-based techniques for detecting and mapping previously unrecognised areas of high radon risk have been developed with case studies in the Cenozoic Neuwied Basin of the Middle Rhine region and in the Paleozoic crystalline basement rocks of Eastern Bavaria in Southern Oberpfalz, Germany. (author)

57

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

Science.gov (United States)

...safety analysis of the geologic repository operations area. The preclosure...safety analysis of the geologic repository operations area must include...equipment, and process activities at the geologic repository operations area;...

2010-01-01

58

Using Layer-Cake Geology to Illustrate Structural Topographic Relationships.  

Science.gov (United States)

Discusses some of the difficulties of visualizing underlying geologic structural patterns by using maps or wooden blocks. Suggests the use of a modified layer cake to show dipping beds, folds, faults and differential erosion, as well as the relationships of stream valleys to outcrop patterns. (TW)

Wagner, John Robert

1987-01-01

59

Indoor Field Study for Structural Geology Course.  

Science.gov (United States)

Explains how basic mapping skills are taught in a large lab space using various arrangements of books to portray structural information. Reports an increase in student confidence and ability to synthesize data during field work. (DDR)

Greenberg, Jeffrey K.

2002-01-01

60

Auscultamiento de estructuras geológicas en la cuenca chacoparanense a partir de la aplicación de métodos potenciales / Analysis of geologic structures in the Chacoparanense basin based on the application of potential methods  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish Se presenta en el área de la cuenca Chacopampeana, noroeste de Argentina, un análisis preliminar geológico - geofísico, basado en los métodos potenciales.El área de estudio se ubica hacia el noreste de la ciudad de Santiago del Estero y parte noroeste de la provincia de Chaco, entre los 25° y 27° S [...] de latitud y 61° a 63° O de longitud. Se relevaron aproximadamente 1.000 nuevos puntos gravimétricos, que fueron agregados a la base de datos del Instituto de Física de Rosario, Universidad Nacional de Rosario y del Instituto Geofísico Sismológico Volponi, Universidad Nacional de San Juan. Con los datos obtenidos se preparó una carta de anomalías de Bouguer. La carta de anomalías, fue filtrada y procesada para separar efectos gravimétricos y se confeccionó un modelo cortical para una sección A-A´. El modelo cortical, indica la presencia de una estructura ubicada en la corteza superior. Este modelo justifica la residual de Bouguer.El área de estudio, posee características geológicas adecuadas de presencia de hidrocarburos, pero hasta el momento no se han descubierto estructuras geológicas de interés económico. En el presente estudio, mostramos una anomalía de Bouguer positiva, sin evidencias superficiales que podría interpretarse como una estructura geológica con potencial económico. Abstract in english A preliminary geological-geophysical analysis of the Chacopampeana area of north-eastern Argentina is presented from the application of potential field methods. The study area is located mostly in the north-east of the province of Santiago del Estero, and partly in north-west of the province of Chac [...] o, between latitudes 25° S and 27° S and longitudes 61° W to 63° W. We obtained approximately 1,000 new gravity points, that were added to the database of the Instituto de Física de Rosario, Universidad Nacional de Rosario and of the Instituto Geofísico Sismológico Volponi, Universidad Nacional de San Juan. A Bouguer anomaly map has been prepared from these data. The map was processed and filtered, and a cortical model produced, confirming the residual Bouguer values and indicating the presence of a structure located in upper crust. The study area has geological characteristics appropriate for the presence of hydrocarbons, although geological structures of economic interest have not yet been discovered. A positive gravity anomaly, without superficial expression, could be interpreted as a geological structure with economic potential.

M.E., Gimenez; P.M., Martínez; F., Ruíz; A., Introcaso.

2005-06-01

61

Auscultamiento de estructuras geológicas en la cuenca chacoparanense a partir de la aplicación de métodos potenciales Analysis of geologic structures in the Chacoparanense basin based on the application of potential methods  

Directory of Open Access Journals (Sweden)

Full Text Available Se presenta en el área de la cuenca Chacopampeana, noroeste de Argentina, un análisis preliminar geológico - geofísico, basado en los métodos potenciales.El área de estudio se ubica hacia el noreste de la ciudad de Santiago del Estero y parte noroeste de la provincia de Chaco, entre los 25° y 27° S de latitud y 61° a 63° O de longitud. Se relevaron aproximadamente 1.000 nuevos puntos gravimétricos, que fueron agregados a la base de datos del Instituto de Física de Rosario, Universidad Nacional de Rosario y del Instituto Geofísico Sismológico Volponi, Universidad Nacional de San Juan. Con los datos obtenidos se preparó una carta de anomalías de Bouguer. La carta de anomalías, fue filtrada y procesada para separar efectos gravimétricos y se confeccionó un modelo cortical para una sección A-A´. El modelo cortical, indica la presencia de una estructura ubicada en la corteza superior. Este modelo justifica la residual de Bouguer.El área de estudio, posee características geológicas adecuadas de presencia de hidrocarburos, pero hasta el momento no se han descubierto estructuras geológicas de interés económico. En el presente estudio, mostramos una anomalía de Bouguer positiva, sin evidencias superficiales que podría interpretarse como una estructura geológica con potencial económico.A preliminary geological-geophysical analysis of the Chacopampeana area of north-eastern Argentina is presented from the application of potential field methods. The study area is located mostly in the north-east of the province of Santiago del Estero, and partly in north-west of the province of Chaco, between latitudes 25° S and 27° S and longitudes 61° W to 63° W. We obtained approximately 1,000 new gravity points, that were added to the database of the Instituto de Física de Rosario, Universidad Nacional de Rosario and of the Instituto Geofísico Sismológico Volponi, Universidad Nacional de San Juan. A Bouguer anomaly map has been prepared from these data. The map was processed and filtered, and a cortical model produced, confirming the residual Bouguer values and indicating the presence of a structure located in upper crust. The study area has geological characteristics appropriate for the presence of hydrocarbons, although geological structures of economic interest have not yet been discovered. A positive gravity anomaly, without superficial expression, could be interpreted as a geological structure with economic potential.

M.E. Gimenez

2005-06-01

62

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

63

Activation analysis of geological materials using short-lived radionuclides  

International Nuclear Information System (INIS)

Tables are shown listing literature data on the activation analysis of geological samples using short-term activation by thermal neutrons. Elements are listed with a half-life of 10 s to 3 h determined in different geological materials, including their interference reactions, irradiation time, cooling time, measurement time, detection limit, and spectral lines. The most frequently determined elements included aluminium, vanadium, titanium, manganese, dysprosium, chlorine, magnesium, and calcium. (J.B.)

64

Expandable tubulars for use in geologic structures  

Energy Technology Data Exchange (ETDEWEB)

An expandable tubular includes a plurality of leaves formed from sheet material that have curved surfaces. The leaves extend around a portion or fully around the diameter of the tubular structure. Some of the adjacent leaves of the tubular are coupled together. The tubular is compressed to a smaller diameter so that it can be inserted through previously deployed tubular assemblies. Once the tubular is properly positioned, it is deployed and coupled or not coupled to a previously deployed tubular assembly. The tubular is useful for all types of wells and boreholes.

Spray, Jeffery A.; Svedeman, Steven; Walter, David; Mckeighan, Peter; Siebanaler, Shane; Dewhurst, Peter; Hobson, Steven; Foss, Doug; Wirz, Holger; Sharpe, Aaron; Apostal, Michael

2014-08-12

65

Effects of Rock Type and Geologic Process on the Structure and Evolution of Nano, Meso and Micro-Scale Porosity: A (U)SANS, SEM/BSE Analysis  

Science.gov (United States)

The microstructure and evolution of porosity in time and space play a critical role in many geologic processes, including the migration and retention of water, gas and hydrocarbons, the evolution of hydrothermal systems, weathering, diagenesis and metamorphism, as well as technological processes such as CO2 sequestration, shale gas and secondary oil recovery. The size, distribution and connectivity of these confined geometries collectively dictate how fluids migrate into and through these micro- and nanoenvironments, wet and react with mineral surfaces. (Ultra)small-angle neutron scattering and autocorrelations derived from SEM/BSE imaging provide a method of quantifying pore structures in a statistically significant manner from the nanometer to the centimeter scale. Data from this approach suggests that there are significant primary and evolutionary differences between the multiscale pore structures of carbonate and clastic rocks. Our work on the St. Peter sandstone shows total porosity correlates with changes in pores structure including pore size ratios, surface fractal dimensions, and lacunarity. There is no evidence of mass-fractal scattering and while previous scattering data from sandstones suggest scattering is dominated by surface fractal behavior over many orders of magnitude, our data show both fractal and pseudo-fractals. Larger pores fill at a faster rate than small pores as overgrowths form, leading to an increase in the small/large pore ratio. Overall, therefore, the relative importance of fluid reactions in confined geometries is likely to increase with increased silcrete formation. The changes observed with overgrowth formation in sandstones contrast with available data for metamorphism of chemical sediments (limestones) in both the Marble Canyon contact aureole, TX (Anovitz et al., 2009), and the Hatrurim Fm. (the Mottled Zone), Israel. The unmetamorphosed limestones both show distinct multifractal scattering patterns at larger scales, and true surface fractals at smaller scales. Total porosity increases with metamorphism, as does the surface area to volume ratio. The mass fractal dimension increases with metamorphic grade. In the Hatrurim the surface fractal dimension also increase suggesting that increases in pore mass density and formation of less branching pore networks are accompanied by a roughening of pore/grain interfaces. Ds changes are more complex at Marble Canyon, possibly due to hydrothermal processes. Pore evolution during combustion metamorphism is also characterized by reduced contributions from small-scale pores to the cumulative porosity in the high-grade rocks. The evolution of pore/grain microstructures may be correlated to the growth (nucleation) of high-temperature phases that preferentially close small pores, producing a rougher morphology with increasing temperature. The transition to a rough morphology may be a consequence of pore/grain surface free energies that are smaller than those that arise from heterogeneous phase contacts. Large-scale pores may also develop at the expense of small-scale pores. [1] Anovitz et al. (2009) Geochimica et Cosmochimica Acta 73, 7303-7324. Research sponsored by the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy.

Anovitz, L.; Wang, H.; Cole, D. R.; Rother, G.

2012-12-01

66

Using Concept Maps to Plan an Introductory Structural Geology Course  

Science.gov (United States)

This report presents the results of incorporating constructivist methods, including concept maps, into an undergraduate structural geology curriculum. A concept map is a visual representation of concepts and their relationship to each other in a body of knowledge. They show the hierarchy of these concepts and emphasize the links between them. The overall goal of this project was to encourage students to adopt a deep/holistic approach to learning in order to better understand the concepts of structural geology. The authors sought to determine whether teaching methods became more overtly constructivist, whether there was a change in the order of presentation of topics, and whether the order of presentation normally followed by textbooks was the same as the order determined using concept maps.

2004-05-01

67

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.)

68

Determination of subsurface geological structure with borehole gravimetry  

International Nuclear Information System (INIS)

Conventional gamma-gamma and gravimetric density measurements are routinely gathered for most holes used for underground nuclear tests. The logs serve to determine the subsurface structural geology near the borehole. The gamma-gamma density log measures density of the rock within about 15 cm of the borehole wall. The difference in gravity measured at two depths in a borehole can be interpreted in terms of the density of an infinite, homogeneous, horizontal bed between those depths. When the gravimetric density matches the gamma-gamma density over a given interval it is assumed that the bed actualy exists, and that rocks far from the hole must be the same as those encountered adjacent to the borehole. Conversely, when the gravimetric density differs from the gamma-gamma density it is apparent that the gravimeter is being influenced by a rock mass of different density than that at the hole wall. This mismatch can be a powerful tool to deduce the local structural geology. The geology deduced from gravity mesurements in emplacement hole, U4al, and the associated exploratory hole, UE4al, is an excellent example of the power of the method

69

Spatial Abilities of High-School Students in the Perception of Geologic Structures.  

Science.gov (United States)

Characterizes specific spatial abilities required in geology studies through the examination of the performance of high school students in solving structural geology problems on the geologic spatial ability test (GeoSAT). Concludes that visual penetration ability and the ability to perceive the spatial configuration of the structure are…

Kali, Yael; Orion, Nir

1996-01-01

70

Induced seismicity constraints on subsurface geological structure, Paradox Valley, Colorado  

Science.gov (United States)

Precise relative hypocentres of seismic events induced by long-term fluid injection at the Paradox Valley Unit (PVU) brine disposal well provide constraints on the subsurface geological structure and compliment information available from deep seismic reflection and well data. We use the 3-D spatial distribution of the hypocentres to refine the locations, strikes, and throws of subsurface faults interpre­ted previously from geophysical surveys and to infer the existence of previously unidentified subsurface faults. From distinct epicentre lineations and focal mechanism trends, we identify a set of conjugate fracture orientations consistent with shear-slip reactivation of late-Palaeozoic fractures over a widespread area, as well as an additional fracture orientation present only near the injection well. We propose simple Mohr-Coulomb fracture models to explain these observations. The observation that induced seismicity preferentially occurs along one of the identified conjugate fracture orientations can be explained by a rotation in the direction of the regional maximum compressive stress from the time when the fractures were formed to the present. Shear slip along the third fracture orientation observed near the injection well is inconsistent with the current regional stress field and suggests a local rotation of the horizontal stresses. The detailed subsurface model produced by this analysis provides important insights for anticipating spatial patterns of future induced seismicity and for evaluation of possible additional injection well sites that are likely to be seismically and hydrologically isolated from the current well. In addition, the interpreted fault patterns provide constraints for estimating the maximum magnitude earthquake that may be induced, and for building geomechanical models to simulate pore pressure diffusion, stress changes and earthquake triggering.

Block, Lisa V.; Wood, Christopher K.; Yeck, William L.; King, Vanessa M.

2015-02-01

71

Entropic component analysis and its application in geological data  

Science.gov (United States)

We present an entropic component analysis for identifying key parameters or variables and the joint effects of various parameters that characterize complex systems. This approach identifies key parameters through solving the variable selection problem. It consists of two steps. First, a Bayesian approach is utilized to convert the variable selection problem into the model selection problem. Second, the model selection is achieved uniquely by evaluating the information difference of models by relative entropies of these models and a reference model. We study a geological sample classification problem, where a brine sample from Texas and Oklahoma oil field is considered, to illustrate and examine the proposed approach. The results are consistent with qualitative analysis of the lithology and quantitative discriminant function analysis. Furthermore, the proposed approach reveals the joint effects of the parameters, while it is unclear from the discriminant function analysis. The proposed approach could be thus promising to various geological data analysis.

Tseng, Chih-Yuan; Chen, Chien-Chih

2011-11-01

72

The spectroscopic properties and electronic structure of the vanadium in complex materials: Geological and technological implications.  

OpenAIRE

The aim of this thesis is the investigation of the spectroscopic properties and the electronic structure of vanadium in minerals with a geological and/or technological interest. V K-edge HERFD-XAS experiments were combined with a theoretical determination of the measured spectra. Two approaches were complementary used to calculate the spectra: an ab initio approach and a multielectronic one. Theoretical developments based on a spherical tensor analysis and the coset method were achieved and a...

Bordage, Ame?lie

2009-01-01

73

Geological Geophysical and structural studies in Mina Ratones (Pluton de Albala)  

International Nuclear Information System (INIS)

Mina Ratones environmental restoration project included petrological, structural,geophysical, hydrogeological and hydrogeochemical studies. The main objective of the geologic-structural and geophysical studies was the Albala granite structural characterization around the Mina Ratones uranium mine. The location of facies, fault zones (faults and dykes) as well as the distribution of some physical properties inside the rock massif was obtained for a granitic black of 900, 500, and 500 m. The geologic-structural and geophysical techniques applied to Mina Ratones provided a multidisciplinary approach for high resolution characterization of rock massif, and the structures potentially containing fluids,able to be applied to the hydrogeological modelling to a particular area. Geological studies included a detailed structural mapping of the area surrounding the mine (1:5,000 scale), the geometric, kinematics, and dynamics analysis of fractures of all scales, the petrology and geochemistry of fault rocks and altered areas surrounding fractures, and the microstructural studies of samples from surface and core lags. The construction of geostatistical models in two and three dimensions had helped to characterize the Mina Ratones rock massif showing the spatial distribution of fault zones, fracture intensity, granite composition heterogeneities, fluid-rock interaction zones, and physical properties. (Author)

74

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

75

Characteristics of geological structure with the Lira explosions and possible ways of radionuclide migration  

International Nuclear Information System (INIS)

Peaceful nuclear explosions were detonated on the northern side of Karachaganak deposit to create cavities for storing gas condensate. Despite the detailed study of the salt dome by means of drilling, a number of questions were not answered, regarding internal structure of space above the dome, and salt tectonics. These questions are important for prognosis of radionuclide contamination of territory. By means of acquisitions, and analysis of geologic information, and reconstruction of structures, one can forecast four stratigraphic levels for possible migration of radionuclides. It is recommended to use the acquired data during the experimental researches of 'Lira' explosions. (author)

76

Evaluation of structural behavior, geological and hydrogeological characteristics  

International Nuclear Information System (INIS)

In order to understand the behavior of an underground structure properly, this report includes the study on the structural behavior of rock masses surrounding underground openings considering the effect of excavation. Before analyzing the underground structure, the followings are studied: initial stress distribution before excavation, stress release and redistribution due to the sequential excavation, comparison of analysis methods, discussions on numerical simulation techniques for the sequential excavation and an numerical analysis modeling. The underground structure in then analyzed using the finite element and distinct element methods of analysis considering the effect of sequential excavation, Based on the results of the analysis, the followings are discussed: shape of the opening, distance between openings, method and sequence of excavation, and structural reinforcement. (Author)

77

Hudson Valley Fold and Thrust Belt Field Trip (Structural Geology)  

Science.gov (United States)

This structural geology field trip in the Hudson Valley region reinforces class discussions about fold and thrust belts and thin-skinned tectonics. Students observed a ramp anticline over a ramp-flat geometry fault. The anticline has minor faulting and veining in the hinge zone and folding occurred by flexural slip (evident from down-dip slickenlines on bedding surfaces). Students make observations and sketches of the outcrop and take strike and dip measurements of bedding and fault surfaces. Students can also look for a very weak cleavage. Students can use attitude measurements to reinforce key principles of stereonets including plotting lines, planes, and poles and interpreting the orientation of the fold axis (or other information) from these nets.

Growdon, Martha

78

Instrumental neutron activation analysis at the US geological survey  

International Nuclear Information System (INIS)

The United States Geological Survey (USGS) Triga Reactor (GSTR) has been in operation since 1969 and is maintained by the USGS to perform nuclear analyses of geological and biological samples. Controlled irradiation of samples by neutrons permit multi-element analyses by instrumental neutron activation analysis (INAA), Ar-Ar age dating, and fission track radiography and dating. More than 420 000 sample irradiations have been performed since the facility began operation. The analyses provide valuable information about both the composition and age of the samples. The design of the GSTR is well suited for INAA, fission track radiography and age dating, in that the slow rotation of samples around the reactor core results in samples being subjected to a homogeneous irradiation field, allowing the use of a single fluence monitor for an entire batch of samples being irradiated. The central irradiation facility of the GSTR is used for Ar-Ar age dating because of the high neutron flux available there

79

Significance of Geophysical and Geological Investigations of Deep Structure for Safety Evaluation of Nuclear Power Plants  

International Nuclear Information System (INIS)

The faulting process and subsurface deformation as well as the complicated underground structure of the Niigata area in relation to ground motion were explained, which was followed by an explanation of the importance of the following items. - Understanding geological history to construct the current geological structure, - Construction of an integrated ground model by geophysical exploration; topographical, geological, and morphological data; and boring data, and - Confirmation of model validation by simulation. (author)

80

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

81

Multipass SAR interferometry. A tool for geologic analysis  

International Nuclear Information System (INIS)

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 ologic interpretation and the observation of detailed features of the terrain

82

Large volcanoes on Venus: Examples of geologic and structural characteristics from different classes  

Science.gov (United States)

Large volcanoes characterized by radial lava flows and similar evidence for a topographic edifice are widely distributed over the surface of Venus and geologically diverse. Based on the global identification of more than 165 examples and preliminary geologic mapping, large volcanoes range from those characterized geologically as simple lava edifices to those bearing evidence of complexly developed volcanic and structural histories. Many large volcanoes exhibit characteristics transitional to other large magnetic center types such as coronae and novae. In this study, we examine the geology and structure of several type examples of large volcanoes not addressed in previous studies which are representative of several of the morphological classes.

Crumpler, L. S.; Head, J. W.; Aubele, J. C.

1993-01-01

83

Water Testing and Analysis by the United States Geological Survey  

Science.gov (United States)

This activity enables students to meet and interact with practicing scientists, to see scientific equipment being used by professionals, and to participate in a local data gathering and analysis exercise. It also should provide the student with some information on the attributes of clean or potable water. Each student will collect a water sample and bring it to class to be tested by a visiting United States Geological Survey (USGS) scientist. They will then fill out data sheets and answer questions based on this data.

2005-10-06

84

Uranium analysis by K X-rays from geological samples  

International Nuclear Information System (INIS)

Uranium analysis at trace levels from geological samples was performed by K X-ray fluorescence using a semiconductor detector and radioisotope excitation. The exciting 57Co-source was constructed in such a way as to produce a high peak to background ratio. Using 10 minutes counting times the detection limit with a 0.26 GBq source was 24 ?g/g improving to about 9 ?g/g with a ten times stronger source. The detection limits for tin, cerium, tungsten and thorium were also measured. (author)

85

Detection limits in epithermal neutron activation analysis of geological material  

International Nuclear Information System (INIS)

The improvement of detection limits for trace elements in geological samples by epithermal neutron activation analysis is examined. The relative merits of cadmium, boron and composite cadmium + boron filters are compared for trace elements Ni, As, Pd, Cd, Sb, W, Ir Pt and Au and interfering elements Na, K, Sc, Cr, Fe, Co and Cu. A boron filter gives optimum sensitivity for the trace elements based on interference from 46Sc, but the detection limits are only improved 2-5 times. Maximum possible improvement, which is shown by Ni, gives sensitivities 5 times better under cadmium and 15 times under boron. (author)

86

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

87

Geologic datasets for weights of evidence analysis in northeast Washington: 1. geologic raster data  

Science.gov (United States)

This dataset contains the combination of geology data (geologic units, faults, folds, and dikes) from 6 1:100,000 scale digital coverages in eastern Washington (Chewelah, Colville, Omak, Oroville, Nespelem, Republic). The data was converted to an Arc grid in ArcView using the Spatial Analyst extension.

Boleneus, David E.; Causey, J. Douglas

2000-01-01

88

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

89

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

Energy Technology Data Exchange (ETDEWEB)

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.

Wyatt, D. [Westinghouse Savannah River Company, AIKEN, SC (United States); Aadland, R.K.; Cumbest, R.J.; Stephenson, D.E.; Syms, F.H.

1997-12-01

90

Diversion path analysis for the Swedish geological repository  

Energy Technology Data Exchange (ETDEWEB)

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

Fritzell, Anni (Dept. of Physics and Astronomy, Uppsala Univ., Uppsala (Sweden)); Meer, Klaas Van Der (Belgian Nuclear Research Center SCK.CEN (BG))

2008-02-15

91

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

92

Geological structure of the Paradox Valley Region, Colorado, and relationship to seismicity induced by deep well injection  

Science.gov (United States)

Bureau of Reclamation (Reclamation) operates a deep injection well at Paradox Valley in western Colorado. Seismicity has been recorded since 1985, with more than 5900 likely induced earthquakes detected since injection operations began in 1991, making this project a unique and valuable case study in the long-term development of injection-induced seismicity. Likely induced earthquakes occur in a complex pattern with clusters separated by aseismic gaps of 2 km or more, and have been observed up to 16 km from the injection well. To evaluate how the subsurface geologic structure may control the occurrence of induced seismicity, we compare the earthquake locations to a set of geologic models that Reclamation commissioned prior to drilling the injection well. Our analysis indicates that many aspects of the observed seismicity pattern can be attributed to the complex geologic structure. The earthquake depths and locations are generally consistent with the structural trends of the primary injection target formation, within the uncertainty of the models, and some of the mapped basement faults appear to serve as boundaries in the earthquake locations, suggesting that they are barriers to flow. Additionally, the majority of events follow the predicted fluid flow pattern, which trends northwest-southeast and wraps around Paradox Valley. Some features of the seismicity pattern, such as the early onset of seismicity to the northwest of the injection well and the distinct clustering, are not explained by the current geologic models and may be related to unmapped geologic features or local variations in the stress field.

King, Vanessa M.; Block, Lisa V.; Yeck, William L.; Wood, Christopher K.; Derouin, Sarah A.

2014-06-01

93

Analysis and design of SSC underground structures  

International Nuclear Information System (INIS)

This paper describes the analysis and design of underground structures for the Superconducting Super Collider (SSC) Project. A brief overview of the SSC Project and the types of underground structures are presented. Engineering properties and non-linear behavior of the geologic materials are reviewed. The three-dimensional sequential finite element rock-structure interaction analysis techniques developed by the author are presented and discussed. Several examples of how the method works, specific advantages, and constraints are presented. Finally, the structural designs that resulted from the sequential interaction analysis are presented

94

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

95

The structural geology of boulby (potash) mine, Cleveland, United Kingdom  

Science.gov (United States)

This is the first description of the structural geology of the Upper Permian potash and salt of the third Zechstein Cycle exposed in Boulby Mine. The near seam lithologies are described briefly and the associated veins, vein networks, shear zones and slides are introduced. It is argued that the Boulby Potash migrated from lower levels to those at which it is now found to fill fractures which developed in a grey anhydrite shale produced by the reduction and wetting of the lower parts of the Carnallitic (Rotten) Marl. Continued introduction of chlorides of Na and K into vein networks dispersed the shale as clasts of ever decreasing size in a sub-horizontal zone of gneissose sylvinite which, when it reached a significant thickness, began to flow in an extraordinary manner. Hundreds of asymmetric sub-horizontal lobes of gneissose sylvinite root to and repeat the first formed layer in structures which developed to various degrees in different parts of the mine. These are shown to represent small-scale movement cells (e.g. 15 × 30 to 100m in axial section) in which the movements integrate within a pattern of larger-scale movement cells ( 15 × 200 to 400 m). Where the sylvinite was thickest these movement cells progressed to a stage which involved the complete circulation of a compound layer of sylvinite and grey shale. Continued circulation almost homogenised this compound layer to sylvinite in which the grey shale has been disrupted and dispersed to small aggregates and individual clay particles included within the chloride grains. The circulation cells in the sylvinite are rectilinear rolls close to where thin but extensive sub-horizontal lobes of Boulby Halite moved through and over them late in the structural history. Away from such salt lobes, the small-scale circulation cells are concentric within the boundaries of larger cells which have polygonal planforms. After rejecting explanations invoking near surface slumping for the small-scale circulation cells it is argued that they developed near their maximum depth of burial in late Jurassic or Cretaceous times. The multiwavelength circulation pattern in the Boulby Potash is interpreted as due to thermal convection influenced by primary gravitational instabilities on a larger scale. The sub-horizontal lobes of Boulby Halite are assigned to a final Laramide transcurrent reactivation of faults inherited from the basement during earlier phases of movement.

Talbot, C. J.; Tully, C. P.; Woods, P. J. E.

1982-05-01

96

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

OpenAIRE

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...

Fengshan Wang; Hongjun Zhang; Quanbing Rong

2012-01-01

97

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)

98

Application of structural geology in exploration for residual gem deposits of Sri Lanka  

OpenAIRE

Geological investigations of some major gem-bearing areas of Sri Lanka have shown that the gem deposits are controlled by the geological structure. Corundum deposits are generally associated with axial plane areas of tight, doubly plunging synclinoria and anticlinoria where occurrences of crystalline limestones and pegmatites are observed. Corundum deposits also occur at sites of heavy structural disturbances such as discontinuities, faults, folds, joints, lensing and necking zones etc. if oc...

Mendis, D. P. J.; Rupasinghe, M. S.; Dissanayake, C. B.

1993-01-01

99

The method of instrumental neutron activation analysis of geological samples  

International Nuclear Information System (INIS)

Full text: With beginning of work of the nuclear reactor Salaspils a new branch of applied nuclear physics has been developed in Latvia - the neutron activation analysis (NAA). NAA is based on radioactivity of the elements in sample, which is induced in a neutron flux. The NAA is one of the most sensitive methods of multielement analysis. Taking in account high intensity, sufficient precision, possibility to determine a large amount of elements in one sample at the same time, without chemical treatment of this sample, this method is practically irreplaceable in geochemical research. It makes possible to determine the concentration and distribution of rare earth and other elements in rocks and minerals, and so to judge about genetic factors in the formation of minerals. For the determination of 32 elements in geological samples two methods of instrumental neutron activation analysis have been developed. In the first method short-lived radionuclides are detected, in the second one - long-lived species. The efficiency of irradiation with epithermal neutrons is estimated and following conclusions are obtained: a) the activity of the matrix elements decreases; b) the detection limits of As, Mo, Ni, Rb, W decrease; c) the length of analysis decreases 2 times. The developed methods were applied in the analysis of rock samples for the S/E ''Latvijas geologija''. 132 rock samples from bore holes in different depth (till 1000 m) were analysed. Using the same methods, sample of wastes from the ore processing plant in Silama, Estonia, were analysed. Also in this case, in order to determine the activities of the plant in different periods , the samples were taken from different depth of the waste deposit. the detection limits and the concentration intervals of the analysed elements are given lower. (author)

100

Precambrian Basement Structure Map of the Continental United States - An Interpretation of Geologic and Aeromagnetic Data  

Science.gov (United States)

The Precambrian basement rocks of the continental United States are largely covered by younger sedimentary and volcanic rocks, and the availability of updated aeromagnetic data (NAMAG, 2002) provides a means to infer major regional basement structures and tie together the scattered, but locally abundant, geologic information. Precambrian basement structures in the continental United States have strongly influenced later Proterozoic and Phanerozoic tectonism within the continent, and there is a growing awareness of the utility of these structures in deciphering major younger tectonic and related episodes. Interest in the role of basement structures in the evolution of continents has been recently stimulated, particularly by publications of the Geological Society of London (Holdsworth and others, 1998; Holdsworth and others, 2001). These publications, as well as others, stress the importance of reactivation of basement structures in guiding the subsequent evolution of continents. Knowledge of basement structures is an important key to understanding the geology of continental interiors.

Sims, Paul K.; Saltus, Richard W.; Anderson, Eric D.

2008-01-01

101

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

102

Research and development of methods and technologies for CO2 capture in fossil fuel power plants and storage in geological formations in the Czech Republic, stage E4: Risk analysis. Risk analysis methods for CO2 storage in geological structures. Revision 0  

International Nuclear Information System (INIS)

The basis for any treatment of this issue is European Directive 2009/31/EC on the geological storage of carbon dioxide. It is demonstrated that the principles of underground storage of radioactive waste can be applied to the storage of CO2, and the same assessment tools, including mathematical models, can be used or modified. (P.A.)

103

Formation of secondary phases during deep geological final disposal of research reactor fuel elements. Structure and phase analysis; Bildung von sekundaeren Phasen bei tiefengeologischer Endlagerung von Forschungsreaktor-Brennelementen. Struktur- und Phasenanalyse  

Energy Technology Data Exchange (ETDEWEB)

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 UAl{sub x}-Al were subjected to magnesium chloride rich brine (brine 2, salt repository) and to clay pore solution, respectively and furthermore of the type U{sub 3}Si{sub 2}-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 UAl{sub x}-Al and U{sub 3}Si{sub 2}-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 U{sub 3}Si{sub 2}-Al in brine 2 being prepared with water. Contrary to these observations the system UAl{sub x}-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 UAl{sub 4} 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 UAl{sub x}-Al und U{sub 3}Si{sub 2}-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 UAl{sub x}-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 latt

Neumann, Andreas

2012-07-01

104

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 withints 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.

105

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

106

Radioactive waste disposal process geological structure for the waste disposal  

International Nuclear Information System (INIS)

The process described here consists to carry out the two phases of storage operation (intermediate and definitive) of radioactive wastes (especially the vitrified ones) in a geological dispositif (horizontal shafts) at an adequate deepness but suitable for a natural convection ventilation with fresh air from the land surface and moved only with the calorific heat released by the burried radioactive wastes when the radioactive decay has reached the adequate level, the shafts are totally and definitely occluded

107

Shorter contributions to stratigraphy and structural geology, 1979  

Science.gov (United States)

PART A: A system of anticlines lies along the trend of the sinuous course of the Colorado River for a distance of 97 km in the central Grand Canyon. Similar anticlines occur in some perennially wet side canyons. The anticlines are most abundant and well developed along northeast-trending reaches of the main canyon where it is floored by the Cambrian Muav Limestone. Dips of the folded strata are as great as 60?, and the folding locally extends more than 250 m from the river. Low-angle thrust faults in the limbs of the anticlines parallel the river and have formed in response to folding of the comparatively brittle carbonate strata. High-angle reverse kink bands, along which rocks are displaced up toward the river, also parallel the anticlines and have develop2d in response to the upward bulging of the canyon floor. The river anticlines are an unloading phenomenon. They result from lateral squeezing toward the river of saturated shaly parts of the Muav Limestone and underlying Bright Angel Shale. The driving mechanism for the deformation is a stress gradient that results from a difference in lithostatic load between the heavily loaded rocks under the 650-m-high canyon walls and the unloaded canyon floor. Saturation appears to weaken the shaly rocks sufficiently to allow deformation to take place. River anticlines are not present in the eastern Grand Canyon, where the Cambrian rocks also occur at river level. Their absence is explained by a lack of shaly rocks that could flow when saturated. PART B: The current interest in contemporary tectonic processes in the Eastern United States is turning up abundant evidence of crustal movements in late geologic time. Topographic analysis of the highland areas from the southern Blue Ridge to the Adirondack Mountains indicates that most of the landforms owe their origin to erosion of rocks of different resistance rather than to tectonic processes. Most areas of high relief and high altitude have been formed on resistant rocks. The Cambrian and Ordovician belt, containing mostly shale and carbonate rock, on the other hand, forms an extensive lowland from Alabama to the Canadian border and girdles the Adirondack Mountains. Differences in altitude can be explained by the presence of resistant rocks outside the belt; these resistant rocks form local base levels on the streams that drain the belt. A few areas may have undergone local uplift at a higher rate than areas nearby--for example, the Piedmont region northwest of Chesapeake Bay. Most estimates of erosion rates, based on the load transported by streams and of uplift rates, based on removal during a known period of time, are of the same order of magnitude, averaging almost 4x 10^-2 millimeters per year. Rates of uplift, based on study of tilted Pleistocene beaches and repeated geodetic traverses, are at least an order of magnitude higher for comparable areas. Tectonic uplift of the highlands has been slow and involves mostly warping or tilting on a large scale. Erosion rates keep up with or exceed the rate of uplift and have been sufficient to mask evidence of faulting or other differential movements. The high rates of uplift that are inferred on tilted water planes in the glaciated regions or that are measured by differences in repeated geodetic traverses cannot have been sustained for long periods of time. PART C: The Hanson Creek Formation southwest of Eureka, Nev., in the Bellevue Peak Quadrangle is composed of three lithostratigraphic members: (1) a basal dark-gray dolomite, (2) a middle silty thin- to thick-bedded, locally nodular, dark-gray, light-yellow-mottled limestone topped by light-gray dolomite, and (3) an upper dark-gray dolomite, which is herein named the Combs Canyon Dolomite Member. Detailed geologic mapping and accompanying fossil collecting prove that the same lithostratigraphic and biostratigraphic sequence is present in the Mountain Boy Range and 11 km to the south near Wood Cone Peak. Minor differences in

U.S. Geological Survey

1980-01-01

108

Comparison of structural and least-squares lines for estimating geologic relations  

Science.gov (United States)

Two different goals in fitting straight lines to data are to estimate a "true" linear relation (physical law) and to predict values of the dependent variable with the smallest possible error. Regarding the first goal, a Monte Carlo study indicated that the structural-analysis (SA) method of fitting straight lines to data is superior to the ordinary least-squares (OLS) method for estimating "true" straight-line relations. Number of data points, slope and intercept of the true relation, and variances of the errors associated with the independent (X) and dependent (Y) variables influence the degree of agreement. For example, differences between the two line-fitting methods decrease as error in X becomes small relative to error in Y. Regarding the second goal-predicting the dependent variable-OLS is better than SA. Again, the difference diminishes as X takes on less error relative to Y. With respect to estimation of slope and intercept and prediction of Y, agreement between Monte Carlo results and large-sample theory was very good for sample sizes of 100, and fair to good for sample sizes of 20. The procedures and error measures are illustrated with two geologic examples. ?? 1990 International Association for Mathematical Geology.

Williams, G.P.; Troutman, B.M.

1990-01-01

109

A brief guide to synchrotron radiation-based microtomography in (structural) geology and rock mechanics  

Science.gov (United States)

This contribution outlines Synchrotron-based X-ray micro-tomography and its potential use in structural geology and rock mechanics. The paper complements several recent reviews of X-ray microtomography. We summarize the general approach to data acquisition, post-processing as well as analysis and thereby aim to provide an entry point for the interested reader. The paper includes tables listing relevant beamlines, a list of all available imaging techniques, and available free and commercial software packages for data visualization and quantification. We highlight potential applications in a review of relevant literature including time-resolved experiments and digital rock physics. The paper concludes with a report on ongoing developments and upgrades at synchrotron facilities to frame the future possibilities for imaging sub-second processes in centimetre-sized samples.

Fusseis, F.; Xiao, X.; Schrank, C.; De Carlo, F.

2014-08-01

110

Mapping Vesta South Polar Quadrangle V-15SP: A Complex Geological Structure Dominates Vesta  

Science.gov (United States)

Images of the asteroid and protoplanet 4Vesta by the Hubble Space Telescope in 1994 and 1996 revealed a ~460 km diameter feature at its south pole that was interpreted to be a large impact structure. NASA's Dawn spacecraft arrived at the asteroid Vesta on July 15, 2011 and collected science data during the approach to Vesta, a circular polar orbit at an altitude of 2700 km providing ~ 230 m/pix camera resolution and a lower main mapping orbit, at 700 km altitude with a camera resolution of ~ 65 m/pixel. As part of the geological analysis of Vesta's surface, a series of 15 quadrangle maps are being produced. We present the results of the geological mapping achieved for quadrangle V-15SP. Unit boundaries and feature characteristics were determined primarily using morphologic data. Color and spectral data was utilized to refine unit contacts and to separate compositional or mineralogical distinctions. Those units that could be discerned both in morphology and in the color data were interpreted as geologically derived units. The south polar feature is a semi-circular structure with a central hill that is characterized by a white-grey color and smoother texture distinctive from the surrounding terrain. Some images show patches of bright, smooth terrain on the central hill, perhaps indicative of impact melt or ponded volcanic flows. A complex network of deep grooves and ridges is the primary characteristic on the feature floor; these grooves appear radial to the central mound or trend along a north-south line. The structure also has a distinctive color from both the central hill and surrounding terrain, consistent with a different composition or texture. A steep semi-arcuate scarp bounds part of the outer perimeter of the south polar feature. Although asymmetric in general form, these characteristics do not contradict an impact origin but may also allow endogenic processes like convective downwelling or hybrid modification of an impact. Rapid rotation of Vesta during impact may explain some anomalous features (Jutzi and Asphaug, 2010). The crater size frequency and the chronology function is derived from the lunar chronology, scaled to impact frequencies modeled for Vesta according to (Bottke et al., 1994) and (O'Brien and Sykes, 2011) on Vesta. Preliminary crater counts indicate only small differences in absolute surface model ages between the northern region and the south polar structure.

Jaumann, R.; Yingst, R.; Schenk, P.; Schmedemann, N.; Williams, D. A.; Pieters, C. M.; Buczkowski, D.; Stephan, K.; Roatsch, T.; Preusker, F.; Scholten, F.; Neukum, G.; O'Brien, D. P.; Mest, S. C.; Krohn, K.; Marchi, S.; Filacchione, G.; Russell, C. T.; Raymond, C. A.; De Sanctis, M. C.

2011-12-01

111

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

112

Precision neutron activation analysis of lunar and geological samples  

International Nuclear Information System (INIS)

Improvements were made in systems for the determination of O, Si, Al, Mg, and Fe in lunar and geological samples by 14 MeV neutron activation analysis. Methods were developed for use of a 1 mg 252Cf neutron source in the determination of Mn and Na in lunar samples. The effects of geometric reproducibility, 14 MeV neutron flux instability, and dead time and pulse pile-up in the neutron monitor and counting systems were examined. A new method of gamma-ray peak integration for use with NaI(Tl) spectra is presented. Major and minor elemental abundance data on three Apollo 14 and three Apollo 15 samples were determined. Data on the elements above are presented for four Apollo 16 crystalline rocks, seven Apollo 16 soils, seven Apollo 16 breccias, three Apollo 17 basalts, one Apollo 17 breccia, and ten Apollo 17 soils. Elemental abundance summations for these samples average 98.9 +- 0.2 percent, and would be higher by a few tenths of one percent if elements not determined (e.g., K, Cr, P and S) were included. Evidence suggestive of an oxygen deficiency in lunar materials was obtained. Possible causes are discussed. Correlations of iron with aluminum and iron with manganese are presented for data from all Apollo landing sites. An overview of elemental abundance correlations for 21 major, minor, and trace eleme

113

Structural geology and geological history of the Perrine and Nun Sulci Quadrangles (Jg-2 and Jg-5), Ganymede  

Science.gov (United States)

Grooves are the dominant structural features on Ganymede. While single grooves are found in many areas, it is somewhat more common to find them grouped together in groove sets (groupings of grooves with common structural trends). It is generally believed that the grooves are extensional features. Their underlying geologic nature cannot be determined from Voyager images, however. It appears likely that they are grabens, but the images are insufficient to rule out the possibility that they are modified extension fractures or some kind of ductile necking features. The oldest materials within the Nun Sulci and Perrine quadrangles occur within the cratered dark materials unit, as is generally the case for all of Ganymede. This is the most widespread of the dark units mapped in these two quadrangles. Crater densities within cratered dark materials are consistent with an age on the order of several billion years, and thus cratered dark terrain probably represents crust that has survived from the end of the primordial intense bombardment phase of solar system history. The brief geologic history is greatly oversimplified as a result of the poor resolution and unfavorable viewing geometry of the images covering the area.

Mcgill, George E.; Squyres, Steven W.

1991-01-01

114

Application of structural geology in exploration for residual gem deposits of Sri Lanka  

Directory of Open Access Journals (Sweden)

Full Text Available Geological investigations of some major gem-bearing areas of Sri Lanka have shown that the gem deposits are controlled by the geological structure. Corundum deposits are generally associated with axial plane areas of tight, doubly plunging synclinoria and anticlinoria where occurrences of crystalline limestones and pegmatites are observed. Corundum deposits also occur at sites of heavy structural disturbances such as discontinuities, faults, folds, joints, lensing and necking zones etc. if occurrences of marbles and/or intrusions of granite and pegmatites have taken place. Alluvial gem deposits do not necessarily exist close to the area where they originate, but most concentrations of alluvial gem beds still remain close to the source area. Detailed investigations of the geological structure of a gem-bearing area and the relationship of these structural elements with appropriate source rocks will yield vital clues to the existence of gem deposits.

Mendis, D.P.J.

1993-06-01

115

Constructing a large-scale 3D Geologic Model for Analysis of the Non-Proliferation Experiment  

Energy Technology Data Exchange (ETDEWEB)

We have constructed a regional 3D geologic model of the southern Great Basin, in support of a seismic wave propagation investigation of the 1993 Nonproliferation Experiment (NPE) at the Nevada Test Site (NTS). The model is centered on the NPE and spans longitude -119.5{sup o} to -112.6{sup o} and latitude 34.5{sup o} to 39.8{sup o}; the depth ranges from the topographic surface to 150 km below sea level. The model includes the southern half of Nevada, as well as parts of eastern California, western Utah, and a portion of northwestern Arizona. The upper crust is constrained by both geologic and geophysical studies, while the lower crust and upper mantle are constrained by geophysical studies. The mapped upper crustal geologic units are Quaternary basin fill, Tertiary deposits, pre-Tertiary deposits, intrusive rocks of all ages, and calderas. The lower crust and upper mantle are parameterized with 5 layers, including the Moho. Detailed geologic data, including surface maps, borehole data, and geophysical surveys, were used to define the geology at the NTS. Digital geologic outcrop data were available for both Nevada and Arizona, whereas geologic maps for California and Utah were scanned and hand-digitized. Published gravity data (2km spacing) were used to determine the thickness of the Cenozoic deposits and thus estimate the depth of the basins. The free surface is based on a 10m lateral resolution DEM at the NTS and a 90m lateral resolution DEM elsewhere. Variations in crustal thickness are based on receiver function analysis and a framework compilation of reflection/refraction studies. We used Earthvision (Dynamic Graphics, Inc.) to integrate the geologic and geophysical information into a model of x,y,z,p nodes, where p is a unique integer index value representing the geologic unit. For seismic studies, the geologic units are mapped to specific seismic velocities. The gross geophysical structure of the crust and upper mantle is taken from regional surface-wave studies. For regional seismic simulations we convert this realistic geologic model into elastic parameters. Upper crustal units are treated as seismically homogeneous while the lower crust and upper mantle are parameterized by a smoothly varying velocity profile. In order to mitigate spurious reflections, the lower crust and upper mantle are treated as velocity gradients as a function of depth.

Wagoner, J; Myers, S

2008-04-09

116

Hands-On Exercise in Environmental Structural Geology Using a Fracture Block Model.  

Science.gov (United States)

Describes the use of a scale analog model of an actual fractured rock reservoir to replace paper copies of fracture maps in the structural geology curriculum. Discusses the merits of the model in enabling students to gain experience performing standard structural analyses. (DDR)

Gates, Alexander E.

2001-01-01

117

Geological interpretation of Mount Ciremai geothermal system from remote sensing and magneto-teluric analysis  

CERN Document Server

The exploration of geothermal system at Mount Ciremai has been started since the early 1980s and has just been studied carefully since the early 2000s. Previous studies have detected the potential of geothermal system and also the groundwater mechanism feeding the system. This paper will discuss the geothermal exploration based on regional scale surface temperature analysis with Landsat image to have a more detail interpretation of the geological setting and magneto-telluric or MT survey at prospect zones, which identified by the previous method, to have a more exact and in depth local scale structural interpretation. Both methods are directed to pin point appropriate locations for geothermal pilot hole drilling and testing. We used four scenes of Landsat Enhanced Thematic Mapper or ETM+ data to estimate the surface manifestation of a geothermal system. Temporal analysis of Land Surface Temperature or LST was applied and coupled with field temperature measurement at seven locations. By combining the TTM with ...

Sumintadireja, Prihadi; Irawan, Dasapta E; Irawan, Diky; Fadillah, Ahmad

2015-01-01

118

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)

119

Seismic and geologic investigations of the Sandia Livermore Laboratory site and structural investigations of the Tritium Research Facility  

Energy Technology Data Exchange (ETDEWEB)

This report consists of two parts. Part I, Seismic and Geologic Investigations of the Sandia Livermore Laboratory Site, covers the review and investigation of existing data as well as the acquisition and analysis of new data from field explorations and field examinations of the site. Part II, Structural Investigations of the Tritium Research Facility, covers: (a) the structural evaluation of the existing buildings and vital systems of the facility, and (b) concept studies of various schemes to strengthen the buildings and systems. Separate abstracts were prepared for each part.

1978-09-01

120

Geological characterization of Ia volcanic structure, Boyaca - Colombia  

International Nuclear Information System (INIS)

Iza volcanic structure (5 grades 36 minutes 20 seconds N; 72 grades 59 minutes 33 seconds W) is the result of rising riodacitic to ryolithicmagmatic pulses, which didn't reach the surface, the first of them giving origin to intrusive breccias, interpreted as the result of indirect hot deep magma interaction with a sedimentary aquifer, leading to vapor overpressure and consequent fragmentation of the host rocks. The intrusive breccia form the southern part of the Iza edifice, it is massive beige to light red in color, locally with pseudo columnar joint; it is composed by angular to sub rounded sedimentary and minor igneous rock fragments in a porphyry rhyolitic matrix. This stage is followed by dome emplacement which a riodacitic to rhyolitic in composition. Petrographic analysis shows that they are similar to the matrix breccia; they have a porphiritic texture, phenocrist of sanidine, quartz and plagioclase and glassy matrix. Locally the domes are fractured presenting breccia facies (auto breccia and jig saw breccias, among others). Relationship with the host rock allow to interpreting the volcanic body as a cryptodomes, outcropping at surface by faulting and erosion.

121

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)

122

Geophysical and remote sensing methodologies applied to the analysis of regolith and geology in Burkina Faso, West Africa  

OpenAIRE

The oldest parts of continents, so-called cratons, are the focus of worldwide research not only because they represent primary constraints for our understanding of the early evolution of the Earth, but also because of their significant mineral potential. This work contributes to the understanding of the geological and geomorphological evolution of the West African Craton, by an integrated analysis of airborne geophysical and satellite remote sensing data constrained by field structural, litho...

Metelka, Va?clav

2011-01-01

123

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

124

The Results of Borehole Acoustic Imaging from a Granite in the Jihlava District, Czech Republic: Implications for Structural Geological Research  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents utilisation of the acoustic borehole imaging method within the frame of structural geology research. Acoustic borehole imaging is a useful tool describing borehole walls. The method allows an identification of various inhomogenieties along the borehole including fractures. Despite the more or less subjective nature of interpretation of the acoustic borehole imaging similar to other geophysical method interpretations, is a careful comparison of the interpreted fractures and the fractures observed on a core allows us to orient both core and fractures. Furthermore it is possible to determine direction of present kinematic indicators on the oriented core (and fracture planes. Identified fault planes and kinematic indicators are valuable information for structural geology research, particularly for paleostress analysis. The procedure described here was applied in the PDV-1 borehole drilled in the immediate vicinity of the quarry near the Panské Dubenky village, Jihlava district, Czech Republic, Europe. The results are consistent with previous standard structural geology research conducted in the quarry. 

Lucie Nováková

2012-08-01

125

ENGINEERING GEOLOGICAL AND STRUCTURAL GEOLOGICAL CHARACTERISTICS USED TO PROVE THE STABILITY OF HIGH CUTS IN COMPACT ROCKS ON THE ROAD MC-11, SOLIN-KLIS  

Directory of Open Access Journals (Sweden)

Full Text Available The paper deals with the engineering geological characteristics of the rock massif in charge to compute and provide the stability of high cuts in solid fractured rocks. The data for the structural geological processing have been obtained by measuring and analyzing the system of fissures. In addition to the supposed and simulated straight fracture the maximum slope of the high cut has been determined considering additional forces which were introduced into the rock mass.

Ivica Samaržija

1992-12-01

126

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

127

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

Science.gov (United States)

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

128

Development of geological structure modeling technology based on regional tectonic process (Joint research)  

International Nuclear Information System (INIS)

The geological structure relates to the groundwater flow and the water chemistry, so it is needed to understand the geological features such as the material transfers in the rock. In addition, it is possible to apply its information to the design and the construction of the geological disposal system. Some of faults with northwest strike developed in and around the Mizunami Underground Research Laboratory (MIU) control groundwater flow. It has been pointed out that these faults were formed as a part of pull-apart structure formed by right lateral movement of the Tsukiyoshi fault distributed in the north of the MIU site. But the formational mechanism of these faults is still uncertain. In this joint research, the analogue experiment and the numerical simulation were used to restore the real geological structures. Then, the distribution of unconfirmed faults was forecasted based on the result. The paleo-stress analyses revealed an ancient deformation mechanism, and the formation timing was presumed in the regional tectonics. The results were adopted for the design of the analog experiment and the numerical simulation. (author)

129

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)

130

Structural geology of the Kinsevere Copper Deposit, DRC  

OpenAIRE

The Kinsevere mine is a copper deposit located in the Democratic Republic of Congo (DRC), within the Central African Copperbelt. This area is situated in the Katangan basin within the SE portion of the Lufilian Arc, which is a large, arcuate structure that extends from SE Angola, across the DRC, and into NW Zambia. The purpose of this study is to characterise the brittle deformation observed around the Kinsevere copper deposit to lead to an understanding of the deformation history of the area...

Kazadi Banza, Samuel-barry

2013-01-01

131

Development of computer assisted system for analysis management in the performance assessment of geological disposal  

International Nuclear Information System (INIS)

The computer assisted system for analysis management CAPASA (Computer Assisted Performance Assessment System Analysis) has been developed to insure quality of performance assessment (PA) calculations for geological disposal of high level radioactive waste. CAPASA is an integrated system for assembling and executing systems of analysis codes and data sets for the purpose of PA. It provides a graphical user interface which allows the analyst to assemble the direction of flow of data and sequences of execution of the analysis code. Also, CAPASA automatically controls the relation among the used codes and input/output files used in PA calculations to ensure reproducibility and traceability of PA calculations. Input/output data sets and used libraries with auxiliary information are maintained in the system in the form of hierarchical structure. Therefore, an object-oriented method has been introduced in order to efficiently realize CAPASA's function. The use of an integrated computer system like CAPASA is very effective to improve the quality and efficiency of PA calculations. (author)

132

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 resether 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

133

Mapping Geological Structures In Wadi Ghoweibaarea, Northwest Gulf Of Suez, Egypt, Using Aster-Spot Data Fusion And Aster DEM  

International Nuclear Information System (INIS)

Practical and economical constraints prompt the need of obtaining lithological and structural information for development of desert areas with reduced field effort. The fusion of multi-sensor satellite data is an effective mean of exploiting the complimentary nature of different data types. This technique allows fusion of spectral-spectral information of multi-source data with high accuracy. In the present study, fusion of SPOT and ASTER data was applied to test the potentiality of this technique in mapping geological formations and structural lineaments in Wadi Ghoweiba area, to the west of the northwestern tip of the Gulf of Suez, Egypt. ASTER data is characterized by a wide range of spectral bands (14 bands), while SPOT panchromatic data is characterized by high (10 meters) spatial resolution. Based on spectral characteristic analysis (SCA) of the 3 VNIR and the 6 SWIR bands of ASTER data, two false-color band-ratio images (1/3, 2/5, and 4/ 9) and (1/5, 8/9, and 4/6) in R, G, B were produced for better lithological discrimination. SPOT panchromatic image data was fused with ASTER band ratio images data using principal component (PC) and color normalization or Brovey transformation techniques. The fused images proved to be excellent for lithological discrimination. ASTER data includes bands 3N (Nadir) and 3B (Backward) that are acquired in the spectral range of near infrared region (from 0.78 to 0.86 microns) allowing extraction of digital elevation model (DEM). Thrtion of digital elevation model (DEM). Three-dimensional perspective views were generated by draping SPOT-ASTER ratio fused images over ASTER DEM. This technique was used to enhance morphologically-defined structures. The fused images and the 3D perspective views were interpreted to produce a photo geological-structural map that was verified using the available geological maps and subsequent field check. The produced photo geological map indicates that fusion of SPOT and ASTER ratio image's data is a reliable technique for geological mapping especially in remote and inaccessible areas

134

Middle infrared multispectral aircraft scanner data - Analysis for geological applications  

Science.gov (United States)

Multispectral middle IR (8-13 microns) data were acquired with an aircraft scanner over Utah. Because these digital image data were dominated by temperature, all six channels were highly correlated. Extensive processing was required to allow geologic photointerpretation based on subtle variations in spectral emittance between rock types. After preliminary processing, ratio images were produced and color ratio composites created from these. Sensor calibration and an atmospheric model allowed determination of surface brightness, temperature, emittance, and color composite emittance images. The best separation of major rock types was achieved with a principal component transformation, followed by a Gaussian stretch, followed by an inverse transformation to the original axes.

Kahle, A. B.; Madura, D. P.; Soha, J. M.

1980-01-01

135

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)

136

Structural geology investigation on Massif Central and Parisian Basin (France)  

Science.gov (United States)

The author has identified the following significant results. Band 5 gives the most information concerning the fracturing in the Massif Central and Parisian Basins. Band 6 and 7 show the fractures emphasized by forest boundaries and by the linear trace of water courses. The most remarkable information drawn from the preliminary investigation of two ERTS-1 images covering two different landscapes, a regular relief of shelving plateau bounded by cuestas having a sedimentary origin and a mountainous region built in crystalline and volcanic rocks, is that the deep structural elements under a thick sedimentary cover can be translated on the surface by indirect criteria. MSS imagery has permitted the Metz fault to be extended towards the west and shows clearly, through land use on the Rhone Valley fluvial deposit, the continuation towards the east of the carboniferous basin of St. Etienne.

Weecksteen, G. (principal investigator)

1973-01-01

137

Neutronic analysis of the Geological Survey TRIGA Reactor  

International Nuclear Information System (INIS)

Highlights: • We develop a detailed MCNP model of the Geological Survey TRIGA Reactor. • We present a simplified approach to considering burnup. • The model is validated against available reactor data. • We present evidence of inaccuracies in the ENDF B/VII zirconium libraries. - Abstract: 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% to 20% void. The core water temperature reactivity coefficient is +0.012 $/K

138

Natural pseudowollastonite: Crystal structure, associated minerals, and geological context  

Science.gov (United States)

Pseudowollastonite, an extremely rare constituent of ultrahigh-temperature combustion metamorphic and igneous rocks, has been found as a rock-forming mineral in Ca-rich paralava veins of Nabi Musa fossil mud volcano (Dead Sea area). Pseudowollastonite-bearing paralavas are the products of combustion metamorphism associated with spontaneous burning of methane. The melt began to crystallize at 1480-1500 °C about the ambient pressure. Pseudowollastonite enters two mineral assemblages: (1) rankinite, larnite, nagelschmidtite, wollastonite (1T), gehlenite-rich melilite, Ti-rich andradite, cuspidine, and fluorapatite; (2) parawollastonite (2M), wollastonite (1T), gehlenite-rich melilite, Ti-rich andradite, fluorellestadite. In this study we present the first single-crystal structure determination of natural pseudowollastonite. Pseudowollastonite from Nabi Musa dome is stoichiometric CaSiO3 and belongs to the most widespread four-layer polytype: a = 6.83556(10) Å, b = 11.86962(18) Å, c = 19.6255(3) Å, ? = 90.6805(13)°, V = 1592.21(4) Å3, space group C2/c. We argue that pseudowollastonite is so scarce in nature because its formation requires joint action of several uncommon factors: availability of hot melts of T > 1200 °C that bear free calcium but are poor in Mg and Fe (mostly as Fe3 +) and their crystallization in the shallow crust followed by quenching.

Seryotkin, Yurii V.; Sokol, Ella V.; Kokh, Svetlana N.

2012-03-01

139

Evaluation of structural behavior, geological and hydrogeological characteristics  

International Nuclear Information System (INIS)

This study suggests a quantitative evaluation method of joint roughness coefficient (JRC). It was accomplished by using several statistical parameters to the 10 standard profiles. The results show that some of these parameters (Root mean square gradient, Structure function, and Fractal dimension) are suitable to represent the roughness characteristics. With these selected parameters, further studys have succeeded to examine the variance upon scale effect. The result shows that the fractal dimension is the most correlated parameter of all to JRC. The modified empirical equation of shear strength by introducing fractal dimension to determine JRC was suggested. To prove its validity and to examine the applicable limit of the estimated strength by this equation, the values were compared to those obtained in laboratory works. The results show that the quantification procedure for JRC permits more reliable results when the scale effect is considered. The equation which relates normal stress to shear strength of natural joints developed in gneissic rocks is also suggested. This provides inexpensive method to evaluate rock mass porperty and it can be applied to usual engineering practice. (Author)

140

Geologic and morphological structure of the Bell region (a photographic map of the surface of Venus, plate V-23)  

International Nuclear Information System (INIS)

Four geologic and morphological units have been distinguished within the plate: (1) relics of complexes predating the plains; (2) banded plains; (3) smooth plains; and (4) volcanic and tectonic complexes. The Bell rise includes several individual large volcanic structures. Besides, faults of different directions and meteorite craters have been interpreted. The history of the region's geological development has been briefly examined

141

Earth fissures triggered by groundwater withdrawal and coupled by geological structures in Jiangsu Province, China  

Science.gov (United States)

Earth fissures in Jiangsu Province, China have caused serious damages to properties, farmlands, and infrastructures and adversely affected the local or regional economic development. Under the geological and environmental background in Jiangsu Province, this paper presents the earth fissures caused by excessive groundwater withdrawal and coupled by distinctive geological structures such as Ancient Yellow River Fault in Xuzhou karst area, and Ancient Yangtze River Course and bedrock hills in Suzhou, Wuxi, and Changzhou area. Although all the earth fissures are triggered by groundwater exploitation, the characteristics are strongly affected by the specific geological and hydrogeological settings. In particular, in the water-thirsty Xuzhou city, the cone of depression caused by groundwater extraction enlarged nearly 20 times and the piezometric head of groundwater declined 17 m over a decade. As groundwater is extracted from the shallowly buried karst strata in the Ancient Yellow River Fault zone, the development of earth fissures is highly associated with the development of karstic cavities and sinkholes and their distribution is controlled by the Ancient Yellow River Fault with all the 17 sinkholes on the fault. On the other hand, in the rapidly developing Southern Jiangsu Province, groundwater is mainly pumped from the second confined aquifer in the Quaternary, which is distributed neither homogeneously nor isotropically. The second confined aquifer comprises more than 50 m thick sand over the Ancient Yangtze River Course, but this layer may completely miss on the riverbank and bedrock hills. With a typical drawdown rate of 4-6 m per annum, the piezometric head of groundwater in the second confined aquifer has declined 76 m at Maocunyuan since 1970s and 40 m at Changjing since mid-1980s, and a large land subsidence, e.g., 1,100 mm at Maocunyuan, is triggered. Coupled with the dramatic change of the bedrock topography that was revealed through traditional geological drilling and modern seismic reflection methods, the geological-structure-controlled differential settlement and earth fissures are phenomenal in this area.

Wang, G. Y.; You, G.; Shi, B.; Yu, J.; Li, H. Y.; Zong, K. H.

2009-05-01

142

3D stochastic inversion of potential field data using structural geologic constraints  

Science.gov (United States)

We introduce a new method to include structural orientation constraints into potential field inversion using a stochastic framework. The method considers known geological interfaces and planar orientation data such as stratification estimated from seismic surveys or drill hole information. Integrating prior geological information into inversion methods can effectively reduce ambiguity and improve inversion results. The presented approach uses cokriging prediction with derivatives. The method is applied to two synthetic models to demonstrate its suitability for 3D inversion of potential field data. The method is also applied to the inversion of gravity data collected over the Lalor volcanogenic massive sulfide deposit at Snow Lake, Central Manitoba, Canada. The results show that using a structurally-constrained inversion leads to a better-resolved solution.

Shamsipour, Pejman; Schetselaar, Ernst; Bellefleur, Gilles; Marcotte, Denis

2014-12-01

143

TI-Octree: Spatial index for geological structures TI-Octree: Índice espacial para estructuras geológicas  

Directory of Open Access Journals (Sweden)

Full Text Available Modeling and visualization of three-dimensional geological structures is one of the main activities in the mining industry. Miners and geologists most maintain an exhaustive control of the extracted volume of mineral of a deposit, using computer programs for processing the obtained information. In the mining process, a mineral deposit is commonly represented by a block model, which represents the morphology of the laying geological structures. For modeling those geological structures and the volume of extracted mineral they use tetrahedral networks. The tetrahedral network is an spatial structure that, given it characteristics, allows modeling geological structures in the fields of mining and geology, making easier the volume calculus. Aiming to improve the tetrahedral search process given an spatial region,  this work  presents a proposal of one spatial data structure for indexing tetrahedral networks, demonstrating by some experiments that the searching time over this proposal is less compared with the searching time over a linear structure. La modelación y visualización en tres dimensiones de estructuras geológicas es una de las actividades fundamentales realizadas en la industria minera. Los mineros y geólogos deben mantener un control exhaustivo del volumen de extracción de los minerales de un yacimiento, utilizando generalmente programas de cómputo para procesar la información obtenida. En la minería un yacimiento mineral es habitualmente representado por un modelo de bloques y este modelo debe respetar la morfología de las estructuras geológicas. Para modelar las estructuras geológicas y los volúmenes de extracción de mineral se utilizan mallas de tetraedros. La malla de tetraedros es una estructura espacial  que, por sus características, permite modelar las estructuras geológicas en la rama de la geología y la minería, facilitando el cálculo del volumen del sólido. Con el objetivo de mejorar el rendimiento en la búsqueda de tetraedros dada una región determinada del espacio, el presente artículo propone la implementación de una estructura de datos espaciales para indexar la malla de tetraedros, realizando pruebas que permiten obtener como conclusión que el tiempo de búsqueda de la propuesta realizada disminuye en comparación con el tiempo de búsqueda en una estructura lineal.

Dagoberto Antonio Suárez Morales

2012-09-01

144

Geomechanics to solve geological structure issues: forward, inverse and restoration modeling  

OpenAIRE

Different applications of linear elasticity in structural geology are presented in this thesis through the development of three types of numerical computer codes. The first one uses forward modeling to study displacement and perturbed stress fields around complexly faulted regions. We show that incorporating inequality constraints, such as static Coulomb friction, enables one to explain the angle of initiation of jogs in extensional relays. Adding heterogeneous material properties and optimiz...

Maerten, Frantz

2010-01-01

145

Evaluation of geological structure and uranium mineralization model in West Lemajung Sector, Kalan Basin, West Kalimantan  

International Nuclear Information System (INIS)

The fieldwork is based on the data of strike (S0) and schistosity (S1) of cores that could not penetrate the geological structure model and result of observation on some cores has shown that U mineralization veins are not always parallel to S1. The problems were encountered in core drill data to improve the estimation of U resources from indication category to measured category. The purpose of the evaluation is to establish the advisability of geological structure model and U mineralization model which was applied by this time. The research used remapping of geological structure with surface method in the scale of 1:1000. The result of remapping shows the difference of the dipping between new geological structure model and the old model. The dipping of the new model is to South East until vertical and the old model is to North West until vertical and to South East until vertical. Despite the difference between both of them, the substantive of folding system is identical so that the new and old models can be applied in drilling in West Lemajung sector. U mineralization model of remapping result consists of 3 types : type 1 U mineralization lens form with West-East direction and vertical dipping which is associated with tourmaline, type 2 U mineralization filling in the open fractures with West-East direction and 70o to North dipping and parallel with S1, and type 3 U mineralization fill in opening fractures with N 110o - 130o E the direction and 60o to North East until subvertical dipping while the old model is only one type. It is U mineralization filling in the open fractures with West-East the direction and 70o to North the dipping and parallel with S1. Because of this significant difference, data collection of drill core must follow the new mineralization model. (author)

146

Geological structure and origin of the Kaochaison hot spring in Phattalung, Southern Thailand  

OpenAIRE

Geophysical measurements were conducted in the Kaochaison hot spring area in southern Thailand. The purpose ofthis work is to determine subsurface geological structures related to the hot spring. Ninety-five gravity points and thirtysevenresistivity soundings were measured in the study area. A positive gravity anomaly is observed in the same area of highresistive bedrock over the Kaochaison hot spring. Both anomalies have an elongated shape with its major axis in N010Wdirection. A shallow Per...

Sukrit Jonjana2; Worawut Lohawijarn2; Helmut Dürrast

2012-01-01

147

Geology and structure of Rio Tinto Mine (Iberian Pyrite Belt, Spain)  

OpenAIRE

The Rio Tinto mining district is regarded as the largest volcanogenic massive sulphide district worldwide, but its geologic and structural setting remains poorly disclosed. The mineralized sequence includes a lower unit of interbedded mafic volcanics, shale and conglomerate overlain by a felsic dome-sill complex. The massive sulphides occur within the felsic rocks, either as exhalative deposits on the top or as replacive masses within the volcaniclastic rocks. The present revie...

Mellado, D.; Gonza?lez Clavijo, Emilio J.; Tornos, Fernando; Conde, C.

2006-01-01

148

COI Structural Analysis Presentation  

Science.gov (United States)

This report discusses the structural analysis of the Next Generation Space Telescope Mirror System Demonstrator (NMSD) developed by Composite Optics Incorporated (COI) in support of the Next Generation Space Telescope (NGST) project. The mirror was submitted to Marshall Space Flight Center (MSFC) for cryogenic testing and evaluation. Once at MSFC, the mirror was lowered to approximately 40 K and the optical surface distortions were measured. Alongside this experiment, an analytical model was developed and used to compare to the test results. A NASTRAN finite element model was provided by COI and a thermal model was developed from it. Using the thermal model, steady state nodal temperatures were calculated based on the predicted environment of the large cryogenic test chamber at MSFC. This temperature distribution was applied in the structural analysis to solve for the deflections of the optical surface. Finally, these deflections were submitted for optical analysis and comparison to the interferometer test data.

Cline, Todd; Stahl, H. Philip (Technical Monitor)

2001-01-01

149

Structural analysis of DAEs  

DEFF Research Database (Denmark)

Differential algebraic equations (DAEs) constitute a fundamental model class for many modelling purposes in engineering and other sciences, especially for dynamical simulation of component based systems. This thesis describes a practical methodology and approach for analysing general DAE. The methodology is mainly based on strutural index analysis which is not limited by the index of the DAE as other methodologies. As a result of structural index analysis one can perform index reduction of the DAE and obtain the so-called augmented underlying ODE. It is also described, how to use the augmented underlying ODE for finding consistent initial values and solve the initial value problem for the original DAE. As a methodology for integrating the augmented underlying ODE, the dummy derivative method is investigated. The methodology avoids the traditional stability and drift-of problems of using the underlying ODE. The investigations concern the identification of quantities that can trigger the automatic choice of new dummy derivatives during integration. This is a practical problem that needs to be solved before implementations of the method are possible. The general methodology is tested in practice, by the implementation of the Simpy tool box. This is an object oriented system implemented in the Python language. It can be used for analysis of DAEs, ODEs and non-linear equation and uses e.g. symbolic representations of expressions and equations. The presentations of theory and algorithms for structural index analysis of DAE is original in the sense that it is based on a new matrix representation of the structural information of a general DAE system instead of a graph oriented representation. Also the presentation of the theory is found to be more complete compared to other presentations, since it e.g. proves the uniqueness of the structural index reduction process. Also included, is a discussion of criticism and defence of structural analysis.

Poulsen, Mikael Zebbelin

2002-01-01

150

Bedrock geology of snyderville basin: Structural geology techniques applied to understanding the hydrogeology of a rapidly developing region, Summit County, Utah  

Science.gov (United States)

The availability of ground water is a problem for many communities throughout the west. As these communities continue to experience growth, the initial allocation of ground water supplies proves inadequate and may force restrictions on existing, and future, development plans. Much of this new growth relies on ground water supplies extracted from fractured bedrock aquifers. An example of a community faced with this problem is western Summit County, near Park City, Utah, This area has experienced significant water shortages coupled with a 50% growth rate in the past 10-15 years. Recent housing development rests directly on complexly deformed Triassic to Jurassic sedimentary rocks in the hanging wall of the Mount Raymond-Absaroka thrust system. The primary fractured bedrock aquifers are the Nugget Sandstone, and limestones in the Thaynes and Twin Creek Formations. Ground water production and management strategies can be improved if the geometry of the structures and the flow properties of the fractured and folded bedrock can be established. We characterize the structures that may influence ground water flow at two sites: the Pinebrook and Summit Park subdivisions, which demonstrate abrupt changes (less than 1 mi/1.6 km) within the hydrogeologic systems. Geologic mapping at scales of 1:4500 (Pinebrook) and 1:9600 (Summit Park), scanline fracture mapping at the outcrop scale, geologic cross sections, water well data, and structural analysis, provides a clearer picture of the hydrogeologic setting of the aquifers in this region, and has been used to successfully site wells. In the Pinebrook area, the dominate map-scale structures of the area is the Twomile Canyon anticline, a faulted box-like to conical anticline. Widely variable bedding orientations suggest that the fold is segmented and is non-cylindrical and conical on the western limb with a fold axis that plunges to the northwest and also to the southeast, and forms a box-type fold between the middle and eastern limbs with a fold axis that plunges to the northeast. The fold is cut by several faults including the Toll Canyon fault, which we interpret as a west-directed folded hanging-wall splay off the east-directed Mt. Raymond thrust. These complex geometries may be due to at least two phases of deformation. Results from outcrop analyses show that the fractured bedrock aquifers are lithologically heterogeneous, anisotropic, and compartmentalized. Two exposures of the Toll Canyon fault show that even though the fault cores may be thin, extensive damage zones develop in the Nugget Sandstone and Thaynes Limestone, and shale smears form in the Triassic shales. The damaged zones may be regions of enhanced fracture permeability, whereas the shale smears act as flow barriers. The orientation, density, and hydrogeologic characteristics for predominate fracture sets vary within meters. In the Summit Park area, chronic water shortages required new wells to be sited in the northeast-plunging Summit Park anticline. The anticline experienced two phases of folding and at least one episode of faulting. Structural analysis of the fold defined the geometry of the structure, and a down plunge projection along the fold hinge was used to estimate the location of the Nugget Sandstone at a depth of 700 ft (213 m). The crestal region of the anticline was drilled in order to intercept regions of higher fracture density in the fold. The test well penetrated the Nugget Sandstone at 698 ft depth, and two production wells with long-term yields of 120 and 180 gpm completed. One well in the Sliderock Member (Twin Creek Formation) experiences seasonal fluctuations whereas production in the Nugget sandstone has only subdued seasonal variations, suggesting the Nugget may have great storage. Complex structures work against the typical basin yield approach for water budgets, therefore, water supply estimates may benefit from detailed studies within local areas. The results of this study demonstrate how tradition

Keighley, K.E.; Yonkee, W.A.; Ashland, F.X.; Evans, J.P.

1997-01-01

151

Multiscale analysis of the structural evolution of the southern flank of the Western Jabal Akhdar anticline, Oman (vein examination, structural mapping and inverse remote sensing)  

OpenAIRE

Structural geology models greatly benefit from multi-scale investigations. To understand the complex structural geology of the southern flank of the western Jabal Akhdar anticline (Oman Mountains), this thesis presents a multi-scale analysis on structural elements like faults, fractures and veins of two study areas. Therefore observations from vein analysis, mapping and remote sensing are combined. The outcome is compared to recent models of the regional structural history. The study areas un...

Laurich, Ben

2010-01-01

152

Gas hydrates and magnetism : comparative geological settings for diagenetic analysis  

Energy Technology Data Exchange (ETDEWEB)

Geophysical and geochemical methods assist in locating and quantifying natural gas hydrate deposits. They are also useful in understanding these resources, their climate impacts and their potential role in geohazards. In order to understand the mechanisms of gas hydrate formation and its natural distribution in sediments, magnetic studies were conducted on cores from three different geological settings. This paper presented the results of a detailed magnetic investigation, as well as petrological observations, that were conducted on cores from a permafrost setting in the Mackenzie Delta located in the Canadian Northwest Territories Mallik region, and two marine settings, from the Cascadia margin off Vancouver Island and the Indian National Gas Hydrate Program from the Bengal Fan. The paper provided background information on the permafrost setting in Mallik region of the Mackenzie Delta as well as the Cascadia margin. The magnetic properties of gas hydrate bearing sediments were found to be a combination of the original detrital content and the diagenetic transformations of iron minerals caused by the unique environment produced by gas hydrate formation. The availability of methane to provide food for bacteria coupled with the concentration of solutes outside gas hydrate accumulation zones led to the creation of iron sulphides. These new minerals were observable using magnetic techniques, which help in delineating the gas hydrate formation mechanism and may be developed into new geophysical methods of gas hydrate exploration. 7 refs., 7 figs.

Esteban, L.; Enkin, R.J. [Natural Resources Canada, Sidney, BC (Canada). Geological Survey of Canada; Hamilton, T. [Camosun College, Victoria, BC (Canada)

2008-07-01

153

TBR-2 structural analysis  

International Nuclear Information System (INIS)

This paper presents the structural analysis developed during the TBR-2 tokamak project studies. Starting with electromagnetic interaction forces on each, toroidal and poloidal coils many structural calculations have been carried out using locally developed usual E.M. interaction codes and a finite element method stress code. Following the analysis it has been determined that there is radially inward force of 1235 kN and overturning torque of 243 kNm acting on toroidal coils. This stress and displacements due to in plane loads have been calculated using a finite element code which show that the maximum stress of 240 MPa and displacement of 0.21 mm can be present at the inner part of the toroidal field coil. (Author)

154

Geological structure of central Java, Indonesia from ambient seismic noise tomography  

Science.gov (United States)

Geological structure in the region of central Java is very important for understanding its tectonic setting. The presence of several active volcanoes such as Mt. Merapi, Mt. Sumbing and Mt. Lawu, as well as the Kendeng Basin and Opak fault all contribute to the complex geology of central Java. Understanding some of the characteristics of the geological structure can be improved using a geophysical approach such as seismic tomography. In this study we show the image of the subsurface in central Java obtained from ambient seismic noise tomography. We use simultaneously operated 134 short period and broadband seismometers from the Merapi Amphibious Experiment (MERAMEX) network covering a region of 150 x 200 km around central Java and Yogyakarta. More than 5000 Rayleigh wave component of the Green's function are extracted from cross-correlations of available station pairs. We filter the retrieved Green's functions with a phase-matched filter to measure Rayleigh wave group dispersion at periods between 0.5 and 20 s. We apply a 2-D nonlinear iterative tomographic method for inverting the measured travel times. The results are then used to create group velocity perturbation maps. The velocity perturbation maps show a high correlation with local tectonic features. The Kendeng basin and active volcanoes in the central part of central Java are clearly imaged with lower group velocities and the southern part has the carbonate region is marked with higher group velocities.

Zulhan, Z.; Saygin, E.; Cummins, P. R.; Widiyantoro, S.; Nugraha, A. D.

2012-12-01

155

Structure and dating errors in the geologic time scale and periodicity in mass extinctions  

Science.gov (United States)

Structure in the geologic time scale reflects a partly paleontological origin. As a result, ages of Cenozoic and Mesozoic stage boundaries exhibit a weak 28-Myr periodicity that is similar to the strong 26-Myr periodicity detected in mass extinctions of marine life by Raup and Sepkoski. Radiometric dating errors in the geologic time scale, to which the mass extinctions are stratigraphically tied, do not necessarily lessen the likelihood of a significant periodicity in mass extinctions, but do spread the acceptable values of the period over the range 25-27 Myr for the Harland et al. time scale or 25-30 Myr for the DNAG time scale. If the Odin time scale is adopted, acceptable periods fall between 24 and 33 Myr, but are not robust against dating errors. Some indirect evidence from independently-dated flood-basalt volcanic horizons tends to favor the Odin time scale.

Stothers, Richard B.

1989-01-01

156

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

157

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

158

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 theLevels (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)

159

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. 154 Eu and 152 Eu radioisotopes emit gamma rays with energies too close to those emitted by 95 Zr and they cause interferences. (author)

160

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)

161

Structural Analysis Made 'NESSUSary'  

Science.gov (United States)

Everywhere you look, chances are something that was designed and tested by a computer will be in plain view. Computers are now utilized to design and test just about everything imaginable, from automobiles and airplanes to bridges and boats, and elevators and escalators to streets and skyscrapers. Computer-design engineering first emerged in the 1970s, in the automobile and aerospace industries. Since computers were in their infancy, however, architects and engineers during the time were limited to producing only designs similar to hand-drafted drawings. (At the end of 1970s, a typical computer-aided design system was a 16-bit minicomputer with a price tag of $125,000.) Eventually, computers became more affordable and related software became more sophisticated, offering designers the "bells and whistles" to go beyond the limits of basic drafting and rendering, and venture into more skillful applications. One of the major advancements was the ability to test the objects being designed for the probability of failure. This advancement was especially important for the aerospace industry, where complicated and expensive structures are designed. The ability to perform reliability and risk assessment without using extensive hardware testing is critical to design and certification. In 1984, NASA initiated the Probabilistic Structural Analysis Methods (PSAM) project at Glenn Research Center to develop analysis methods and computer programs for the probabilistic structural analysis of select engine components for current Space Shuttle and future space propulsion systems. NASA envisioned that these methods and computational tools would play a critical role in establishing increased system performance and durability, and assist in structural system qualification and certification. Not only was the PSAM project beneficial to aerospace, it paved the way for a commercial risk- probability tool that is evaluating risks in diverse, down- to-Earth application

2005-01-01

162

Review of recently-developed techniques for analysis of rare-earth elements in geological samples  

International Nuclear Information System (INIS)

Rare-earth elements (REE) are increasingly used in other fields besides geology viz. superconductivity and magnets, molecular sieves, etc. The semblance in their geochemical properties besides their occurrence in low-to trace amounts makes it difficult to analyse them by conventional chemical methods and a wide spectrum of analytical techniques have been developed for REE analysis. It has become necessary to review the state-of-art techniques for geological samples. The micro-analytical techniques are not suitable for whole rock or general purpose in view of the small area of sample analysed. Amongst the methods, instrumental neutron activation analysis can detect ultra-trace amounts but of a selective few REE only besides requiring a nuclear reactor. The mass spectrometry type of inductively coupled plasma (ICP) is ideal for REE purpose but equipment cost is much higher than the emission spectrometry which is currently better suited for bulk REE analysis. (author). 33 refs., 1 tab

163

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

Science.gov (United States)

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…

Fratesi, Sarah E.; Vacher, H. L.

2008-01-01

164

Cyberinfrastructure for the Unified Study of Earth Structure and Earthquake Sources in Complex Geologic Environments  

Science.gov (United States)

The Southern California Earthquake Center (SCEC) is developing a Community Modeling Environment (CME) to facilitate the computational pathways of physics-based seismic hazard analysis (Maechling et al., this meeting). Major goals are to facilitate the forward modeling of seismic wavefields in complex geologic environments, including the strong ground motions that cause earthquake damage, and the inversion of observed waveform data for improved models of Earth structure and fault rupture. Here we report on a unified approach to these coupled inverse problems that is based on the ability to generate and manipulate wavefields in densely gridded 3D Earth models. A main element of this approach is a database of receiver Green tensors (RGT) for the seismic stations, which comprises all of the spatial-temporal displacement fields produced by the three orthogonal unit impulsive point forces acting at each of the station locations. Once the RGT database is established, synthetic seismograms for any earthquake can be simply calculated by extracting a small, source-centered volume of the RGT from the database and applying the reciprocity principle. The partial derivatives needed for point- and finite-source inversions can be generated in the same way. Moreover, the RGT database can be employed in full-wave tomographic inversions launched from a 3D starting model, because the sensitivity (Fréchet) kernels for travel-time and amplitude anomalies observed at seismic stations in the database can be computed by convolving the earthquake-induced displacement field with the station RGTs. We illustrate all elements of this unified analysis with an RGT database for 33 stations of the California Integrated Seismic Network in and around the Los Angeles Basin, which we computed for the 3D SCEC Community Velocity Model (SCEC CVM3.0) using a fourth-order staggered-grid finite-difference code. For a spatial grid spacing of 200 m and a time resolution of 10 ms, the calculations took ~19,000 node-hours on the Linux cluster at USC's High-Performance Computing Center. The 33-station database with a volume of ~23.5 TB was archived in the SCEC digital library at the San Diego Supercomputer Center using the Storage Resource Broker (SRB). From a laptop, anyone with access to this SRB collection can compute synthetic seismograms for an arbitrary source in the CVM in a matter of minutes. Efficient approaches have been implemented to use this RGT database in the inversions of waveforms for centroid and finite moment tensors and tomographic inversions to improve the CVM. Our experience with these large problems suggests areas where the cyberinfrastructure currently available for geoscience computation needs to be improved.

Zhao, L.; Chen, P.; Jordan, T. H.; Olsen, K. B.; Maechling, P.; Faerman, M.

2004-12-01

165

Evaluation model of commercial geological exploration and mining development project and analysis of some technical problems in commercial negotiation  

International Nuclear Information System (INIS)

A composite evaluation model of commercial geological exploration and mining development project was discussed, this new model consists of polity-economy-technique (PET) synthetic evaluation sub-model and geology-mining-metallurgy (GMM) technique evaluation sub-model. Besides, some key technical problems in commercial negotiation, such as information screening, quoted price and analysis of deadline, were briefly analyzed. (author)

166

Geologic datasets for weights of evidence analysis in Northeast Washington: 4. mineral industry activity in Washington, 1985-1997  

Science.gov (United States)

This report includes a table of 339 sites representing mineral activities for mining and mineral exploration in the State of Washington from 1985 through 1997. The table was primarily compiled from annual reports in Washington Geologic Newsletter and Washington Geology. The information was compiled for use in a weights-of-evidence analysis of mineral resources in northeastern Washington.

Boleneus, D.E.; Derkey, R.E.

2000-01-01

167

GEOLOGICAL MAPPING AND ANALYSIS OF DAEDALIA PLANUM LAVA FIELD (MARS)  

OpenAIRE

Volcanism is the most important rock-forming processes of the planetary surfaces and represents one of the main clues to investigate the chemical composition of the interior and the thermal history of a planet. Our study has been focused on the Daedalia Planum volcanic region, located to south-west of Arsia Mons, where some of the longest lava flows on Mars were emplaced. THEMIS, MOC and HiRISE images were analyzed in order to perform a stratigraphic and morphological analysis of the area...

Giacomini, Lorenza

2010-01-01

168

Dynamic structure and data sets of a GIS database for geological riskanalysis in the Azores volcanic islands  

Directory of Open Access Journals (Sweden)

Full Text Available Geological hazards in the Azores archipelago include earthquakes, volcanic eruptions, degassing phenomena and landslides, being the cause of thousands of deaths and severe damage and loss. To reduce the impact of future events it is necessary to improve the emergency response and reinforce land-use planning, and this has given rise to the development of AZORIS, a GIS database for risk analysis in the Azores. At present this computer-based system comprises nine main dynamic data sets where elemental, monitoring and historical data are grouped in layers of first and second order. The logical structure of the database was conceived in order to facilitate interactivity between data sets and to guarantee the evolution of the system, as determined by the input and the generation of new and more detailed information. Archive organization was designed taking into account regional and local aspects of geological hazard. In order to ensure consistency of the database and the quality of the data within it, an internal process of validation was included.

J. L. Gaspar

2004-01-01

169

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

170

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 tranvides 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)

171

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

172

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

173

An evaluation of Compton suppression neutron activation analysis for determination of trace elements in some geological samples  

International Nuclear Information System (INIS)

Compton suppressed neutron activation analysis has been used for a variety of applications, but never has a detailed discussion of its use in far more complex matrices, such as geological samples, been fully addressed. This investigation seeks to serve as a qualitative evaluation of Compton suppression neutron activation analysis (CSNAA) and to illustrate the benefits of using Compton suppression with thermal and epithermal neutrons for the analysis of several geological specimens.

174

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)

175

Isotopic geology  

International Nuclear Information System (INIS)

Born from the application to geology of nuclear physics techniques, the isotopic geology has revolutionized the Earth's sciences. Beyond the dating of rocks, the tracer techniques have permitted to reconstruct the Earth's dynamics, to measure the temperatures of the past (giving birth to paleoclimatology) and to understand the history of chemical elements thanks to the analysis of meteorites. Today, all domains of Earth sciences appeal more or less to the methods of isotopic geology. In this book, the author explains the principles, methods and recent advances of this science: 1 - isotopes and radioactivity; 2 - principles of isotope dating; 3 - radio-chronological methods; 4 - cosmogenic isotope chronologies; 5 - uncertainties and radio-chronological results; 6 - geochemistry of radiogenic isotopes; 7 - geochemistry of stable isotopes; 8 - isotopic geology and dynamical analysis of reservoirs. (J.S.)

176

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

177

FY 1993 report on the survey of geothermal development promotion. Geological structure (geology/alteration zone) (No. A-2 - Mt. Shibetsudake area); 1993 nendo chinetsu kaihatsu sokushin chosa. Chishitsu kozo (chishitsu henshitsutai) chosa hokokusho (No. A-2 Shibetsudake chiiki)  

Energy Technology Data Exchange (ETDEWEB)

For the contribution to elucidation of a possibility of existence of geothermal reservoir in the Shibetsudake area, Hokkaido, survey of geological structure (geology/alteration zone) was carried out. The survey was made for the area of about 300km{sup 2} in terms of the route survey of 122km, fabrication/judgment of 55 rock slices, whole rock chemical analysis of 20 rock pieces, age determination (K-Ar method) of 20 rock pieces, rock mineral analysis of 35 rock pieces, alteration mineral X-ray diffraction analysis of 43 rock pieces, data/literature collection (1,200 pages), etc. As a result of the examinational survey, the following five were extracted as a region where the geothermal resource is promising: region north of Mt. Musadake (the NW-SE system fracture developed, and it is near Volcano Musadake), region south of Mt. Shibetsudake (the NW-SE system fracture developed, and it is near Volcano Shibetsu), region southwest of Mt. Musadake (the NE-SW system fault developed, and it is near Volcano Musadake), Yunosawa region (the almost round-shaped caldera structure in the late Pliocene Epoch was recognized, and it is near Volcano Musadake), region south of Shitabanupuri (the NW-SE system fault developed, and it is near Volcano Shibetsu/volcano in the late Pliocene Epoch). (NEDO)

NONE

1994-01-01

178

Analysis of geological condition of uranium mineralization in the Xiangshan northern uranium orefield in central region of Jiangxi Province  

International Nuclear Information System (INIS)

According to the basic conditions of 'source, guide, transportation, storage' for uranium mineralization in strata and different types of geological structure, departure from the condition, the coupling effect of stratigraphy, lithology and structure are studied in the process of uranium mineralization in northern Xiangshan volcanic basin. Studies show that the northern ore field are of good metallogenic geological conditions and the uranium rich ancient land mass and uranium rich magma generated by the melting of deep metamorphic rocks. The main geologic events are volcanic eruptions, accompanied by repeated subvolcanic magma intrusion and strong faults and nappe tectonics which result in volcanic collapse and volcanic ring structures. These ore-forming geological condition control the structural frame for the formation of main uranium deposit type-subvolcanic rocks in northern Xiangshan ore field. (authors)

179

Application Of Geowall Technology To The Analysis Of A Three Dimensional Geologic Map Of The Santa Clara (Silicon) Valley, California  

Science.gov (United States)

Geowall, a stereo projection system suitable for meetings and conferences, is being used to visualize, understand, interpret, and test a three-dimensional geologic map of the Santa Clara (Silicon) Valley, southern San Francisco Bay area, California. Geowall*, developed at the Electronic Visualization Laboratory associated with the University of Illinois, uses dual polarized images projected onto a polarization-preserving screen to create the illusion of three dimensions when viewed through polarized glasses. The map of Santa Clara Valley encompasses a 45 by 45 km area, extends to a depth of 14 km, and includes the northern Santa Clara Valley and surrounding hillsides between the active Calaveras and San Andreas faults. It is currently divided by several major faults into tectonic blocks, within which 9 units represent the Cenozoic and Mesozoic sections. Many of these units will be subdivided as the map evolves. The map is being constructed in EarthVision*(TM, Dynamic Graphics, Inc.), a geologic modeling software that includes three dimensional rendering and model manipulation capabilities. Earthvision generates data and model images of which the entire, or only portions of the model, can be viewed in three dimensions. The geowall presentation will explore the datasets and three-dimensional geologic map of Santa Clara Valley and structures defined by geologic mapping, stratigraphy, hydrology, potential field geophysics, seismic reflection, and earthquake seismicity. The map is the result of a collaborative effort among several earth science disciplines, and as such requires the integration of diverse datasets and the communication of diverse ideas. The geowall is particularly effective at promoting group discussion and analysis of the three-dimensional map, because the map can be displayed in a group setting as a 6x6 ft., stereo image. The spatial relationships of the datasets are easily seen, and the map can be deconstructed and particular relationships isolated. For example, trends in scattered clouds of point data are often difficult to perceive in two dimensions. The rendering of earthquake hypocenter data coupled with the ability to view only the fault planes in the map, from any perspective, permits rapid examination of coherent point patterns relative to modeled fault planes. Visualizing hydrologic data simultaneously with geologic data permits scientists to see relationships that were not apparent in two-dimensions or individually. Such concurrent analysis among project scientists is vital to the iterative process of exploring relationships between data sets, hypothesis testing, and model improvement. Another important use of the geowall is the communication of project ideas and results to others. The geowall has proven to be an effective tool for conveying information about Santa Clara Valley to managers, scientific audiences, and local citizens. Managers and scientists are able to grasp the geologic problems quickly and ask targeted questions, whereas citizens with non-earth science backgrounds are able to understand such concepts as pull-apart basins and gain knowledge of the scale of geologic structures. * Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Phelps, G. A.; Jachens, R. C.; Wentworth, C. M.; Langenheim, V. E.; Hanson, R. T.; Faunt, C. C.

2003-12-01

180

Geological structure and origin of the Kaochaison hot spring in Phattalung, Southern Thailand  

Directory of Open Access Journals (Sweden)

Full Text Available Geophysical measurements were conducted in the Kaochaison hot spring area in southern Thailand. The purpose ofthis work is to determine subsurface geological structures related to the hot spring. Ninety-five gravity points and thirtysevenresistivity soundings were measured in the study area. A positive gravity anomaly is observed in the same area of highresistive bedrock over the Kaochaison hot spring. Both anomalies have an elongated shape with its major axis in N010Wdirection. A shallow Permian limestone of about 1 km thickness was modeled to explain this positive gravity anomaly. ThisPermian limestone is likely to be a part of a horst and graben structure related to the regional tectonics and the normal faultsact as pathways of the hot waters from a deeper heat source.

Sukrit Jonjana2

2012-04-01

181

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

182

Study on systemizing the technology on the investigation and analysis of deep underground geological environment, 2003  

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 and numerical/chemical analyses were enforced about the following item and extracted some subjects with the viewpoint of radioactive waste disposal. 1. The subjects extracted with the viewpoint of the repository design and engineering technology. The evaluation technique of the excavation disturbed zone (EDZ) by acoustic emission (AE) or micro seismicity measurement. Fracture sealing technique such as vibration grouting toward low permeable rock mass. 2. The subject extracted with the viewpoint of the safety assessment. Precipitation of the metal hydroxide ((non-crystallized) through migration process in rock mass and change to the crystallized oxide. 3. The subjects extracted with the viewpoint of the geological environment. Fracture distribution characteristics around the fault, it can think to meet in the underground facilities and the prediction of lrground facilities and the prediction of long term activities of the fault. Natural sealing process by the secondary filling materials (iron oxide and carbonate etc.) in the fracture of rock mass and that influence which may be given to the long-term migration and release of nuclides. The advanced research subjects among the each field of 1, 2, 3 were also discussed. Concerning (2), the evaluation of the results and a way to the practical use were discussed on the R and D activities of the following item. 1. The introduction of the genetic algorithms to the hydraulic analysis of fractured rock mass. 2. The applicable evaluation of the tracer test and the numerical analysis tool to investigate the ground water path in fractured rock mass. 3. Ground water temperature and pore pressure measuring system which optical fiber was used for. 4. Modeling on the migration of the material and the regional ground water circulation. 5. Grasping of the ground water flow mechanism by stable isotope. The R and D activities of the committee member concerning (2) are related to the fundamental and elemental technology. It was also discussed if these results could be taken in the practical investigation program for characterization of the geological environment and engineering technology in the Tono Geoscience Center, the Japan Nuclear Cycle Development Institute (JNC). (author)

183

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

Science.gov (United States)

...and process activities at the geologic repository operations area...human-induced hazards at the geologic repository operations area...human-induced hazards at the geologic repository operations area... (2) Means to limit the time required to perform work...

2010-01-01

184

Multielement analysis of geologic materials by inductively coupled plasma-atomic emission spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Atomic emission spectroscopy using an inductively coupled plasma (ICP) source permits the rapid acquisition of multielement geochemical data from a wide variety of geologic materials. Rocks or other solid samples are taken into solution with a four acid digestion procedure and introduced directly into the plasma; fluid samples are acidified or analyzed directly. The entire process is computer-controlled, fully-automated, and requires less than five minutes per sample for quantitative determination of 37 elements. The procedures and instrumentation employed at the ESL for multielement ICP analysis of geologic materials are described and these are intended as a guide for evaluating analytic results reported from this laboratory. The quality of geochemical data can be characterized by precision, limits of quantitative determination, and accuracy. Precision values are a measure of the repeatability of analyses. In general, major element and analyses have precision of better than 5% and trace elements of better than 10% of the amount present. (MHR)

Christensen, O.D.; Kroneman, R.L.; Capuano, R.M.

1980-03-01

185

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.

186

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)

187

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 Manures 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)

188

Mapping Geology and Structure in Hyper-Rugged Terrain Using ASTER Remote Sensing Data: A Case Study From Northern Pakistan  

Science.gov (United States)

Extreme topography in mountainous terrane introduces radiometric distortion in remote sensing data. This effect influences the ability to correctly map lithology based on unique spectra. In this study we utilize several topographic correction regimes to accommodate spectral variation caused by topography, including the Cosine-correction and the Minnaert-correction methods. The study area is located in Chitral, northern Pakistan. In this area, the world's three greatest mountain ranges, the Himalayas (represented by Kohistan terrane), the Karakoram, and the Hindukush terrane merge together. The Himalayas are separated from the Karakoram terrane by the Shyok Suture. Whereas, the Karakoram plate is separated from the Hindukush terrane by the Reshun Fault. The area is extremely rugged; local relief is more than 2,500 meters. Many peaks are higher than 5,000 m and Tirch Mir, 12 km north of the mapped area, is 7,702 m high. ASTER imagery and a digital elevation model developed from the ASTER data is used to first apply the topographic correction then perform image analysis techniques, such as relative band-depth, to characterize the lithology. High pass filtering and textural analysis are also used to help delineate the structures in the region. This study aims to update the most current geologic map, produced by Calkins et al. (1981) in order to fully understand the interaction between the Kohistan, Karakroam and Hindukush along the Shyok Suture and the Reshun Fault. We utilized the published geological map and our field knowledge of the area to classify the ASTER data with spectral angle mapper (SAM) and Mixture Tuned Matched Filtering (MTMF).

Glenn, N.; Khan, S.

2004-12-01

189

San Andreas Structural Interpretation: Merging Geophysical and Geological Data at SAFOD and Vicinity  

Science.gov (United States)

Cross sections across the San Andreas Fault (SAF) have gradually evolved from depicting the fault as a simple vertical strike-slip fault into an elaborate network of faults. We present new data bearing on this issue from the San Andreas Fault Observatory at Depth (SAFOD) project. We have integrated borehole geology and geophysics with earlier surface mapping to reveal an imbricate fault zone with complex lithologic and structural interactions. Our data include vertical seismic profiles (VSP) from the drill bit seismic (DBS) method and sample analyses along the SAFOD borehole. The DBS method yields a seismic profile which complements surface seismic data as the drill bit penetrated the rock. The SAFOD Pilot Hole (PH) array of seismometers was used to record waves from steeply dipping reflectors in and around the fault zone. The DBS images resolve the subvertical structure below 2 km depth - previously hidden in surface seismic data. These data can be combined with P-wave velocity tomography and fault-guided wave data to reveal features not seen on surface data, but that are important elements of the fault zone structure. We find that the fault consists of an 83° SW-dipping active plane to a depth of 5 km. At this depth it approaches the steeply NE-dipping Buzzard Canyon fault. Together these faults bound a highly fractured and steeply dipping sequence of the deformed arkosic rocks retrieved from the SAFOD borehole. The bounding faults may merge at ~ 6 km depth, each consisting of several subparallel strands. The seismic reflectors and borehole well logs document the presence of steep-dipping arkosic beds and steeply SW-dipping faults. The main trace of the SAF resides within a low-velocity zone (LVZ) ~ 200 m wide. A well-defined reflector ~ 400 m northeast of this zone may be the fault contact between the Cretaceous Great Valley and Jurassic Franciscan formations, consistent with the down-dip projection of the Gold Hill Fault. These data indicate the faults bound a set of rock units which has been transported and left along the segment, and the active and main traces may have switched and migrated through time to establish a straighter path. With multiple geophysical methods available to depict subsurface geometry we attempt to combine these methods with borehole geology to create a plausible geologic model of the SAF near Parkfield, California and to ultimately contribute to our understanding of the true nature of plate boundary complexity.

Wood, R. E.; Evans, J. P.; Malin, P.

2010-12-01

190

Structural controls on leakage from a natural CO 2 geologic storage site: Central Utah, U.S.A.  

Science.gov (United States)

Faults and associated fracture networks can significantly influence regional flow of groundwater, hydrocarbons and other fluids. The distribution of CO 2 springs and seeps along the Little Grand Wash fault and Salt Wash faults in central Utah is controlled by along-fault flow of CO 2-charged groundwater from shallow aquifers (celestine veins and minor hydrocarbon staining. The field evidence shows that the pathways for multiple phases of fluid flow were structurally controlled utilising the fracture network developed in the damage zone of the faults. To investigate the likely effect of these faults on the regional fluid-migration pathways at depth, a 3D model of the faulted system was generated and a fault seal analysis applied to predict the cross-fault sealing capabilities of the studied faults. Due to the scarcity of subsurface data, the results are not conclusive but suggest probable multiple cross-fault leak points for fluids to migrate across the fault, in contrast to the field observations that indicate fault-parallel flow. This comparison of field observations to the modelling approach demonstrates the inability of conventional seal analysis techniques to predict fault-parallel fluid leakage and highlight the effects fracture networks in the damage zone, especially at structural complexities along the fault, have in producing pathways for vertical flow. Multiple fluids have utilised similar fault-parallel pathways over geological time demonstrating that such pathways have the potential to cause long-term leakage from hydrocarbon reservoirs and CO 2 storage sites.

Dockrill, Ben; Shipton, Zoe K.

2010-11-01

191

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

192

A new interpretation of geological structure of Tempoku Coal Field by crooked-line survey  

Energy Technology Data Exchange (ETDEWEB)

Tempoku Coal Field is located in the northern area of Japan's northern island, Hokkaido. Here the exploration target, the Soya Coal-Bearing Formation, is of Tertiary age overlying Cretaceous basement. The regional structure of the area is characterised by a series of synclines and anticlines trending north-northwest, with several reverse faults. A suite of surveys was carried out in 1991, in the Asajino area in the central part of the coal field. The study included drilling, vertical seismic profiling, and trenching, as well as a reflection seismic survey with the crooked-line method, which is the subject of this paper. The crooked-line method was adopted because of the mountainous terrain of the area. The seismic lines were laid out along existing tracks and valleys. The main geological structure of the area had long been considered to be a monotonous series of folds. However, the 1991 survey revealed a large-scale thrust-related structure in the main coal seams, which presented clear reflectors. Together with the data from other surveys, a reinterpretation of the structure of the Asajino area is proposed. 2 refs., 6 figs.

Nakano, O.; Endo, M.; Ishii, E.; Watanabe, H. (Dia Consultants Co. Ltd., Tokyo (Japan))

193

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

194

Influence of ecological and geological features on rangewide patterns of genetic structure in a widespread passerine.  

Science.gov (United States)

Geological and ecological features restrict dispersal and gene flow, leading to isolated populations. Dispersal barriers can be obvious physical structures in the landscape; however microgeographic differences can also lead to genetic isolation. Our study examined dispersal barriers at both macro- and micro-geographical scales in the black-capped chickadee, a resident North American songbird. Although birds have high dispersal potential, evidence suggests dispersal is restricted by barriers. The chickadee's range encompasses a number of physiological features which may impede movement and lead to divergence. Analyses of 913 individuals from 34 sampling sites across the entire range using 11 microsatellite loci revealed as many as 13 genetic clusters. Populations in the east were largely panmictic whereas populations in the western portion of the range showed significant genetic structure, which often coincided with large mountain ranges, such as the Cascade and Rocky Mountains, as well as areas of unsuitable habitat. Unlike populations in the central and southern Rockies, populations on either side of the northern Rockies were not genetically distinct. Furthermore, Northeast Oregon represents a forested island within the Great Basin; genetically isolated from all other populations. Substructuring at the microgeographical scale was also evident within the Fraser Plateau of central British Columbia, and in the southeast Rockies where no obvious physical barriers are present, suggesting additional factors may be impeding dispersal and gene flow. Dispersal barriers are therefore not restricted to large physical structures, although mountain ranges and large water bodies do play a large role in structuring populations in this study. PMID:25074576

Adams, R V; Burg, T M

2015-02-01

195

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

196

Yasny lode-placer cluster: Geological and structural features and gold potential  

Science.gov (United States)

The geological and structural features and gold potential of the Yasny lode-placer cluster in Amur province have been investigated. The lode-placer cluster is an intrusive domal uplift elongated in the nearmeridional direction and surrounded by Neogene loose sediments. The cluster comprises placers that yielded 15 t gold mined from there and small occurrences of gold-quartz and gold-base-metal lodes. Association of native gold with cinnabar in the Yasny Creek placer allows us to forecast a new source of gold-mercury mineralization in the basin of this creek, which could be compared with the Kyuchyus deposit in Yakutia. Gold nuggets 79 kg in total weight were mined from Gar-2 River placer. They are comparable in weight and association with quartz to the world's largest Holtermann Plate nugget from Australia. Gold-quartz lodes have been forecasted in the basin of the Gar-2 Creek.

Mel'nikov, A. V.; Stepanov, V. A.

2014-03-01

197

Characteristics of the geological structure of oil margins of the Orenburg gas condensate deposit  

Energy Technology Data Exchange (ETDEWEB)

The geological structure of the oil margins from two gas condensate deposits, one of which is isolated in the carbonate sediments of the Philippine level of the Kungursk stage (the Philippian) while the other is isolated in the carbonate sediments of the Artinsk to middle Carboniferous age (the basic) is analyzed. The important role of dense, screened carbonate interlayers in the formation of commercial accumulations of oil is shown. It is recommended that special attention be paid to the morphology of the oil overburden series and to the presence of shallow caps, thanks to which favorable conditions are created for commercial accumulations of oil in the oil margins, in exploring the gas condensate deposits in the nearflank zone of the Caspian Sea depression.

Kozlov, N.F.; Makarov, G.V.

1984-01-01

198

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)

199

Applicability of direct total reflection X-ray fluorescence spectrometry for multielement analysis of geological and environmental objects  

Science.gov (United States)

The research aim is to demonstrate our experience in the applicability of TXRF analysis of various geological and environmental objects using minimal sample treatment. The study was focused on the evaluation of different factors affecting the TXRF results obtained for solid and liquid samples such as rock, mineral, ore, and natural water. Powdered geological samples were prepared as suspensions. Natural water samples were analyzed directly or after dilution. Testing various experimental parameters, e.g. sample amount, type of dispersant, and others was performed. For chosen conditions of the sample preparation procedure analytical figures of merit were estimated. Presented analytical results display the possibilities of TXRF applications in geological and environmental fields.

Cherkashina, T. Yu.; Panteeva, S. V.; Pashkova, G. V.

2014-09-01

200

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

201

X-ray microfluorescence analysis of thin- and thick-sectioned geologic materials  

International Nuclear Information System (INIS)

X-ray microfluorescence (XRMF) combined with simultaneous elemental digital mapping provides a new analytical tool for the elemental analyses of thick and thin sectioned metallurgical, geological, biological, and other types of materials. The penetrating nature of the x-ray beam allows elemental information to be obtained not only from the surface of the sample, but from beneath the sample surface (5 to 100+ microns depending on the sample elemental composition and the x-ray source used). The depth information when combined with the requirement for little or no sample preparation and the ability of the XRMF method to examine materials in air enhances the utility of the microfluorescence and digital mapping technique. Furthermore, the combination of the depth information from the XRMF method and surface information (typically only 1 to 2 microns in depth) from electron optical methods makes for a more complete analysis of a sample. Geologic materials are good specimens to illustrate the XRMF and data analysis technique because of the variety of other analytical techniques that can be used for verification of the XRMF method. Three different geologic specimens were examined by XRMF to illustrate the capability of the technique to detect small elemental variations within a specimen, to image microscopic objects within a larger sample matrix, and to obtain elemental information from beneath the sample surface resulting from the penetration of the x-ray beam. The informatinetration of the x-ray beam. The information obtained by the XRMF method was corroborated by optical microscopy, scanning electron microscopy-SEM, and electron microprobe analysis-EPMA

202

Risk methodology for geologic disposal of radioactive waste: sensitivity analysis techniques  

International Nuclear Information System (INIS)

Statistical techniques for sensitivity analysis of a complex model are presented. Included in these techniques are Latin hypercube sampling, partial rank correlation, rank regression, and predicted error sum of squares. The synthesis of these techniques was motivated by the need to analyze a model for the surface movement of radionuclides. The model and statistical techniques presented in this report are part of a project funded by the Nuclear Regulatory Commission to develop a methodology to assess the risk associated with geologic disposal of radioactive waste

203

How Students and Field Geologists Reason in Integrating Spatial Observations from Outcrops to Visualize a 3-D Geological Structure  

Science.gov (United States)

Geologists and undergraduate students observed eight artificial "rock outcrops" in a realistically scaled field area, and then tried to envision a geological structure that might plausibly be formed by the layered rocks in the set of outcrops. Students were videotaped as they selected which of fourteen 3-D models they thought best represented the…

Kastens, Kim A.; Agrawal, Shruti; Liben, Lynn S.

2009-01-01

204

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

205

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

206

Experimental performance evaluation of a compton suppression system by an analysis of geological reference materials  

International Nuclear Information System (INIS)

Compton scattering is one of major sources inducing a high background when a gamma ray spectrum is acquired from a radioactive sample. The high background spectrum deteriorates the detection sensitivity for an analysis of the nuclide of interest. To improve the detection sensitivity by the reduction of the spectrum background, a Compton suppression system (CSS) applying an anti coincidence mode was developed and has been used for a neutron activation analysis. A Compton suppression system (CSS) was implemented for an instrumental neutron activation analysis (INAA) at an NAA laboratory of the Korea Atomic Energy Research Institute (KAERI) in 2009. The CSS consists of a high purity Ge (HPGe) detector and bismuth germinate (BGO) with electronic modules. An evaluation of the performance of the CSS was carried out based on the measurement of the gamma ray emitting source and the detectable nuclides created thorough neutron activation of biological reference materials. This study was executed to evaluate the performance of the CSS for geological standard reference materials (SRMs). Four geological SRMs produced by the National Institute of Standards and Technology (NIST) in the USA were selected and irradiated using an NAA 1 irradiation hole at HANARO. Gamma ray spectra with normal mode and anti coincidence mode were acquired at the same time, and advantage factors of CSS for each nuclide detected were calculated on the basis of the signal to noise ratio signal to noise ratio

207

Experimental performance evaluation of a compton suppression system by an analysis of geological reference materials  

Energy Technology Data Exchange (ETDEWEB)

Compton scattering is one of major sources inducing a high background when a gamma ray spectrum is acquired from a radioactive sample. The high background spectrum deteriorates the detection sensitivity for an analysis of the nuclide of interest. To improve the detection sensitivity by the reduction of the spectrum background, a Compton suppression system (CSS) applying an anti coincidence mode was developed and has been used for a neutron activation analysis. A Compton suppression system (CSS) was implemented for an instrumental neutron activation analysis (INAA) at an NAA laboratory of the Korea Atomic Energy Research Institute (KAERI) in 2009. The CSS consists of a high purity Ge (HPGe) detector and bismuth germinate (BGO) with electronic modules. An evaluation of the performance of the CSS was carried out based on the measurement of the gamma ray emitting source and the detectable nuclides created thorough neutron activation of biological reference materials. This study was executed to evaluate the performance of the CSS for geological standard reference materials (SRMs). Four geological SRMs produced by the National Institute of Standards and Technology (NIST) in the USA were selected and irradiated using an NAA 1 irradiation hole at HANARO. Gamma ray spectra with normal mode and anti coincidence mode were acquired at the same time, and advantage factors of CSS for each nuclide detected were calculated on the basis of the signal to noise ratio.

Moon, J. H.; Sun, G. M.; Kim, S. H.; Chung, Y. S. [KAERI, Daejeon (Korea, Republic of)

2012-10-15

208

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)

209

Geomorphology and structural geology of Saturnalia Fossae and adjacent structures in the northern hemisphere of Vesta  

Science.gov (United States)

Vesta is a unique, intermediate class of rocky body in the Solar System, between terrestrial planets and small asteroids, because of its size (average radius of ?263 km) and differentiation, with a crust, mantle and core. Vesta's low surface gravity (0.25 m/s2) has led to the continual absence of a protective atmosphere and consequently impact cratering and impact-related processes are prevalent. Previous work has shown that the formation of the Rheasilvia impact basin induced the equatorial Divalia Fossae, whereas the formation of the Veneneia impact basin induced the northern Saturnalia Fossae. Expanding upon this earlier work, we conducted photogeologic mapping of the Saturnalia Fossae, adjacent structures and geomorphic units in two of Vesta's northern quadrangles: Caparronia and Domitia. Our work indicates that impact processes created and/or modified all mapped structures and geomorphic units. The mapped units, ordered from oldest to youngest age based mainly on cross-cutting relationships, are: (1) Vestalia Terra unit, (2) cratered highlands unit, (3) Saturnalia Fossae trough unit, (4) Saturnalia Fossae cratered unit, (5) undifferentiated ejecta unit, (6) dark lobate unit, (7) dark crater ray unit and (8) lobate crater unit. The Saturnalia Fossae consist of five separate structures: Saturnalia Fossa A is the largest (maximum width of ?43 km) and is interpreted as a graben, whereas Saturnalia Fossa B-E are smaller (maximum width of ?15 km) and are interpreted as half grabens formed by synthetic faults. Smaller, second-order structures (maximum width of structure, by the use of the general descriptive term 'adjacent structures', which encompasses minor ridges, grooves and crater chains. For classification purposes, the general descriptive term 'minor ridges' characterizes ridges that are not part of the Saturnalia Fossae and are an order of magnitude smaller (maximum width of structural features on Vesta by presenting findings of a photogeologic, structural mapping study which highlights how impact cratering and impact-related processes are expressed on this unique, intermediate Solar System body.

Scully, Jennifer E. C.; Yin, A.; Russell, C. T.; Buczkowski, D. L.; Williams, D. A.; Blewett, D. T.; Ruesch, O.; Hiesinger, H.; Le Corre, L.; Mercer, C.; Yingst, R. A.; Garry, W. B.; Jaumann, R.; Roatsch, T.; Preusker, F.; Gaskell, R. W.; Schröder, S. E.; Ammannito, E.; Pieters, C. M.; Raymond, C. A.

2014-12-01

210

Delineation of Near-Surface Structure in the Southern Part of 15th of May City, Cairo, Egypt Using Geological, Geophysical and Geotechnical Techniques  

Science.gov (United States)

The integration of geological, geophysical, and geotechnical interpretation at the southern part of 15th of May City, have been used to evaluate the subsurface stratigraphy, especially the clay layer which may cause serious danger to construction. Those techniques have been used to delineate the subsurface structures as normal faults, which play a critical role on the stability of buildings. Geological setting of the area has been evaluated through the construction of a geological map from different geological sections and samples obtained from more than 30 observation points. Geophysical tools such as vertical electrical soundings (12 VESs), 2-D dipole-dipole array (7 sections), P-wave shallow seismic refraction (31 profiles) and multiple channel analysis of surface waves (31 MASW profiles) have been carried out to image the subsurface situation. Geotechnical evaluation using 26 boreholes, samples, laboratory tests and geotechnical parameters has been done at the area of interest. The geological setting demonstrates that the city had been constructed on the second and third members of Qurn Formation (Upper Eocene) composed of argillaceous limestone, marl and shale. Two normal faults are passing through the area were observed. The resistivity (VES and dipole-dipole) and seismic (P-waves and MASW) results reflect the presence of the two normal faults cross the study area, affecting the obtained section of marl, clayey marl and limestone layers. The geotechnical information indicate the presence of the normal faults and the existence of clay layer with swelling ability reaching 140%, which may cause cracks in the upper layers and/or subsidence.

Mohamed, Adel M. E.; Araffa, Sultan A. Sultan; Mahmoud, Nagi I.

2012-09-01

211

The structure and kinematics of the central Taiwan mountain belt derived from geological and seismicity data  

Science.gov (United States)

The structure of the Taiwan mountain belt is thought to be that of an imbricate thrust and fold belt developed in a forward breaking sequence above a shallowly dipping basal detachment. In recent years, however, a growing amount of seismicity data from the internal part of the mountain belt indicates the existence of widespread fault activity in the middle and lower crust, suggesting that deeper levels of the crust must be involved in the deformation than predicted by the shallow detachment, imbricate thrust belt model. To address this issue, we present new geological mapping, together with earthquake focal mechanism and seismic energy release data from the central part of Taiwan. We concur with the interpretation that the foreland basin part of the Western Foothills comprises an imbricate thrust system that is developing as a forward breaking sequence that is structurally and kinematically linked to a basal detachment at between 7 and 10 km depth. To the east of the foreland basin, however, in the Hsuehshan and Central Ranges, our data show the presence of two fault systems. An earlier, inactive thrust system with a well-developed cleavage is cut by a system of steeply dipping active faults that penetrate to a depth of 25 to 30 km or more. In the Hsuehshan Range, the second fault system is best represented by a structural and kinematic model in which this part of the mountain belt forms a zone of transpression with a structural architecture similar to that of a crustal-scale positive flower structure. Eastward, in the Central Range, Mesozoic basement rocks are over thrusting strongly folded and cleaved deep water sediments of the first, now inactive, thrust system. The involvement of deep crustal levels and Mesozoic basement in the second fault system is suggestive of the reactivation of preexisting basin-bounding faults that were located on the Eurasian continental margin.

Brown, D.; Alvarez-Marron, J.; Schimmel, M.; Wu, Y.-M.; Camanni, G.

2012-10-01

212

Spectral analysis of geologic samples with using double-jet plasmatron  

International Nuclear Information System (INIS)

The method of quantitative spectral analysis of Ti, Cr, Ni, Bi V, Zr, Nb, Mo, Sn, Ce, Y, Yb, La, Be, Se, Co Sb, Pb, Mn, Ga in geologic samples the composition of which is complex and difficult to control (rocks, ores and minerals) using plasma jet of double-jet plasmotron as an eight source is given. The detection limit is nx10-5-nx10-7%. It is revealed the influence of analysed matter composition of the analysis results is not significant in plasma jet so it is possible to analyse samples complex in composition by the same standards. Dispersional analysis of resuultant products by the worked out method demonstrated that the error in plasma jet caused by uncontrolled changes in composition is 2-3 relative percents that 7-10 times lesser in comparison with the alternating current arc

213

Structural geology investigation in the republics of Dahomey and Togoland, Africa, using ERTS-1 multi-spectral images  

Science.gov (United States)

The author has identified the following significant results. Recent geological studies in the Republics of Dahomey and Togoland put in light a new chronology and propose a schema indicating that the structural geology of this region is very complicated. The new observations made possible by the ERTS images concern the main orientations, the folded units, and the lithology. The correlation between different types of laterite and the petrology of the basement seems possible, and is the most significant result of this investigation but unfortunately conducted with poor quality images because of atmospheric haze.

Weecksteen, G. (principal investigator)

1974-01-01

214

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

215

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

OpenAIRE

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 struct...

Eduard Prelogovi?; Renato Buljan

1997-01-01

216

Geological techniques used in the siting of South Africa's nuclear facilities  

International Nuclear Information System (INIS)

Nuclear site selection studies begin with an initial screening phase in order to pick regions which could be potentially suitable. When assessing a potential nuclear site from a structural geological point of view, the most important factors are the presence of 'capable faults', the seismicity of the area, and the existence of good foundation rock. A geological evaluation of a potential site involves a literature survey for all existing geological data on the site, geophysical investigations, structural domain analysis and geological mapping

217

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

218

Strategies for Mars remote Laser-Induced Breakdown Spectroscopy analysis of sulfur in geological samples  

International Nuclear Information System (INIS)

The key to understanding the sulfur history on Mars is to identify and determine sulfate and sulfide compositions and then to draw from them geologic clues about their environments of formation. To lay a foundation for use of remote LIBS to sulfur analysis in planetary exploration, we have undertaken a focused study of sulfur LIBS in geological samples in a simulated Mars atmosphere, with experimental parameters replicating the ChemCam LIBS instrument. A suite of twelve samples was selected, including rocks rich in minerals representative of sulfates and sulfides that might be encountered on Mars. Univariate analysis of sulfur emission lines did not provide quantitative information. Partial least squares (PLS) analysis was successful at modeling sulfur concentrations for a subset of samples with similar matrices. Sulfide minerals were identified on the basis of other siderophile or chalcophile peaks, such as those arising from Zn and Cu. Because the S lines are very weak compared to those of other elements, optimal PLS results were obtained by restricting the wavelength range to channels close to the most intense sulfur lines ? 540-570 nm. Principal components analysis was attempted on the dataset, but did not differentiate the samples into meaningful groups because the sulfur lines are not strong enough. However, areas of the relatively weak S, H, and O peaks may be used to correctly classify all samples. Based on these outcomes, a flowchart that outlines a possiblmes, a flowchart that outlines a possible decision tree for identification and quantification of sulfur in remote LIBS analysis was constructed. Results suggest that LIBS data acquired under Mars conditions can meet the science requirements for the ChemCam instrument.

219

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

220

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)

221

Geological and geophysical signatures of the Jemez lineament: a reactivated Precambrian structure  

Energy Technology Data Exchange (ETDEWEB)

The Jemez lineament (N52/sup 0/E) is one of several northeast-trending lineaments that traverse the southwestern United States. It is defined by a 500-km-long alignment of late Cenozoic volcanic fields extending southwest from at least the Jemez Mountains in the north-central New Mexico to the San Carlos-Peridot volcanic field in east-central Arizona. Geochronologic data from Precambrian basement rocks indicate that the lineament is approximately coincident with a boundary between Precambrian crustal provinces. Characteristics of the lineament are high heat flow (>104.5 mW/m/sup 2/), an attenuated seismic velocity zone from 25 to 140 km depth, and an upwarp of the crustal electrical conductor inferred from magnetotelluric studies. The high electrical conductivity is probably caused by the presence of interstitial magma in the rocks of the mid-to-upper crust. The average electical strike within the Precambrian basement is N60/sup 0/E, supporting a relationship between the Precambrian structural grain and the Jemez lineament. The geological and geophysical data suggest that the lineament is a structural zone that extends deep into the lithosphere and that its location was controlled by an ancient zone of weakness in the Precambrian basement. Ages of late Cenozoic volcanic rocks along the lineament show no systematic geographic progression, thus indicating that a mantle plume was not responsible for the alignment of the volcanic fields.Most of the faults, dikes, and cinder cone alignments along the lineament trend approximately N25/sup 0/E and N5/sup 0/W. These trends may represent Riedel shears formed by left-lateral transcurrent movement along the structure. Less common trends of cinder cone alignments and dikes are approximately N65/sup 0/W and N85/sup 0/W. The diversity in orientation indicates that the magnitudes of the two horizontal principal stresses within the lineament have been approximately equal for at least the last 5 m.y.

Aldrich, M.J. Jr.; Ander, M.E.; Laughlin, A.W.

1981-01-01

222

New structural and stratigraphic interpretation of Lake Superior basin from hydrocarbon exploration geophysics and geology  

Energy Technology Data Exchange (ETDEWEB)

Between October 1987 and April 1992, two deep boreholes were drilled along the south shore of Lake Superior in a test of the hydrocarbon potential of the conglomerate, sandstone and shale composing the Middle Proterozoic Oronto Group ({approximately}1 billion years). These drilling ventures, preceded by geophysical programs, and combined with wireline and core information, support new interpretations of the structural and stratigraphic geology associated with the Midcontinent Rift System in the Lake Superior district. No.7-22 Terra-Patrick: A stratigraphic, but not structural fit. This borehole in Bayfield County, Wisconsin, drilled an expected sequence of Oronto Group clastic redbeds. No viable hydrocarbon shows were encountered. Six second reflection seismology profiles collected in northwestern Wisconsin indicate the Douglas Fault decreases in throw in an easterly direction, changing to a fold northeast of the borehole. This termination is associated with the south flank of White`s Ridge, a pre-rift residual high identified through modeling studies and seismic interpretations by local absence of Midcontinent Rift volcanics and overlying strata. To the southwest of Isle Royale, the pre-rift Grand Marias Ridge exhibits similar characteristics. No.1-29 St. Amour: A structural, but not stratigraphic, fit. Drilled in Alger County, Michigan, the St. Amour well appears to bottom in pre-rift metamorphic basement rocks. This hole was 100% cored. No hydrocarbon shows were reported. Reflection seismology profile analyses verify a change in strike, from northeast to southeast, of the Keweenaw Fault in the eastern Lake Superior Basin. The drilled section included 6,000 feet of pre-Paleozoic red-beds containing cross-bedding, ripple marks, and multiple fining-upward strata.

Dickas, A.B. [Univ. of Wisconsin, Superior, WI (United States)

1996-09-01

223

Interactive editing of 3D geological structures and tectonic history sketching via a rigid element method  

Science.gov (United States)

Numerical models of geological structures are generally built with a geometrical approach, which lacks an explicit representation of the deformation history and may lead to incompatible structures. We advocate that the deformation history should be investigated and represented from the very first steps of the modelling process, provided that a series of rapid, interactive or automated, deformation tools are available for local editing, forward modelling and restoration. In this paper, we define the specifications of such tools and emphasise the need for rapidity and robustness. We briefly review the different applications of deformation tools in geomodelling and the existing deformation algorithms. We select a deformation algorithm based on rigid elements, first presented in the Computer Graphics community, which we refer to as Reed. It is able to rapidly deform any kind of geometrical object, including points, lines or volumes, with an approximated mechanical behaviour. The objects to be deformed are embedded in rigid cells whose displacement is optimised by minimising a global cost function with respect to displacement boundary conditions. This cost function measures the difference in displacement between neighbouring elements. The embedded objects are then deformed based on their original position with respect to the rigid elements. We present the basis of our implementation of this algorithm and highlight its ability to fulfil the specifications we defined. Its application to geomodelling specific problems is illustrated through the construction of a synthetic structural model of multiply deformed layers with a forward modelling approach. A special boundary condition adapted to restore large folds is also presented and applied to the large anticline of Han-sur-Lesse, Belgium, which demonstrates the ability of this method to efficiently perform a volumetric restoration without global projections.

Laurent, Gautier; Caumon, Guillaume; Jessell, Mark

2015-01-01

224

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

OpenAIRE

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 stu...

Hariri, Mustafa M.

2003-01-01

225

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.

226

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

227

Collapse Analysis of Timber Structures  

DEFF Research Database (Denmark)

A probabilistic based collapse analysis has been performed for a glulam frame structure supporting the roof over the main court in a Norwegian sports centre. The robustness analysis is based on the framework for robustness analysis introduced in the Danish Code of Practice for the Safety of Structures and a probabilistic modelling of the timber material proposed in the Probabilistic Model Code (PMC) of the Joint Committee on Structural Safety (JCSS). Due to the framework in the Danish Code the timber structure has to be evaluated with respect to the following criteria where at least one shall be fulfilled: a) demonstrating that those parts of the structure essential for the safety only have little sensitivity with respect to unintentional loads and defects, or b) demonstrating a load case with „removal of a limited part of the structure? in order to document that an extensive failure of the structure will not occur if a limited part of the structure fails, or c) demonstrating sufficient safety of key elements, such that the entire structure with one or more key elements has the same reliability as a structure where robustness is documented by b). Based on investigations with respect to criteria a) and b) the timber frame structure has one column with a reliability index a bit lower than an assumed target level. By removal three columns one by one no significant extensive failure of the entire structure or significant parts of it are obtained. Therefore the structure can be considered to behave robust according to the sued probabilistic approach. However, the present probabilistic approach for robustness evaluation has to be further developed for a general application to timber systems, and a simplified approach suitable for day-to-day engineering purposes must be identified.

Kirkegaard, Poul Henning; SØrensen, John Dalsgaard

2008-01-01

228

Information on subsoil geological structure in the city of Catania (Eastern Sicily from microtremor measurements  

Directory of Open Access Journals (Sweden)

Full Text Available Nakamura?s technique, or the H/V spectral ratio method, has been applied to microtremor measurements carried out in the urban area of Catania (Eastern Sicily to obtain information on the geological structure of some sites,and to make a hypothesis on their seismic response. In general, sites located on soft soils or anthropic debris fillings have shown greater amplification at high frequencies (above 1 Hz. However, a strong lateral variation was observed in the frequency band, thus a denser grid of measurement points is necessary for a precise mapping of the resonant frequencies. In the low frequency range, between 0.1 and 1 Hz, a common peak around 0.2 Hz was observed. The fundamental resonant frequency inferred from the main peak in the H/V spectrum has been used to calculate the depth of the interface between the clays and the main reflector on the basis of the shear-wave velocity: it has been estimated as about 700 m.

M. R. Gallipoli

2001-06-01

229

The Geology Robot: A Collaborative Effort for improving Outcrop Visualization and Analysis  

Science.gov (United States)

Geologic mapping is one of the most important skills a geologist will attempt to master during their education and well into their career. Mapping requires the ability to identify rocks and minerals, an understanding of geologic principles of history, deformation, and tectonics, as well as the ability to access the geology in question. As a student, the first two items are cognitive, and generally gained through education and experience. However, the third involves external, especially physical factors, often outside of a student’s control. Mapping and outcrop analysis can be difficult in areas of especially varied terrain depending on one’s will and physical ability. In our area of southwestern Pennsylvania, steep terrain and dense vegetation dominate the landscape. Road cuts are often the only options for identifying local bedrock. Many outcrops are avoided based on their sheer size or integrity, which can pose risks of physical harm. In order to address some of these concerns, we have developed a robot, able to scale and image rocks in the vertical. The principle behind the robot’s capabilities is to reach steep or over-steep cliff faces to view and measure rock type and stratigraphic relationships. The robot carries a movable camera, allowing the operator a clear view of the rock face in an area that he or she wouldn’t normally be able to access. The robot is suspended from climbing rope over the cliff edge and connected to a power source and video monitor. The current prototype is operated with a handheld remote control including independent camera manipulation. Future development may include detachable wheel tracks for navigating less than vertical surfaces and a coring bit for sampling. Potential uses exist beyond visualization for classroom instruction, including detailed mapping, evaluating geological engineering challenges, viewing down-well conditions in large-bore wells, etc. We believe this robot will allow students (and possibly professionals) an opportunity to use a simple tool to accomplish previously difficult, dangerous, or even impossible tasks. This work is an example of cross-discipline collaboration on our campus. It was conceived from a Geologist’s point of view, shared with a Robotics expert, and offered as a challenge to the university’s Robotics students. Several interested students designed and built the robot from scratch as an extra-curricular project. This is a great demonstration of capturing the interests of students across disciplinary boundaries to achieve a unique and creative outcome.

Fredrick, K. C.; Valoski, M. P.; Rodi, A. F.

2010-12-01

230

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

231

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 km2-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 106 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 104 to 105 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 105 to 106 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.)

232

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

233

Progress on 129I analysis and its application in environmental and geological researches  

DEFF Research Database (Denmark)

Iodine-129 is a naturally generated isotope, but anthropogenic releases are the dominated source of 129I in the present environment. Among many measurement techniques, neutron activation analysis (NAA) and accelerator mass spectrometry (AMS) are only methods used for measurement of 129I in environmental level. Based on its source terms, chemical properties and environmental behaviors, 129Ican be applied for geological dating in a range of 2–80Ma, investigation of formation and migration of hydrocarbon, circulation of ocean water, atmospheric process of iodine, as well as reconstruction of dispersion and migration of short-lived radioisotopes of iodine released from nuclear accidents. This article aims to summarize and critically compare the analytical techniques used for 129I measurement and chemical methods for separation of iodine from various sample matrices, purification from the interferences, as well as preparation of suitable target for AMS measurement. The major applications in environmental and geological researches are reviewed, which mainly focus on the new progress and potential development in the future. The application of 129I in the investigation of radioactive contamination from the Fukushima accident is discussed.

Fan, Yukun; Hou, Xiaolin

2013-01-01

234

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

235

Lithospheric Structure of Antarctica and Implications for Geological and Cryospheric Evolution  

Science.gov (United States)

Recent broadband seismic deployments, including the AGAP/GAMSEIS array of 24 broadband seismographs over the Gamburtsev Subglacial Mountains (GSM) in East Antarctica and the POLENET/ANET deployment of 33 seismographs across much of West Antarctica, reveal the detailed crust and upper mantle structure of Antarctica for the first time. The seismographs operate year-around even in the coldest parts of Antarctica, due to novel insulated boxes, power systems, and modified instrumentation developed in collaboration with the IRIS PASSCAL Instrument Center. We analyze the data using several different techniques to develop high-resolution models of Antarctic seismic structure. We use Rayleigh wave phase velocities at periods of 20-180 s determined using a modified two-plane wave decomposition of teleseismic Rayleigh waves to invert for the three dimensional shear velocity structure. In addition, Rayleigh wave group and phase velocities obtained by ambient seismic noise correlation methods provide constraints at shorter periods and shallower depths. Receiver functions provide precise estimates of crustal structure beneath the stations, and P and S wave tomography provides models of upper mantle structure down to ~ 500 km depth along transects of greater seismic station density. The new seismic results show that the high elevations of the GSM are supported by thick crust (~ 55 km), and are underlain by thick Precambrian continental lithosphere that initially formed during Archean to mid-Proterozoic times. The absence of lithospheric thermal anomalies suggests that the mountains were formed by a compressional orogeny during the Paleozoic, thus providing a locus for ice sheet nucleation throughout a long period of geological time. Within West Antarctica, the crust and lithosphere are extremely thin near the Transantarctic Mountain Front and topographic lows such as the Bentley Trench and Byrd Basin, which represent currently inactive Cenozoic rift systems. Slow seismic velocities beneath Marie Byrd Land at asthenospheric depths suggest a major thermal anomaly, possibly due to a mantle plume. Volcanic earthquakes detected in this region indicate the presence of currently active magma systems. The results suggest large lateral changes in parameters needed for glaciological models, including lithospheric thickness, mantle viscosity, and heat flow. Extremely high heat flow is predicted for much of West Antarctica, consistent with recent results from the WAIS ice drilling. Using the seismic results to estimate mantle viscosity, we find several orders of magnitude difference in viscosity between East and West Antarctica, with lowest viscosities found beneath Marie Byrd Land and the West Antarctic Rift System. Realistic glacial isostatic adjustment models must take these large lateral variations into account.

Wiens, Douglas; Heeszel, David; Sun, Xinlei; Lloyd, Andrew; Nyblade, Andrew; Anandakrishnan, Sridhar; Aster, Richard; Chaput, Julien; Huerta, Audrey; Hansen, Samantha; Wilson, Terry

2013-04-01

236

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

237

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

238

Geological structure of Charity Shoal crater, Lake Ontario, revealed by multibeam bathymetry  

Science.gov (United States)

Acoustic images of Charity Shoal in Lake Ontario, derived from a 1 × 1 m grid model of bathymetry assembled by the Canadian Hydrographic Service in 2010-2011, confirm the existence of a crater, as revealed by its surface morphology. With these higher quality data, it is possible to describe the crater in much greater detail, and arrive at a better interpretation of the geology than was possible using the earlier bathymetry of Lake Ontario. This new bathymetry of Charity Shoal reveals a continuous rim encircling an ovoid-shaped crater floor 1,200-1,500 m in diameter, with the crater floor being largely devoid of relief. Extending 3-4 km southwest of the crater is a ridge capped by a linear zone of unstratified debris that resembles a medial moraine. NE-SW erosional valleys cut across the crater rim in its southwestern sector. Apparently, glacial erosion has stripped the soil zone off stratified bedrock beneath the crater rim, exposing an intricate pattern of micro-ridges and grooves that bear the record of differential resistance to erosion of successive beds within the sequence of rock strata. Mapping of the shallow structure of the bedrock reveals a continuous ring anticline coinciding with the crater rim, with rock strata dipping gently in both directions away from the rim axis. In combination with existing evidence on the regional stratigraphy, these observations and interpretations are consistent with the Charity Shoal crater having formed in a shallow marine environment by an extraterrestrial impact event in the Middle Ordovician, followed by post-impact sedimentation, and much later, erosion during Pleistocene glaciations. Apparently, post-impact sediments infilled the crater and eventually covered the crater rim, leaving only a diminished structural expression of a crater having no more than 20 m of surface relief. Further details of crater history and origin, and a test of the hypothesis of impact, will likely come from acoustic reflection profiling and direct sampling.

Holcombe, Troy L.; Youngblut, Scott; Slowey, Niall

2013-08-01

239

Thai Rhetorical Structure Analysis  

CERN Document Server

A rhetorical structure tree (RS tree) is a representation of discourse relations among elementary discourse units (EDUs). A RS tree is very useful to many text processing tasks employing relationships among EDUs such as text understanding, summarization, and question answering. Thai language with its unique linguistic characteristics requires a unique RS tree construction technique. This paper proposes an approach for Thai RS tree construction which consists of three major steps: EDU segmentation, Thai RS tree construction, and discourse relation (DR) identification. Two hidden markov models derived from grammatical rules are used to segment EDUs, a clustering technique with its similarity measure derived from Thai semantic rules is used to construct a Thai RS tree, and a decision tree whose features extracted from the rules is used to determine the DR between EDUs. The proposed technique is evaluated using three Thai corpora. The results show the Thai RS tree construction and the DR identification effectiven...

Sinthupoun, Somnuk

2010-01-01

240

Reliability analysis of structures  

Directory of Open Access Journals (Sweden)

Full Text Available The process of building an object consists of planning, design, construction, use and eventual demolition [1]. In each of these components in the process of building uncertainties occurs, which can be caused by human or natural effect. Human cause of uncertainties includes intentional and unintentional deviation from the optimal realization, the use of inappropriate materials, unverified construction methods, poor quality of connections between elements, changes to the building design without the consent of all parties. Natural effects are often unpredictable. Reliability is the ability of the structure to meet the construction requirements set out under specific conditions during the service life, according which it is designed to [2]. It refers to the carrying capacity, serviceability and durability of construction and according to them different degrees of reliability can be defined. One of the best ways of presenting the size of the uncertainty in the theory of reliability is the reliability index ?.

Stanojev Milovan

2014-01-01

241

Sequence stratigraphic analysis and integrated 3D geological modeling of M1 block, Wenmingzhai oilfield, Dongpu depression, China  

Science.gov (United States)

The M1 block is a typically complex fault-block oilfield, whose recovery has reached 30.5% through the twenty years waterflooding development. Remaining oil scatters very widely and the production between layers is in a high degree. However, many problems have been exposed at the same time which hinder improvement of the recovery rate and sustainable development of the reservoir. Hence, it is important to carry out basic geological research and form a comprehensive understanding of reservoir properties. However, few such studies have been conducted in China. In this study, work related to basic geological research was conducted based on high-resolution sequence stratigraphy, seismic interpretation technology and 3D visual geological modeling, and significant results were achieved. Three sequence orders and three types of interfacies in the stratigraphic architecture of M1 block were identified through seismic sections, logging curve characteristics and entropy spectrum analysis. Thirty-two short-term sequence cycles (fifth order), eight mid-term sequence cycles (fourth order) and two long-term sequence cycles (third order) were identified, followed by the establishment of a high-resolution isochronous stratigraphic correlation framework. Finally, a regional 3D geological model was established on the basis of these preliminary studies. The integrated 3D geological model is a valuable tool for reflecting geological bodies accurately, and it can accurately represent and describe reservoir heterogeneity.

Li, Xue; Zhang, Jinliang; Yuan, Yong; Li, Cunlei; Meng, Ningning

2013-09-01

242

Analysis of geological condition and prospecting potential of uranium metallogenesis in Maling granite mass  

International Nuclear Information System (INIS)

Based on the study of regional geological evolution of Maling granite mass, uranium content of granite mass and its peripheric strata, petrogeochemistry and the known spatial distribution pattern of uranium mineralization and ore-controlling structures, new recognition is 1) Maling composite mass is the 'S' type re-melted granite, 2) the accumulative area of regional uranium metallogenic substances forms uranium-rich re-melted strata, 3) magma evolution is the matter base for the uranium-rich hydrotherm, 4) NE-trending main faults are channels for metallogenesis and the lateral high-angle dipping faults, fractures and interlayer fractures in the peripheric strata are the spaces of mineralization. The ore intersected by drilling in Maling granite is acidic type. Prospecting potential of Maling granite mass is analyzed, and preferable prospecting space is delineated for further exploration. (authors)

243

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

244

Morphology and shallow geological structure of the continental slope located between Manzanillo, Colima and Chamela, Jalisco, Mexico, using multibeam bathymetry and high resolution seismic reflection data  

Science.gov (United States)

The west coast of Mexico presents a complex array of tectonic processes related with the subduction of the Rivera plate beneath the Jalisco Block/North American plate including seamount subduction and forearc slivering. To better understand these processes and related deformation, an analysis and integration of marine geophysical data was undertaken to map the morphology and shallow geologic structure of the continental slope located between Manzanillo, Colima and Chamela, Jalisco, Mexico (Longitude: 104 ° 20 'to 106 ° 0 Latitude: 18 ° 24 'to 19 ° 48'). These data include multibeam bathymetry and seafloor backscatter data (Kongsberg EM300 system) and high-resolution seismic reflection data (Kongsberg TOPAS system) collected during the MORTIC07 campaign aboard the oceanographic vessel "El Puma". 3D models of the bathymetry and acoustic backscatter strength were constructed along with maps of the major geological and structural features, such as landslides and active faults and folds. The analysis indicates that the continental slope in this area has undergone significant vertical and horizontal movements producing several large slump blocks, a prominent sedimentary filled basin, and a series of transpressional ridges suggestive of a recent collision and subduction of a seamount, or similar bathymetric features.

Castillo, M.; Bandy, W. L.; Mortera-Gutierrez, C. A.

2013-05-01

245

Multielement analysis of unweighed biological and geological samples using backscatter and fundamental parameters  

International Nuclear Information System (INIS)

This chapter describes extended capabilities of the backscatter with fundamental parameter (BFP) method, which was originally applied only to well-defined samples over a more restricted range of compositions. It demonstrates that the BFP calculation method accurately computes both the effective thickness and the bulk composition of individual samples. It shows how the BFP method provides accurate multielement analyses of biological and geological materials without similar standards. It also examines the analyses of loose powders as well as pelletized quantitative analysis of unknown, unweighed samples by calculation of sample bulk constituents and thickness from the backscatter peaks. Besides reducing preparation and calibration costs, the BFP method avoids the potential contamination and dilution often associated with sample preparation because most materials can be directly analyzed as loose powders, solid lumps or pellets

246

Distribution and geology accumulation contamination analysis of heavy metal cadmium in agricultural soil of Zunyi county  

International Nuclear Information System (INIS)

The pollution of heavy metal Cd in agricultural soils of Zunyi County, Guizhou Province, was investigated and assessed by using geology accumulation indices (igeo) and pollution index method in this study. Results showed that the average content of Cd is 0.356 mg/kg, and the geochemistry baseline content of Cd was 0.147 mg/kg. The Igeos of Cd was 0.691, which suggested that non-contaminated soil accounts for 13.84%, 59.17% of tested soils was between non-polluted and mid-level polluted, 21.37% with mid-level polluted and 5.17% was between mid-level polluted and severely polluted, 0.45% of which was severely polluted. Contamination degree analysis indicated that non-contaminated soil was only 10.57%, 54.44% was influenced by Cd and 34.98% was seriously influenced by Cd. (authors)

247

Rare earths in environment and geologic samples determined by neutron activation analysis  

International Nuclear Information System (INIS)

Neutron activation analysis allows to determine rare earth elements (REE) with a sensivity much higher than non-nuclear methods. In this work, this technique has been applied to the determination of REE in environmental samples, such as marine suspended particulate matter and sea, lake and river sediments. The importance of lanthanides in the environmental field is due to the fact that some REE, because of their nearly identical physico-chemical behaviour, can simulate the environmental behaviour of actinides, generated by activation or fission processes. Am(III) can be simulated by Eu(III) and Nd(III), that can simulate also Cm(III). As regardes REE in geological studies, their distribution and fractionation in rocks provide information about the genesis and the evolution of the rocks themselves. In this work, some data relevant to Kenya rocks are presented

248

Multidimensional inversion of MT data from Alid Geothermal area, Eritrea. Comparison with geological structures and identification of a geothermal reservoir  

OpenAIRE

Abstract Electrical resistivity methods have been the most powerful tool in geothermal exploration for decades. Of these, MT and TEM are important methods in delineating geothermal resources. The main objective of this study is to understand the nature (dimensionality) of the MT data from Alid Geothermal area, Eritrea and apply multidimensional inversion to the data and compare the result with geological structures and the identification of a geothermal reservoir. In this project, 47 M...

Teklesenbet, Andemariam

2012-01-01

249

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

International Nuclear Information System (INIS)

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)

250

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 improvement over conventional techniques, with 53% of natural samples analysed replicating to better than ±0.1 per mille

251

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.

252

The upper Rhenish Shield basement (Vosges, Upper Rhinegraben and Schwarzwald): Main structural features deduced from magnetic, gravimetric and geological data  

Science.gov (United States)

Interpretation of magnetic and gravimetric data and correlations with geological observations on outcrops and in boreholes have enabled the construction of a geological sketch map of the pre-Westphalian basement in the area of the upper Rhenish shield. The map demonstrates the contrast between the "heavy" and "magnetic" Saxothuringian, characterized by Palaeozoic units metamorphosed to varying degrees and intruded by Early Carboniferous basites, and the "lighter" Moldanubian, consisting mainly of gneisses and granites. Geological structures and tectonic features are recorded beneath the Mesozoic and Cenozoic cover. The present picture of the basement is mainly the result of late Visean-early Namurian structural features represented by a linear arrangement of magmatic bodies and the distribution of strike-slip and thrust faults. The major structural features are the E-W Vittel-Lalaye-Lubine- Baden-Baden fault that marks the border between Saxothuringian and Moldanubian, the N35° left-lateral wrench-fault system running along the present Rhinegraben, the N60° grain of the northern Vosges and the Saar basin, and the S-verging crustal thrusts of Moldanubian.

Edel, J. B.; Fluck, P.

1989-11-01

253

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

254

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

255

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. The authors' goal was to create an open source and self-contained desktop application that does not require any additional third party framework (such as .NET) or the Java Virtual Machine. The software has a clear and highly modular structure enabling good code portability, easy maintainability, reusability and extensibility. A Windows installer is publicly available and the program is also fully functional on Linux. The Mac OS X port should be feasible with minimal effort. The install file with test and demo data sets, detailed manual, and links to the GitHub repositories are available on the regularly updated website www.sg2ps.eu.

Sasvári, Ágoston; Baharev, Ali

2014-05-01

256

Wavelet Based Analysis of Airborne Gravity Data For Interpretation of Geological Boundaries  

Science.gov (United States)

Airborne gravimeters have only very recently been developed with the sensitivity necessary for useful exploration geophysics. In this study, an airborne gravimeter - an inertially-stabilized platform which converts accelerometer readings into gravity values - has been installed aboard the NRC's Convair 580 research aircraft and a survey performed over the Geological Survey of Canada's gravity test area. These data are used in a new wavelet transform methodology that quickly analyses and locates geological boundaries of various spatial extents within real aerogravity data. The raw aerogravity data were GPS corrected and then noise minimised - to reduce high frequency random noise - with a separate wavelet transform denoising algorithm. The multi-resolution nature of the wavelet transform was then used to investigate the presence of boundaries at various scales. Examination of each wavelet detail scale shows that there is a coherent and localizable signal that conforms to geological boundaries over the entire range of scales. However, the boundaries are more apparent in the lower wavelet scales (corresponding to higher frequencies). The location of the local maximum values of the wavelet coefficents on each wavelet level provides a means to quickly determine and evaluate regional and/or local boundaries. The boundaries that are determined as a function of wavelet scale are able to be well-localized with the wavelet transform, and provides a method to locate, in ground coordinates, the edges of the boundary. In this study it is clear that wavelet methodologies are very well suited to being used effectively with aerogravity data due to the non-stationary nature of these data. Using these same methods on the horizontal and vertical derivatives of the data can provide visually clearer boundary definition, however, thus far there has not been any new boundaries identified in the derivative data. It is also possible to draw potential structural information, such as general dip direction, from the multi- resolution nature of the transformed data. In this regard, observation of the association between various scales could provide information on how the boundaries change laterally or in depth.

Leblanc, George E.; Ferguson, Stephen

257

Structural analysis of NPP components and structures  

Energy Technology Data Exchange (ETDEWEB)

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)

Saarenheimo, A.; Keinaenen, H.; Talja, H. [VTT Manufacturing Technology, Espoo (Finland)

1998-07-01

258

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)

259

Evaluation and analysis of geological condition of in-situ fragmentation leaching uranium  

International Nuclear Information System (INIS)

The ore geological condition, hydrogeological condition, engineering geological condition and technological mineralogical character of in-situ fragmentation leaching uranium are analyzed, and it is considered that the implementation of in-situ fragmentation leaching uranium technology is decided by different geological factor. Previously prospecting and geological condition evaluation of uranium ore is based on traditional mining method. If in-situ fragmentation leaching uranium method is adopted, one must re-evaluate previously prospected deposits before they are mined, or one must evaluate new prospecting deposits according to geological conditions of in-situ fragmentation leaching uranium method. The feasibility evaluation method of uranium deposit by in-situ fragmentation leaching uranium put forward by B. N. Mociniets is introducd, and it is considered that B. N. Mociniets method has guidable significance for geological condition evaluation before uranium deposits are mined. A feasibility study is done by applying B. N. Mociniets method to a uranium deposit. (authors)

260

Hyperspectral imagery and LiDAR for geological analysis of Cuprite, Nevada  

Science.gov (United States)

Fusion of Light Detection and Ranging (LiDAR) and Hyperspectral Imagery (HSI) products is useful for geological analysis, particularly for visualization of geomorphology and hydrology. In early 2007, coincident hyperspectral imagery and LiDAR were acquired over Cuprite, Nevada. The data were analyzed with ENVI and the ENVI LiDAR Toolkit. Results of the analysis of these data suggest, for some surfaces, a correlation between mineral content and surface roughness. However, the LiDAR resolution (~1 meter ground sampling distance) is likely too coarse to extract surface texture properties of clay minerals in some of the alluvial fans captured in the imagery. Though not demonstrated in this particular experiment (but a goal of the research), the relation between surface roughness and mineral composition may provide valuable information about the mechanical properties of the surface cover-in addition to generating another variable useful for material characterization, image classification, and scene segmentation. Future mission planning should include consideration of determining optimal ground sampling to be used by LiDAR and HSI systems. The fusion of LiDAR elevation data and multi- and hyperspectral classification results is, in and of itself, a valuable tool for imagery analysis and should be explored further.

West, Michael S.; Resmini, Ronald G.

2009-05-01

261

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

262

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 cated, as well as associated issues to be discussed have been clarified. (author)

263

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

264

A low dilution fusion method for major and trace element analysis of geological samples  

International Nuclear Information System (INIS)

The fusion bead method is known as an effective sample preparation technique to analyse major elements in geological samples since the ellimination of heterogeneity effects such as partical size effect and mineralogical effect in homogeneous fusion disk is a major advantage over the use of powder pellets. On the other hand, for trace element analysis, a powder pellet method is mainly applied to obtain the higher sensitivity than the fusion technique. In general, two sample preparation methods are necessary to analyse both major and trace elements. In this study, a low dilution fusion method using a 1 : 2 sample-to-flux ratio is discussed for the accurate determination of major and trace elements. By using this low dilution fusion method, the improvement in sensitivity as well as the solution of heterogeneity effects can be obtained. In sulfur analysis, this method demonstrate the better analysis result compared with the powder pellet method. A new correction method by using fundamental parameter program has been also established to compensate the error cause by loss on ignition, gain on ignition and inaccuracy of dilution ratio due to the weighing error or the evaporation of flux. (author)

265

Azimuth F inder: a software for data reading in structural geology  

OpenAIRE

Here is presented a computational tool named AzimuthFinder, for functioning inside the set of programs of ArcGis®. The developed program is intended to facilitate and optimize the generation of azimuth data tables, using structural lineaments previously traced in maps that are being worked on that automatic information system. The characteristics of AzimuthFinder allow that, upon the user’s choice, different tables get generated for the same analysis object, depending on the relative weigh...

Gustavo Lopes Queiroz; Eduardo Salamuni; Edenilson Roberto do Nascimento

2014-01-01

266

A multidisciplinary geological and geophysical approach to define structural and hydrogeological implications of the Molinaccio spring (Spello, Italy)  

Science.gov (United States)

In this paper, a multidisciplinary geological and geophysical approach has been applied in the complex area of Molinaccio spring (Spello, Umbria, Central Italy) to: 1) understand the large-scale geologic and tectonic structure of the area; 2) define the hydrogeological behavior of the various formations in relationship with the identified structural elements; 3) highlight at small-scale the tectonic structures and their relationships with the water caption tunnel, which is the draining structure of a still working, ancient Roman aqueduct giving water to the village of Spello and to the surrounding plain. Our approach includes different techniques like Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT), direct geological investigations, archaeological studies, GIS data collection and integration. The GPR data revealed, in the area of the water-caption tunnel, two main tectonic structures, both also confirmed by ERT data: the presence of a zone (maximum 2 m wide), interpreted as a normal fault area and an overthrust that puts in contact the permeable Scaglia Rossa limestone (Early Turonian-Middle Eocene), and the Scaglia Variegata-Cinerea marly limestones (Middle Eocene-Upper Oligocene) on the footwall, characterized by lower hydraulic permeability. Using some rough information available on the sub-surface path of the tunnel, that shows a sharp bend after a long straight course, together with the geophysical images, was possible to describe how Romans built the tunnel: they probably followed the wet outcropping rock during the excavation, and changed abruptly the dig direction when they intercepted the normal fault area, aligning then the excavation along its strike. This latter result is important also because recently a multidisciplinary project has been developed to restore and exploit the entire water supply structure, which is not only a well-preserved example of Roman remains with high archaeological value, but also a vital infrastructure for a zone with great tourist potential.

Ercoli, Maurizio; Pauselli, Cristina; Forte, Emanuele; Di Matteo, Lucio; Mazzocca, Massimiliano; Frigeri, Alessandro; Federico, Costanzo

2012-02-01

267

Terrestrial lidar and hyperspectral data fusion products for geological outcrop analysis  

Science.gov (United States)

Close-range hyperspectral imaging is an emerging technique for remotely mapping mineral content and distributions in inaccessible geological outcrop surfaces, allowing subtle chemical variations to be identified with high resolution and accuracy. Terrestrial laser scanning (lidar) is an established method for rapidly obtaining three-dimensional geometry, with unparalleled point density and precision. The combination of these highly complementary data types - 3D topography and surface properties - enables the production of value-added photorealistic outcrop models, adding new information that can be used for solving geological problems. This paper assesses the benefits of merging lidar and hyperspectral imaging, and presents qualitative and quantitative means of analysing the fused datasets. The integration requires an accurate co-registration, so that the 2D hyperspectral classification products can be given real measurement units. This stage is reliant on using a model that correctly describes the imaging geometry of the hyperspectral instrument, allowing image pixels and 3D points in the lidar model to be related. Increased quantitative analysis is then possible, as areas and spatial relationships can be examined by projecting classified material boundaries into 3D space. The combined data can be interpreted in a very visual manner, by colouring and texturing the lidar geometry with hyperspectral mineral maps. Because hyperspectral processing often results in several image products and classifications, these can be difficult to analyse simultaneously. A novel visualisation method is presented, where photorealistic lidar models are superimposed with multiple texture-mapped layers, allowing blending between conventional and hyperspectral imaging products to assist with interpretation and validation. The advantages and potential of the data fusion are illustrated with example outcrop data.

Buckley, Simon J.; Kurz, Tobias H.; Howell, John A.; Schneider, Danilo

2013-04-01

268

Structural analysis of aligned RNAs.  

Science.gov (United States)

The knowledge about classes of non-coding RNAs (ncRNAs) is growing very fast and it is mainly the structure which is the common characteristic property shared by members of the same class. For correct characterization of such classes it is therefore of great importance to analyse the structural features in great detail. In this manuscript I present RNAlishapes which combines various secondary structure analysis methods, such as suboptimal folding and shape abstraction, with a comparative approach known as RNA alignment folding. RNAlishapes makes use of an extended thermodynamic model and covariance scoring, which allows to reward covariation of paired bases. Applying the algorithm to a set of bacterial trp-operon leaders using shape abstraction it was able to identify the two alternating conformations of this attenuator. Besides providing in-depth analysis methods for aligned RNAs, the tool also shows a fairly well prediction accuracy. Therefore, RNAlishapes provides the community with a powerful tool for structural analysis of classes of RNAs and is also a reasonable method for consensus structure prediction based on sequence alignments. RNAlishapes is available for online use and download at http://rna.cyanolab.de. PMID:17020924

Voss, Björn

2006-01-01

269

Crustal structure across the San Andreas Fault at the SAFOD site from potential field and geologic studies  

Science.gov (United States)

We present newly compiled magnetic, gravity, and geologic datasets from the Parkfield region around the San Andreas Fault Observatory at Depth (SAFOD) pilot hole in order to help define the structure and geophysical setting of the San Andreas Fault (SAF). A 2-D cross section of the SAF zone at SAFOD, based on new, tightly spaced magnetic and gravity observations and surface geology, shows that as drilling proceeds NE toward the SAF, it is likely that at least 2 fault bounded magnetic slivers, possibly consisting of magnetic granitic rock, serpentinite, or unusually magnetic sandstone, will be encountered. The upper 2 km of the model is constrained by an order of magnitude increase in magnetic susceptibility at 1400 m depth observed in pilot hole measurements. NE of the SAF, a flat lying, tabular body of serpentinite at 2 km depth separates two masses of Franciscan rock and truncates against the SAF.

McPhee, D.K.; Jachens, R.C.; Wentworth, C.M.

2004-01-01

270

Computer Modelling of 3D Geological Surface  

CERN Document Server

The geological surveying presently uses methods and tools for the computer modeling of 3D-structures of the geographical subsurface and geotechnical characterization as well as the application of geoinformation systems for management and analysis of spatial data, and their cartographic presentation. The objectives of this paper are to present a 3D geological surface model of Latur district in Maharashtra state of India. This study is undertaken through the several processes which are discussed in this paper to generate and visualize the automated 3D geological surface model of a projected area.

Kodge, B G

2011-01-01

271

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)

272

Porphyry copper deposit tract definition - A global analysis comparing geologic map scales  

Science.gov (United States)

Geologic maps are a fundamental data source used to define mineral-resource potential tracts for the first step of a mineral resource assessment. Further, it is generally believed that the scale of the geologic map is a critical consideration. Previously published research has demonstrated that the U.S. Geological Survey porphyry tracts identified for the United States, which are based on 1:500,000-scale geology and larger scale data and published at 1:1,000,000 scale, can be approximated using a more generalized 1:2,500,000-scale geologic map. Comparison of the USGS porphyry tracts for the United States with weights-of-evidence models made using a 1:10,000,000-scale geologic map, which was made for petroleum applications, and a 1:35,000,000-scale geologic map, which was created as context for the distribution of porphyry deposits, demonstrates that, again, the USGS US porphyry tracts identified are similar to tracts defined on features from these small scale maps. In fact, the results using the 1:35,000,000-scale map show a slightly higher correlation with the USGS US tract definition, probably because the conceptual context for this small-scale map is more appropriate for porphyry tract definition than either of the other maps. This finding demonstrates that geologic maps are conceptual maps. The map information shown in each map is selected and generalized for the map to display the concepts deemed important for the map maker's purpose. Some geologic maps of small scale prove to be useful for regional mineral-resource tract definition, despite the decrease in spatial accuracy with decreasing scale. The utility of a particular geologic map for a particular application is critically dependent on the alignment of the intention of the map maker with the application. ?? International Association for Mathematical Geology 2007.

Raines, G.L.; Connors, K.A.; Chorlton, L.B.

2007-01-01

273

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

274

In-Situ XRF analysis of environmental, geological and archaeological samples  

International Nuclear Information System (INIS)

The paper presents some considerations and preliminary results on using the portable X-ray fluorescence spectrometry as in-situ method for the analysis of solid samples of environmental, geological or archaeological origin. Field portable x-ray fluorescence (FPXRF) is an exemplary field method, offering extremely rapid, versatile screening by in-situ measurement with accuracy that can rival that of standard laboratory analysis, despite the low detection limits are higher than the limits of detection (LODs) attained by laboratory. Generally elements of atomic number 12 or greater up to elements as Thorium (Th) and Uranium (U) can be detected and quantitated by FPXRF. Detection limits depend on several factors, the analyte of interest, the type of detector used, the type of excitation source, the strength of the excitation source, counting times used to irradiate the sample, physical matrix effects, chemical matrix effects, and interelement spectral interferences. These detection limits are given for guidance only and will vary depending on the sample matrix, which instrument is used, and operating conditions, important for such samples as those considered. (authors)

275

Risk methodology for geologic disposal of radioactive waste: sensitivity analysis of the environmental transport model  

International Nuclear Information System (INIS)

Results are presented from a sensitivity analysis study of a model developed to represent the surface movement of radionuclides. The study has two purposes: (1) to develop a capability to perform sensitivity analyses of the model; and (2) to acquire insight with respect to the variables which influence predictions made by the model. Two variations of a hypothetical river receiving a radionuclide discharge are defined. Independent variables of the following types are introduced: variables which define physical properties of the river system (e.g., soil depth, river discharge and sediment resuspension) and variables which summarize radionuclide properties (i.e., distribution coefficients). The following dependent variables are investigated: (1) radionuclide concentration in soil; (2) dissolved radionuclide concentration in surface-water; and (3) total radionuclide concentration in surface-water. The investigation employs sensitivity analysis techniques based on stepwise regression. This work constitutes part of a project at Sandia National Laboratories funded by the Nuclear Regulatory Commission to develop a methodology to assess the risk associated with geologic disposal of radioactive waste

276

Analysis on the use of engineered barriers for geologic isolation of spent fuel in a reference salt site repository  

International Nuclear Information System (INIS)

A perspective on the potential durability and effectiveness requirements for the waste form, container and other engineered barriers for geologic disposal of spent nuclear fuel has been developed. This perspective is based on calculated potential doses to individuals who may be exposed to radioactivity released from a repository via a groundwater transport pathway. These potential dose commitments were calculated with an integrated geosphere transport and bioshpere transport model. A sensitivity analysis was accomplished by varying four important system parameters, namely the waste radionuclide release rate from the repository, the delay prior to groundwater contact with the waste (leach initiation), aquifer flow velocity and flow path length. The nuclide retarding capacity of the geologic media, a major determinant of the isolation effectiveness, was not varied as a parameter but was held constant for a particular reference site. This analysis is limited to looking only at engineered barriers whose net effect is either to delay groundwater contact with the waste form or to limit the rate of release of radionuclides into the groundwater once contact has occurred. The analysis considers only leach incident scenarios, including a water well intrusion into the groundwater near a repository, but does not consider other human intrusion events or catastrophic events. The analysis has so far been applied to a reference salt site repository system and conclusions are presented.Basically, in nearly all cases, the regional geology is the most effective barrier to release of radionuclides to the biosphere; however, for long-lived isotopes of carbon, technetium and iodine, which were poorly sorbed on the geologic media, the geology is not very effective once a leach incident is initiated

277

Analysis on the use of engineered barriers for geologic isolation of spent fuel in a reference salt site repository  

Energy Technology Data Exchange (ETDEWEB)

A perspective on the potential durability and effectiveness requirements for the waste form, container and other engineered barriers for geologic disposal of spent nuclear fuel has been developed. This perspective is based on calculated potential doses to individuals who may be exposed to radioactivity released from a repository via a groundwater transport pathway. These potential dose commitments were calculated with an integrated geosphere transport and bioshpere transport model. A sensitivity analysis was accomplished by varying four important system parameters, namely the waste radionuclide release rate from the repository, the delay prior to groundwater contact with the waste (leach initiation), aquifer flow velocity and flow path length. The nuclide retarding capacity of the geologic media, a major determinant of the isolation effectiveness, was not varied as a parameter but was held constant for a particular reference site. This analysis is limited to looking only at engineered barriers whose net effect is either to delay groundwater contact with the waste form or to limit the rate of release of radionuclides into the groundwater once contact has occurred. The analysis considers only leach incident scenarios, including a water well intrusion into the groundwater near a repository, but does not consider other human intrusion events or catastrophic events. The analysis has so far been applied to a reference salt site repository system and conclusions are presented.Basically, in nearly all cases, the regional geology is the most effective barrier to release of radionuclides to the biosphere; however, for long-lived isotopes of carbon, technetium and iodine, which were poorly sorbed on the geologic media, the geology is not very effective once a leach incident is initiated.

Cloninger, M.O.; Cole, C.R.; Washburn, J.F.

1980-12-01

278

Dinosaur tectonics : structural geology as a tool to interpret theropod walking dynamics  

DEFF Research Database (Denmark)

A dinosaur trackway in the Middle Jurassic eolian Entrada Sandstone of southern Utah, USA, exposes three undertracks that we have modeled as isolated tectonic regimes showing the development of fold-thrust ramp systems induced by the dinosaur's feet. The faulted and folded sequence is comparable to crustal scale tectonics associated with plate tectonics and foreland fold-thrust belts. A structural analysis of the dinosaur tracks shows the timing and direction of the forces exercised on the substrate by the animal's foot during the stride. Based on the structural analysis, we establish a scenario for foot movements and weight distribution in the feet. During the end of the weight-bearing phase of the stride, the weight of the animal was transferred to the front of the digits, creating a rotated disc below the foot that was bounded by an extensional fault at the front and a thrust ramp toward the back. As the body accelerated, the foot was forced backward. The rotated disc was forced backward along a detachmentfault that was bounded by lateral ramps. The interramp segment matches the width of the dinosaur's foot which created an imbricate fan thrust system that extended to the far end of the undertrack. The total length of the tectonic disturbance created by the dinosaur is up to three times that of the original footprint. Early, near-surface cementation gave the substrate the rheological properties necessary for development of the observed structures.

Graversen, Ole; Milàn, Jesper

2007-01-01

279

Structural and stratigraphic evolution of the central Mississippi Canyon area: Interaction of salt tectonics and slope processes in the formation of engineering and geologic hazards  

Science.gov (United States)

Approximately 720 square miles of digital 3-dimensional seismic data covering the eastern Mississippi Canyon area, Gulf of Mexico, continental shelf was used to examine the structural and stratigraphic evolution of the geology in the study area. The analysis focused on salt tectonics and sequence stratigraphy to develop a geologic model for the study area and its potential impact on engineering and geologic hazards. Salt in the study area was found to be established structural end-members derived from shallow-emplaced salt sheets. The transition from regional to local salt tectonics was identified through structural deformation of the stratigraphic section on the seismic data and occurred no later than ˜450,000 years ago. From ˜450,000 years to present, slope depositional processes have become the dominant geologic process in the study area. Six stratigraphic sequences (I-VI) were identified in the study area and found to correlate with sequences previously defined for the Eastern Mississippi Fan. Condensed sections were the key to the correlation. The sequence stratigraphy for the Eastern Mississippi Fan can be extended ˜28 miles west, adding another ˜720 square miles to the interpreted Fan. A previously defined channel within the Eastern Fan was identified in the study area and extended the channel ˜28 miles west. Previous work on the Eastern Fan identified the source of the Fan to be the Mobile River; however, extending the channel west suggests the sediment source to be from the Mississippi River, not the Mobile River. Further evidence for this was found in ponded turbidites whose source has been previously established as the Mississippi River. Ages of the stratigraphic sequences were compared to changes in eustatic sea level. The formation stratigraphic sequences appear decoupled from sea level change with "pseudo-highstands" forming condensed sections during pronounced Pleistocene sea level lowstands. Miocene and Pleistocene depositional analogues suggest the location of the shifting Mississippi River Pleistocene depocenter is a more dominant influence on sequence formation. Thus, the application of traditional sequence interpretation with respect to sea level change should be reconsidered to also account for the shifting depocenter for both the study area as well as the broader Eastern Mississippi Fan.

Brand, John Richard

280

Major episodes of geologic change - Correlations, time structure and possible causes  

Science.gov (United States)

Published data sets of major geologic events of the past about 250 Myr (extinction events, sea-level lows, continental flood-basalt eruptions, mountain-building events, abrupt changes in sea-floor spreading, ocean-anoxic and blackshale events and the largest evaporite deposits) have been synthesized (with estimated errors). These events show evidence for a statistically significant periodic component with an underlying periodicity, formally equal to 26.6 Myr, and a recent maximum, close to the present time. The cycle may not be strictly periodic, but a periodicity of about 30 Myr is robust to probable errors in dating of the geologic events. The intervals of geologic change seem to involve jumps in sea-floor spreading associated with episodic continental rifting, volcanism, enhanced orogeny, global sea-level changes and fluctuations in climate. The period may represent a purely internal earth-pulsation, but evidence of planetesimal impacts at several extinction boundaries, and a possible underlying cycle of 28-36 Myr in crater ages, suggests that highly energetic impacts may be affecting global tectonics. A cyclic increase in the flux of planetesimals might result from the passage of the Solar System through the central plane of the Milky Way Galaxy - an event with a periodicity and mean phasing similar to that detected in the geologic changes.

Rampino, Michael R.; Caldeira, Ken

1993-01-01

281

Teaching Strain Theory in Structural Geology Using Graphics Programs for the Apple Macintosh Computer.  

Science.gov (United States)

Describes three microcomputer programs that allow geology students to deform two-dimensional images on a computer screen and then to measure changes in angular relationships. Two of the programs simulate pure and simple shear and the third simulates variations in shear strain that occur in shear zones. (ML)

McEachran, David Ballard; Marshak, Stephen

1986-01-01

282

Structured functional principal component analysis.  

Science.gov (United States)

Motivated by modern observational studies, we introduce a class of functional models that expand nested and crossed designs. These models account for the natural inheritance of the correlation structures from sampling designs in studies where the fundamental unit is a function or image. Inference is based on functional quadratics and their relationship with the underlying covariance structure of the latent processes. A computationally fast and scalable estimation procedure is developed for high-dimensional data. Methods are used in applications including high-frequency accelerometer data for daily activity, pitch linguistic data for phonetic analysis, and EEG data for studying electrical brain activity during sleep. PMID:25327216

Shou, Haochang; Zipunnikov, Vadim; Crainiceanu, Ciprian M; Greven, Sonja

2014-10-18

283

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)

284

Structural analysis of vacuum chamber  

International Nuclear Information System (INIS)

Structural analysis of vacuum chamber of an RFP, which consists of thin bellows and straight cylinder is presented. Electro-magnetic force due to eddy currents in a vacuum chamber and a shell is considered. The eddy current induced in the shell rises with characteristic time of plasma current disruption. The eddy current induced in the vacuum chamber reaches its peak value in much shorter time than the shell current. A stress analysis of the chamber is carried out. It is confirmed that a bellows section tends to bulge outward of torus. 8 figs

285

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

286

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

287

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)

288

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

289

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

290

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)

291

Azimuth F inder: a software for data reading in structural geology  

Directory of Open Access Journals (Sweden)

Full Text Available Here is presented a computational tool named AzimuthFinder, for functioning inside the set of programs of ArcGis®. The developed program is intended to facilitate and optimize the generation of azimuth data tables, using structural lineaments previously traced in maps that are being worked on that automatic information system. The characteristics of AzimuthFinder allow that, upon the user’s choice, different tables get generated for the same analysis object, depending on the relative weight attributed to the lineaments, giving for example greater weight to those of greater extension. Another characteristic of the tool is the file exportation in TXT format, which is universal to several types of programs, with specific formatting to one the software between Stereo32, Win Tensor, OpenStereo and StereoNet7, which are all free software prepared to the confection of rose diagrams. Tests with the program showed that it is very efficient and fast for generating the azimuth data tables, effectively allowing easier confection of rose diagrams, which are necessary for the structural analysis in areas submitted to fragile deformation.

Gustavo Lopes Queiroz

2014-03-01

292

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)

293

Geological aspects of radon risk  

International Nuclear Information System (INIS)

Geological factors like geochemistry, structural geology and soil physics controlling radon risk are discussed. A model for estimation of radon risk is proposed and examples from Germany are given. (orig.)

294

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

295

Structural Analysis of Plate Based Tensegrity Structures  

DEFF Research Database (Denmark)

Plate tensegrity structures combine tension cables with a cross laminated timber plate and can then form e.g. a roof structure. The topology of plate tensegrity structures is investigated through a parametric investigation. Plate tensegrity structures are investigated, and a method for determination of the structures pre-stresses is used. A parametric investigation is performed to determine a more optimized form of the plate based tensegrity structure. Conclusions of the use of plate based tensegrity in civil engineering and further research areas are discussed.

Hald, Frederik; Kirkegaard, Poul Henning

2013-01-01

296

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

297

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)

298

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

299

High-heat geodynamic setting during the Palaeozoic evolution of the Mount Painter Province, SA, Australia: evidence from combined field structural geology and potential-field inversions  

Science.gov (United States)

A method for subsurface recognition of blind geological bodies is presented using combined surface constraints and 3-D structural modelling that incorporates constraints from detailed mapping, and potential-field inversion modelling. This method is applied to the Mount Painter Province and demonstrates that addition of low density material is required to reconcile the gravity signature of the region. This method may be an effective way to construct 3-D models in regions of excellent structural control, and can be used to assess the validity of surface structures with 3-D architecture. Combined geological and potential-field constrained inversion modelling of the Mount Painter Province was conducted to assess the validity of the geological models of the region. Magnetic susceptibility constrained stochastic property inversions indicates that the northeast to southwest structural trend of the relatively magnetic meta-sedimentary rocks of the Radium Creek Group in the Mount Painter Inlier is reconcilable with the similar, northeast to southwest trending positive magnetic anomalies in the region. Radium Creek Group packages are the major contributor of the total magnetic response of the region. However field mapping and the results of initial density constrained stochastic property inversion modelling do not correlate with a large residual negative gravity anomaly central to the region. Further density constrained inversion modelling indicates that an additional large body of relatively low density material is needed within the model space to account for this negative density anomaly. Through sensitivity analysis of multiple geometrical and varied potential-field property inversions, the best-fitting model records a reduction in gravity rms misfit from 21.9 to 1.69 mGal, representing a reduction from 56 to 4.5 per cent in respect to the total dynamic range of 37.5 mGal of the residual anomaly. This best-fitting model incorporates a volumetrically significant source body of interpreted felsic, low density material (1012 m3) impinging on the central-west of the Mount Painter Inlier and overlying Neoproterozoic sequences, and the emplacement of more mafic affinities in the northeast and east. The spatial association and circular geometry of these granitoid bodies suggests an affinity with the Palaeozoic ˜460-440 Ma British Empire Granite that outcrops in the Mount Painter Inlier. The intrusion of this additional material in the Palaeozoic could either be the product of; or contributed to, an increased local geotherm and heat flow in the region during the Palaeozoic.

Armit, R. J.; Ailleres, L.; Betts, P. G.; Schaefer, B. F.; Blaikie, T. N.

2014-10-01

300

Geology and structural outline of the Lagoa Real Complex, BA, Brazil  

International Nuclear Information System (INIS)

The Lagoa Real Complex is constituted by 1.7 Ga granitoids that occur along the Paramirim valley. The granitoids are formed by the Sao Timoteo Granite and a set of alkali-gneisses that were crystallized during a compressional sin-metamorphic deformation episode. The carried out structural analysis has identified two deformation patterns. The compressional episode is represented by shear zones, compositional layering, milonite foliation and folds. The extensional episode is characterized by the nucleation of normal shear zones. The geometric patterns of the finite deformation are similar to the ones that occur in the Ituacu synclinal where the Salitre e Bebedouro formations of Una Group outcrop. An ancient geometric pattern was not found in the area; consequently we propose that the deformation episodes were related to the neoproterozoic Orogeny. (author)

301

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

302

Structural analysis of nuclear components  

International Nuclear Information System (INIS)

THe report describes the activities accomplished in the project 'Structural Analysis Project of Nuclear Power Plant Components' during the years 1974-1982 in the Nuclear Engineering Laboratory at the Technical Research Centre of Finland. The objective of the project has been to develop Finnish expertise in structural mechanics related to nuclear engineering. The report describes the starting point of the research work, the organization of the project and the research activities on various subareas. Further the work done with computer codes is described and also the problems which the developed expertise has been applied to. Finally, the diploma works, publications and work reports, which are mainly in Finnish, are listed to give a view of the content of the project. (author)

303

Earthquakes and Geology  

Science.gov (United States)

In this activity, students investigate the relationship between intensity of ground motion and type of rock or alluvium, as seen in the 1994 Northridge, California earthquake. They will examine a map of Mercalli intensity, a cross-section showing geologic structures and rock types, and a map of surficial geology, and answer questions pertaining to amplification of ground motion and S-wave velocities.

Ozsvath, David

304

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.

305

‘Designerly’ Analysis of Participation Structures  

DEFF Research Database (Denmark)

With the inclusion of not only users but stake-holders of many different kinds, design processes turn into complex collaborative challenges. Thus, improving design practices requires research into how people participate and contribute in social interaction. But research methods for understand-ing such activities tend to be highly analytical and hence difficult for design researchers to engage with, if results are meant to be actionable. Through a series of experiments we develop tangible support for a ‘designerly’ interaction analysis of one important aspect of collaborative design activities: the participatory structures.

Buur, Jacob; Beuthel, Maria Rosa

306

The use of microtomography in structural geology: A new methodology to analyse fault faces  

Science.gov (United States)

This paper describes a new methodology to kinematically analyze faults in microscale dimensions (voxel size = 40 ?m), using images obtained by X-ray computed microtomography (?CT). The equipment used is a GE MS8x-130 scanner. It was developed using rocks samples from Santa Catarina State, Brazil, and constructing micro Digital Elevation Models (?DEMs) for the fault surface, for analysing microscale brittle structures including striations, roughness and steps. Shaded relief images were created for the ?DEMs, which enabled the generation of profiles to classify the secondary structures associated with the main fault surface. In the case of a sample with mineral growth that covers the fault surface, it is possible to detect the kinematic geometry even with the mineral cover. This technique proved to be useful for determining the sense of movement of faults, especially when it is not possible to determine striations in macro or microscopic analysis. When the sample has mineral deposit on the surface (mineral cover) this technique allows a relative chronology and geometric characterization between the faults with and without covering.

Jacques, Patricia D.; Nummer, Alexis Rosa; Heck, Richard J.; Machado, Rômulo

2014-09-01

307

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)

308

Geology, structure, and statistics of multi-ring basins on Mars  

Science.gov (United States)

Available data on Martian multi-ring basins were compiled and evaluated using the new 1:15 million scale geologic maps of Mars and global topography was revised as base maps. Published center coordinates and ring diameters of Martian basins were plotted by computer and superimposed onto the base maps. In many cases basin centers or ring diameters or both had to be adjusted to achieve a better fit to the revised maps. It was also found that additional basins can explain subcircular topographic lows as well as map patterns of old Noachian materials, volcanic plains units, and channels in the Tharsis region.

Schultz, Richard A.; Frey, Herbert V.

1990-01-01

309

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 parausion 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

310

Geologic reports used in evaluation of nuclear reactor sites  

International Nuclear Information System (INIS)

More than a decade has passed since the earliest geologic reports relating to proposed nuclear reactor sites were completed. Then, guidelines were few, and the safety analysis was brief and general. Today, the geologic portions of Preliminary Safety Analysis Reports (PSARs) and Final Safety Analysis Reports (FSARs) are by requirement more complex. Through the cooperative efforts of the Nuclear Regulatory Commission (NRC; formerly the Atomic Energy Commission) and the American Nuclear Society, specific seismic and geologic criteria for nuclear plant sites and a standard format for the presentation of data have been developed. These standards and requirements have shifted the emphasis of power plant siting from one that considered mainly the economics of the site and its proximity to the service area, as in the case of fossil fuel plants, to one that gives important consideration to the geologic suitability of the site. Geologic studies of nuclear plant sites require a comprehensive exposition of the areal and structural geology, hydrology, and seismicity in addition to site exploration of engineering-geology and foundation characteristics, which are the major concerns in geologic studies for fossil fuel plants. For each site a design acceleration (g) value must be derived from studies of local and regional geology and seismicity

311

Quantitative analysis of geological samples using energy dispersive x-ray fluorescence  

International Nuclear Information System (INIS)

A quantitative analytical methodology is proposed for geological samples presenting a high fraction of light elements ( atomic number less than 130, using the energy dispersive X-ray fluorescence technique with radioisotopic excitation. The proposed procedure is based on the method of the fundamental parameters for analytical element (Z? 13) evaluation, and coherent and incoherent scattered radiation for the quantitation of the light fraction of the matrix. In this method, standard samples made of pure elements and simple compounds of previously known and superficial density were used to estimate the relationship between the fluorescence intensity and the element concentration through elemental sensitivity and geometric factor for fluorescence. The relationship between scattered intensities and matrix light fraction was based on geometry and scattering factors as well as deferential cross sections. In order to obtain the characteristic x-rays of the elements in the Mn to Zr range a Cd Cd-109 annular radioactive source (1.70 GBq) was used, and for Al to Cr, Fe-55 (0.74 GBq). For the x-ray detection a Si(Li) detector coupled to a multichannel emulation card was employed. The characteristic x-ray net intensity as well as the coherent and incoherent scattered intensities were obtained by using the AXIL software for spectra analysis. To test the proposed procedure, six certified samples (soil-5 / AIEA, SL-2 / AIEA, SARM-2 / SABS, SARM-3 / SABS, SARM-4 / SABS and SARM-6 /ARM-3 / SABS, SARM-4 / SABS and SARM-6 / SABS) were analyzed. The samples were diluted with boric acid in a 1:4 proportion to make pellets with superficial density of approximately 100 mg. cm-2. (author)

312

The analysis of thallium in geological materials by radiochemical neutron activation and x-ray fluorescence spectrometry: a comparison  

Energy Technology Data Exchange (ETDEWEB)

Carrier-based radiochemical neutron activation (RNAA) is a precise and accurate technique for the analysis of Tl in geological materials. For about a decade, until the mid-80s, a procedure modified from Keays et al. (1974) was used at the University of Melbourne to analyse for Tl in a wide variety of geological materials. Samples of powdered rock weighing several hundred milligrams each were irradiated in HIFAR for between 12 hours and 1 week, and subsequently fused with a sodium hydroxide - sodium peroxide mixture and several milligrams of inactive Tl carrier. Following acid digestion of the fusion mixture anion exchange resin was used to separate Tl from the major radioactive rock constituents. The Tl was then stripped from the resin and purified as thallium iodide and a yield measured gravimetrically. Activity from {sup 204}Tl (a {beta}-emitter with a 3 8 year half-life) was measured and Tl determined by reference to pure chemical standards irradiated and processed along with the unkowns. Detection limits for the longer irradiations were about one part per billion. Precision was monitored by repeat analyses of `internal standard` rocks and was estimated to be about five to ten percent (one standard deviation). On the other hand, X-ray fluorescence spectrometry (XRF) was seen as an excellent cost-effective alternative for thallium analysis in geological samples, down to 1 ppm. 6 refs. 1 tab., 1 fig.

McGoldrick, P.J.; Robinson, P. [Tasmania Univ., Sandy Bay, TAS (Australia)

1993-12-31

313

Ground subsidence geo-hazards induced by rapid urbanization: implications from InSAR observation and geological analysis  

Directory of Open Access Journals (Sweden)

Full Text Available Due to the convenient transportation and construction, cities are prone to be situated in areas with flat terrain and unstable sediments, resulting in the concurrence of ground subsidence and urbanization. Here the interaction between geology, anthropogenic processes and ground subsidence geo-hazards were investigated in the Greater Pearl River Delta region of China. Geological evidences and 2006–2010 persistent scatterer data indicate that anthropogenic activities are dominant, although the distribution of river system and Quaternary sediments are also highly related to significant displacements (primarily at a rate of ?15 to 15 mm a?1. The surface displacements derived by synthetic aperture radar interferometry suggest that the urbanization rhythm has to be routinely monitored. Considering analogous urbanization modes, particularly in developing countries, ground subsidence monitoring together with the analysis of its driving force are critical for geo-hazards early-warning, city planning as well as sustainable urbanization.

F. Chen

2012-04-01

314

Geologic guide to the island of Hawaii: A field guide for comparative planetary geology  

Science.gov (United States)

With geological data available for all inner planets except Venus, we are entering an era of true comparative planetary geology, when knowledge of the differences and similarities for classes of structures (e.g., shield volcanoes) will lead to a better understanding of general geological processes, regardless of planet. Thus, it is imperative that planetologists, particularly those involved in geological mapping and surface feature analysis for terrestrial planets, be familiar with volcanic terrain in terms of its origin, structure, and morphology. One means of gaining this experience is through field trips in volcanic terrains - hence, the Planetology Conference in Hawaii. In addition, discussions with volcanologists at the conference provide an important basis for establishing communications between the two fields that will facilitate comparative studies as more data become available.

Greeley, R. (editor)

1974-01-01

315

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

316

Robustness Analysis of Kinetic Structures  

DEFF Research Database (Denmark)

The present paper considers robustness of kinetic structures. Robustness of structures has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. Especially for these types of structural systems, it is of interest to investigate how robust the structures are, or what happens if a structural element is added to or removed from the original structure. The present paper discusses this issue for kinetic structures in architecture.

Kirkegaard, Poul Henning; SØrensen, John Dalsgaard

2009-01-01

317

Sublake geologic structure from high-resolution seismic-reflection data from four sinkhole lakes in the Lake Wales Ridge, Central Florida  

Science.gov (United States)

Seismic-reflection profiles from Lake Wales, Blue Lake, Lake Letta, and Lake Apthorp located along the Lake Wales Ridge in central Florida provide local detail within the regional hydrogeologic framework as described by litho- and hydrostratigraphic cross sections. Lakes located with the mantled karst region have long been considered to be sinkhole lakes, originating from subsidence activity. High-resolution seismic- reflection data confirm this origin for these four lakes. The geologic framework of the Lake Wales Ridge has proven to be a suitable geologic setting for continuous high-resolution seismic-reflection profiling in lakes; however, the nature of the lake-bottom sediments largely controls the quality of the seismic data. In lakes with significant organic-rich bottom deposits, interpretable record was limited to areas where organic deposits were minimal. In lakes with clean, sandy bottoms, the seismic-reflection methods were highly successful in obtaining data that can be correlated with sublake subsidence features. These techniques are useful in examining sublake geology and providing a better understanding of how confining units are affected by subsidence in a region where their continuity is of significant importance to local lake hydrology. Although local geologic control around each lake generally corresponds to the regional geologic framework, local deviations from regional geologic trends occur in sublake areas affected by subsidence activity. Each of the four lakes examined represents a unique set of geologic controls and provides some degree of structural evidence of subsidence activity. Sublake geologic structures identified include: (1) marginal lake sediments dipping into bathymetric lows, (2) lateral discontinuity of confining units including sags and breaches, (3) the disruption and reworking of overlying unconsolidated siliciclastic sediments as they subside into the underlying irregular limestone surface, and (4) sublake regions where confining units appear to remain intact and unaffected by nearby subsidence activity. Each lake likely is underlain by several piping features rather than one large subsidence feature.

Tihansky, A.B.; Arthur, J.D.; DeWitt, D.W.

1996-01-01

318

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

319

Preliminary analysis on cost estimates for high level radioactive waste geological repository  

International Nuclear Information System (INIS)

This paper briefly introduced cost estimates results and the financing system for HLW repositories in some countries. A rough cost estimate was thereafter made and some proposals regarding the finance and current investment were put forwards for China's future HLW geological repository. (authors)

320

Geological reference materials for standardization and quality assurance of instrumental neutron activation analysis  

International Nuclear Information System (INIS)

Results are presented from the INAA of 34 elements in NIST and USGS geological reference materials that were analysed relatively to multielemental SRM-1633a Coal Flyash standards. The data compare favorably with works reported by other investigations. The application of historical control charts for continuous monitoring of quality assurance and detection of systematic errors is demonstrated. (author) 16 refs.; 2 figs.; 7 tabs

321

Construction of Subsurface Geological Structures Using a Drilling Database: A Case Study for an Intra-Arc Basin, the Osaka Plain, Southwest Japan  

Directory of Open Access Journals (Sweden)

Full Text Available Subsurface geological cross sections of 0 - 200 m depth were constructed using a dense drilling database of the Osaka Plain in the intra-arc Osaka Basin of the Japan island arc, an active plate margin. The cross sections revealed the subsurface geological structures and the geometry of folding and faulting in the basin. The comparison between the constructed subsurface cross sections and the seismic sections of the basement and basin fills at a depth of 1500 - 2000 m showed that the basement and shallow subsurface structures are similar; however, the shallow cross sections were of higher resolution than the deep seismic profiles.

Minao Sakurai

2013-04-01

322

Geological characteristics of dike-structural belt in Taoshan orefield and its relationship to uranium deposits  

International Nuclear Information System (INIS)

Taoshan uranium field is occurred in the Taoshan composite batholith in the central Jiangxi Province. The main body of the batholith was formed in Triassic-Early Cretaceous. In Late Cretaceous-Eogene, NE strike fault structure and dike belt were developed in the batholith. From the north to the south, there are successive Xiaobu-Matian dike-structural belt, Wangnitian dike- structural belt, Huangtan-Yueyuan dike-structural belt, Xibei-Shangluo dike-structural belt, Jipoling dike-structural belt, Wangce dike-structural belt and Shiyuanling dike-structural belt. These belts are controlled by the main fault, share the same space and similar time with the uranium mineralization, which is one of the important factors in positioning the uranium ore as well as the prospecting direction of exploration. (authors)

323

Geological Time  

Science.gov (United States)

"Why do engineers need to know about geologic time?" That question is answered in this resource from the University of Saskatchewan's Department of Civil and Geological Engineering. Provided here is a discussion of the concepts of geological time; relative dating methods, such as correlation; and absolute dating methods, such as radiometric methods. Diagrams and charts are included to demonstrate these complex concepts.

324

Safety analysis of an ancient iron structure  

International Nuclear Information System (INIS)

Safety analysis of an ancient iron structure, Danggan, constructed over than a thousand years ago was performed. The structure is consisted of 24 iron cylinders of which the total height is about 15.4 m. The analysis was done by the ultrasonic test to measure thickness of each cylinder, the radiographic test to investigate the inside of cylinders, the measurement of inclination of the structure and the structural analysis to estimate the stress level applied by the wind. Results showed that Danggan structure was on state being well safe at present, but it could be dangerous when the inclination of the structure becomes severely progressive.

325

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

326

Analysis on the use of engineered barriers for geologic isolation of spent fuel  

International Nuclear Information System (INIS)

Results are completed in considerable detail for a reference salt site repository and in somewhat less detail for reference granite, basalt and shale systems. Based on those results, the following conclusions were reached: In nearly all cases, the regional geology is the most effective barrier to release of radionuclides to the biosphere, however, for long-lived isotopes of carbon, technetium and iodine, which were poorly sorbed on the geologic media, the geology is not very effective once a leach incident is initiated. While the need for, and the effectiveness of, a release-rate limiting barrier function is somewhat dependent on the sorption properties of the geologic media, generally a release rate of less than 10-3 yr-1 is necessary to reduce the potential dose from 14C, 99Tc, and 129I to a baseline level below that of the actinides, and beyond that, a rate of less than 10-5 is required before the potential dose from the actinide chains can be further lowered by this mechanism. Only in extreme cases of the intrusion water well scenario is there a direct relationship between release rate from the repository and release to the biosphere. Generally, the delay in leach initiation that an engineered delay function might provide, 104 years or less, is insufficient to accomplish any maximum potential dose reduction. Only the delay provided by a dry, stable geology, 105 years or more can accomplish this. However, in thr more can accomplish this. However, in the extreme and very unlikely case of the water well scenario the maximum potential dose is optimally reduced by a containment function lasting about 400 years. Primary nuclides of concern, in no particular order are 99Tc, 129I, 14C, 226Ra + daughters (U), 237Np (Am, Np) 234U, and for the extreme case of the well scenario, 90Sr

327

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

328

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 assu 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

329

Retroposon analysis and recent geological data suggest near-simultaneous divergence of the three superorders of mammals.  

Science.gov (United States)

As a consequence of recent developments in molecular phylogenomics, all extant orders of placental mammals have been grouped into 3 lineages: Afrotheria, Xenarthra, and Boreotheria, which originated in Africa, South America, and Laurasia, respectively. Despite this advancement, the order of divergence of these 3 lineages remains unresolved. Here, we performed extensive retroposon analysis with mammalian genomic data. Surprisingly, we identified a similar number of informative retroposon loci that support each of 3 possible phylogenetic hypotheses: the basal position for Afrotheria (22 loci), Xenarthra (25 loci), and Boreotheria (21 loci). This result indicates that the divergence of the placental common ancestor into the 3 lineages occurred nearly simultaneously. Thus, we examined whether these molecular data could be integrated into the geological context by incorporating recent geological data. We obtained firm evidence that complete separation of Gondwana into Africa and South America occurred 120 +/- 10 Ma. Accordingly, the previous reported time frame (division of Pangea into Gondwana and Laurasia at 148-138 Ma and division of Gondwana at 105 Ma) cannot be used to validate mammalian divergence order. Instead, we use our retroposon results and the recent geological data to propose that near-simultaneous divisions of continents leading to isolated Africa, South America, and Laurasia caused nearly concomitant divergence of the ancient placental ancestor into 3 lineages, Afrotheria, Xenarthra, and Boreotheria, approximately 120 Ma. PMID:19286970

Nishihara, Hidenori; Maruyama, Shigenori; Okada, Norihiro

2009-03-31

330

Comparison of neutron activation analysis techniques for the determination of uranium concentrations in geological and environmental materials  

International Nuclear Information System (INIS)

We have described the determination of uranium in environmental, geological, and agricultural specimens by three different non-destructive nuclear methods. The effectiveness, as defined as the lower limits of detection in this work, of quantifying trace levels of bulk uranium in geological samples was evaluated for several common NAA techniques. These techniques include short-lived and medium-lived neutron activation analysis using thermal and epithermal neutrons; these results were compared with an assessment of Compton suppressed gamma-ray counting. A careful evaluation of three major (n,?) reactions with chlorine, manganese and sodium that could impede determining low levels of uranium due to high Compton continuums was done. The evaluation of Compton suppressed passive gamma counting revealed that uranium concentrations below 50 mg kg?1 were not adequate to achieve good counting statistics using the 234mPa the second daughter product of 238U. -- Highlights: ? Determination of uranium concentrations in geological, environmental, and agricultural specimens. ? Use of several NAA and passive counting methods. ? Identified several key interferences. ? Use of Compton suppression to minimize effects of interferences

331

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

332

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

333

Seismic response of the geologic structure underlying the Roman Colosseum and a 2-D resonance of a sediment valley  

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Full Text Available The seismic response of the geologic structure beneath the Colosseum is investigated using a two-dimensional modeling for a vertically incident plane SH wave. Computations indicate that the southern part of the Colosseum may be exposed to a seismic ground motion with significantly larger amplitudes, differential motion and longer duration than the northern part. because the southern part of the Colosseum is underlain by a sedimentfilled valley created by sedimentary filling of the former tributary of the River Tiber. A 2-D resonance may develop in the valley. Unlike the previous theoretical studies on 2-D resonance in sediment-filled valleys, an effect of heterogeneous valley surroundings on the resonance is partly investigated. A very small sensitivity of the maximum spectral amplifications connected with the fundamental and first higher modes to the presence of a horizontal surface layer (with an intermediate velocity in the valley surroundings is observed in the studied models.

P. Labak

1995-06-01

334

New insights on shallow and deep crustal geological structures of BABEL line 7 marine reflection seismic data revealed from reprocessing  

Science.gov (United States)

The BABEL project (Baltic And Bothnian Echoes from the Lithosphere) was a collaboration among British, Danish, Finnish, German and Swedish geoscientists to collect deep-crustal reflection and wide-angle refraction profiles in Baltic Shield and Gulf of Bothnia. The acquisition of 2,268km of deep marine reflection seismic data was carried out in 1989. The BABEL line 7 runs in E-W direction in the Bothnian Sea, north of the Åland islands and east of the city of Gävle. Several authors presented the seismic results but with a main focus of imaging and interpreting deep crustal geological structures and the nature and the depth of Moho discontinuity along line 7. Based on this seismic data, several publications about velocity distributions within the crust, the depth and texture of Moho discontinuity and seismic reflectivity patterns in the crust were presented. Some evidence from the reflection seismic data was also presented to suggest Early Proterozoic plate tectonics in the Baltic Shield. Previous seismic images of the BABEL line 7 reflection data show a dramatic change in the reflectivity pattern from weakly reflective lower crust in the west to a more reflective lower crust in the east, which was attributed to a change from a rigid crust to a plastic crust from the west to the east. The BABEL line 7 reflection data were acquired with a total profile length of 174km, a set of 48 airguns towed at 7.5m depth, and 3000m long streamer with 60 channels spaced with 50m intervals and towed at 15m depth. Seismic data were recorded for 25s using 4ms sampling interval and 75m shot interval. Seismic data is characterized by strong source-generated noise at shallow travel times and strong but randomly distributed spurious spikes at later arrival times. In this study, we have recovered and reprocessed the seismic data along BABEL line 7. Using modern processing and imaging techniques, which were not available at the time, and with a focus on the shallow parts of the seismic data, we have managed to reveal reflections as shallow as 1s in the data. Some of these reflections appear to be a continuation of deeper reflections but now they appear to reach to the surface, allowing correlation with the near-surface geology. At least two major moderately dipping shear zones are visible in the reprocessed data in comparison with the previous results. Deeper reflections are also improved which together with the improvements in the shallow parts of the data should allow small-scale geological structures encounter along the BABEL line 7 to be refined.

Shahrokhi, H.; Malehmir, A.; Sopher, D.

2012-04-01

335

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

336

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

337

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)

338

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

339

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

Energy Technology Data Exchange (ETDEWEB)

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.

McKee, E.H.

1998-02-01

340

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

341

Estimation of groundwater flow directions and the tensor of hydraulic conductivity in crystalline massif rocks using information from surface structural geology and mining exploration boreholes  

Science.gov (United States)

In the elaboration of a hydrogeological conceptual model in regions of mining exploration where there is significant presence of crystalline massif rocks., the influence of physical and geometrical properties of rock discontinuities must be evaluated. We present the results of a structural analysis of rock discontinuities in a region of the Central Cordillera of Colombia (The upper and middle Bermellon Basin) in order to establish its hydrogeological characteristics for the improvement of the conceptual hydrogeological model for the region. The geology of the study area consists of schists with quartz and mica and porphyritic rocks, in a region of high slopes with a nearly 10 m thick weathered layer. The main objective of this research is to infer the preferential flow directions of groundwater and to estimate the tensor of potential hydraulic conductivity by using surface information and avoiding the use of wells and packer tests. The first step of our methodology is an analysis of drainage directions to detect patterns of structural controls in the run-off; after a field campaign of structural data recollection, where we compile information of strike, dip, continuity, spacing, roughness, aperture and frequency, we built equal area hydro-structural polar diagrams that indicate the potential directions for groundwater flow. These results are confronted with records of Rock Quality Designation (RQD) that have been systematically taken from several mining exploration boreholes in the area of study. By using all this information we estimate the potential tensor of hydraulic conductivity from a cubic law, obtaining the three principal directions with conductivities of the order of 10-5 and 10-6 m/s; the more conductive joint family has a NE strike with a nearly vertical dip.

Florez, C.; Romero, M. A.; Ramirez, M. I.; Monsalve, G.

2013-05-01

342

Open Plot Project: an open-source toolkit for 3-D structural data analysis  

Directory of Open Access Journals (Sweden)

Full Text Available In this work we present the Open Plot Project, an open-source software for structural data analysis, including a 3-D environment. The software includes many classical functionalities of structural data analysis tools, like stereoplot, contouring, tensorial regression, scatterplots, histograms and transect analysis. In addition, efficient filtering tools are present allowing the selection of data according to their attributes, including spatial distribution and orientation. This first alpha release represents a stand-alone toolkit for structural data analysis.

The presence of a 3-D environment with digitalising tools allows the integration of structural data with information extracted from georeferenced images to produce structurally validated dip domains. This, coupled with many import/export facilities, allows easy incorporation of structural analyses in workflows for 3-D geological modelling. Accordingly, Open Plot Project also candidates as a structural add-on for 3-D geological modelling software.

The software (for both Windows and Linux O.S., the User Manual, a set of example movies (complementary to the User Manual, and the source code are provided as Supplement. We intend the publication of the source code to set the foundation for free, public software that, hopefully, the structural geologists' community will use, modify, and implement. The creation of additional public controls/tools is strongly encouraged.

S. Tavani

2011-05-01

343

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

344

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

Energy Technology Data Exchange (ETDEWEB)

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).

Doll, W.E. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Miller, R.D.; Xia, J. [Kansas Geological Survey, Lawrence, KS (United States)

1997-02-01

345

Determination of rare earth elements in geological sample by Pre-group separation on-neutron activation analysis  

International Nuclear Information System (INIS)

Thirteen rare earth elements in geological sample are determined by neutron activation analysis. The sample is decomposed by acid. The interference elements such as Fe, Sc, Cr, U and Th are removed by Topo-cyclohexane extraction. The rare earth elements are separated and concentrated by passig through D2EHPA-Kel-F Column. After irradiation the concentrate in reactor for 20 hours and waiting for some time, the ?-spectra of activated rare earth elements are measured by program control Ge(Li) ?-spectrometer. The precision of method is less than±15%. The recovery of the separation process is more than 90%

346

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)

347

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)

348

Seismic analysis of sliding structures  

International Nuclear Information System (INIS)

To limit seismic effects, structures may be base isolated. A sliding system located between the structure and the support allows differential motion between them. The aim of this paper is the presentation of the method to calculate the response of the structure when the structure is represented by its eigenmodes, and the sliding phenomenon by the Coulomb friction model. Finally, an application to a simple structure shows the influence on the response of the main parameters (friction coefficient and stiffness)

349

Energy dispersive X-ray fluorescence: quantitative analysis of geological samples  

International Nuclear Information System (INIS)

A quantitative analytical methodology is proposed for geological and intermediates samples presenting a high light fraction elements (atomic number, Z 109 Cd annular radioactive source (1.70 GBq) was used, and for Al to Cr, 55Fe (0.74 GBq). A Si(Li) detector coupled to a multichannel emulation card was employed for the X-ray detection. To test the recommend procedure, three certified samples (Soil-5/IAEA, SL-2/IAEA, SARM-3/SABS) were analyzed. (author)

350

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

351

30 CFR 784.22 - Geologic information.  

Science.gov (United States)

...mining. This description shall include the areal and structural geology of the permit and adjacent areas, and other parameters...reclamation and it shall also show how the areal and structural geology may affect the occurrence, availability,...

2010-07-01

352

X-ray fluorescence analysis of geological samples: exploring the effect of sample thickness on the accuracy of results  

International Nuclear Information System (INIS)

The accuracy of the simple quantitative method of elemental XRF analysis applied to thick and thin geological samples was investigated with certified reference materials. In the case of thick samples, the intensity of the calcium signal was used as a characteristic of the sample for the dark matrix correction, as it had been found to be inversely correlated with the intensity of the silicon signal. The results of the analysis of thick samples did not depend on the sample form (pressed disc or a powder in a cup), and the absorption factors were very high. In the analysis of thin samples, the detection limits, sensitivity, and accuracy have been improved, particularly for light elements. As the absorption factors are close to unity for thin samples, there is no need for a matrix-effect correction or certified reference materials

353

X-ray fluorescence analysis of geological samples: exploring the effect of sample thickness on the accuracy of results  

Energy Technology Data Exchange (ETDEWEB)

The accuracy of the simple quantitative method of elemental XRF analysis applied to thick and thin geological samples was investigated with certified reference materials. In the case of thick samples, the intensity of the calcium signal was used as a characteristic of the sample for the dark matrix correction, as it had been found to be inversely correlated with the intensity of the silicon signal. The results of the analysis of thick samples did not depend on the sample form (pressed disc or a powder in a cup), and the absorption factors were very high. In the analysis of thin samples, the detection limits, sensitivity, and accuracy have been improved, particularly for light elements. As the absorption factors are close to unity for thin samples, there is no need for a matrix-effect correction or certified reference materials.

Al-Merey, R. [Department of Chemistry, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)]. E-mail: ralmerey@aec.org.sy; Karajou, J. [Department of Chemistry, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic); Issa, H. [Department of Chemistry, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)

2005-03-01

354

Heat transfer analysis of the geologic disposal of spent fuel and high-level waste storage canisters  

International Nuclear Information System (INIS)

Near-field temperatures resulting from the storage of high-level waste canisters and spent unreprocessed fuel assembly canisters in geologic formations were determined. Preliminary design of the repository was modeled for a heat transfer computer code, HEATING5, which used the Crank-Nicolson finite difference method to evaluate transient heat transfer. The heat transfer system was evaluated with several two- and three-dimensional models which transfer heat by a combination of conduction, natural convention, and radiation. Physical properties of the materials in the model were based upon experimental values for the various geologic formations. The effects of canister spacing, fuel age, and use of an overpack were studied for the analysis of the spent fuel canisters; salt, granite, and basalt were considered as the storage media for spent fuel canisters. The effects of canister diameter and use of an overpack were studied for the analysis of the high-level waste canisters; salt was considered as the only storage media for high-level waste canisters. Results of the studies on spent fuel assembly canisters showed that the canisters could be stored in salt formations with a maximum heat loading of 134 kw/acre without exceeding the temperature limits set for salt stability. The use of an overpack had little effect on the peak canister temperatures. When the total heat load per acre decreased, the peak temperatures reached in the geologic formations decreased; however, the tlogic formations decreased; however, the time to reach the peak temperatures increased. Results of the studies on high-level waste canisters showed that an increased canister diameter will increase the canister interior temperatures considerably; at a constant areal heat loading, a 381 mm diameter canister reached almost a 500C higher temperature than a 305 mm diameter canister. An overpacked canister caused almost a 300C temperature rise in either case

355

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

356

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

OpenAIRE

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

357

The role of inherited structures in the evolution of the Meknassy Basin, Central Tunisia, based on geological-geophysical transects  

Science.gov (United States)

This paper uses seismic data, well data, and surface geologic data to present a detailed description of the Meknassy Basin in the Atlas fold and thrust belt of central Tunisia. These data reveal that the Meknassy Basin is bounded by major faults, along which Triassic evaporites have been intruded. The anticlines and synclines of the basin are delimited by two N-S main faults (the North-South Axis and the Sidi Ali Ben Oun fault) and are subdivided by associated N120° and N45° trending fault-related anticlines. The Meknassy Basin is characterized by brittle structures associated with a deep asymmetric geometry that is organized into depressions and uplifts. Halokinesis of Triassic evaporites began during the Jurassic and continued during the Cretaceous period. During extensional deformation, salt movement controlled the sediment accumulation and the location of pre-compressional structures. During compressional deformation, the remobilization of evaporites accentuated the folded uplifts. A zone of decollement is located within the Triassic evaporites. The coeval strike-slip motion along the bounding master faults suggests that the Meknassy Basin was initiated as a pull-apart basin with intrusion of Triassic evaporites. The lozenge structure of the basin was caused by synchronous movements of the Sidi Ali Ben Oun fault and the North-South Axis (sinistral wrench faults) with movement of NW-SE first-order dextral strike-slip faults. Sediment distribution and structural features indicate that a major tectonic inversion has occurred at least since Late Cretaceous and Cenozoic. The transpressional movements are marked by reverse faults and folds associated with unconformities and with remobilization of Triassic evaporites. The formation of different structural features and the evolution of the Meknassy Basin and its neighboring uplifts have been controlled by conjugate dextral and sinistral strike-slip movements and thrust displacement.

Haji, Taoufik; Zouaghi, Taher; Boukadi, Noureddine

2014-08-01

358

Structural geology of Qaleh Sorkh-Nowzad fault East of Birjand (Sarbisheh)  

International Nuclear Information System (INIS)

East Iranian structural Belt, one of pre-Cenomanian age. Stratigraphical and lithological evidence indicating the beginning of tensional movements between Iranian and Afghan microcontinents in Early Cretaceous. Thus, creating the sedimentary basins of East Iran and this in turn led to the appearance of the ophiolitie sequence in the area. The alleged ocean, created in this area, was closed during the Late Cretaceous and furthermore, the foreland basins were dominant features throughout the Cenozoic times. Regarding the structural evolution of the area, varying hypotheses have been propounded. But, considering the structural characteristics of the area as. compared to the other parts of the Lut Block, the structural model of the Ghalehsorrh-Nowzad Fault is more feasible solution for the emplacement of the metamorphics as well as the ophiolitic sequences. The latter fault itself is one of the branches of the Neh Main Fault. However, that Segment of Ghalehsorkh-Nawzad Fault in the east of the area of Sarbisheh, 1:100,000 Map is a strike-slip fault with a dextral displacement in its first order class, whereas, occasionally sinistral in its secondary-third orders. the structural evolution of this fault occurred in the Riedel system with positive/negative flower structures in its compressional and tensional parts. The stress mainly concentrating in the junction of different segments and in their tip points. The release of these stresses are likely the cause of the recent easses are likely the cause of the recent earthquakes

359

Tripeptide analysis of protein structures  

OpenAIRE

Abstract Background An efficient building block for protein structure prediction can be tripeptides. 8000 different tripeptides from a dataset of 1220 high resolution (? 2.0°A) structures from the Protein Data Bank (PDB) have been looked at, to determine which are structurally rigid and non-rigid. This data has been statistically analyzed, discussed and summarized. The entire data can be utilized for the building of protein structures. Results Tripeptides hav...

Pennathur Gautam; Anishetty Sharmila; Anishetty Ramesh

2002-01-01

360

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)

361

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

Science.gov (United States)

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(11)n/cm(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. PMID:20236830

El-Taher, A

2010-09-01

362

Mesoscopic Structure of the Punchbowl Fault, Southern California and the Geologic and Geophysical Structure of Active Strike-Slip Faults  

OpenAIRE

We examine the distribution, density, and orientation of outcrop-scale structures related to the Punchbowl Fault, an exhumed ancient trace of the San Andreas Fault, southern California, in order to determine the structure of the fault zone. The Punchbowl Fault has 44 km of right-lateral slip, and cuts the Cretaceous Pelona Schist in the study area. The mesoscopic structures examined include fractures, small faults, and veins; they were inventoried using scan lines at closely spaced stations a...

Schulz, Steven E.; Evans, James P.

2000-01-01

363

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

OpenAIRE

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

364

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

365

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

366

Johnston Geology Museum  

Science.gov (United States)

The Johnston Geology Museum is part of the Emporia State University Earth Science Department. There is an online virtual tour of the collection which includes a Cretaceous mosasaur, a giant ground sloth, mastodon bones and tusk, brachiopods, Paleozoic corals, sedimentary structures, minerals and crystals. The Museum contains geological specimens predominantly from Kansas, and include the world famous Hamilton Quarry Fossil Assemblage, the Tri-State Mining Display, petrified tree stumps, and the Hawkins and the Calkins Indian Artifact Collections.

367

CO2 leakage in a Geological Carbon Sequestration system: Scenario development and analysis.  

OpenAIRE

The aim of this project was to study the leakage of CO2 in a Geological Carbon Sequestration (GCS) system. To define the GCS system, a tool that is known as an FEP database was used. FEPs are the features, processes and events that develop scenarios for the goal of the study. Combinations of these FEPs can produce thousands of scenarios. However, among all of these scenarios, some are more important than others for leakage. The FEPs that were used as scenario developers were the formation of ...

Basirat, Farzad

2011-01-01

368

Analysis of siliceous geologic materials by energy-dispersive X-ray fluorescence  

International Nuclear Information System (INIS)

The determination of the elements Al, Si, K, Ca, Ti, Cr, Mn and Fe in siliceous geologic samples by energy-dispersive X-ray fluorescence is investigated using the most adequate excitation conditions: direct excitation mode (rhodium anode X-ray tube) for the former two elements, and the secondary targets titanium for K and Ca, and germanium for Ti, Cr, Mn and Fe. For the correction of matrix effects the use of ratio methods has been tested. Procedure files have been defined allowing the automatic simultaneous acquisition and processing of spectra. (author)

369

Geologic repository work breakdown structure and dictionary---Development and evaluation phase (PE-02)  

International Nuclear Information System (INIS)

Revision 2 of the OGR Work Breakdown Structure and Dictionary -- Development and Evaluation Phase (PE-02) supersedes Revision 1, August 1989, in its entirety. The revision is to delete the ''Exploratory Shaft Facility'' work scape and replace it with ''Exploratory Studies Facility'' work scape

370

A Simple Device to Aid Plotting of Pi Diagrams in Structural Geology.  

Science.gov (United States)

A simple device that aids in plotting poles to planes on structural equal-area diagrams (pi diagrams) is described. It is used in conjunction with a standard equal area Schmidt net to assist students in understanding principles of plotting pi diagrams and for rapid plotting of large amounts of data. (BC)

Draper, Grenville

1984-01-01

371

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

Science.gov (United States)

Many three-dimensional (3D) 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 2D deformation processes causing these structures are relatively well studied, however, several processes during large-strain 3D deformation are still incompletely understood. One of these 3D processes is the lateral propagation of these structures, such as fold and cusp propagation in a direction orthogonal to the shortening direction or neck propagation in direction orthogonal to the extension direction. We study the 3D 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 3D 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 3D FEM code is applied to model 3D 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 2D numerical results for large amplitudes. The code is further used to study the 3D lateral propagation of folding and viscoplastic necking from an initially localized perturbation and also the lateral propagation of cusps due to initial half graben geometry. Thereby, the small initial geometrical perturbations for folding and necking are exactly followed by the FEM mesh, whereas the initial large perturbation describing a half graben is defined by a contour line intersecting the finite elements, where more numerical integration points are applied in the corresponding elements. Furthermore, the code is applied to study 3D folding in an extensional setting.

von Tscharner, Marina; Schmalholz, Stefan

2013-04-01

372

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

373

Regional gravity analysis of the crustal structure of Tunisia  

Science.gov (United States)

Gravity data were integrated with seismic refraction/reflection data, well data and geological investigations to determine a general crustal structure of Tunisia. The gravity data analysis included the construction of a complete Bouguer gravity anomaly map, residual gravity anomaly maps, horizontal gravity gradient maps and a 2.5-D gravity model. Residual gravity anomaly maps illustrate crustal anomalies associated with various structural domains within Tunisia including the Sahel Block, Saharian Flexure, Erg Oriental Basin, Algerian Anticlinorium, Gafsa Trough, Tunisian Trough, Kasserine Platform and the Tell Mountains. Gravity anomalies associated with these features are interpreted to be caused either by thickening or thinning of Palæozoic and younger sediments or by crustal thinning. Analysis of the residual gravity anomaly and horizontal gravity gradient maps also determined a number of anomalies that may be associated with previously unknown structures. A north-south trending gravity model in general indicated similar subsurface bodies as a coincident seismic model. However, thinner Mesozoic sediments within the Tunisian Trough, thinner Palæozoic sediments in the Gafsa Trough, and a greater offset on the Saharian Flexure were required by the gravity data. Additionally, basement uplifts under the Kasserine Platform and Gafsa Trough, not imaged by seismic data, were required by the gravity data. The gravity model revealed two previously unknown basins north and south of the Algerian Anticlinorium (5 km), while the Erg Oriental Basin is composed of at least two sub-basins, each with a depth of 5 km.

Jallouli, Chokri; Mickus, Kevin

2000-01-01

374

Non-linear analysis of concrete structures  

International Nuclear Information System (INIS)

Work in progress on the inelastic analysis of concrete structures using the finite element method is described. The study serves two objectives, the working stress design and the ultimate load analysis. The distribution of temperature, of particular importance in nuclear structures, is studied. The basis for the non linear analysis of instantaneous deformations is given, based in plasticity theory. Linear and non linear viscoelasticity based in the state variables approach are studied. Several numerical examples are presented. (Author)

375

Estimating the supply and demand for deep geologic CO2 storage capacity over the course of the 21st Century: A meta-analysis of the literature  

Energy Technology Data Exchange (ETDEWEB)

Whether there is sufficient geologic CO2 storage capacity to allow CCS to play a significant role in mitigating climate change has been the subject of debate since the 1990s. This paper presents a meta- analysis of a large body of recently published literature to derive updated estimates of the global deep geologic storage resource as well as the potential demand for this geologic CO2 storage resource over the course of this century. This analysis reveals that, for greenhouse gas emissions mitigation scenarios that have end-of-century atmospheric CO2 concentrations of between 350 ppmv and 725 ppmv, the average demand for deep geologic CO2 storage over the course of this century is between 410 GtCO2 and 1,670 GtCO2. The literature summarized here suggests that -- depending on the stringency of criteria applied to calculate storage capacity – global geologic CO2 storage capacity could be: 35,300 GtCO2 of “theoretical” capacity; 13,500 GtCO2 of “effective” capacity; 3,900 GtCO2, of “practical” capacity; and 290 GtCO2 of “matched” capacity for the few regions where this narrow definition of capacity has been calculated. The cumulative demand for geologic CO2 storage is likely quite small compared to global estimates of the deep geologic CO2 storage capacity, and therefore, a “lack” of deep geologic CO2 storage capacity is unlikely to be an impediment for the commercial adoption of CCS technologies in this century.

Dooley, James J.

2013-08-05

376

Data Fusion: A decision analysis tool that quantifies geological and parametric uncertainty  

International Nuclear Information System (INIS)

Engineering projects such as siting waste facilities and performing remediation are often driven by geological and hydrogeological uncertainties. Geological understanding and hydrogeological parameters such as hydraulic conductivity are needed to achieve reliable engineering design. Information from non-invasive and minimally invasive data sets offers potential for reduction in uncertainty, but a single data type does not usually meet all needs. Data Fusion uses Bayesian statistics to update prior knowledge with information from diverse data sets as the data is acquired. Prior knowledge takes the form of first principles models (e.g., groundwater flow) and spatial continuity models for heterogeneous properties. The variability of heterogeneous properties is modeled in a form motivated by statistical physics as a Markov random field. A computer reconstruction of targets of interest is produced within a quantified statistical uncertainty. The computed uncertainty provides a rational basis for identifying data gaps for assessing data worth to optimize data acquisition. Further, the computed uncertainty provides a way to determine the confidence of achieving adequate safety margins in engineering design. Beyond design, Data Fusion provides the basis for real time computer monitoring of remediation. Working with the DOE Office of Technology (OTD), the author has developed and patented a Data Fusion Workstation system that has been used on jobs at the Hanford, Savannah River, Pantex and Fernald DOE sites. Further applications include an army depot at Letterkenney, PA and commercial industrial sites

377

Data Fusion: A decision analysis tool that quantifies geological and parametric uncertainty  

International Nuclear Information System (INIS)

Engineering projects such as siting waste facilities and performing remediation are often driven by geological and hydrogeological uncertainties. Geological understanding and hydrogeological parameters such as hydraulic conductivity are needed to achieve reliable engineering design. Information form non-invasive and minimal invasive data sets offers potential for reduction in uncertainty, but a single data type does not usually meet all needs. Data Fusion uses Bayesian statistics to update prior knowledge with information from diverse data sets as the data is acquired. Prior knowledge takes the form of first principles models (e.g., groundwater flow) and spatial continuity models for heterogeneous properties. The variability of heterogeneous properties is modeled in a form motivated by statistical physics as a Markov random field. A computer reconstruction of targets of interest is produced within a quantified statistical uncertainty. The computed uncertainty provides a rational basis for identifying data gaps for assessing data worth to optimize data acquisition. Further, the computed uncertainty provides a way to determine the confidence of achieving adequate safety, margins in engineering design. Beyond design, Data Fusion provides the basis for real time computer monitoring of remediation. Working with the DOE Office of Technology (OTD), the authors have developed and patented a Data Fusion Workstation system that has been used on jobs at the Hanford, Savannah Riv used on jobs at the Hanford, Savannah River, Pantex and Fernald DOE sites. Further, applications include an army depot at Letterkenney, PA and commercial industrial sites

378

Data Fusion: A decision analysis tool that quantifies geological and parametric uncertainty  

Energy Technology Data Exchange (ETDEWEB)

Engineering projects such as siting waste facilities and performing remediation are often driven by geological and hydrogeological uncertainties. Geological understanding and hydrogeological parameters such as hydraulic conductivity are needed to achieve reliable engineering design. Information from non-invasive and minimally invasive data sets offers potential for reduction in uncertainty, but a single data type does not usually meet all needs. Data Fusion uses Bayesian statistics to update prior knowledge with information from diverse data sets as the data is acquired. Prior knowledge takes the form of first principles models (e.g., groundwater flow) and spatial continuity models for heterogeneous properties. The variability of heterogeneous properties is modeled in a form motivated by statistical physics as a Markov random field. A computer reconstruction of targets of interest is produced within a quantified statistical uncertainty. The computed uncertainty provides a rational basis for identifying data gaps for assessing data worth to optimize data acquisition. Further, the computed uncertainty provides a way to determine the confidence of achieving adequate safety margins in engineering design. Beyond design, Data Fusion provides the basis for real time computer monitoring of remediation. Working with the DOE Office of Technology (OTD), the author has developed and patented a Data Fusion Workstation system that has been used on jobs at the Hanford, Savannah River, Pantex and Fernald DOE sites. Further applications include an army depot at Letterkenney, PA and commercial industrial sites.

Porter, D.W.

1996-04-01

379

Economic analysis of hydrocarbon exploration by simulation with geological uncertainties (exploratory wells)  

International Nuclear Information System (INIS)

A model was developed to help determine the future development of hydrocarbon reserves. The uncertainties of geological parameters were incorporated into the model in an effort to provide an assessment of the distribution of total hydrocarbon discoveries that are expected to be recovered as a result of exploration activity. The economic parameters were also incorporated into the model in an effort to determine the economic worth of multiple-wells exploration activity. The first part of this study included the geological parameters in the initial field size distribution and the number of fields distribution. Dry hole data was also considered to reflect the exploration risk. The distribution of total hydrocarbon discoveries for a selected number of exploratory wells was determined. The second part of the study included the economic parameters such as the price of oil and gas and the cost of exploration, development and production. The distribution of the number of discoveries and the distribution of total hydrocarbon discoveries was compared to produce a probability distribution of the net present value of a proposed exploration program. The offshore Nova Scotia Shelf basin was chosen for testing the methodology. Several scenarios involving changes in economic parameters were shown. This methodology could help in determining future development programs for hydrocarbon reserves. The methodology can also help governments in policy making decisions regarding taxes and roya making decisions regarding taxes and royalty regimes for exploration programs

380

California Geological Survey: Geologic Maps  

Science.gov (United States)

This index provides access to a selection of geologic maps of California, as well as an overview of geologic and other mapping activities in the state. The index, which can be accessed by clicking on an interactive map of the state, contains lists of selected geologic maps in California prepared by the Regional Geologic Mapping Project (RGMP). The RGMP staff monitors the literature and collects references that contain geologic mapping that may be useful for future compilations. In addition, the site has information about Caltrans Highway Corridor Mapping, The Mineral Resources and Mineral Hazards Mapping Program, North Coast Watersheds Assessment Program, The Timber Harvesting Plan Enforcement Program, and The Seismic Hazards Mapping Program. A set of links is provided to other sources of geologic maps and map information.

381

Structural geology of the proposed site area for a high-level radioactive waste repository, Yucca Mountain, Nevada  

Science.gov (United States)

Geologic mapping and fracture studies have documented the fundamental patterns of joints and faults in the thick sequence of rhyolite tuffs at Yucca Mountain, Nevada, the proposed site of an underground repository for high-level radioactive waste. The largest structures are north-striking, block-bounding normal faults (with a subordinate left-lateral component) that divide the mountain into numerous 1-4-km-wide panels of gently east-dipping strata. Block-bounding faults, which underwent Quaternary movement as well as earlier Neogene movement, are linked by dominantly northwest-striking relay faults, especially in the more extended southern part of Yucca Mountain. Intrablock faults are commonly short and discontinuous, except those on the more intensely deformed margins of the blocks. Lithologic properties of the local tuff stratigraphy strongly control the mesoscale fracture network, and locally the fracture network has a strong influence on the nature of intrablock faulting. The least faulted part of Yucca Mountain is the north-central part, the site of the proposed repository. Although bounded by complex normal-fault systems, the 4-km-wide central block contains only sparse intrablock faults. Locally intense jointing appears to be strata-bound. The complexity of deformation and the magnitude of extension increase in all directions away from the proposed repository volume, especially in the southern part of the mountain where the intensity of deformation and the amount of vertical-axis rotation increase markedly. Block-bounding faults were active at Yucca Mountain during and after eruption of the 12.8-12.7 Ma Paintbrush Group, and significant motion on these faults postdated the 11.6 Ma Rainier Mesa Tuff. Diminished fault activity continued into Quaternary time. Roughly half of the stratal tilting in the site area occurred after 11.6 Ma, probably synchronous with the main pulse of vertical-axis rotation, which occurred between 11.6 and 11.45 Ma. Studies of sequential formation of tectonic joints, in the context of regional paleostress studies, indicate that north- and northwest-striking joint sets formed coevally with the main faulting episode during regional east-northeast-west-southwest extension and that a prominent northeast-striking joint set formed later, probably after 9 Ma. These structural analyses contribute to the understanding of several important issues at Yucca Mountain, including potential hydrologic pathways, seismic hazards, and fault-displacement hazards. ?? 2004 Geological Society of America.

Potter, C.J.; Day, W.C.; Sweetkind, D.S.; Dickerson, R.P.

2004-01-01

382

Geologic structure and altitude of the top of the Minnelusa Formation, northeastern Black Hills, South Dakota  

Science.gov (United States)

This map shows the altitude of the top of the Permian--and Pennsylvanian age Minnelusa Formation, the deepest aquifer in the northeastern Black Hills for which there is sufficient data available to construct a structural map. The Minnelusa Formation outcrops in the western part of the map area and is more than 3 ,600 ft below land surface in the northeastern corner of the area. The formation consists of interbedded sandstone, sandy dolomite and limestone, shale, siltstone, gypsum, and anhydrite. The upper beds are an aquifer and the lower beds are a confining or semi-confining unit. Small anticlines and synclines parallel the Minnelusa outcrop. Domal structures and peaks in the study area are the result of Tertiary-age intrusions. (USGS)

Peter, Kathy D.; Kyllonen, David P.; Mills, Kathy R.

1988-01-01

383

Imaging Geological Structures Up to the Acquisition Surface Using a Hybrid Refraction-Reflection Seismic Method  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of seismic imaging is to reconstruct the reflectivity associated with subsurface structures. In standard imaging techniques, the reflectivity model usually starts a few meters below the surface, the actual depth being dependent on data acquisition parameters and the mute used to remove stretching of first arrivals after normal moveout correction. In this paper, we describe a method to image the reflectivity of near-surface structures starting from the acquisition surface. This is achieved by processing both the first arrivals and the reflected phases present in data collected for refraction surveys. The proposed imaging procedure works in three steps. First, we obtain a velocity model for the shallow region by combining the Plus-Minus method of refraction interpretation with tomographic inversion of first arrival times. Second, by processing reflection events present in the refraction data, we obtain a standard reflectivity section for the deeper region. Finally, we compute reflectivity for the shallow region using the velocity model estimated from first arrival information in step 1. This velocity model is used both to compute reflectivity and to convert it in time. The reflectivity obtained for the shallow region is associated with velocity contrasts. In order to merge it with the reflectivity section for the deeper region a scaling factor between the two sets of reflectivity sections must be computed and applied. The novelty of this contribution is the use the tomographic velocity model in evaluating reflectivity for the upper part of the section. This improves the continuity of information about all near-surface structures in comparison with previous works that were limited to reflection data. Three field examples illustrate the proposed procedure showing continuous information about reflectivity of structures starting from the acquisition surface.

Mendes M.

2013-08-01

384

Automating Structural Analysis of Spacecraft Vehicles  

Science.gov (United States)

A major effort within NASA's vehicle analysis discipline has been to automate structural analysis and sizing optimization during conceptual design studies of advanced spacecraft. Traditional spacecraft structural sizing has involved detailed finite element analysis (FEA) requiring large degree-of-freedom (DOF) finite element models (FEM). Creation and analysis of these models can be time consuming and limit model size during conceptual designs. The goal is to find an optimal design that meets the mission requirements but produces the lightest structure. A structural sizing tool called HyperSizer has been successfully used in the conceptual design phase of a reusable launch vehicle and planetary exploration spacecraft. The program couples with FEA to enable system level performance assessments and weight predictions including design optimization of material selections and sizing of spacecraft members. The software's analysis capabilities are based on established aerospace structural methods for strength, stability and stiffness that produce adequately sized members and reliable structural weight estimates. The software also helps to identify potential structural deficiencies early in the conceptual design so changes can be made without wasted time. HyperSizer's automated analysis and sizing optimization increases productivity and brings standardization to a systems study. These benefits will be illustrated in examining two different types of conceptual spacecraft designed using the software. A hypersonic air breathing, single stage to orbit (SSTO), reusable launch vehicle (RLV) will be highlighted as well as an aeroshell for a planetary exploration vehicle used for aerocapture at Mars. By showing the two different types of vehicles, the software's flexibility will be demonstrated with an emphasis on reducing aeroshell structural weight. Member sizes, concepts and material selections will be discussed as well as analysis methods used in optimizing the structure. Analysis based on the HyperSizer structural sizing software will be discussed. Design trades required to optimize structural weight will be presented.

Hrinda, Glenn A.

2004-01-01

385

Structural geology and mineralization of uranium deposits in the Huianpu area, west of Ordos basin  

International Nuclear Information System (INIS)

The thesis discussed the geotectonic setting of west Ordos basin, classification of structural units, fault-fold belt and structural feature of Majiatan region. Finding the stable segment in the strong structural activation region was used as the overall guidance for the uranium research and exploration, the fore-part of an over-thrust nappe belt was proposed as the favorable segment for uranium mineralization in the west of Ordos basin after several years research and exploration. Two oxidation layers of red and yellow colour was identified which the earlier oxidation was red and later oxidation alteration was yellow. The uranium ore was controlled by these two oxidation layers. The early red oxidized sandstone was experienced post-reformation such as thrust pushover, lifting, erosion and bury, block fault separation, the late yellow oxidation tended to inherit the early red oxidation and carried on the superposition modification distributed along the both wings of anticline. The thesis summarized the uranium features and metallogenic which can be used as the guidance for uranium exploration in the basin. (authors)

386

Special analysis problems associated with the PDX tokamak structural analysis  

International Nuclear Information System (INIS)

The finite element model of the PDX Tokamak contains approximately 15,000 structural members and required the solution of more than 30,000 equations. These figures, by themselves, reveal the large magnitude of the analysis effort but do not indicate the complexity nor uniqueness of the structural analysis problems associated with Tokamak-type structures. Some of these problems are described and discussed. 4 refs

387

ELECTROMAGNETIC ANALYSIS USING METALLIC NANOSHELLED STRUCTURES  

OpenAIRE

This paper reports for the metallic nanoshelled structures with rigorous electromagnetic analysis. Two metallic nanoshelled structures are investigated; namely, single nano-shelled cylinder, and nano-shelled photonic crystals. A rigorous Maxwell’s equations solver is used to get insights into the optical properties of the structures. Our numerical simulations show that it is difficult to shift the plasmon resonance to long wavelength in such a structure. Flat bands are f...

Jha, Sony Kumari And S. C.

2014-01-01

388

Geologic Time.  

Science.gov (United States)

One of a series of general interest publications on science topics, the booklet provides those interested in geologic time with an introduction to the subject. Separate sections discuss the relative time scale, major divisions in geologic time, index fossils used as guides for telling the age of rocks, the atomic scale, and the age of the earth.…

Newman, William L.

389

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

OpenAIRE

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 evalua...

Vavrek Pavol; Sasvári Tibor; ?urove Juraj

1999-01-01

390

Soil gas 222Rn concentration in northern Germany and its relationship with geological subsurface structures  

International Nuclear Information System (INIS)

222Rn in soil gas activity was measured across the margins of two active salt diapirs in Schleswig-Holstein, northern Germany, in order to reveal the impact of halokinetic processes on the soil gas signal. Soil gas and soil sampling were carried out in springtime and summer 2011. The occurrence of elevated 222Rn in soil gas concentrations in Schleswig-Holstein has been ascribed to radionuclide rich moraine boulder material deposits, but the contribution of subsurface structures has not been investigated so far. Reference samples were taken from a region known for its granitic moraine boulder deposits, resulting in 222Rn in soil gas activity of 40 kBq/m3. The values resulting from profile sampling across salt dome margins are of the order of twice the moraine boulder material reference values and exceed 100 kBq/m3. The zones of elevated concentrations are consistent throughout time despite variations in magnitude. One soil gas profile recorded in this work expands parallel to a seismic profile and reveals multiple zones of elevated 222Rn activities above a rising salt intrusion. The physical and chemical properties of salt have an impact on the processes influencing gas migration and surface near radionuclide accumulations. The rise of salt supports the breakup of rock components thus leading to enhanced emanation. This work provides a first approach regarding the halokinetic contribution to the 222e halokinetic contribution to the 222Rn in soil gas occurrence and a possible theoretical model which summarizes the relevant processes was developed. - Highlights: ? 222Rn activity in soil gas was measured across salt structures in northern Germany. ? 222Rn activity ranges up to 105 kBq/m3 across the margins of salt structures. ? Activities caused by moraine boulder material are about 40 kBq/m3. ? We suggest that the salt dome environment has an impact on gas migration. ? A theoretical model was developed which explains the relevant processes.

391

The Baltic Basin: structure, properties of reservoir rocks, and capacity for geological storage of CO2  

Directory of Open Access Journals (Sweden)

Full Text Available Baltic countries are located in the limits of the Baltic sedimentary basin, a 700 km long and 500 km wide synclinal structure. The axis of the syneclise plunges to the southwest. In Poland the Precambrian basement occurs at a depth of 5 km. The Baltic Basin includes the Neoproterozoic Ediacaran (Vendian at the base and all Phanerozoic systems. Two aquifers, the lower Devonian and Cambrian reservoirs, meet the basic requirements for CO2 storage. The porosity and permeability of sandstone decrease with depth. The average porosity of Cambrian sandstone at depths of 80–800, 800–1800, and 1800–2300 m is 18.6, 14.2, and 5.5%, respectivel