WorldWideScience
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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.

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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

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Fundamentals of Structural Geology  

Science.gov (United States)

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

Pollard, David D.; Fletcher, Raymond C.

2005-09-01

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Analysis of effects of geological structures in rock driving by TBM  

Directory of Open Access Journals (Sweden)

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

?udmila Tréfová

2006-12-01

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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.

Marli Miller

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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

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

Science.gov (United States)

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

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

2010-12-01

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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

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Quantitative analysis and geological meaning of spatial distribution patterns of structural lineaments in the Huaibei area  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the method of quantitative analysis of spatial distribution patterns of structural lineaments, quantitatively analyzes the spatial distribution feature of structural lineaments in the Huaibei concealed coalfield, and studies the meanings of the extracted information. At the end, some new understandings about the structural development history and distribution feature of igneous bodies are given. 5 refs., 7 figs.

Wang Silong; Liu Yurong; Yang Xiaoqin; Ning Shunian; Liu Bo; Xi Xiaoting [China University of Mining and Technology (China). Beijing Graduate School

1997-07-01

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Analysis of Siting Criteria of Overseas Geological Repository (I): Geology  

Energy Technology Data Exchange (ETDEWEB)

Geology, hydrogeology, and geochemistry are the main technical siting factors of a geological repository for spent nuclear fuels. This paper focused on how rock's different geological conditions, such as topography, soils, rock types, structural geology, and geological events, influence the functions of the geological repository. In the context, the site selection criteria of various countries were analyzed with respect to the geological conditions. Each country established the criteria based on its important geological backgrounds. For example, it was necessary for Sweden to take into account the effect of ice age on the land uplift and sea level change, whereas Japan defined seismic activity and volcanism as the main siting factors of the geological repository. Therefore, the results of the paper seems to be helpful in preparing the siting criteria of geological repository in Korea.

Jung, Haer Yong; Kim, Hyun Joo; Cheong, Jae Yeol; Jeong, Yi Yeong; Lee, Eun Yong [Korea Radioactive-wate Management Corporation, , Daejeon (Korea, Republic of); Kim, Min Jung [NEXGEO Inc., Seoul (Korea, Republic of)

2012-12-15

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Analysis of Siting Criteria of Overseas Geological Repository (I): Geology  

International Nuclear Information System (INIS)

Geology, hydrogeology, and geochemistry are the main technical siting factors of a geological repository for spent nuclear fuels. This paper focused on how rock's different geological conditions, such as topography, soils, rock types, structural geology, and geological events, influence the functions of the geological repository. In the context, the site selection criteria of various countries were analyzed with respect to the geological conditions. Each country established the criteria based on its important geological backgrounds. For example, it was necessary for Sweden to take into account the effect of ice age on the land uplift and sea level change, whereas Japan defined seismic activity and volcanism as the main siting factors of the geological repository. Therefore, the results of the paper seems to be helpful in preparing the siting criteria of geological repository in Korea.

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Structural Geology Musical Chairs  

Science.gov (United States)

This is a culminating activity designed to have students interpret structures in hand sample. Enough hand samples are chosen for the number of students in the class. Students are given a short amount of time to observe all samples. Music is started and they walk around the samples until the music stops. Each student must then present a description and interpretation of the hand sample in front of them.

Geoffrey Pignotta

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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

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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

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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

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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

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Study on geology on the Mizunami Underground Research Laboratory project. Geology and geological structure from the surface to G.L. -300m  

International Nuclear Information System (INIS)

Japan Atomic Energy Agency (JAEA) is performing the Mizunami Underground Research Laboratory (MIU) Project, which is a scientific study of the deep geological environment as a basis of research and development for geological disposal of high level radioactive wastes (HLW), in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in the fractured crystalline rock. The MIU Project has three overlapping phases, Surface-based investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III), with a total duration of about 20 years. The goals of the MIU Project from Phase I to Phase III are to establish techniques for investigation, analysis and assessment of the deep geological environment, and to develop a range of engineering techniques for deep underground application. Currently, the project is under Phase II and Phase III. One of Phase II goals is set up to develop and revise models of the geological environment using the investigation results obtained during excavation, and to determine and assess changes in the geological environment in response to excavation. This report aims compiling results of study on geology and geological structure from the surface to G.L. -300m in the Phase II and provides the fundamental information on the geology and geological structure for future study. This report are utilized in the updating of the geological models in the Phase II. (author)

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Geological structure and hydrogeologic conditions of the Herlany geyser structure (Eastern Slovakia  

Directory of Open Access Journals (Sweden)

Full Text Available Analysis of new geological data from the surroundings of Herlany resulted in a new concept of geological structure and partly also of Herlany geyser`s mechanism. The concept in based on freatic water percolation and saturation by carbon dioxide ascending along faults into the water - bearing and sealed collector in Upper Badenian sequence.

Magyar Július

1996-12-01

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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

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Geologic analysis of Devonian Shale cores  

Energy Technology Data Exchange (ETDEWEB)

Cleveland Cliffs Iron Company was awarded a DOE contract in December 1977 for field retrieval and laboratory analysis of cores from the Devonian shales of the following eleven states: Michigan, Illinois, Indiana, Ohio, New York, Pennsylvania, West Virginia, Maryland, Kentucky, Tennessee and Virginia. The purpose of this project is to explore these areas to determine the amount of natural gas being produced from the Devonian shales. The physical properties testing of the rock specimens were performed under subcontract at Michigan Technological University (MTU). The study also included LANDSAT information, geochemical research, structural sedimentary and tectonic data. Following the introduction, and background of the project this report covers the following: field retrieval procedures; laboratory procedures; geologic analysis (by state); references and appendices. (ATT)

none,

1982-02-01

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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

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Analysis of the natural radioactivity of coal from the Upper Silesian Coal Basin: Aspect of geological structure  

International Nuclear Information System (INIS)

Systematic investigations of the concentrations of the natural radionuclides 226Ra and 228Ra in Polish coal from the Upper Silesian Coal Basin (USCB) reveal that they are lower than average world values. Significant differences in radionuclide concentrations in various layers and various regions were observed, with the highest values being recorded in the south and southwestern parts of the USCB. There were also significant differences in the natural radioactivity of carboniferous coal from various lithological and stratigraphical series. In Upper Silesian sandstone series (Namur B), the lowest concentration of 226Ra was 6 Bq/kg and for 228Ra it was 5 Bq/kg. These values are much lower than similar values in overlying (Namur C + Westphal A, B, C) and below underlying (Namur A) coal. The Namur B structure in the USCB is completely different from Namur C + Westphal A, B, C and Namur A, this feature showing up mainly in the predominance of sandstone and of conglomerates over mudstones. The concentrations were much lower than concentrations measured in the overlying and underlying mudstone layers. The types of admixtures of coexisting waste rocks affect the natural radioactivity of coal, though the effect is different for various stratigraphical parts depending on the character of the accompanying strata. Differences in the 226Ra (uranium series) and 228Ra (thorium series) concentrations in mudstone complexseries) concentrations in mudstone complexes in the Namur B and Namur C + Westphal A, B, C layers result from various sedimentation conditions, while the differences in natural radioactivity in various regions of the USCB probably depend on different geological structure and different tectonics. A map of the natural radioactivity of coal in various stratigraphical layers is given. Some results of the natural radioactivity of coal have been already published: the paper further extends this work. (author). 10 refs, 4 figs

23

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

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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.

Ben van der Pluijm

25

Iapetus: Tectonic structure and geologic history  

Science.gov (United States)

Many papers have been written about the surface of Iapetus, but most of these have discussed either the nature of the strongly contrasting light and dark materials or the cratering record. Little has been said about other geologic features on Iapetus, such as tectonic structures, which would provide constraints on Iapetus' thermal history. Most references have suggested that there is no conclusive evidence for any tectonic activity, even when thermal history studies indicate that there should be. However, a new study of Iapetus' surface involving the use of stereo pairs, an extensive tectonic network has been recognized. A few new observations concerning the craters and dark material were also made. Thus the geology and geologic history of Iapetus can be more fully outlined than before. The tectonic network is shown along with prominent craters and part of the dark material in the geologic/tectonic sketch map. The topology of crater rims and scarps are quite apparent and recognizable in the different image pairs. The heights and slopes of various features given are based on comparison with the depths of craters 50 to 100 km in diameter, which are assumed to have the same depths as craters of similar diameter on Rhea and Titania.

Croft, Steven K.

1991-01-01

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Analysis of the characteristics appearing in LANDSAT multispectral images in the geological structural mapping of the midwestern portion of the Rio Grande do Sul shield. M.S. Thesis - 25 Mar. 1982; [Brazil  

Science.gov (United States)

The central-western part of Rio Grande do Sul Shield was geologically mapped to test the use of MSS-LANDSAT data in the study of mineralized regions. Visual interpretation of the images a the scale of 1:500,000 consisted, in the identification and analysis of the different tonal and textural patterns in each spectral band. After the structural geologic mapping of the area, using visual interpretation techniques, the statistical data obtained were evaluated, specially data concerning size and direction of fractures. The IMAGE-100 system was used to enlarge and enhance certain imagery. The LANDSAT MSS data offer several advantages over conventional white and black aerial photographs for geological studies. Its multispectral characteristic (band 6 and false color composition of bands 4, 5 and 7 were best suitable for the study). Coverage of a large imaging area of about 35,000 sq km, giving a synoptical view, is very useful for perceiving the regional geological setting.

Parada, N. D. J. (principal investigator); Ohara, T.

1982-01-01

27

Structural effects of C{sub 60}{sup +} bombardment on various natural mineral samples-Application to analysis of organic phases in geological samples  

Energy Technology Data Exchange (ETDEWEB)

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 C{sub 60}{sup +} sputter beam and a 25 keV Bi{sub 3}{sup +} analysis beam, oil-bearing inclusions in different minerals were opened and analysed individually. However, sputtering with a C{sub 60}{sup +} 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 C{sub 60}{sup +} 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 C{sub 60}{sup +} 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 (<15 {mu}m) could potentially become entirely covered by sputter-resistant structures and therefore difficult to open. Therefore, it might become necessary, to for example increase the ion energy and rotate the stage to successfully open smaller inclusions for analysis. SIMS, C{sub 60}, carbon deposition, topography, mineral, fluid inclusions, geological samples, depth profiling.

Siljestroem, S., E-mail: sandra.siljestrom@sp.se [Department of Chemistry and Materials Technology, SP Technical Research Institute of Sweden, Box 857, 501 15 Boras (Sweden); Department of Geological Sciences, Stockholm University, 106 91 Stockholm (Sweden); Lausmaa, J.; Hode, T. [Department of Chemistry and Materials Technology, SP Technical Research Institute of Sweden, Box 857, 501 15 Boras (Sweden); Sundin, M. [YKI, Institute for Surface Chemistry, 114 86 Stockholm (Sweden); Sjoevall, P. [Department of Chemistry and Materials Technology, SP Technical Research Institute of Sweden, Box 857, 501 15 Boras (Sweden)

2011-08-15

28

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.

29

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

30

Neutron activation analysis of geological material  

International Nuclear Information System (INIS)

In neutron activation analysis the precision and accuracy of results are often misleading, since only the statistical errors which accompany the measuring of radioactivity are taken into consideration. Several other factors can, however, also influence precision and accuracy. It was found that a geological sample was contaminated with the construction material of the mill in which it had been pulverised. Several geometrical differences which could possibly play a role were also investigated. Impurities in the irradiation containers affect the determination of some elements in the samples; the contamination materials in quarts irradiation tubes were determined. The flux gradients which may effect the relative activities of the samples and standards were measured. Suitable standards are necessary to ensure accurate analyses of geological material. Available natural standards were critically evaluated and several methods were investigated by which synthetic standards may be prepared. In order to accurately determine gallium, lanthanum and samarium by means of neutron activation analysis, sodium first had to be removed. After irradiation the sample was dissolved in a mixture of acids and the soidium absorbed from the solution on a hydrated antimony pentoxide column. Gallium, lanthanum and samarium activities were measured by means of precision gamma-spectrometry

31

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

32

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

33

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

34

Geology  

International Nuclear Information System (INIS)

This chapter summarizes the geology of the single-shell tank (SST) farms in the context of the region's geologic history. This chapter is based on the information in the geology data package for the SST waste management areas and SST RFI Appendix E, which builds upon previous reports on the tank farm geology and Integrated Disposal Facility geology with information available after those reports were published

35

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

36

Initial phases for the development of a Structural Geology database  

Science.gov (United States)

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

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

2014-05-01

37

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".

Lawrence Malinconico

38

Geologic Analysis of Priority Basins for Exploration and Drilling  

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-04-27

39

Expandable tubulars for use in geologic structures  

Science.gov (United States)

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

40

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

41

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.)

42

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

International Nuclear Information System (INIS)

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

43

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

Science.gov (United States)

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

Wellmann, Florian; Jessell, Mark

2014-05-01

44

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

45

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

46

X-ray fluorescent analysis in industry and geology  

International Nuclear Information System (INIS)

An optimization method was developed for finding the optimal filter materials and filter thickness in x-ray fluorescence analysis used in industry and geology. Soules' method was applied to calculate and fit the filtration parameters. Some characteristic results obtained by the new method and equipment are reported. (D.Gy.)

47

Neutron activation analysis of osmium in geological samples  

International Nuclear Information System (INIS)

A neutron activation analysis procedure was developed for the determination of osmium in geological materials. The method consists in the measurement of the 129.4 keV ?-rays of 191Os after radiochemical separation of osmium. The sample decomposition, the chemical separation process and the optimal measuring conditions are described and discussed. (author)

48

Integrating remote sensing and magnetic data for structural geology investigation in pegmatite areas in eastern Afghanistan  

Science.gov (United States)

This study used an integrated approach to investigate pegmatite areas in eastern Afghanistan. The analysis of surface data, including a digital elevation model (DEM), and Landsat Enhanced Thematic Mapper Plus (ETM+) images, was combined with airborne magnetic data to better understand three-dimensional geology in the area. The ETM+ and DEM data were used to map geological structures at the surface, which indicate that the area consists of two main fault systems that trend NNE and E-W. The two trends represent the remnants of reactivated structures that formed under the stress regimes generated during the tectonic evolution of eastern Afghanistan. Magnetic data indicate an NE-SW trending basin. A two-dimensional schematic model shows that the basin gradually deepens toward the SW with depths to the magnetic basement ranging between 2 and 11.5 km. The integration of the results gave new insight into the tectonic evolution and structure patterns near the pegmatites area.

Salehi, Ratib; Saadi, Nureddin M.; Khalil, Ahmed; Watanabe, Koichiro

2015-01-01

49

Engineering geological maps: A cost-benefit analysis  

Science.gov (United States)

This paper describes an eight-step procedure designed for cost-benefit analyses concerning the preparation of engineering geological maps in general. This procedure is discussed in relation to engineering geological maps of Amsterdam as an example of an old city with many historical buildings. From the results of this analysis, it is concluded that the breakeven point will be reached in 3.2 years if only the costs of site investigation and archive searches are taken into account, and in less than 1.2 years if potential savings due to improved site selection are included.

de Mulder, E. F. J.

1990-07-01

50

Risk Analysis and Safety Assessment of Tunnel Geologic Hazard in Karst Areas  

Directory of Open Access Journals (Sweden)

Full Text Available In order to find out the problems of tunnel geological hazard in karst areas during the construction, each risk sources which were influencing the safety of tunnel construction in karst region were relatively comprehensive analyzed based on the typical karst tunnel project of Daguangnan highway in Hubei province. And it carried out the qualitative risk analysis of tunnel geologic hazards. Then, one hierarchical structure model was established to give the relative weights of safety to each risk sources during the tunnel construction in karst region. Furthermore, the multilevel comprehensive safety assessment was carried out based on the fuzzy comprehensive evaluation method. Through the risk analysis and safety assessment of tunnel geologic hazard in karst areas, it is great significance for the correct evaluation of tunnel surrounding rock stability and construction safety.

Ke Wu

2014-12-01

51

Risk analysis of geological disposal of radioactive waste  

International Nuclear Information System (INIS)

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

52

Thermal Analysis Of Geologic High-Level Radioactive Waste Packages  

International Nuclear Information System (INIS)

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

53

THERMAL ANALYSIS OF GEOLOGIC HIGH-LEVEL RADIOACTIVE WASTE PACKAGES  

Energy Technology Data Exchange (ETDEWEB)

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

Hensel, S.; Lee, S.

2010-04-20

54

The Impact of Geological Structures On The Gravity Field  

Science.gov (United States)

In general, a uniform standard density value is used for the calculation of topographic effects for gravity field modelling in Switzerland. Only a limited number of promi- nent mass anomalies is treated with an individual density. In some regions this causes problems in predicting the surface gravity or the deflections of the vertical. An actual example is the construction of a new 57 km railway tunnel, where accurate deflec- tions of the vertical are needed for the orientation of gyroscope measurements. It was rather doubtful if our standard national gravity field model would fulfil the accuracy demands. Therefore, a refinement of the gravity field model was performed by digi- tising all the relevant geological structures in the vicinity of the planned tunnel. This lead to a 3D density model of irregularly shaped polyhedrons. Their influence on the gravity field (potential, gravity, deflections of the vertical and their first derivatives) are calculated rigorously. First results of this study are now available and reveal that the influences of the geological structures on the deflections of the vertical and on gravity are rather small (1 - 2 arcsec, 3 - 5 mgal) in the investigated region and they are at the limit of significance for the technical applications of levelling or gyroscope mea- surements. The largest effects are caused by quaternary sediments with a large density contrast and by some gneiss structures, which show only a small density contrast but their total mass can cause considerable anomalies in the gravity field.

Marti, U.

55

Computer methods for geological analysis of radiometric data  

International Nuclear Information System (INIS)

Whether an explorationist equates anomalies with potential uranium ore deposits or analyses radiometric data in terms of their relationships with other geochemical, geophysical, and geological data, the anomaly or anomalous zone is the most common starting point for subsequent study or field work. In its preliminary stages, the definition of meaningful anomalies from raw data is a statistical problem requiring the use of a computer. Because radiometric data, when properly collected and reduced, are truly geochemical, they can be expected to relate in part to changes in surface or near-surface geology. Data variations caused strictly by differences in gross chemistry of the lithologies sampled constitute a noise factor which must be removed for proper analysis. Texas Instruments Incorporated has developed an automated method of measuring the statistical significance of data by incorporating geological information in the process. This method of computerized geological analysis of radiometric data (CGARD) is similar to a basic method of the exploration geochemist and has been proved successful in its application to airborne radiometric data collected on four continents by Texas Instruments Incorporated. This beginning and its natural follow-on methods of automated or interpretive analysis are based simply on the perception of radiometric data as sets of statistically distributed data in both the frequency and spatial domains. (author)thor)

56

The EVEREST project: sensitivity analysis of geological disposal systems  

International Nuclear Information System (INIS)

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

57

Hydrogeologic role of geologic structures. Part 2: analytical models  

Science.gov (United States)

This paper is the second of two papers that address the influence of geologic structures on ground water flow at various scales in fractured rocks. The ultimate purpose of this research is to investigate the feasibility of grouting preferentially permeable zones as a strategy to minimize the production of acid mine drainage in underground hard rock mines in which the major permeability is structure and fracture controlled. The aim of grouting is to reduce permeability around mined-out openings, to minimize the rate of inflow of ground water into such openings via the structurally controlled preferentially permeable pathways. A series of hydraulic stress tests were conducted to help characterize the role of geologic structures in controlling the ground water flow system in the vicinity of the Bunker Hill Mine in north Idaho. The results of these tests indicate that most of the ground water that flows from the underground drillholes used for hydraulic stress testing is derived from a few discrete, structurally produced fracture zones that are more or less connected through smaller-scale fractures. Four types of analytical models are considered as a means of analyzing the results of multiple drillhole hydraulic stress tests, as follows: cross-hole equivalent porous media; double-porosity equivalent porous media; a solution to flow in and around a single vertical fracture; leaky equivalent porous media, partial penetration. The estimation of hydraulic coefficients in complex fractured rock environments involves the combined application of a number of deterministic analytical models. The models to be used are selected dependent on the location of the drawdown observations relative to the water-producing zone and the length of the test. The result of the tests can be related to the permeability hierarchy discussed in our first paper.

Levens, Russell L.; Williams, Roy E.; Ralston, Dale R.

1994-04-01

58

Problems of solidificated radioactive wastes burial into deep geological structures  

International Nuclear Information System (INIS)

Perspectives are noted of the radioactive wastes burial into deep geopogical structures. For these purposes it has been proposed to investigate severap types of rocks, which do not have intensive gas-generation when beeng heated; salt deposits and clays. Basing on the results of calculations it has been shown that the dimentions of zones of substantial deformations in the case of the high-level radioactive wastes burial to not exceed several hundreds of meters. Conclusion is made that in the case of choosing the proper geotogicat structure for burial and ir the case of inclusion in the structure of the burial site a zone of sanitary alienation, it is possible to isolate wastes safely for all the period of preservation. Preliminary demands have been formulated to geological structures and underground burial sites. As main tasks for optimizatiop of burial sited are considered: determination of necessary types, number and reliability of barriers which ensure isolation of wastes; to make prognoses of the stressed and deformed state of a geological massif on the influence of thermal field; investigation in changes of chemical and physical properties of rocks under heat, radiative and chemical influence; estimation of possible diffusion of radioactivity in a mountin massif; development of a rational mining-thechnological schemes of the burual of wastes of different types. A row of tasks in the farmeworks of this probtem are sotved successfutty. Some resutts are given of theuccessfutty. Some resutts are given of the theoretical investigations in determination of zones of distructions of rocks because of heat-load

59

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)

60

Uncertainty analysis for geologic disposal of radioactive waste  

International Nuclear Information System (INIS)

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

61

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

International Nuclear Information System (INIS)

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

62

Geologic structure in California: Three studies with ERTS-1 imagery  

Science.gov (United States)

Results are presented of three early applications of imagery from the NASA Earth Resources Technology Satellite to geologic studies in California. In the Coast Ranges near Monterey Bay, numerous linear drainage features possibly indicating unmapped fracture zones were mapped within one week after launch of the satellite. A similar study of the Sierra Nevada near Lake Tahoe revealed many drainage features probably formed along unmapped joint or faults in granitic rocks. The third study, in the Peninsular Ranges, confirmed existence of several major faults not shown on published maps. One of these, in the Sawtooth Range, crosses in Elsinore fault without lateral offset; associated Mid-Cretaceous structures have also been traced continuously across the fault without offset. It therefore appears that displacement along the Elsinore fault has been primarily of a dip-slip nature, at least in this area, despite evidence for lateral displacement elsewhere.

Lowman, P. D., Jr.

1974-01-01

63

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

64

Geology of the Upheaval Dome impact structure, southeast Utah  

Science.gov (United States)

Two vastly different phenomena, impact and salt diapirism, have been proposed for the origin of Upheaval Dome, a spectacular scenic feature in southeast Utah. Detailed geologic mapping and seismic refraction data indicate that the dome originated by collapse of a transient cavity formed by impact. Evidence is as follows: (1) sedimentary strata in the center of the structure are pervasively imbricated by top-toward-the-center thrust faulting and are complexly folded as well; (2) top-toward-the-center normal faults are found at the perimeter of the structure; (3) clastic dikes are widespread; (4) the top of the underlying salt horizon is at least 500 m below the surface at the center of the dome, and there are no exposures of salt or associated rocks of the Paradox Formation in the dome to support the possibility that a salt diapir has ascended through it; and (5) planar microstructures in quartz grains, fantailed fracture surfaces (shatter surfaces), and rare shatter cones are present near the center of the structure. We show that the dome formed mainly by centerward motion of rock units along listric faults. Outcrop-scale folding and upturning of beds, especially common in the center, are largely a consequence of this motion. We have also detected some centerward motion of fault-bounded wedges resulting from displacements on subhorizontal faults that conjoin and die out within horizontal bedding near the perimeter of the structure. The observed deformation corresponds to the central uplift and the encircling ring structural depression seen in complex impact craters. Copyright 1999 by the American Geophysical Union.

Kriens, B.J.; Shoemaker, E.M.; Herkenhoff, K.E.

1999-01-01

65

Investigation of oil and gas geology structure exploration using CR-39 detector  

International Nuclear Information System (INIS)

Rn distribution on oil and gas field at Saihuntala of Inner Mongol is measured with CR-39. The experimental results show that Rn anomalous distribution is consistent with oil and geology structure. The mechanism of the information of oil and gas geology structure obtained from Rn anomalous distribution is discussed

66

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

67

Development and improvement of safety analysis code for geological disposal  

International Nuclear Information System (INIS)

In order to confirm the long-term safety concerning geological disposal, probabilistic safety assessment code and other analysis codes, which can evaluate possibility of each event and influence on engineered barrier and natural barrier by the event, were introduced. We confirmed basic functions of those codes and studied the relation between those functions and FEP/PID which should be taken into consideration in safety assessment. We are planning to develop 'Nuclide Migration Assessment System' for the purpose of realizing improvement in efficiency of assessment work, human error prevention for analysis, and quality assurance of the analysis environment and analysis work for safety assessment by using it. As the first step, we defined the system requirements and decided the system composition and functions which should be mounted in them based on those requirements. (author)

68

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.

69

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

70

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

71

Geological and Geophysical aspects of the Kurdashi structure, Azerbaijan  

International Nuclear Information System (INIS)

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

72

Use of structural geology in exploration for and mining of sedimentary rock-hosted Au deposits  

Science.gov (United States)

Structural geology is an important component in regional-, district- and orebody-scale exploration and development of sedimentary rock-hosted Au deposits.Identification of timing of important structural events in an ore district allows analysis and classification of fluid conduits and construction of genetic models for ore formation.The most practical uses of structural geology deal with measurement and definition of various elements that comprise orebodies, which can then be directly applied to ore-reserve estimation,ground control,grade control, safety issues,and mine planning.District- and regional-scale structural studies are directly applicable to long-term strategic planning,economic analysis,and land ownership. Orebodies in sedimentary rock-hosted Au deposits are discrete, hypogene, epigenetic masses usually hosted in a fault zone,breccia mass, or lithologic bed or unit. These attributes allow structural geology to be directly applied to the mining and exploration of sedimentary rock-hosted Au deposits. Internal constituents in orebodies reflect unique episodes relating to ore formation.The main internal constituents in orebodies are ore minerals, gangue, and alteration minerals that usually are mixed with one another in complex patterns, the relations among which may be used to interpret the processes of orebody formation and control.Controls of orebody location and shape usually are due to structural dilatant zones caused by changes in attitude, splays, lithologic contacts,and intersections of the host conduit or unit.In addition,conceptual parameters such as district fabric,predictable distances, and stacking also are used to understand the geometry of orebodies.Controls in ore districts and location and geometry of orebodies in ore districts can be predicted to various degrees by using a number of qualitative concepts such as internal and external orebody plunges,district plunge, district stacking, conduit classification, geochemical, geobarometric and geothermal gradients, and tectonic warps. These concepts have practical and empirical application in most mining districts where they are of use in the exploration for ore, but are of such broad and general application that they may not represent known or inferred ore formation processes. Close spatial relation among some sedimentary rock- hosted Au deposits and their host structures suggests that the structures and the orebodies are genetically linked because they may have shared the same developmental history. Examples of probable syn-deformational genesis and structural control of sedimentary rock-hosted Au deposits are in the large Betze deposit in the Carlin trend, Nevada and in the Lannigou, Jinlongshan, and Maanqiao Au deposits, China.

Peters, Stephen G.

2001-01-01

73

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

Science.gov (United States)

The 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

74

Neutron sources for activation analysis of geological materials  

International Nuclear Information System (INIS)

The success of neutron activation analysis is frequently determined by the intensity, homogeneity and stability of the neutron flux. Thermal neutron fluxes of1012 n.cm-2.s-1 are routinely achieved in research reactors, while small accelerators of the Cockroft-Walton type are able to produce fluxes on the order of 109 n.cm-2.s-1 using the deuterium-tritium fusion reaction. Isotopic neutron sources based upon spontaneous fission, (?,n) or (d,n) reactions produce fluxes of from 103 to 106 n.cm-2.s-1. The reactor, the accelerator and isotope sources each have advantages and disadvantages, and each has been used successfully in the analysis of geologic materials. (L.L.)

75

Analysis of integrated geologic data for uranium exploration in Egypt  

International Nuclear Information System (INIS)

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

76

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

Science.gov (United States)

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

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

2013-12-01

77

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

78

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)

79

A new fast multi-domain BEM to model seismic wave propagation and amplification in 3D geological structures  

OpenAIRE

The analysis of seismic wave propagation and amplification in complex geological structures raises the need for efficient and accurate numerical methods. The solution of the elastodynamic equations using traditional boundary element methods (BEMs) is greatly hindered by the fully-populated nature of the matrix equations arising from the discretization. In a previous study limited to homogeneous media, the present authors have established that the Fast Multipole (FM) method reduces the complex...

Chaillat, Ste?phanie; Bonnet, Marc; Semblat, Jean-franc?ois

2009-01-01

80

Geological images  

Science.gov (United States)

This site from Marli Bryant Miller, a professor at the University of Oregon, presents images of geological features from around the world. Photographs of glacial features, igneous and metamorphic rocks and processes, and structural geology are featured.

Marli Bryant Miller

81

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.)

82

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

International Nuclear Information System (INIS)

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

83

Geology, structure and uranium mineralisation in Kulu, Himachala Himalaya  

International Nuclear Information System (INIS)

Uranium mineralisation as uraninite vein filling is seen in joints and fractures in the quartzites exposed within an eroded cover of crystallines, tectonically thrust from east and NE in Kulu-Banjar area of Himachal Pradesh. Analysis of the joints suggests a tensional origin and can be related to the three main folding events identified from the fold structure in the quartzites. It is believed that the mineralisation is essentially under low temperature-pressure conditions as there is a remarkable absence of large scale wallrock alternation. U-Pb dating of six uraninite samples reveals two distinct episodes of mineralisation at 1200-m.y. and 700 m.y. confirming the Precambrian age of uranium mineralisation and associated metasediments. (author)

84

The Serra da Cangalha impact structure, Brazil: Geological, stratigraphic and petrographic aspects of a recently confirmed impact structure  

Science.gov (United States)

Serra da Cangalha is a complex impact structure with an apparent diameter of 13.7 km located in essentially undisturbed sedimentary rocks of the Parnaíba basin in northeastern Brazil. The stratigraphy of the crater region includes, from bottom to top, the Longá, Poti, Piauí and Pedra de Fogo formations of Devonian to Late Permian age. The age of the impact event is constrained to Serra da Cangalha into four distinctive structural domains (i-iv), from the innermost zone outward. (i) The central domain, with an inner collar ˜1.5 km radius from the center, yielded all the samples with microscopic shock features identified so far. These include planar deformation features (PDF), feather features (FF), and planar fractures (PF) in quartz grains found in polymict breccias and shatter cones from the central depression. Furthermore, significant cementation with iron oxide is observed in the rocks of Serra da Cangalha, especially in the Poti Formation and in the polymict breccias, conferring to them a peculiar red color. Macroscopic deformation involves faulted, folded and subvertical strata within a ˜2.9 km radius from the center. (ii) The annular basin domain has limited outcrops; its most prominent features are two concentric annular ridges formed by chert breccias and fossilized wood-bearing folded strata of the Pedra de Fogo Formation. (iii) The crater rim and (iv) external domains comprise undisturbed strata of the Pedra de Fogo and Piauí formations with well-preserved sedimentary structures. Whilst the existing literature on Serra da Cangalha has focused on the structure morphology, general geology and some shock features, we present here a detailed description of the stratigraphy and the geology of each formation in the interior and around Serra da Cangalha, as well as further detailed microscopic shock feature analysis. This provides significant evidence that the rocks of the central uplift have undergone shock pressures of, at maximum, 10 GPa.

Vasconcelos, Marcos Alberto Rodrigues; Crósta, Alvaro P.; Reimold, Wolf Uwe; Góes, Ana Maria; Kenkmann, Thomas; Poelchau, Michael H.

2013-08-01

85

Relation of geological structure to seismicity at Pahute Mesa  

International Nuclear Information System (INIS)

Some of the abundant and unique geological and seismological data acquired at the Nevada Test Site are integrated with the objectives of (1) resolving some of the ambiguity in explanations of the source of aftershocks of nuclear explosions, and (2) demonstrating the value of using detailed geological and seismological data to infer realistic source parameters of earthquakes. The distribution of epicenters of aftershocks from nuclear explosions at Pahute Mesa suggests that they are related to faults or intersections of faults in the buried ring-fracture zones of calderas rather than to the conspicuous basin-and-range faults exposed at the surface. Histograms of fault length show clearly that faults in a basin-and-range regime differ significantly in length, median length, and distribution of length from faults in a caldera regime. A histogram of fault lengths derived from magnitudes of aftershocks shows both the median and distribution characteristics of caldera faults rather than of basin-and-range faults. Cumulative frequency-fault length-squared plots also show differences in the two fault regimes, and have slopes, herein called bf slopes, of -0.89 and -1.08 for caldera and basin-and-range faults, respectively. The bf slopes are similar to the average slope of a cumulative frequency-strain plot for aftershocks rather than to the b slopes for cumulative frequency-magnitude plots. Although the significance of b and bf slopes and differences between them are not resolvnd differences between them are not resolved clearly, it is concluded that the fault length and strain data reflect dimensions of seismic sources rather than energy of seismic events. The principal conclusion of the investigation is that the most obvious geology of a seismically active area may not provide the proper basis for inferring seismic-source parameters

86

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

87

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.

88

Analysis on geological condition for uranium-polymetal metallization in Bayangshan downfaulted volcanic basin in Xinbaerhuyouqi  

International Nuclear Information System (INIS)

Bayangale downfaulted volcanic basin locates in the same metallogenic area with Er Nuote orefield of Mongolia in China-Russia-Mongolia uranium-polymetal metallogenic belt, and has the similar geological conditions with the Streltsovskoye uranium orefield in Russian. Through investigating the basement, cover rock, uranium content of rocks, structure and uranium-polymetal mineralization in the areas, the basin was believed to bear the geologic structural setting and fairly good condition for volcanic-type uranium -polymetall mineralization. (authors)

89

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)

90

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)

91

Analysis of naturally produced technetium and plutonium in geologic materials.  

Science.gov (United States)

In uncontaminated natural materials, plutonium and technetium exist exclusively as products (daughters) of nuclear reactions in which uranium is the principal reactant (parent). Under conditions of chemical stability over geologic periods of time, the relative abundances of daughter and parent elements are fixed by the rates of nuclear reactions and the decay of the daughter radionuclide. The state of this nuclear secular equilibrium condition is the primary basis of the geochemical study of these elements in nature. Thus, it is critical that nuclear parent and daughter abundances are measured in the same sample. We have developed a quantitative procedure for measuring subpicogram quantities of plutonium and technetium in gram quantities of geologic matrices such as uranium ores. The procedure takes advantage of the aggressive properties of sodium peroxide/hydroxide fusion to ensure complete dissolution and homogenization of complex materials, the precision provided by isotope dilution techniques, and the extreme sensitivity offered by thermal ionization mass spectrometry. Using this technique, a quantitative aliquot can be removed for uranium analysis by isotope dilution thermal ionization mass spectrometry or ? spectrometry. Although the application of the procedure is unique, the analytical concepts may find more general application in studies of environmental contamination by nuclear materials. To assess the precision and accuracy of the analytical results, blanks and standards were analyzed routinely for a 1-year period to ensure quality control of our sample analyses. The average technetium blank is 5 ± 4 fg (n = 8), and that for plutonium is 0.17 ± 0.15 pg (n = 7). Thus, the detection limit for technetium (defined as 3 times the standard deviation of the average blank) is 11 fg, and that for plutonium is 0.44 pg. To assess the procedural precision, Canadian Reference Material BL-5 was analyzed routinely with samples. The results of seven replicate analyses for technetium in this standard reference material yield a technetium concentration of 59.0 fg/g, with a remarkably small standard deviation of 0.6 fg, 1.0% of the average value. The results of six replicate analyses for the concentration of plutonium in BL-5 give 1.012 pg/g, with an equally small standard deviation of 0.016, 1.6% of the average value. No direct measure of accuracy can be done on the technetium or plutonium analyses, because no standard reference material exists for these elements. To help constrain the accuracy of our measurements, equilibrium technetium/uranium and plutonium/uranium abundances were calculated using the nuclear reaction code MCNP. For technetium, such calculations are relatively insensitive to variations in model parameters, and measurements fall within a 21% high/low bias. For plutonium, the calculations are very sensitive to model parameters and hence inherently less precise. Indirectly, spike and isotope mix calibrations made from weighted quantities of certified isotopes (both technetium and plutonium) can be used to determine the bias of the measurement system for these elements. These calibrations show that the measurement system is biased by no more than ±1.5%. PMID:21639292

Dixon, P; Curtis, D B; Musgrave, J; Roensch, F; Roach, J; Rokop, D

1997-05-01

92

The uranium potential of Greenland - A geological analysis of favourability  

International Nuclear Information System (INIS)

The potential for uranium deposits in Greenland is estimated on the basis of the following criteria: (1) the land areas, not covered by inland ice are 340,000 km2, and geologically extremely well exposed; (2) the geological history ranges from the early Archaean to the Quaternary, and a wide range of geological environments and lithologies are present; (3) the level of geological information is generally of a high quality, but the information is heterogeneous; (4) uranium exploration up to the present is mainly of a reconnaissance nature and it has only covered a part of Greenland; (5) only one major uranium deposit is at present known. It is concluded that the area with the highest potential is found in south Greenland and encompasses the early to middle Proterozoic mobile belt and the middle Proterozoic suite of Gardar alkaline igneous plutons. The high favourability of these units is supported by data from recent exploration work in the area as well as by radiometric data of an earlier date. In particular Ketilidian metasedimentary units, and the Ketilidian and post-Ketilidian country rocks of some of the Gardar complexes appear favourable. In view of the limited exploration work carried out, the early Proterozoic mobile belt in north central Greenland as well as the Proterozoic crystalline basement and the overlying suprastrata of the Thule Group in north-west Greenland are classified as being of medium favourability. Further exploration is required witility. Further exploration is required within these areas. (author)

93

Geologic structure mapping database Spent Fuel Test - Climax, Nevada Test Site  

Energy Technology Data Exchange (ETDEWEB)

Information on over 2500 discontinuities mapped at the SFT-C is contained in the geologic structure mapping database. Over 1800 of these features include complete descriptions of their orientations. This database is now available for use by other researchers. 6 references, 3 figures, 2 tables.

Yow, J.L. Jr.

1984-12-04

94

Geologic structure mapping database Spent Fuel Test - Climax, Nevada Test Site  

International Nuclear Information System (INIS)

Information on over 2500 discontinuities mapped at the SFT-C is contained in the geologic structure mapping database. Over 1800 of these features include complete descriptions of their orientations. This database is now available for use by other researchers. 6 references, 3 figures, 2 tables

95

Finite element modeling of long-term fluid-structure interaction problems in geological media  

Energy Technology Data Exchange (ETDEWEB)

A model is developed to predict long-term thermal creep and creep rupture in geological structures under multiaxial stress states and under elevated temperature conditions. An example of the method is given showing the behavior of the crust and mantle while undergoing intrusion by a low density diaper. (ACR)

Anderson, C.A.

1980-01-01

96

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

International Nuclear Information System (INIS)

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

97

Indian geological repository programme  

International Nuclear Information System (INIS)

The paper presents some important components of Indian concept for geological disposal of radioactive waste. Comparative merits and limitations of few major rock types viz. basalts, argillaceous rocks and granites as natural barrier of a deep geological repository evaluated through laboratory based studies are discussed. Some of their engineering geological, rock mechanical and hydraulic properties obtained through Geographic Information System based geo-structural studies coupled with geophysical and borehole based investigation are also elaborated. A conceptual layout of geological repository has been developed and analyzed for optimization of dimension of disposal tunnels and pits, their spacing, depth and geometry. It also presents few salient results on thermo-mechanical analysis of reference disposal tunnels and pits of geological repository. (author)

98

Probabilistic Structural Analysis Program  

Science.gov (United States)

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

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

2010-01-01

99

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

International Nuclear Information System (INIS)

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

100

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)

101

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)

102

A Combined Structural Geology and GIS Approach to Rockslides: an Example from Western Norway  

Science.gov (United States)

The western coast of Norway presents an ideal area to study active rockslide development due to the recent post-glacial uplift. This study presents the preliminary results of a combined GIS-structural geology approach to the examination of a potentially catastrophic rockslide in the Romsdalen area of western Norway, a mountainous area, despite being well populated, that is particularly vulnerable to rockslides. Svarttinden is a 1600m high mountain lying on a 12-1300m plateau 1km from the southern edge of the Romsdalen Valley. Recent landslide activity from the mountain side under investigation is evinced by the presence of a debris fan, which has been previously dated at c.5000BP. The rockslide removed in the region of 5 millions m3 of rock material. The purpose of this study was to determine the cause of the previous slide and evaluate the likelihood of further rockslides from the same mountainside by applying GIS and structural geology. Preliminary investigations have shown that the mountain is dissected by a north-south trending, steeply-dipping brittle fault. This has acted as a transfer fault, delimiting the western extent of the palaeo-rockslide. The palaeo-rockslide failed along a single, flat-lying (30-35°) down-slop dipping brittle fault. Remnants of a fault breccia up to 20cm are found on this surface. Evidence exists for shearing on this structure and we consider this a major fault plane (MFP), along which the rockslide has occurred. SEM examination of the microstructures present in this fault gouge will be presented. The western half of this mountain, which lies to the east of the major north-south transfer fault, is underlain by the same low-angle fault gouge. The volume of the rock mass above this MFP is approximately 7 millions m3. Several other low-angle structures are present above the MFP, further weakening the rockmass. Up to several metres of down-slope displacement is observed on these structures. High angle tension fractures are abundant in the mountainside above the MFP, detaching down onto it. These structures increase in frequency and displacement downslope. The low-angle fault planes lie sub-parallel to a local, shallowly north-dipping foliation in the gneissic host-rocks and appear to be localized along fold discontinuities within the gneisses. These folds appear to have acted as a significant 'locking mechanism' for movement along the failure planes as evidence is seen for fault tip-zones buttressing against the high angle southern limbs of these folds and reverse high angle fault structures in the fold axial planes, representing local vertical extension as opposed to downslope shearing. Local ramp structures in the MFP led to the increased frequency of high-angle tension fractures. This suggests that the geometry of the MFP is probably a significant factor in changing the degree of fracturing of the potential rockslide rockmass and therefore may have an affect on the continuity of the rockmass prior to failure. To estimate the volume above the MFP a potential sliding surface was inferred in 3D from field observations and the concept of "sloping local base level" (SLBL). Using a digital terrain model, the SLBL permits to define a surface above which the rocks are assumed erodible (Jaboyedoff 2004). Then the spatial distribution of the shear stress on the sliding plane and the energy of propagation of blocks can be estimated and introduced in a GIS for hazards assessment and zoning. References Jaboyedoff, M., Baillifard, F., Couture, R., Locat, J., and Locat, P. 2004: Toward preliminary hazard assessment using DEM topographic analysis and simple mechanic modeling.

Henderson, I.; Derron, M. H.; Jaboyedoff, M.

2004-12-01

103

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

104

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

105

The structural-geological map of the Emilia-Romagna Apennines (1:250.000)  

Science.gov (United States)

The Structural-Geological Map of the Emilia-Romagna Apennines (1:250.000) faces problems regarding the polyphase structural evolution of the Emilia-Romagna sector of the Northern Apennines; in many cases the proposed solutions are unconventional and innovative. The Structural-Geological Map represents the result of a positive collaboration between the scientific community (Italian National Research Council and universities) and the Emilia-Romagna Region. The scientific results and the methodological planning have been presented on the Third Seminary on the Geological Cartography (Bologna, February 2002). In the Structural-Geological Map the deformative features (overthrusts, axial planes, fold axes, regional overturned limbs) belonging to the Alpine tectonic cycle (Mesoalpine Phase) have been separated from the deformations of the Apenninic tectonic cycle. The Mesoalpine tectonics has been split in two events (Late Paleocene-Early Eocene and Middle Eocene) and it has been connected to a geodynamic setting consistent with a eastward subduction and a westernward emplacement (i.e. toward the Europe continental margin) of the cover structural units (Ligurides) (Late Paleocene-Early Eocene early phase). At the end of the collisional process, the Middle Eocene phase (Ligurian Phase) controlled the development of an Adria-verging asymmetrical belt, antithetic to the Alpine belt of the Western Alps-Corsica sector. The exumation of the Mesoalpine stacking during the Early Oligocene, testified by the detritism in the episutural Oligocene basins (thrust top basins), marks the transition from the Alpine tectonic cycle to the Apenninic one. The polyphase evolution of the Northern Apennines is recorded in the siliciclastic successions of the Oligocene-Miocene foredeep (Macigno, Cervarola, Marnoso-Arenacea formations). The foredeep final structure represents a regional duplex structure (synorogenic duplex) outcropping in the tectonic halfwindow of the Romagna Apennines (Romagna eroded duplex). The transverse tectonic line known as Sillaro Line, that many authors believe to be a transcurrent or a tear fault, in the Structural-Geological Map has been simply considered as the overthrusting surface of the Ligurides onto the Miocene foredeep (Marnoso-Arenacea Formation); the transverse trend is only due to the northwesternward axial plunging of the Northern Apennines. Thus the “Sillaro Line” represents a natural cross-section of the Emilia-Romagna Apennines. At upper structural levels, the time scanning of the Apenninic cycle is expressed by the thrust top basin evolution which is interrupted by several unconformities representing the sedimentary record of the progressive overthrusting of the thrust belt-front onto the foredeep successions. The western part of the synorogenic duplex was dissected by a system of longitudinal out of sequence thusts; their activity, probably Villafranchian in age, becomes very important as regards the seismicity of the Apenninic ridge. The out of sequence thust system is inserted in a transpressive kinematic model (dextral transpression) that has been considered to be the responsible of the Miocene tectonics of the Northern Apennines. The Structural-geological Map has been supplemented with geological cross-sections (scale 1:100.000), explanatory notes and stratigraphical tables; these latter provide the regional stratigraphical informations that a synthetic map such as the Structural-Geological Map of the Emilia-Romagna Apennines (1:250.000) cannot represents.

Cerrina Feroni, A.; Ottria, G.; Martinelli, P.; Martelli, L.; Catanzariti, R.

2003-04-01

106

Analysis of seismological and geological observations formoderate-size earthquakes: the Colfiorito Fault System(Central Apennines, Italy)  

Science.gov (United States)

To contribute to the understanding of the relationships between moderate earthquakes and the faults that are recognizable in the geological record, we analysed seismological and geological data related to the 1997-1998 Umbria-Marche (Central Italy) earthquake swarm. The seismological recordings, collected by local networks, allowed accurate location of about 1000 events, whereas the geological field observations provided a picture of the structural features and the ground-surface deformations. We also re-examined and used some published data and results, mostly about the fault plane solutions and the geology. On the basis of earthquake locations, fault plane solutions, and geological mapping we explored the possible correlation between the earthquake causative fault planes and the normal faults exposed in the area. Our results show that the two main shocks that occurred on 1997 September 26 (MW=5.7 and MW=6.0) originated on the same structure, reactivating at depth the Colfiorito normal faults. Neither rupture propagated up to the ground surface, but both triggered gravitational sliding that occurred along pre-existing fault scarps. The earthquake that occurred on 1997 October 14 (MW=5.6) originated on another fault branch at a much shallower depth. In spite of its lower magnitude, this earthquake produced tectonic ruptures where the fault plane projects to the surface in an area where no faults were previously mapped. By comparing the palaeostress reconstruction, based on slickenside lineation analysis, and the focal mechanism solutions, we suggest a possible correlation between the long-term (Early Middle Pleistocene) cumulative effects of the Colfiorito Fault System and the short-term behaviour of the fault planes observed during this earthquake swarm, favouring the idea of a seismogenic source producing clustered moderate-size earthquakes rather than large events scattered in time.

Barba, Salvatore; Basili, Roberto

2000-04-01

107

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

108

Uncertainty analysis for 3D geological modeling using the Kriging variance  

Science.gov (United States)

The credible estimation of geological properties is critical in many geosciences fields including the geotechnical engineering, environmental engineering, mining engineering and petroleum engineering. Many interpolation techniques have been developed to estimate the geological properties from limited sampling data such as borehole logs. The Kriging is an interpolation technique that gives the best linear unbiased prediction of the intermediate values. It also provides the Kriging variance which quantifies the uncertainty of the kriging estimates. This study provides a new method to analyze the uncertainty in 3D geological modeling using the Kriging variance. The cut-off values determined by the Kriging variance were used to effectively visualize the 3D geological models with different confidence levels. This presentation describes the method for uncertainty analysis and a case study which evaluates the amount of recoverable resources by considering the uncertainty.

Choi, Yosoon; Choi, Younjung; Park, Sebeom; Um, Jeong-Gi

2014-05-01

109

Mineral target areas in Nevada from geological analysis of LANDSAT-1 imagery  

Science.gov (United States)

Geological analysis of LANDSAT-1 Scene MSS 1053-17540 suggests that certain known mineral districts in east-central Nevada frequently occur near faults or at faults or lineament intersections and areas of complex deformation and flexures. Seventeen (17) areas of analogous characteristics were identified as favorable targets for mineral exploration. During reconnaissance field trips eleven areas were visited. In three areas evidence was found of mining and/or prospecting not known before the field trips. In four areas favorable structural and alteration features were observed which call for more detailed field studies. In one of the four areas limonitic iron oxide samples were found in the regolith of a brecciated dolomite ridge. This area contains quartz veins, granitic and volcanic rocks and lies near the intersection of two linear fault structures identified in the LANDSAT-1 imagery. Semiquantitative spectroscopic analysis of selected portions of the samples showed abnormal contents of arsenic, molybdenum, copper, lead, zinc, and silver. These limonitic samples found were not in situ and further field studies are required to assess their source and significance.

Abdel-Gawad, M.; Tubbesing, L.

1975-01-01

110

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)

111

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

112

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

113

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

Science.gov (United States)

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

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

1988-01-01

114

Changing concepts of geologic structure and the problem of siting nuclear reactors: Examples from Washington State  

Science.gov (United States)

The conflict between regulation and healthy evolution of geological science has contributed to the difficulties of siting nuclear reactors. On the Columbia Plateau in Washington, but for conservative design of the Hanford reactor facility, the recognition of the little-understood Olympic-Wallowa lineament as a major, possibly still active structural alinement might have jeopardized the acceptability of the site for nuclear reactors. On the Olympic Peninsula, evolving concepts of compressive structures and their possible recent activity and the current recognition of a subducting Juan de Fuca plate and its potential for generating great earthquakes—both concepts little-considered during initial site selection—may delay final acceptance of the Satsop site. Conflicts of this sort are inevitable but can be accommodated if they are anticipated in the reactor-licensing process. More important, society should be increasing its store of geologic knowledge now, during the current recess in nuclear reactor siting.

Tabor, R. W.

1986-09-01

115

Changing concepts of geologic structure and the problem of siting nuclear reactors: examples from Washington State  

International Nuclear Information System (INIS)

The conflict between regulation and healthy evolution of geological science has contributed to the difficulties of siting nuclear reactors. On the Columbia Plateau in Washington, but for conservative design of the Hanford reactor facility, the recognition of the little-understood Olympic-Wallowa lineament as a major, possibly still active structural alignment might have jeopardized the acceptability of the site for nuclear reactors. On the Olympic Peninsula, evolving concepts of compressive structures and their possible recent activity and the current recognition of a subducting Juan de Fuca plate and its potential for generating great earthquakes - both concepts little-considered during initial site selection - may delay final acceptance of the Satsop site. Conflicts of this sort are inevitable but can be accommodated if they are anticipated in the reactor-licensing process. More important, society should be increasing its store of geologic knowledge now, during the current recess in nuclear reactor siting

116

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

117

Determination of tungsten in geologic materials by neutron activation analysis  

International Nuclear Information System (INIS)

A method is described for the determination of tungsten in geologic materials. After fusion with sodium peroxide, tungsten is isolated by extraction into chloroform with ?-benzoinoxime, back extraction into aqueous potassium hydroxide, and precipitation with ?-benzoinoxime. The activities of the 0.13- and 0.48- MeV gamma rays are measured. The activity of the 0.155-MeV gamma ray of 188Re (188W), added prior to the fusion, is measured to determine the yield; yields normally range from 40 to 90 percent. The coefficients of variation for less than part-per-million concentrations of tungsten are normally less than 20 percent; the limit of detection is 0.005 ppM for a 100-mg sample. (U.S.)

118

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)

119

Structural genomics: Computational methods for structure analysis  

OpenAIRE

The success of structural genomics initiatives requires the development and application of tools for structure analysis, prediction, and annotation. In this paper we review recent developments in these areas; specifically structure alignment, the detection of remote homologs and analogs, homology modeling and the use of structures to predict function. We also discuss various rationales for structural genomics initiatives. These include the structure-based clustering of sequence space and geno...

Goldsmith-fischman, Sharon; Honig, Barry

2003-01-01

120

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

OpenAIRE

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 ch...

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

2008-01-01

121

Structural geology mapping using PALSAR data in the Bau gold mining district, Sarawak, Malaysia  

Science.gov (United States)

The application of optical remote sensing data for geological mapping is difficult in the tropical environment. The persistent cloud coverage, dominated vegetation in the landscape and limited bedrock exposures are constraints imposed by the tropical climate. Structural geology investigations that are searching for epithermal or polymetallic vein-type ore deposits can be developed using Synthetic Aperture Radar (SAR) remote sensing data in tropical/sub-tropical regions. The Bau gold mining district in the State of Sarawak, East Malaysia, on the island of Borneo has been selected for this study. The Bau is a gold field similar to Carlin style gold deposits, but gold mineralization at Bau is much more structurally controlled. Geological analyses coupled with the Phased Array type L-band Synthetic Aperture Radar (PALSAR) remote sensing data were used to detect structural elements associated with gold mineralization. The PALSAR data were used to perform lithological-structural mapping of mineralized zones in the study area and surrounding terrain. Structural elements were detected along the SSW to NNE trend of the Tuban fault zone and Tai Parit fault that corresponds to the areas of occurrence of the gold mineralization in the Bau Limestone. Most of quartz-gold bearing veins occur in high-angle faults, fractures and joints within massive units of the Bau Limestone. The results show that four deformation events (D1-D4) in the structures of the Bau district and structurally controlled gold mineralization indicators, including faults, joints and fractures are detectable using PALSAR data at both regional and district scales. The approach used in this study can be more broadly applicable to provide preliminary information for exploration potentially interesting areas of epithermal or polymetallic vein-type mineralization using the PALSAR data in the tropical/sub-tropical regions.

Pour, Amin Beiranvand; Hashim, Mazlan

2014-08-01

122

Altitude-Slope Relationships For Each Geology in Accretionary Complex Based on GIS Analysis  

Science.gov (United States)

Quantitative analysis with DEMs based on GIS (Geographic Information System) is a valid method to prove relationships among slope angle, altitude and bedrock geology. This paper discusses the relations among slope angle, geology, and altitude in two regions (Chubu and Kinki) in the Shimanto belt that is Cretaceous to Paleogene accretionary zone at the outer zone of Southwest Japan. Those relations are often compared in these areas for these clear reliefs. We particularly investigated the altitude-slope relationship for each geological unit (e.g. sandstone-dominant, mudstone-dominant, sandstone-mudstone alternation), because of the strong dependence of the slope angle on the altitude has already been indicated for the Southern Japanese Alps. In Chubu region, all of altitude-slope relationships for each geological unit show that the slope angle in lower altitude zones (= ca. 800 m) are relatively constant. Mean slope angles in higher altitude zones are different according to bedrock geology but most of them are between 28 and 35 degrees. In contrast, Paleogene mudstone-dominant Mikura Groups have lower slope angles in high altitude zones. This area correspond to the geology types with markedly low slope angles indicating that the susceptibility to slow gravitational landslides accounts for the variation in the slope angle. In Kinki region, all of altitude-slope relationships for each geological unit show that the slope angle in lower altitude zones (= ca. 500 m) are relatively constant. Mean slope angles in higher altitude zones are different according to bedrock geology but most of them are between 20 and 25 degrees. In contrast, Paleogene mudstone-dominant Otonashigawa Groups have lower slope angles in high altitude zones. This area, similarly in Chubu region, correspond to the geology types with markedly low slope angles indicating that the susceptibility to slow gravitational landslides accounts for the variation in the slope angle. As a result, most terrains in the study area have similar altitude-slope relationships irrespective of bedrock geology indicating that geology plays a relatively minor role in determining slope angles. Terrains underlain by some specific rocks, however, are highly susceptible to slow gravitational landslides and thus have markedly reduced slope angles than other terrains with similar altitudes. Among terrains underlain by rocks with equivalent ages, mudstone-dominant areas tend to have slightly lower slope angles than sandstone-dominant areas. This observation is also ascribable to the higher landslide susceptibility of mudstone.

Kawabata, D.; Okada, A.

2001-12-01

123

Analysis on metallogenetic geological and physicochemical conditions in uranium deposit No.138  

International Nuclear Information System (INIS)

The uranium deposit No.138 is of Mesozoic volcano-sedimentary transformation type. This paper discusses such geological conditions as source of uranium, stratigraphy and lithology, lithofacies and paleogeography, paleoclimate, structure and reworking-regeneration, and such physicochemical conditions as uranium adsorbent and reductant, effective porosity, chemical compositions, pH and Eh of rocks in the deposit

124

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

125

Geodetic And Geological Analysis Of The Tandilia Crust  

Science.gov (United States)

Keywords: Tandilia-Geoid-Anomaly-Collision-Transamazonic The oldest Precambrian rocks of the south-western Gondwana in South America are cropping out in the Río de la Plata craton, it encompasses the western region of Uruguay, the Martín Garcia island and the Tandilia Ranges in the Buenos Aires Province, Argentina. The Tandil Ranges are the oldest region in Argentina (1.8- 2.2Ga); however, some features of the crust still remain unknown. These rocks evolved during two main events:Transamazonian and Brasilian tectonic cycles. The local and regional gravitational effects were analyzed on gravity and height anomalies. The studied are extended on 400 km x 400 km area which includes three geological units: the Tandilia ranges, and the Claromecó and Salado basins. Due the dependence of gravity and height anomalies with the distance, the seconds are more suitable to analyze the crust interior. For this reason a very precise cuasi geoid model was calculated using the point masses method, from gravity and GPS/leveling data. Taking into account the topography (less than 500 m high hills) and the Bouguer anomalies values (| AB | associated to thrusting and transcurrence; as well as minor lenses of ultrabasic rocks, that seem to also be part of the suture as a result of a "mantel pinching" during collision.

Del Cogliano, D.; Dallasalda, L.

2007-05-01

126

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

127

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

128

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

OpenAIRE

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 se...

Schiavone, D.; Quarto, R.; Loddo, M.

1996-01-01

129

Quantitative analysis of lunar crater's landscape: automatic detection, classification and geological applications  

Science.gov (United States)

Lunar craters are the most important geological tectonic features on the moon; they are among the most studied subjects when it comes to the analysis of the surface of the moon since they provide us with the relative age of the surface unit and more information about lunar geology. Quantitative analysis of landscape on lunar crater is an important approach in lunar geological unit dating which plays a key role in understanding and reconstruction of lunar geological evolution. In this paper, a new approach of automatic crater detection and classification is proposed based on the quantitative analysis of crater's landscape with different spatial resolution digital terrain models. The approach proposed in this paper includes the following key points: 1) A new crater detection method which selects profile similarity parameters as the distinguishing marks is presented. The new method overcomes the high error defect of former DTM based crater detection algorithm; 2) Craters are sorted by the morphological characteristics of profiles. The new quantitative classification method overcomes the subjectivity of the previously descriptive classification method. In order to verify the usefulness of the proposed method the pre-selected landing area of China's Chang'e-III lunar satellite-Sinus Iridum is chosen as the experimental zone. DTM with different resolutions from the Chang'e-I Laser Altimeter, the Chang'e-I Stereoscopic Camera and the Lunar Orbiter Laser Altimeter (LOLA) are used for crater detection and classification. Dating results of each geological unit are gotten using crater size-frequency distribution method (CSFD). By comparing the former dating and manual classification data, we found that the results obtained by our method and the former results have the strong consistency. With the combination of automatic crater detection and classification, this paper basically provided a quantitative approach which can analyze the lunar crater's landscape and get geological information from it. And the approach can be widely used on other planets like Mars.

Li, Ke; Chen, Jianping; He, Shujun; Zhang, Mingchao

2013-04-01

130

Solar illumination geometry and its influence on the observance of geological structures in orbital imagery  

Science.gov (United States)

The geology of the westernmost part of Rio de Janeiro State (Brazil) is characterized by the conspicuous presence of the Alem Paraiba lineament, a large shear zone extending more than 200 km in N50-60E direction. Parts of Paraiba do Sul river and of the regional topography are strongly related to this geologic feature. Several other lineament directions complete the structural framework that can be seen on remote sensing products. According to well accepted theories of photointerpretation, LANDSAT images with low sun elevation angles should more clearly show those lineaments, because the shadow enhancement of the relief is greatest. Also, considering the high grade of relief conditionment by the Alem Paraiba lineament, it is expected that this structure could be clearly observed on LANDSAT images of all seasons. However, these hypotheses are not confirmed. The images with low sun elevation angles belong to the epoch (winter) in which the solar azimuths are nearly parallel to the regional structure, making its identification difficult. In summer, the images have high sun elevation angles but their solar azimuths, oblique to the regional structures, allow an adequate identification of the main structural trend.

Rodrigues, Jose Eduardo; Liu, Chan Chiang

1991-04-01

131

Combining Electrical Resistivity Tomography and Ground Penetrating Radar to study geological structuring of karst Unsaturated Zone  

Science.gov (United States)

This paper highlights the efficiency and complementarity of a light package of geophysical techniques to study the structure of karst Unsaturated Zone (UZ) in typical Mediterranean environment where soil cover is thin or absent. Both selected techniques, 2D Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT), are widely used in environmental studies and their application is accessible for a lot of scientists/engineers. However, GPR or ERT alone is not able to provide an enhanced characterization of geological features in karst media. In the present study, GPR results supply a near surface high resolution imaging and thus can provide relevant geological information such as stratifications and fractures. Despite the quality of the results GPR's investigation depth remains limited to around 12 m. Apparent and inverted resistivity provided by ERT surveys shows strong lateral and vertical variations. These variations can inform about general geological structuring and feature orientation. ERT is able to prospect down to 40 m but it's a low resolution integrative technique. In the study area the investigated limestone is a commonly electrical resistive formation (more than 2000 ?.m). However deeper than 5-7 m, the ERT profiles reveal several zones of moderate resistivity (around 900 ?.m). In these zones a stratification change corresponding to slanted bedding is clearly identified by GPR results. The combination of both GPR and ERT results can allow a well-established geological interpretation. These moderate resistivity zones with slanted beddings can explain the presence of a perennial water flow point 35 m below the surface of the studied site within the underground gallery of the Low-Noise Underground Laboratory (LSBB).

Carrière, Simon D.; Chalikakis, Konstantinos; Sénéchal, Guy; Danquigny, Charles; Emblanch, Christophe

2013-07-01

132

Macro- and micro- geodynamic of Terebliya-Riksk geodetic man-caused polygon of Ukrainian Carpathians influenced by specificities of structure-geological and hydro-geological conditions  

Science.gov (United States)

Terebliya-Riksk diversion power station is located on two levels ( with difference of 180m ) of south mountainside of Ukrainian Carpathians and separate parts of this power station lie inside rock. Therefore influential parameters of it's stability are geological, tectonic and hydrogeological conditions in complex. Monitoring of intensity and nature of displacements of flow ( pressure) pipe and other objects of power station with geoditic methods indicates that fluctuations of water-level in reservoir caused bouth by natural and artificial efects are of great influence on objects mentioned. Based on geodetical high-precision observations made by LeicaTPS 1201 robotic total station short-periodic components of fundamental vibrations which result in their destructive deformation were determined. Mathematical apparatus ( which uses function of Fourie series and theory of cinematic coefficients ) for displacements determinations of pressure pipe was disigned. Complex of engineering-geological surveys gave an opportunity to define the origin of macro- and micro- geodynamics movements of Terebliya-Riksk diversion power station region. Engineering-geological conditions which influence on power station structure most of all were determined as following : small foldings and cleavage areas appearances, also fluctuations of level of underground water (refered to hydrogeological conditions). Periodic micro-displacemets appearances ( which operate on reducing-stretching scheme) fixed on power station structure are turned to be in direct relation on to what exend reservoir is filled up. Permanent macro- displacements appearances ( which operates in north-west direction ) fixed on pressure pipe are the result sum of residual micro-displacements caused by return periodic movements and are determined by structure-geological, engineering-geological and tectonic conditions.

Kulchyzkyy, A.; Serebryannyy, Y.; Tretyak, K.; Trevogo, I.; Zadoroznnyy, V.

2009-04-01

133

Geological evolution and analysis of confirmed or suspected gas hydrate localities  

Energy Technology Data Exchange (ETDEWEB)

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

Finley, P.D.; Krason, J.

1988-10-01

134

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)

135

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

Science.gov (United States)

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

Eppelbaum, Lev; Katz, Youri

2014-05-01

136

Local geologic structure for realistic seismic shaking simulation in northern Italy  

Science.gov (United States)

Realistic calculation of seismic ground motion in complex local geologic structures is today technically very feasible. Well-tested numerical techniques can go even beyond linear elastic constitutive equations, they are easier to use — thanks to community resources such as SPECFEM — and high-performance computing infrastructures are becoming more widely accessible. The limit to how well we can model real ground motion is clearly in the fidelity of the representation of the Earth structure. We wish to apply such numerical deterministic methodologies to the Po Plain in Northern Italy — a region with relatively rare earthquakes but having large property and industrial exposure. The destructive effects and high community cost of the M~6 events of May 20-29, 2012, showed the need and urgence to provide more accurate estimates of possible ground shaking in a region where known hazardous seismicity must be sought up to five or more centuries ago, or inferred on geological grounds. The Po Plain is characterized by a deep sedimentary basin that covers a bedrock folded and fractured by compressional structures, imaged by the extensive surveys carried out for more than two decades for hydrocarbon exploration. Local amplification effects of the wavefield can be quite significant and need to be taken into account in detailed seismic hazard assessment. To provide a representation of this structure, appropriate for our target, we need to complement information coming from seismic tomographic studies, with high-resolution constraints deriving from exploration profiles, and geological information. The new high-resolution, three-dimensional, model we present has been built merging together such information, applying geostatistical techniques. The model is then calibrated through test numerical simulations made for the few moderate-magnitude events of the region, for which adequate instrumental records are available. These simulations allow us to adjust some critical parameters — such as Vp/Vs scaling ratio and few other parameters — keeping the shape of interfaces as constraints. We plan to use the new model for calculation of seismic scenarios.

Morelli, A.; Molinari, I.; Basini, P.; Danecek, P.

2012-12-01

137

Instrumental neutron activation analysis of geological materials from Northern Palawan and Mariduque Island, Philippines  

International Nuclear Information System (INIS)

An instrumental neutron activation analysis of geological materials comprising of heavy mineral panned concentrates and surface soil samples taken from northern Palawan and Marinduque Island, Philippines was conducted. This work was carried out primarily to determine the distribution of uranium, thorium, rare earths and other trace elements in the Philippine environment in connection with the nationwide geochemical exploration program and the IAEA technical co-operation project on gamma ray spectrometric survey in the country. Moreover, the geochemical data obtained will form part of the national database for nuclear resource assessment, mineral exploration and environmental studies. The utilization of the instrumental neutron activation analysis technique in the multielemental determination of geological materials has been very useful in mineral exploration, environmental studies and other related researches. The sensitivity of this technique has been very effective not only in the determination of the major elements but for the trace elements as well. In this study, about 96 geological samples wee analyzed for 15 elements after the spectral analysis. In all, 810 elemental determinations were completed. In the northern Palawan district, the areas with high radioactivity were disclosed by the relatively high concentrations of thorium and, to a lesser extent, uranium. Moreover, areas with possible potential for gold was delineated as well as for the rare earth metals. ted as well as for the rare earth metals. In Marinduque Island, the distribution of the elements are generally sporadic which indicate various lithological sources and a diverse geology. (author). 7 refs., 1 fig., 9 tabs

138

The upgrading of instrumentational methods of neutron activation analysis of geological objects  

International Nuclear Information System (INIS)

The system of automized neutron-activation analysis of geological objects in the form of small weight samples is described. The experimental apparatus includes automatical sample supply to the gamma spectrometer. The productivity of the system is not less then 300 element determinations in one cycle (30 samples). The results of analysis of mountain rocks from various gold ore mines of Tashkent region are presented. (A.A.D.). 4 refs

139

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

Science.gov (United States)

The homogeneity of geological reference samples was analyzed to improve the quality of elemental concentration data available on these materials, or use in a verification of factor analysis source resolution procedures. The analyses was performed by instrumental neutron activation analysis (INAA). The INAA has high sensitivity which is attained in determining elemental concentrations. The basic theory and technique are reviewed to show where problems can arise and how thay can be dealt with.

Daly, A. T.

1981-02-01

140

Potential structures for CO2 geological storage in the Baltic Sea: case study offshore Latvia  

Directory of Open Access Journals (Sweden)

Full Text Available This study is focused on two structures in the Baltic offshore region (E6 and E7 structures in Latvia prospective for the geological storage of carbon dioxide (CO2. Their CO2 storage capacities were estimated recently with different levels of reliability. Petrophysical, geophysical, mineralogical and geochemical parameters of reservoir rocks represented by quartz sandstones of the Deimena Formation of Middle Cambrian in two wells and properties of Silurian and Ordovician cap rocks were additionally studied and interpretedin the present contribution. Extended methodology on rock measurements and estimation of conservative and optimistic storage capacity are presented. Uncertainties and risks of CO2 storage in the offshore structure E6 estimated as the most prospective for CO2geological storage in the Baltic Region, and the largest among all onshore and offshore structures studied in Latvia, were discussed. We re-estimated the previous optimistic capacity of the E6 structure (265–630 Mt to 251–602 Mt. Considering fault system within the E6 structure we estimated capacity of two compartments of the reservoirseparately (E6-A and E6-B. Estimated by the optimistic approach CO2storage capacity of the E6-A part was 243–582 Mt (mean 365 Mt and E6-B part 8–20 Mt (mean 12 Mt. Conservative capacity was 97–233 Mt (mean 146 Mt in the E6-A, and 4–10 Mt (mean 6 Mt in the E6-B. The conservative average capacity of the E6-B part was in the same range as this capacity in the E7 structure (6 and 7 Mt respectively. The total capacity of the two structures E6 and E7, estimated using the optimistic approach was on average 411 Mt, and using the conservative approach, 159 Mt.

Kazbulat Shogenov

2013-07-01

141

Automated grid generation from models of complex geologic structure and stratigraphy  

Energy Technology Data Exchange (ETDEWEB)

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

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

1996-04-01

142

Geological Geophysical and structural studies in Mina Ratones (Pluton de Albala); Estudios geologico-estructurales y geofisicos en Mina Ratones (Pluton de Albala)  

Energy Technology Data Exchange (ETDEWEB)

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)

Perez-Estaun, A.; Carbonell, R.; Marti, D.; Flecha, I. [Instituto de Ciencias de la Tierra Jaume Almera. Barcelona (Spain); Escuder Viruete, J. [Universidad complutense de Madrid. Madrid (Spain)

2002-07-01

143

High-energy proton beam analysis of geological materials  

Science.gov (United States)

Partitioning of trace elements between mineral phases reflects the physical, chemical and kinetic conditions of crystallization. Variations in environmental conditions during growth often result in complex and small-scale chemical zoning in minerals. The low abundance of trace elements and their spatial inhomogeneity on a ?m scale makes their analysis by a muprobe technique essential for addressing many petrological problems. ?-PIXE (2-3 MeV) has been successfully applied to many mineralogical problems and is rapidly becoming a routine analytical tool for geologists. High-energy PIXE (40-60 MeV) provides a new dimension in mineralogical analysis. The K X-rays for many petrologically important trace elements occur in the 25-90 keV region, here the X-rays are not affected by interference from the X-rays of more abundant geochemically coherent elements. Furthermore, the K X-ray spectrum for an element is less complex than its corresponding L X-ray spectrum so data reduction is simplified. The use of high energy protons for elemental analysis makes high-energy PIGE accessible, here on-line emission of ?-rays can be used to provide information on element (or in some cases isotope) concentrations. For the analysis of chemically complex materials such as rocks and minerals it is necessary to thoroughly characterize the material beforehand such that likely proton induced reactions can be predicted. Nuclear reactions produced by proton interaction with mineral samples occur during on-line exposure of the sample. The by-products of such reactions may have significant half-lives which will make them amenable to off-line analysis. One such case is where Pt undergoes (p, xn) reactions to form Au which then decays back to Pt via electron capture. The off-line spectrum after such a run contains Au X-rays and the background to such spectra is low, which raises the possibility that this form of analysis will provide low detection limits. This is the proton analogue of neutron activation analysis — proton activation analysis (PAA).

Halden, Norman M.

1993-05-01

144

High-resolution 3D spatial modelling of complex geological structures for an environmental risk assessment of abundant mining and industrial megasites  

Science.gov (United States)

Conceptual geological models of industrial and mining megasites are an essential task of groundwater investigations as well as environmental risk assessment studies. Therefore, the conceptualization process of the structural geological model has depended on the development of a set of 2D cross-sections to portray a 3D picture of groundwater flow. This attempt always includes some simplifications that require, only to some extent, the true 3D situation of heterogeneous aquifers. Consequently, the modelled predictions of the path flow and transport conditions of contaminated groundwater are not satisfying in terms of a flow-path and risk based modelling approach. A more structured approach to develop the hydrogeological framework for the conceptual model is advocated, using different 3D geological modelling software packages to assemble the data, working in three dimensions and using this platform for subsequent groundwater flow modelling. Attention is given to the capability of different 3D modelling approaches, indicated by geostatistically based versus constructive cross-section based interpolations of complex sedimentary successions, that are compared in their results and suitability for subsequent hydrogeological modelling requirements. The paper describes the results, in high-resolution 3D modelling, of the complex geological environment of the Bitterfeld/Wolfen megasite in the eastern part of Germany. Identification, assessment, and remediation of large-scale groundwater contamination require a detailed knowledge of the heterogeneous geological structure to predict the fate and pathways of contaminants and their potential interaction with, e.g., surface water. An area of 16 km 2 of the model area of the Bitterfeld/Wolfen area was chosen to transfer the complex structural geological setting. The subsurface geology could be assigned to 31 lithostratigraphic units and depicted using a 10×10 m GIS grid. This constructive and "knowledge-driven" 3D modelling allows the prediction of vertical and horizontal sections, visualization purposes, volumetric calculations of distinct sedimentary units, GIS applications, and the use of the detailed digital information within the subsequent flow and transport groundwater modelling. The high-resolution digital 3D model improves the hydrogeological modelling results. It is considered a basic requirement for groundwater modelling and investigations on environmental risk and impact assessment by fate, and pathway exposure route analysis of the complex geological and groundwater situations.

Wycisk, P.; Hubert, T.; Gossel, W.; Neumann, Ch.

2009-01-01

145

Geological storage of CO2: sensitivity analysis and risk assessment using arbitrary polynomial chaos expansion  

Science.gov (United States)

Geological storage of CO2 is a proposed solution for fighting the climate change. The considerable costs and potential hazards of the technique requires feasibility studies to assess all possible risks embedded in the process. Modeling of CO2 storage, requires working with large time and space scales, which in practice are accompanied by huge geological uncertainties. In this work, we practice a study of geological CO2 storage for injection and early migration time. A typical CO2 injection scenario is implemented on a set of geological realizations. A number of uncertain parameters are chosen with an assumed knowledge of probability. A framework based on arbitrary polynomial chaos expansion is used for projection of flow responses on high-dimensional orthonormal polynomial bases, which forms a so-called response surface. This approach works with arbitrary probability knowledge and treats available input data directly without additional assumption on shape of uncertainty distribution. Sensitivity analysis is used to rank the model parameters by their influence in the modeling outcome. For global sensitivity analysis we use Sobol indices which are robust for a general problem in terms of non-linearity and complexity. The reduced model represented by the response surface is vastly faster than the full original model and used for probabilistic risk assessment via Monte-Carlo post-process.

Ashraf, M.; Oladyshkin, S.; Nowak, W.

2012-04-01

146

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

147

A project of classification of large geologic structures of the earth's crust according to the conditions of radioactive waste disposal  

International Nuclear Information System (INIS)

A firm tendency outlined in recent years consists in using the lithosphere as a site of disposal of highly toxic and power rich radioactive wastes, which extends considerably the range of problems connected with the geologic reasons for these measures in every definite case. A traditional information on a geologic object, on physical-chemical, geotechnical and hydrogeologic processes occuring in undisturbed conditions and expected after the underground repository creation is not sufficient at present. Modern data on the earth's crust power, on the range and planetary centrifugal direction of the heatmass transfer processes are indicative of the necessity to take into consideration a possible relation of a geologic object to deepseated zones of enclosing large geologic structures; a density of heat flows and an intensity of mass transfer in a section: deep crustal zones ? earth's surface (basement ? earth's surface -- for sedimentary basins); the resulting effects of interactions of the natural thermal and geochemical fields with analogous artificial formations - products of radioactive element disintegration in the buried waste composition; seismic effects of decreasing the volume of sedimentary rock as a result of their catagenetic transformations in deep-seated zones of sedimentary basins. A project of general classification of geologic megastructures according to conditions of radioactive wastes burial was developed and is discussed. The project is based on a cdiscussed. The project is based on a concept of power potential of large geologic structures involving their seismic activity and geologic-geochemical effects of deep heat and mass transfer in the earth's crust upper parts

148

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

149

Modified FILTERSIM Algorithm for Unconditional Simulation of Complex Spatial Geological Structures  

Directory of Open Access Journals (Sweden)

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

Mohammadreza Rasaei

2012-07-01

150

Geological Structure of the Itoigawa - Shizuoka Tectonic Line, Northern Fossa Magna, Central Japan  

Science.gov (United States)

Geological structure of two different natures is recognized in the Northern Fossa Magna (NFM). NFM is situated near the zone where the central Japan Island bent geographically and a graben zone formed between the North Alps and the Kanto highland. NFM is characterized by thick Neogene deposits and with active tilting of the crustal blocks and active folding bloc. At the present the sedimentary basin is the Saigawa hill due to the active faulting and folding in the Fossa Magna. Active fault system of Itoigawa-Shizuoka Tectonic Line (ISTL) is an eastward - dip of reverse fault which strikes N-S along the western margin of the NFM. The vertical displacement rate of ISTL is estimated to be maximum 9 mm/yr from the offset amount and the formation age of flexure scarp which appeared in the fluvial terrace [ex. Ikeda et al., (2002)]. Besides, the last event and the reccurrence interval are presumed to be about about 1,500 years aga and 2,000 years, respectively [Okumura (2001)]. In addition the western margin fault of the Nagano basin (NBF) strikes NNE-SSW along the east edge of NFM. The NBF is an eastward-dip of reverse fault, and the Zenkoji earthquake (M7.4) in 1847 was occurred. The purpose of present study is to discuss the geometry of ISTL and geological process of NFM based on the geomorphological and geological survey using the geological dip and strike already obtained at the more than 1,500 data points. Based on these geological data, the geological structure provinceis divided into two types those are a tilt block and a folding belt at west and east sides, respectively. The Western tilting block and an Eastern folding belt trend NS strike and NNE-SSW strike, respectively. As a result of the geomorphic decipherment in alignment with ISTL using the air photograph, flexure scarp of east side upheaval is formed in the fluvial terrace side and it is difficult for the terrace riser which crosses flexure scarp and a valley to observe lateral offset. The tilt block, ‘Omine belt’, exists along east side of ISTL. The Omine belt is exposed of the Omine formation which is mainly composed of alluvial conglomerate with several tuff layers. The Omine formation is inferred to contact with the ISTL from the situated. The dips of bedding surface are ranged in 20 - 50 degrees east. The ISTL, thus, is an emergent thrust with a low angle fault plane. The eruption age of the upper tuff layer, which was observed in the uppermost member, are presumed to be ca. 1.65 Ma from the stratigraphy and K-Ar age measurement. The Otari-Nakayama Fault (ONF) is already mapped near the boundary between the Omine belt and the folding belt [ex. Saito (1962), Kato et al. 1989]. The fault plane is almost vertical. The Omine formation (Plio-Pleistocene ) is distributed over its west side and the Aoki and Ogawa formations (Miocene) is over the east side. The Omine formation is crushed [ex. Saito (1962), Kato et al. 1989]. The activity stage of this fault is still unknown. The large-scale folding structures are appeared in the Miocene zone. Folding structures strike NNE-SSW and different from the Omine belt.The slip partitioning is recognized by the different mode of several faults which are distributed in and around the NFM.

Kim, H.; Iwasaki, T.

2009-12-01

151

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

Science.gov (United States)

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

Zhang, Y.; Chen, C.

2010-12-01

152

Regional scale genetic structure within two Central American tree species: the influence of geography, biology and geological history.  

OpenAIRE

We examine spatial genetic structure occurring at a regional scale for two widely distributed tree species from Central America, Vochysia ferruginea and Cedrela odorata, and speculate on some of the geographic, edaphic and geological factors that may be responsible in a continent that has a complex geological history and is rich in natural resources. For V. ferruginea, the central mountain ranges of Costa Rica coincide with a major genetic differentiation and are probably acting to maintain t...

Cavers, S.; Lowe, A. J.

2002-01-01

153

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

OpenAIRE

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

Menichetti, Marco

2008-01-01

154

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

155

Geophysical investigations of geology and structure at the Martis Creek Dam, Truckee, California  

Science.gov (United States)

A recent evaluation of Martis Creek Dam highlighted the potential for dam failure due to either seepage or an earthquake on nearby faults. In 1972, the U.S. Army Corps of Engineers constructed this earthen dam, located within the Truckee Basin to the north of Lake Tahoe, CA for water storage and flood control. Past attempts to raise the level of the Martis Creek Reservoir to its design level have been aborted due to seepage at locations downstream, along the west dam abutment, and at the base of the spillway. In response to these concerns, the U.S. Geological Survey has undertaken a comprehensive suite of geophysical investigations aimed at understanding the interplay between geologic structure, seepage patterns, and reservoir and groundwater levels. This paper concerns the geologic structure surrounding Martis Creek Dam and emphasizes the importance of a regional-scale understanding to the interpretation of engineering-scale geophysical data. Our studies reveal a thick package of sedimentary deposits interbedded with Plio-Pleistocene volcanic flows; both the deposits and the flows are covered by glacial outwash. Magnetic field data, seismic tomography models, and seismic reflections are used to determine the distribution and chronology of the volcanic flows. Previous estimates of depth to basement (or the thickness of the interbedded deposits) was 100 m. Magnetotelluric soundings suggest that electrically resistive bedrock may be up to 2500 m deep. Both the Polaris Fault, identified outside of the study area using airborne LiDAR, and the previously unnamed Martis Creek Fault, have been mapped through the dam area using ground and airborne geophysics. Finally, as determined by direct-current resistivity imaging, time-domain electromagnetic sounding, and seismic refraction, the paleotopography of the interface between the sedimentary deposits and the overlying glacial outwash plays a principal role both in controlling groundwater flow and in the distribution of the observed seepage.

Bedrosian, P.A.; Burton, B.L.; Powers, M.H.; Minsley, B.J.; Phillips, J.D.; Hunter, L.E.

2012-01-01

156

Hydrogeological Properties of Geological Elements in Geological Model around KURT  

International Nuclear Information System (INIS)

To develop site characterization technologies for a radioactive waste disposal research in KAERI, the geological and hydrogeological investigations have been carried out since 1997. In 2006, the KURT (KAERI Underground Research Tunnel) was constructed to study a solute migration, a microbiology and an engineered barrier system as well as deeply to understand geological environments in in-situ condition. This study is performed as one of the site characterization works around KURT. Several investigations such as a lineament analysis, a borehole/tunnel survey, a geophyscial survey and logging in borehole, were used to construct the geological model. As a result, the geological model is constructed, which includes the lithological model and geo-structural model in this study. Moreover, from the results of the in-situ hydraulic tests, the hydrogeological properties of elements in geological model were evaluated.

157

Applications of instrumental neutron activation analysis (INAA) for geological samples in AMD for uranium exploration programme  

International Nuclear Information System (INIS)

Full text: Non-destructive Instrumental Neutron Activation Analysis has been used over last three decades in AMD for analysis of geological samples for estimation of Na, K, Ca, Sc, Cr, Fe, Co, Cu, Zn, Ga, As, Br, Zr, Ag, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Tm, Ho, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Au, Th and U. The estimation has been done using various international standards. The irradiation of samples has been done in Cirus/Apsara Reactor in BARC, Mumbai. The measurement of desired gamma emission are carried out by Huge detector. The various geological samples from different parts of India are: 1. granites 2. charnokites 3. Basalts 4. Carbonatites 5. Xenotime 6. Monazite 7. Core samples 8. Black slabs. The efficiency modelling of HPGe detector was done using different sources and mathematical and statistical techniques. (author)

158

Results concerning the use of seismic and well log data for defining the geological model of the productive structures on the Romanian Continental Shelf of the Black Sea  

Energy Technology Data Exchange (ETDEWEB)

The contribution of the 3D seismics on the East-Lebada Structure of the Romanian Continental Shelf of the Black Sea, together with the complex well logging have led to the improvement of the reservoir geological model. The interpretation has been performed on 3d seismic profiles. Time migrated profiles were interpreted, by means of the program system OASIIS. The acoustic logging data were used for calibration, in order to identify the reflections corresponding to the geological boundary. By means of these reflections on the seismic profiles, the adequate geological model has been defined. A system of tectonic accidents which were not known till now were rendered evident. The interpretation of the complex well loggings, through the Well Log Analysis Program System - Express - allowed to determine the petrophysical-petrographical parameters necessary for reservoir evaluation, in correlation with core analysis. Thus, four horizons corresponding to the Albian age with favorable collector properties were rendered evident, in alternance with unfavorable collector properties zones. The well logs, performed at different time periods and with different tools were corrected and standardized for the well environment conditions and, depending on the logging program, different program modules were used to obtain the most adequate results. The parameter averaging performed by zones, for each well, together with the image furnished by the seismic data, allowed us to build the final geometrical and isoparametric model of the reservoir, used for further reservoir simulation. Based on the results obtained, the analysis was extended to West-Lebada Structure.

Babskow, A.; Baleanu, I.; Popa, D. [Institute for Research and Technology, Prahova (Romania)] [and others

1995-08-01

159

Instrumental neutron activation analysis of geological and biological reference materials using the ko-standardization method  

International Nuclear Information System (INIS)

The ko-standardization method used in instrumental neutron activation analysis (INAA) was applied to the determination of some elements in geological and biological reference materials. The authors analyzed NBS SRM 1572 Citrus Leaves and SRM 1645 River Sediment and the CRM materials, IAEA Soil-7, SL-1, and MA-A-2. Comparison is made with reference values whenever available. Good agreement is found. The potential of the ko-standardization method in reactor INAA is discussed

160

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

International Nuclear Information System (INIS)

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

161

Evaluation of reactor induced (n,p) reactions for activation analysis of titanium in geological materials  

International Nuclear Information System (INIS)

The possibilities of reactor induced (n,p) reactions as a tool for neutron activation analysis of titanium in geological samples are discussed. The interference of calcium and scandium is experimentally evaluated. Results for Ti, Ca and Sc in GSP-1 and PCC-1 standard rocks are presented. Based on the experimental values, it is concluded that the 47Ti(n,p)47Sc reaction is the most favourable for titanium determination. (author)

162

Structural Geology of Graciosa Island - a contribution for the geodynamics of the Azores triple junction  

Science.gov (United States)

The Azores geodynamic setting, its geological, geochemical and geophysical characteristics, and the frequent seismic and volcanic activity, motivated the development of multidisciplinary studies aiming at the creation of a coherent model explaining the geodynamic and kinematic particularities that characterize the Azores triple junction - the contact between the North American, Eurasian and Nubian lithospheric plates. The tectonic regime determination at any given region, through the identification and characterisation of active faults, is a major contribution to the development of geodynamic models. In this domain the geometric and kinematic characterisation of Graciosa Island active faults was performed and a structural map was produced. The stress fields responsible for the development of the identified tectonic structures were also deduced. Two main fault systems were identified at Graciosa. One system (A) is composed of two sets of conjugated faults, one trending NW-SE and dipping to SW, presenting normal-dextral or dextral-normal oblique slip, and another striking NNE-SSW and dipping to ESE, with oblique normal-left lateral or left lateral-normal slip. The second fault system (B) includes NNE-SSW to NE-SW trending faults, dipping to WNW or NW, presenting normal-dextral or dextral-normal oblique slip. A family of conjugated faults with these structures was not found. The structural data indicate two distinct stress fields acting in Graciosa region that could be separated in time and/or in space. A stress field I, responsible for the occurrence of fault system A, with ?1 (maximum horizontal compressive stress axis) NNW-SSE to N-S, ?3 (maximum horizontal tensile stress axis) trending ENE-WSW to E-W, and an intermediate vertical compressive stress axis (?2); permutations between ?1 and ?2 may occur according to the alternation between transtensile and tensile tectonic regimes. A second stress field, II, is characterised by horizontal ?1, trending E-W to WSW-ENE, horizontal ?3, trending NNW-SSE to N-S, and vertical ?2. Permutation may also occur between ?2 and ?1 after events of stress drop during transtensile phases. Fault system B is associated to stress field II. The kinematic solutions shown in recent geodetic works and the stress fields determined from neotectonic analysis seem to point out to the presence of two distinct stress fields on the islands located near the margins of the shear zone where the Azorean islands of the central and eastern groups stand. Stress field I agrees with the local stress regime proposed by several authors for the shear zone that constitutes the western segment of the Eurasia - Nubia plate boundary. To explain the existence of stress field II, two hypothesis are proposed: (1) an intermediate region, with a transtensile regime, making the transition between the area subjected to the Mid-Atlantic Ridge tensile stress field and the more distal region with a compressive stress field; or (2) an intermediate region (established when the interplate shear stress is weaker), with a transtensile regime, defining a narrow band between the region of dextral transtension (resulting from the differential motion between the Eurasian and the Nubian plates) and the external compressive stress field established as the sea-floor moves away from the Ridge. Narrowing or widening of the area under influence of local stress field (I) may justify that the margins of the sheared region will become temporarily under the influence of the external stress field (II).

Hipólito, Ana; Madeira, José; Gaspar, João.; Carmo, Rita

2010-05-01

163

Structural analysis system THANKS  

International Nuclear Information System (INIS)

The analytical codes THANKS (Three Dimensional Analysis of NIPPON KOKAN Systems) V-1, THANKS V-2, and THANKS V-3 were developed to analyze the structures having complicated configuration, to simulate the actual phenomena including elastoplastic property, creep, large deformation and dynamic behavior, and to analyze thermal and hydraulic characteristics. These codes are supported with the development of pre-processor PRE-THANKS and post-processor POST-THANKS. The special features of this code system are as follows: 1) it is possible to analyze the strength of three dimensional structures having any complex configuration and to calculate the large scale problems with 160,000 freedom, 2) it is possible to treat the broad range of linear and nonlinear problems of both static and dynamic and thermal conduction, 3) the calculating time is shortened, 4) the program consists of modules, therefore the partial improvement is simple, and the addition of new functions is easy, 5) the graphic display utilizing cathode ray tubes (CRT) is available, and 6) the high efficiency and the reduction of labor are planned. The hardwares of THANKS system consist of a computer IBM S370/168, a card reader, magnetic discs, a printer, a graphic display and a plotter, and PRE-THANKS, THANKS V-1 THANKS V-2 THANKS V-3 and POST-THANKS are included in this computer system. PRE-THANKS has the functions such as the input of two and three dimensional mesh configurations, the production of mesh files, anurations, the production of mesh files, and the display with a CRT. POST-THANKS has the function displaying stress contours, stress distribution, change of stress in course of time and deformation on CRT or drawing them utilizing a plotter. (Nakai, Y.)

164

Maps Showing Geology, Structure, and Geophysics of the Central Black Hills, South Dakota  

Science.gov (United States)

This 1:100,000-scale digital geologic map details the complex Early Proterozoic granitic rocks, Early Proterozoic supracrustal metamorphic rocks, and Archean crystalline basement of the Black Hills. The granitic rocks host pegmatite deposits renowned for their feldspar, mica, spodumene, and beryl. The supracrustal rocks host the Homestake gold mine, which produced more than 40 million ounces of gold over a 125-year lifetime. The map documents the Laramide deformation of Paleozoic and Mesozoic cover rocks; and shows the distribution of Laramide plutonic rocks associated with precious-metals deposits. Four 1:300,000-scale maps summarize Laramide structures; Early Proterozoic structures; aeromagnetic anomalies; and gravity anomalies. Three 1:500,000-scale maps show geophysical interpretations of buried Early Proterozoic to Archean rocks in western South Dakota and eastern Wyoming.

Redden, Jack A.; DeWitt, Ed

2008-01-01

165

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

Energy Technology Data Exchange (ETDEWEB)

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

NONE

2000-03-01

166

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.)

167

Site selection and design basis of the National Disposal Facility for LILW. Geological and engineering barriers  

International Nuclear Information System (INIS)

Content of the presentation: Site selection; Characteristics of the “Radiana” site (location, geological structure, physical and mechanical properties, hydro-geological conditions); Design basis of the Disposal Facility; Migration analysis; Safety assessment approach

168

The role of INAA as compared to conventional methods of analysis for geological samples in Canada  

International Nuclear Information System (INIS)

The instrumental neutron activation analytical technique (INAA) both competes with and complements conventional commercial analytical methods like X-ray fluorescence emission spectrometry (XRF), direct coupled plasma emission spectrometry (DCP), inductively coupled plasma emission spectrometry (ICP), inductively coupled plasma-mass spectrometry (ICP-MS) and atomic absorption (A.A.). The major advantages to the use of INAA in the geological field includes the fact that the analysis can be done non-destructively without encountering the many problems inherent in acid dissolution or fire assay techniques. The sensitivity for many elements are still unrivalled by commercially available analytical techniques for gold, platinum-group-elements, many of the rare earth elements and other elements. The multi-element nature of the analysis combined with ease of automation, data collection and spectral analysis procedures allows for rapid turnaround of samples at low cost. This technique competes very favourably with virtually all other analytical techniques. The geological market being served by INAA includes university and government researchers as well as the mineral exploration industry. The needs of these groups varies considerably and will be discussed. The various applications of INAA to the geological community will also be discussed. (author). 6 refs, 5 tabs

169

Analysis of granite isotopic geological data and periods of magma-tectonic action in mesozoic in South China  

International Nuclear Information System (INIS)

Based on the analysis of isotopic geological data after 230 Ma in south china, as a whole there is a young tendency from northwest to southeast and it is proved by one trend surface analysis. There is from east to west migration of magma action peak value both stages 165-137 Ma and 112-80 Ma. Which is based on subzone statistic of NE structure. In the stage of 140-110 Ma, magma action peak value is coincident with the rapid subduction of Cora plate-form and volcanic rocks chemical constitution change of southeast coastland, it changes un-clearly with the time. From above all, this area is divide into three ages by the characteristics of magma action

170

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

Science.gov (United States)

...analysis; (e) An analysis of the performance of the structures, systems, and components...availability of safety systems. The analysis required in this...Radiation alarm system to warn of significant...discussion of the design, both surface...

2010-01-01

171

The tunnel project. Drill hole logging and structural geologic studies in the Grualia, the Lunner county  

International Nuclear Information System (INIS)

In connection with the project ''Environmental and community useful tunnels'' the Norwegian Geologic Survey (NGU) has made geologic and geophysical investigations along parts of the tunnel at the Grualia in the Lunner county. The purpose of the geologic studies was to map and investigate weakness zones in the rock foundations. The geophysical studies aimed at testing techniques that was in little use in preliminary studies for tunnel operations. The methods used have been optical inspection of drill holes, measurements of temperature and conductivity in the water and the measuring of the natural gamma radiation in the drill holes. The resistivity in the drill holes is also determined and test pumping with flow measurements is carried out in order to calculate the well water influx capacity. These methods may contribute to information about the rock condition (cracking, water influx). Previously the NGU has made 2D resistivity measurements at the ground in the tunnel in order to map the weakness zones. The results from the measurements in 6 wells show large variations in the rock qualities. The wells are drilled towards indicated weakness zones. Open water conducting cracks and sections with largely cracked rocks are detected in or in the proximity of the tunnel route. The weakness zone between the hornfels and the syenite west of the Langvatnet is largely cracked, has a large water conducting capacity and there are some unstable masses. Further east several open, watele masses. Further east several open, water- conducting cracks are detected in the syenite. Furthest to the east in the route cracked and unstable rocks are found. Several of the holes are blocked by ravines which confirm the poor rock quality. In the particular areas problems are to be expected during the operation with respect to water influx and stability. Methodically the drill hole studies have shown great value for the follow up of the 2D resistivity measurements on the ground. The indicated weakness zones through the 2D have been confirmed and characterised. The testing of the geophysical techniques has so far shown promising results. The 2D resistivity measurements on the ground with subsequent drilling, drill hole logging, pumping and flow measurements would give a good characterisation of the ground where the rock construction is planned. With a good geological foundation (structural mapping) the above techniques would contribute with valuable information concerning what may be expected in front of the hand specimen in tunnel work

172

Geological structures and geochronology of the Gonam Complex in the Gyeonggi Massif, South Korea  

Science.gov (United States)

Geological structures and geochronology of the Gonam Complex in the Gyeonggi Massif, South Korea You Hong Kihm and Sung Won Kim The Gonam complex is exposed in the westernmost part of the Gyeonggi Massif, which is recently thought be related with Triassic collision of China. This complex consists of various lithologies such as quartz schist, mica schist, quartzite, marble, leucocratic granite, mafic dyke and alkali granite. The Gonam complex can be divided into three units from south to north. The first is dominated by alternation of quartz schist and mica schist, which are intruded by leucocratic granites and mafic dykes. The second unit is highly sheared and folded quartzite. The last unit is composed of schists and marble intruded by acidic dykes, mafic dykes and foliated syenite. The deformation of the Gonam complex is characterized by one ductile shearing, two generations of folding, and four generations of faulting. The most prominent geological structures developed in the Gonam Complex are ductile structures, such as mylonitic foliations, mineral stretching lineations, sheath folds and oblique folds. At most outcrops the Gonam Complex was strongly sheared and intruded by amphibolitic dykes and leucocratic granites, which are also sheared. Widely developed mylonite indicates the ductile shearing occurred in high temperature metamorphic condition. SHRIMP zircon ages of detrital zircons obtained from schist and quartzite range from 3313 to 1819 Ma indicating the Gonam Complex deposited after Paleoproterozoic. Intrusion ages of foliated leucocratic granite, mafic dyke and foliated syenite are 821 Ma, 812 Ma and 751 Ma, respectively. And massive mafic dyke, syenite and two-mica granite (232~228 Ma) are interpreted as post-collisional igneous activity. These events are similar to those of Qinling-Dabie Belt and suggest that the Gyeonggi Massif is probably correlated to the Qinling-Dabie Belt.

Kihm, You Hong; Kim, Sung Won

2013-04-01

173

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)

174

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 (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

175

Systematization of survey and analysis of deep geological environment. Fiscal 2002  

International Nuclear Information System (INIS)

The survey and analysis of geological environment for practical use is studied from the view point of techniques, evaluation and geological environment. On techniques, EDZ (Excavation Disturbed Zone) was evaluated by AE (Acoustic Emission) measurement. The dynamic grouting technique for the improvement of low-permeable rock masses was developed and the grout effect by dynamic injection method was evaluated. The injection mechanism of grout was decided. On evaluation, the radionuclide transport was estimated by the mean, the standard deviation and the skewness of permeability. On the geological environment, the distribution of fissure and generation of micro crack in the rock near fault showed a tendency to distance from the fault. Systematization of following five survey and analysis methods was studied: evaluation of permeability of discontinuous rock in the deep underground, 3-D characteristics of stream in the rock, development of hydraulic test method and its equipment, survey and modeling method of material transport in deep underground, effects of drift on porewater in the different sedimentary rocks and evaluation of outflow of groundwater in river water in Kikuchi platform. (S.Y.)

176

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)

177

Methodology of safety assessment and sensitivity analysis for geologic disposal of high-level radioactive waste  

International Nuclear Information System (INIS)

A deterministic safety assessment methodology has been developed to evaluate long-term radiological consequences associated with geologic disposal of high-level radioactive waste, and to demonstrate a generic feasibility of geologic disposal. An exposure scenario considered here is based on a normal evolution scenario which excludes events attributable to probabilistic alterations in the environment. A computer code system GSRW thus developed is based on a non site-specific model, and consists of a set of sub-modules for calculating the release of radionuclides from engineered barriers, the transport of radionuclides in and through the geosphere, the behavior of radionuclides in the biosphere, and radiation exposures of the public. In order to identify the important parameters of the assessment models, an automated procedure for sensitivity analysis based on the Differential Algebra method has been developed to apply to the GSRW. (author)

178

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

International Nuclear Information System (INIS)

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

179

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

180

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

181

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

182

The geology and structural controls of the Olkaria geothermal system, Kenya  

Energy Technology Data Exchange (ETDEWEB)

Olkaria is a high-temperature geothermal system located within the central sector of the Kenya Rift Valley and associated with an area of late Quaternary rhyolitic volcanism. The geology is dominated by Pleistocene-Holocene comenditic rhyolite flows on the surface and basalts, trachytes and tuffs in the subsurface. The Olkaria field can be separated into east and west stratigraphic zones with the divide through the Olkaria Hill. The reservoir characteristics also follow this zonation. The geothermal reservoir in the east is hosted within Pleistocene Plateau Trachytes, while in the west it is within the Pliocene Mau Tuffs. Structural, geochemical, and hydrothermal alteration patterns indicate that the west field is at the margin of the larger Olkaria system. The anomalous bicarbonate enrichment in the west sector is due to additional adsorbed carbon dioxide from the mantle. (Author)

Omenda, Peter A. [Kenya Power Company, Naivasha (Kenya)

1998-02-01

183

FY 2000 report on the survey of the overseas geological structure. Japan-China joint coal exploration - Yu Xian project; 2000 nendo kaigai chishitsu kozo nado chosa hokokusho. Nippon Chugoku sekitan kyodo tansa Yu Xian project  

Energy Technology Data Exchange (ETDEWEB)

The geological survey was carried out which is needed for coal mine design in the Yu Xian coal mine area, Yu Xian coal field, Hebei province, China. The term of survey was 5 years from 1996 to 2000. Activities are mainly for seismic survey and boring survey. Japan was in charge of the seismic survey, and China in charge of the boring survey. Both attained the goal. The results of the activities were summed up in the following 7 items: 1) outline of the survey; 2) general investigation; 3) state of the exploration related materials/machinery; 4) field survey; 5) items of survey; 6) results of the survey; 7) conclusion. In 6), the geological analysis, coal quality survey and coal amount survey were conducted. In the geological analysis, analyzed were the succession of strata, geological structure, and the situation of existence of coal seams. In 7), the following were made clear: geological structure of the survey area, coal seam, coal quality, hydrological geology, other conditions of drilling technology, and coal amount. The coal amount was 328.34 million tons in a total of A/B/C class coals. The total coal amount of Nos. 1 and 5 coal seams was 259.79 million tons, which was 79.1% of the total coal amount in all area. The average thickness of Nos. 1 and 5 coal seams, which are the main minable coal seams, was 3.10m and 2.66m, respectively. (NEDO)

NONE

2001-03-01

184

Comparing results from neutron tomography and X-ray microtomography on sedimentary and metamorphic rocks with application to structural geology  

Science.gov (United States)

New techniques of data acquisition have provoked a rapidly increasing popularity of 3D analysis of geological structures, e.g. 3D seismic reflection on the large scale or tomographic methods on the sample scale. While reflection seismic data are an almost standard method to develop 3D structural subsurface models of sedimentary basins or fold- and thrust belts, the application of 3D tomographic analysis on hand specimen of structural interest is in its beginnings. We investigated drill cores from (1) a pegmatite mylonite and (2) a deformation band within highly porous limestones with (a) Neutron Tomography (NT) at the Atomic Institute of the Austrian Universities and (b) X-ray microtomography (X-ray CT) at the University of Mainz. Due to the specific setup of the radiation source and detectors, the two methods have different resolution of 200-300 microns (NT) and 10-100 microns (X-ray) CT. While X-ray measurements are mostly sensitive to density variations of the material, NT allows a certain level of chemical analysis, as individual elements show different attenuation of neutrons, in relation to the properties of the atom nucleus. Both methods depict the distribution of pore space within the limestone samples, but while X-ray CT shows clear contrast with simply air-filled pores, the results are of higher quality in the NT measurements if the pores are filled with water during measurements. On the one hand, the ability of the NT to distinguish between certain chemical elements, e.g. strong neutron scatterers (hydrogen) and neutron absorbers (boron, rare earth elements), may provide a useful tool for determination of 3D mineral shapes and distribution in metamorphic rock samples with well-known chemical composition and clearly distinguishable mineral phases. On the other hand, the high resolution X-ray measurements allows for very precise calculation of porosity and permeability in sedimentary rocks, which might be useful for petrophysical investigations in sedimentary rocks in hydrocarbon reservoirs.

Exner, U.; Hameed, F.; Zawisky, M.; Schwarz, J.-O.; Rath, A.; Grasemann, B.

2009-04-01

185

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)

186

The effect of geological structure and heterogeneity on CO2 storage in simple 4-way dip structures; a modeling study from the UK Southern North Sea  

OpenAIRE

The Bunter Sandstone Formation in the Southern North Sea is folded into a number of simple 4-way dip-closed structures (domes). Most of these structures are saline water-bearing, although some of them do contain significant gas accumulations, suggesting that the brine-saturated domes may have potential for the long-term storage of CO2. This study investigates the effect of geological structure and heterogeneity on CO2 storage through the use of geological models and reservoir simulation. Dyna...

Williams, J. D. O.; Bentham, M.; Jin, M.; Pickup, G.; Mackay, E.; Gammer, D.; Green, A.

2013-01-01

187

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

188

Geologic framework, structure, and hydrogeologic characteristics of the Knippa Gap area in eastern Uvalde and western Medina Counties, Texas  

Science.gov (United States)

The Edwards aquifer is the primary source of potable water for the San Antonio area in south-central Texas. The Knippa Gap was postulated to channel or restrict flow in the Edwards aquifer in eastern Uvalde County, and its existence was based on a series of numerical simulations of groundwater flow in the aquifer. To better understand the function of the area known as the Knippa Gap as it pertains to its geology and structure, the geologic framework, structure, and hydrogeologic characteristics of the area were evaluated by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers-Fort Worth District. The principal structural feature in the San Antonio area is the Balcones Fault Zone, which is the result of Miocene age faulting. In Medina County, the faulting of the Balcones Fault Zone has produced a relay-ramp structure that dips to the southwest from the Edwards aquifer recharge zone and extends westward and below land surface from Seco Creek. Groundwater flow paths in the Edwards aquifer are influenced by faulting and geologic structure. Some faults act as barriers to groundwater flow paths where the aquifer is offset by 50 percent or more and result in flow moving parallel to the fault. The effectiveness of a fault as a barrier to flow changes as the amount of fault displacement changes. The structurally complex area of the Balcones Fault Zone contains relay ramps, which form in extensional fault systems to allow for deformation changes along the fault block. In Medina County, the faulting of the Balcones Fault Zone has produced a relay-ramp structure that dips to the southwest from the Edwards aquifer recharge zone. Groundwater moving down the relay ramp in northern Medina County flows downgradient (downdip) to the structural low (trough) from the northeast to the southwest. In Uvalde County, the beds dip from a structural high known as the Uvalde Salient. This results in groundwater moving from the structural high and downgradient (dip) towards a structural low (trough) to the northeast. These two opposing structural dips result in a subsurface structural low (trough) locally referred to as the Knippa Gap. This trough is located in eastern Uvalde County beneath the towns of Knippa and Sabinal. By using data that were compiled and collected for this study and previous studies, a revised map was constructed depicting the geologic framework, structure, and hydrogeologic characteristics of the Knippa Gap area in eastern Uvalde and western Medina Counties, Tex. The map also shows the interpreted structural dip directions and interpreted location of a structural low (trough) in the area known as the Knippa Gap.

Clark, Allan K.; Pedraza, Diana E.; Morris, Robert R.

2013-01-01

189

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

190

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

191

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 medium-scale impacts (diameters of medium-scale impacts, is interpreted to form minor ridges because seismic shaking induces flow of regolith, which subsequently accumulates as minor ridges that are roughly parallel to the regional slope. In this work we expand upon the link between impact processes and 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

192

Ore lead isotopic composition as defined by geological structure: the central part of the North-East Asia territory  

International Nuclear Information System (INIS)

By means of mass-spectroscopy one investigated into isotopic composition of lead of sulfide ore galenites from the deposits in the North-East of Russia to determine correlation between isotopic characteristics of ore lead, on the one hand, geological structure and history of this region, on the other hand. On the basis of the obtained experimental data one calculated a model 207Pb-206Pb-age of ore deposits in that region. It is shown that within the limits of Verkhoyano-Chukot folding territory there are three lead-isotopic provinces differing in age of deposits, in geological and physicochemical conditions of orebody formation

193

NMR analysis of proteins structure  

International Nuclear Information System (INIS)

The nuclear magnetic resonance (NMR) analysis of proteins aims at determining the 3-D folding of the polypeptide chain. Because of the high number of nuclei observed in the samples, the NMR protein spectra are extremely complex. The different steps of the structure determination are: the preparation of the samples, the acquisition and processing of the NMR signal, the analysis and attribution of spectra, and the calculation of the coordinates of the atoms using the NMR spectra parameters. Content: 1 - proteins and peptides (composition and structure, secondary, tertiary and quaternary structure); 2 - NMR of proteins in solution (characteristics, structures determination, homonuclear experiments, heteronuclear experiments, proteins with a size higher than 20 kDa, intermolecular interactions, stability factors, internal molecular dynamics); 3 - structures calculation (calculation framework, distance geometry, molecular dynamics and simulated annealing, quality of the structure obtained). (J.S.)

194

Structural Setting of Northern Tunisia Insights from Gravity Data Analysis Jendouba Case Study  

Science.gov (United States)

Detailed gravity data in conjunction with available surface geology are analyzed to infer the organization of the underlying structures in Jendouba area. Gravity data analysis benefits from the gravity Bouguer anomaly, upward continuations, residual distribution, derivatives and Euler deconvolved maps. The main results display a positive amplitude gravity anomaly as the response of Triassic evaporitic bodies and important NE trending features at the boundaries between the Triassic outcrops and their enveloping strata. Integration of gravity, geological and structural maps let to the identification of major structural directions and trends of the study area. It confirms some structural elements gathered from outcrops. It defines also new ones.

Hamdi Nasr, Imen; Amiri, Adnen; Hédi Inoubli, Mohamed; Ben Salem, Abdelhmid; Chaqui, Abdelhak; Tlig, Said

2011-10-01

195

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

196

Study of the effects of local geological structure on seismic ground motion and building vulnerability with microtremors  

OpenAIRE

Examples of several earthquakes in last decades have shown that the influenceoflocalgeological structure (site effects) on seismic ground motion was often underestimated; the effects of the earthquake were therefore greater than expected. Especially dangerous is the situation when both the fundamental frequency of sediments and of structures are similar and a resonance occurs. Among the other methods for assessing the effects of local geology the use of microtremors achieved a recognition in ...

Andrej Gosar

2007-01-01

197

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

198

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

199

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

200

Surface geology of the Jeptha Knob cryptoexplosion structure, Shelby County, Kentucky  

Science.gov (United States)

The Jeptha Knob crytoexplosion structure, described by Bucher in 1925, was remapped in 1973 as part of the U.S. Geological Survey and the Kentucky Geological Survey cooperative mapping program. The knob is in the western part of the Blue Grass region. Hilltops in the rolling farmland adjacent to the knob are underlain by the nearly flat-lying Grant Lake and Callaway Creek Limestones of middle Late Ordovician age, and the valleys are cut in interbedded limestone and shale of the Clays Ferry Formation of late Middle and early Late Ordovician age. Precambrian basement is estimated to be 4,000 ft below the surface. The mapped area is 50 miles west of the crest of the Cincinnati arch; the regional dip is westward 16 ft per mile. The 38th parallel lineament is 50 miles to the south. The structure, about 14,000 ft in diameter, consists of a central area 6,300 ft in diameter of uplifted Clays Ferry Formation surrounded by a belt of annular faults that are divided into segments by radial faults. The grass structure of the Clays Ferry Formation is that of a broad dame, but same evidence indicates that, in detail, the beds are complexly folded. The limestone of the Clays Ferry is brecciated and infiltrated by limonite. The brecciation is confined to single beds, and there is no mixing of fragments from different beds. A small plug of the Logana Member of the Lexington Limestone (Middle Ordovician) has been upfaulted at least 700 ft and emplaced within the Clays Ferry. The central uplift is separated by high-angle and, in places, reverse faults from the belt of annular faulting. The concentric faults in the zone of annular faults are extensional, and the general aspect is of collapse and inward movement. Lenses of breccia are present along many of the concentric faults, but not along the radial faults. At least same of the breccia was injected from below. The youngest beds involved in the faulting are in the Bardstown Member of the Drakes Formation of late Late Ordovician age. The faulted and brecciated beds are overlain by nearly horizontal dolomite and shale of Early and Middle Silurian age. The basal 5 ft of the oldest Silurian unit, the Brassfield Formation, contains calcarenite and calcirudite composed, in large part, of locally derived fragments from the Upper Ordovician formations. The Jeptha Knob structure was formed in latest Late Ordovician or earliest Early Silurian time. At the time of formation, the area was either very slightly above or very slightly below sea level; the sediments were already largely indurated. At the onset of Silurian deposition, the area of the central uplift was probably a broad shallow depression not more than about 15 ft deep, possibly surrounded by a rim of Upper Ordovician rocks or rock fragments. The origin of the Jeptha Knob structure cannot be determined from the available data. Shatter cones and coesite, considered by many to be definitive criteria far origin by impact, have not been found. On the other hand, geophysical studies indicate that there is no coincident uplift of the basement, and there is no certain relation of Jeptha Knob to any obvious structural trend.

Cressman, Earle Rupert

1981-01-01

201

Fracture zone drilling through Atotsugawa fault in central Japan - geological and geophysical structure -  

Science.gov (United States)

Drilling is an effective method to investigate the structure and physical state in and around the active fault zone, such as, stress and strength distribution, geological structure and materials properties. In particular, the structure in the fault zone is important to understand where and how the stress accumulates during the earthquake cycle. In previous studies, we did integrate investigation on active faults in central Japan by drilling and geophysical prospecting. Those faults are estimated to be at different stage in the earthquake cycle, i.e., Nojima fault which appeared on the surface by the 1995 Great Kobe earthquake (M=7.2), the Neodani fault which appeared by the 1891 Nobi earth-quake (M=8.0), the Atera fault, of which some parts have seemed to be dislocated by the 1586 Tensyo earthquake (M=7.9), and Gofukuji Fault that is considered to have activated about 1200 years ago. Each faults showed characteristic features of fracture zone structure according to their geological and geophysical situations. In a present study, we did core recovery and down hole measurements at the Atotsugawa fault, central Japan, that is considered to have activated at 1858 Hida earthquake (M=7.0). The Atotsugawa fault is characterized by active seismicity along the fault. But, at the same time, the shallow region in the central segment of the fault seems to have low seismicity. The high seismicity segment and low seismicity segments may have different mechanical, physical and material properties. A 350m depth borehole was drilled vertically beside the surface trace of the fault in the low seismicity segment. Recovered cores were overall heavily fractured and altered rocks. In the cores, we observed many shear planes holding fault gouge. Logging data showed that the apparent resistance was about 100 - 600 ohm-m, density was about 2.0 - 2.5g/cm3, P wave velocity was approximately 3.0 - 4.0 km/sec, neutron porosity was 20 - 40 %. Results of physical logging show features of fault fracture zone that were the same as the fault fracture zones of other active faults that we have drilled previously. By the BHTV logging, we detected many fractures of which the strikes are not only parallel to the fault trace bur also oblique to the fault trace. The observations of cores and logging data indicate that the borehole passed in the fracture zone down to the bottom, and that the fracture zone has complicate internal structure including foliation not parallel to the fault trace. The core samples are significant for further investigation on material properties in the fracture zone. And we need data of geophysical prospecting to infer the deeper structure of the fracture zone.

Omura, K.; Yamashita, F.; Yamada, R.; Matsuda, T.; Fukuyama, E.; Kubo, A.; Takai, K.; Ikeda, R.; Mizuochi, Y.

2004-12-01

202

2D resistivity survey in complex geological structure area. Application to the volcanic area; Fukuzatsuna chishitsu kozo chiiki ni okeru hiteiko nijigen tansa. Kazangan chiiki deno tekiorei  

Energy Technology Data Exchange (ETDEWEB)

Introduced herein is an application of 2D resistivity survey to a volcanic rock area where the survey result is difficult to interpret because of its complex geological structure. In a dam site survey, main problems involve the permeability of water through faults and weathered, altered zones. At this site, a 2D resistivity survey was conducted, a 2D geological structure was deduced from the resistivity section, and the result was examined. It was found that resistivity distribution was closely related to hydrographic factors, but no obvious correlation was detected between rock classes and R, Q, and D. In conducting investigations into a section planned for a highway tunnel, it was learned that the problem was a volcanic ash layer to collapse instantly upon absorbing water, and the distribution of the ash layer, not to be disclosed by boring, was subjected to a 2D resistivity survey. The survey was conducted into the structure above where the tunnel would run, and further into the face, and studies were made about what layer was reflected by the resistivity distribution obtained by analysis. The result of the analysis agreed with the details of the layer that was disclosed afterward. 4 figs., 1 tab.

Asakawa, S.; Ikuma, T.; Tanifuji, R. [DIA Consultants Co. Ltd., Tokyo (Japan)

1996-05-01

203

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

204

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

205

Predictive uncertainty analysis of plume distribution for geological carbon sequestration using sparse-grid Bayesian method  

Science.gov (United States)

Because of the extensive computational burden, parametric uncertainty analyses are rarely conducted for geological carbon sequestration (GCS) process based multi-phase models. The difficulty of predictive uncertainty analysis for the CO2 plume migration in realistic GCS models is not only due to the spatial distribution of the caprock and reservoir (i.e. heterogeneous model parameters), but also because the GCS optimization estimation problem has multiple local minima due to the complex nonlinear multi-phase (gas and aqueous), and multi-component (water, CO2, salt) transport equations. The geological model built by Doughty and Pruess (2004) for the Frio pilot site (Texas) was selected and assumed to represent the 'true' system, which was composed of seven different facies (geological units) distributed among 10 layers. We chose to calibrate the permeabilities of these facies. Pressure and gas saturation values from this true model were then extracted and used as observations for subsequent model calibration. Random noise was added to the observations to approximate realistic field conditions. Each simulation of the model lasts about 2 hours. In this study, we develop a new approach that improves computational efficiency of Bayesian inference by constructing a surrogate system based on an adaptive sparse-grid stochastic collocation method. This surrogate response surface global optimization algorithm is firstly used to calibrate the model parameters, then prediction uncertainty of the CO2 plume position is quantified due to the propagation from parametric uncertainty in the numerical experiments, which is also compared to the actual plume from the 'true' model. Results prove that the approach is computationally efficient for multi-modal optimization and prediction uncertainty quantification for computationally expensive simulation models. Both our inverse methodology and findings can be broadly applicable to GCS in heterogeneous storage formations.

Shi, X.; Zhang, G.

2013-12-01

206

Constructive epistemic modeling of groundwater flow with geological structure and boundary condition uncertainty under the Bayesian paradigm  

Science.gov (United States)

Constructive epistemic modeling is the idea that our understanding of a natural system through a scientific model is a mental construct that continually develops through learning about and from the model. Using hierarchical Bayesian model averaging (BMA), this study shows that segregating different uncertain model components through a BMA tree of posterior model probability, model prediction, within-model variance, between-model variance and total model variance serves as a learning tool. First, the BMA tree of posterior model probabilities permits the comparative evaluation of the candidate propositions of each uncertain model component. Second, systemic model dissection is imperative for understanding the individual contribution of each uncertain model component to the model prediction and variance. Third, the hierarchical representation of the between-model variance facilitates the prioritization of the contribution of each uncertain model component to the overall model uncertainty. We illustrate these concepts using the groundwater flow model of a siliciclastic aquifer-fault system. We consider four uncertain model components. With respect to geological structure uncertainty, we consider three methods for reconstructing the hydrofacies architecture of the aquifer-fault system, and two formation dips. We consider two uncertain boundary conditions, each having two candidate propositions. Through combinatorial design, these four uncertain model components with their candidate propositions result in 24 base models. The study shows that hierarchical BMA analysis helps in advancing knowledge about the model rather than forcing the model to fit a particularly understanding or merely averaging several candidate models.

Elshall, Ahmed S.; Tsai, Frank T.-C.

2014-09-01

207

Crustal structure under the central High Atlas Mountains (Morocco) from geological and gravity data  

Science.gov (United States)

Seismic wide angle and receiver function results together with geological data have been used as constraints to build a gravity-based crustal model of the central High Atlas of Morocco. Integration of a newly acquired set of gravity values with public data allowed us to undertake 2-2.5D gravity modelling along two profiles that cross the entire mountain chain. Modelling suggests moderate crustal thickening, and a general state of Airy isostatic undercompensation. Localized thickening appears restricted to the vicinity of a north-dipping crustal-scale thrust fault, that offsets the Moho discontinuity and defines a small crustal root which accounts for the minimum Bouguer gravity anomaly values. Gravity modelling indicates that this root has a northeasterly strike, slightly oblique to the ENE general orientation of the High Atlas belt. A consequence of the obliquity between the High Atlas borders and its internal and deep structure is the lack of correlation between Bouguer gravity anomaly values and topography. Active buckling affecting the crust, a highly elevated asthenosphere, or a combination of both are addressed as side mechanisms that help to maintain the high elevations of the Atlas mountains.

Ayarza, P.; Alvarez-Lobato, F.; Teixell, A.; Arboleya, M. L.; Tesón, E.; Julivert, M.; Charroud, M.

2005-05-01

208

Proposed structural design criteria for high-level radioactive waste containment for deep geologic disposal  

International Nuclear Information System (INIS)

The United States government has established a program for the disposal of spent nuclear fuel and high-level radioactive waste. The Nuclear Waste Policy Act (NWPA) of 1982 requires the first nuclear waste repository to begin receiving high-level radioactive waste in 1998. One of the potentially acceptable sites currently being evaluated is the Hanford Site in the Pasco Basin where the host rock is basalt. Under the direction of the United States Department of Energy (DOE), Rockwell International's Rockwell Hanford Operations (RHO) has initiated the Basalt Waste Isolation Project (BWIP). The BWIP must design waste packages for emplacement in the repository. The current approach to waste package structural design is to directly apply the design rules provided for Class 1 Nuclear Components in the ASME Boiler and Pressure Vessel Code. A repository container differs from a typical power plant vessel in a number of significant areas. Perhaps most important is the fact that personnel access to the container is impossible once it is loaded by hydrostatic or lithostatic pressure. This paper recommends new design criteria applicable to metallic containment vessel for deep geologic disposal of high-level waste. These criteria provide adequate safety under repository conditions without placing unreasonable requirements on the container or requiring unnecessary wall thickness

209

Geological evolution and analysis of confirmed or suspected gas hydrate localities. Volume 2. Baltimore Canyon Trough and environs - US East Coast  

Energy Technology Data Exchange (ETDEWEB)

This document is Volume 2 of a series of reports entitled ''Geological Evolution and Analysis of Confirmed or Suspected Gas Hydrate Localities.'' Volume 2 provides an analysis of the ''Baltimore Canyon Trough and Environs - US East Coast.'' The report presents a geological description of the Baltimore Canyon Trough region, including regional and local structural settings, geomorphology, geological history, stratigraphy, and physical properties. Included also is a discussion of bottom simulating acoustic reflectors, sediment acoustic properties, distribution of hydrates within the sediments, and the relation of hydrate distribution to other features such as salt diapirism. The formation and stabilization of gas hydrates in sediments are discussed in terms of phase relations, nucleation, and crystallization constraints, gas solubility, pore fluid chemistry, inorganic diagenesis, and sediment organic content. A depositional analysis of the area is discussed in order to better understand the thermal evolution of the locality and to assess the potential for thermogenic hydrocarbon generation. 117 refs., 31 figs., 8 tabs.

Krason, J.; Ridley, W.I.

1985-06-01

210

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

211

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

212

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.)

213

Certain features of occurrence and geological structure of natural bitumen accumulations  

Energy Technology Data Exchange (ETDEWEB)

Questions are examined of classification of natural bitumen accumulations. It was established that the largest accumulations are confined to traps of the structural type. In the example of specific fields, an analysis was made of the conditions for occurrence of natural bitumens and the nature of interrelationships between individual parameters of beds and formations.

Klimushin, I.M.; Messineva, N.I.; Vorontsova, G.V.; Zhidenko, Ye.A.

1981-01-01

214

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

215

Analysis of geological aspects and visual impact rising from the realisation of a wind power station in an Italian mountain area (Central Appennines)  

International Nuclear Information System (INIS)

This study evaluates some aspects of the environmental impacts arising from the wind power station in the Central Appennines of Italy, particularly with reference to the geological and geotechnical conditions of the site and the visual impact on the landscape. Starting from a large-scale analysis that takes into account the Appennines orogeny and their geodynamic process, it is possible to define the geological characteristics of the considered area. It is possible to analyse structural and morphological aspects, in this way it is possible to identify the most suitable location of power generators in the area and to optimise the road network. The geo-stratigraphical study aids decisions about foundations, excavations and works of containments. Considerations on earth traspiration and on rill identify the necessity of controlling surface waters, evolutionary phenomena and the soil stability of the considered areas. Particular attention has been given to analyse effects on the landscape. (author)

216

Geological control of canopy structure and function in Panamanian forests as identified by CAO-AToMS  

Science.gov (United States)

Geological formations and their edaphic properties are known to control plant species composition in tropical forests. It has been speculated that these edaphic and compositional patterns might also be translated into functional patterns, but this has been difficult to test due to a lack of broad-scale but detailed canopy structural and functional data. Here we use the Carnegie Airborne Observatory (CAO) Airborne Taxonomic Mapping System (AToMS), which combines a 480-band visible-to-shortwave imaging spectrometer (VSWIR) with dual waveform LiDAR, to generate ultra-high resolution data on geomorphology, canopy structure, and canopy chemistry for forests in the vicinity of the Panama Canal. Using these remotely-sensed data, in conjunction with field data on soils and plant species composition, we demonstrate that geological formations regulate forest structure and chemistry in these forests via changes in soils and plant species composition. These chemical properties, moreover, correspond to canopy functional properties including photosynthetic investment and anti-herbivore defenses. Together, our findings indicate that forest canopy structure and function in these forests are an expression their geological history, over which variations due to contemporary variables such as climate are overlaid.

Higgins, M.; Asner, G. P.; Martin, R. E.; Knapp, D. E.

2012-12-01

217

Adaptive analysis of plate structures  

OpenAIRE

The thesis deals with adaptive ?nite element modeling of plate structures. The ?nite element modeling of plates has grown to a mature research topic, which has contributed signi?cantly to the development of the ?nite element method for structural analysis due to its complexity and inherently speci?c issues. At present, several validated plate models and corresponding families of working and e?cient ?nite elements are available, o?ering a sound basis for an engineer to choose f...

Bohinc, Uros?

2011-01-01

218

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

219

Structural analysis for LMFBR applications  

International Nuclear Information System (INIS)

Firstly, we discuss the use of elastic analysis for structural design of LMFBR components. The elastic analysis methods have been used for structural design of the Fast Breeder Test Reactor as well as the proposed prototype Test Breeder Reactor. The design of Fast Breeder Test Reactor which is nearing completion is the same as that of Rapsodie. Nevertheless, the design had to he checked against the latest design codes available, namely the ASME Code case 1592. This paper however, is confined to Structural analysis of PFBR components. The problems faced in the design of some of the components, in particular, the inner vessel (plenum separator) are discussed. As far as design codes are concerned, we make use of ASME Code Section III and the Code Case N-47, for high temperature design. The problem faced in the use of these rules are also described along with the description of analysis. Studies in the field of cyclic loading include extension of Bree's breakdown and plastic cycling criteria for ratchet free operation to biaxial stress fields. In other fields, namely, inelastic analysis, piping analysis in the creep regime etc. we are only at a start

220

Characterization of Geologic Structures and Host Rock Properties Relevant to the Hydrogeology of the Standard Mine in Elk Basin, Gunnison County, Colorado  

Science.gov (United States)

The Standard Mine Superfund Site is a source of mine drainage and associated heavy metal contamination of surface and groundwaters. The site contains Tertiary polymetallic quartz veins and fault zones that host precious and base metal sulfide mineralization common in Colorado. To assist the U.S. Environmental Protection Agency in its effort to remediate mine-related contamination, we characterized geologic structures, host rocks, and their potential hydraulic properties to better understand the sources of contaminants and the local hydrogeology. Real time kinematic and handheld global positioning systems were used to locate and map precisely the geometry of the surface traces of structures and mine-related features, such as portals. New reconnaissance geologic mapping, field and x-ray diffraction mineralogy, rock sample collection, thin-section analysis, and elemental geochemical analysis were completed to characterize hydrothermal alteration, mineralization, and subsequent leaching of metallic phases. Surface and subsurface observations, fault vein and fracture network characterization, borehole geophysical logging, and mercury injection capillary entry pressure data were used to document potential controls on the hydrologic system.

Caine, Jonathan S.; Manning, Andrew H.; Berger, Byron R.; Kremer, Yannick; Guzman, Mario A.; Eberl, Dennis D.; Schuller, Kathryn

2010-01-01

221

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)

222

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

223

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

224

Capability Study For Using the Impulse Graphite Reactor For Activation Analysis of Geological Materials  

International Nuclear Information System (INIS)

The IGR reactor facility available in the Institute of Atomic Energy NNC RK is mainly used for testing the going and newly developed fuel compositions and reactor materials. In connection with a decrease of the demand in investigations like that there was considered the capability to use the reactor for solving another research and, particularly, applied problems. A mineral exploration is one of the urgent objectives in the Republic of Kazakstan, and in Semipalatinsk region in particular. To perform the exploration like that it's required, in addition to rough field investigations, the methods of analysis for element composition of geological materials, the difference of which is in their effectiveness, quality and low first cost. Activation methods of analysis allow to provide with a high analysis quality and effectiveness. Therefore, there was proposed to study the capability to use the IGR reactor for the activation analysis of geological materials. To solve this goal the following activity in three basic trends is required: 1. To create the needed theoretical and, on its basis, the methodical base for performing the analytical activity; 2. To create the experimental and technical and organizational infrastructure for the investigations, providing with a high productivity and low prime cost of work; 3. To conduct works on marketing and to use the going methodical and technical base on the market of services. Major objectives for the creation of the theoretical and methodical base for analysis are: a) the study of neutron and physical IGR reactor characteristics under various operation modes; b) the study of the radiation effect on the results of activation analysis; c) the simulation of the temperature mode for irradiation of samples in the reactor and experimental model survey; d) the study of the capability to use non-traditional elements and materials as neutron reactor flux monitors; e) the development of the technique for the experimental and computational determination of neutron flux fluence and its spectral composition; f) the development, fabrication and experimental testing of irradiation devices of various types; g) the study of the sample geometry effect on the outcomes of the analysis; h) the optimization of the processes for the samples preparation to the irradiation and gamma-spectrometric analysis of the irradiated material; i) the development of the methodical provision for the activation analysis; j) the development of the software for the complex of works on the activation analysis; Major targets solved in the field of creating the required infrastructure for the work implementation: a) to create the site for samples production for the activation analysis; b) to create the system for the samples shipping to the area for conducting analysis; c) to create the site close to the reactor to conduct the activation analysis; d) to create the site for radiochemical preparation of samples for activation analysis. In addition, the capability to create the anticipated technical base is considered: a) for analyzing samples by the method of gamma-activation analysis (in particular, to identify beryllium); b) for determining the fission materials composition (including plutonium) in samples by various methods (for example, on delayed neutrons)

225

Study of the deep electrical structure and geological significance in south of Lishui-Haifeng fault  

Science.gov (United States)

Consider the southern part of Zhenghe-Dafu fault and its extension to Guangdong as Lishui-Haifeng fault,it is the most important earthquake development belt and metallogenic belt in southeasten coast of China.The paper studies the deep electrical structure and geological property by using the 4 magnetotellurc profiles which perpendicular to the strike direction of the fault.There are three symbolic electric layers in the study area.The first layer with high resistivity is widely distributed along the profile, the resistivity is up to 5000ohm-m.In the west of the fault,the resistors are discontinuously distributed.In the east of the fault, the resistors are continuously,these resistors are speculated to be granite from different periods.The second electrical layer is a conductive layer with the resistivity of 10ohm-m which discontinuously distributed in the depth of 10km-30km,the layer is speculated as a highly conductive layer in the crust.The third electrical layer is a medium low-resistivity layer with resistivity value between 100-1000ohm-m and its top interface connects with the high-conductivity layer.The distribution of this layer is at a very wide range. Bounded by the fault,the electrical structures on both sides of the fault zone are quite different.The distribution of the resistors is thick in the west and thin in the east,the granite with high resistivity in the west of the fault is thicker than 20km,the granite in the east of the fault is linearly distributed with the thickness less than 10km,The southern part of Lishui-Haifeng fault zone performed as thrusting structure between the late Indosinian stage and the early Yanshan period which had a strong invasive activity along the west side of the fault zone and led to the formation of the thick granites in the west side of the fault zone;As the invasion continued,this part performed mainly as the extension-collapse in the Yanshan period,upwelling of the shallow magma chamber formed the distribution pattern of granite in the east side of the fault zone.The results confirm that the granite from late Yanshan period in south China mainly distributed in the east of Lishui-Haifeng fault.

Han, J.; Liu, G.; Han, K.; Shan, C.; Han, S.

2011-12-01

226

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.

227

Geologic studies  

International Nuclear Information System (INIS)

The modern Great Divide Basin is the end product of natural forces influenced by the Green River lake system, Laramide tectonism, and intermittent volcanic events. It ranks as one of the most complex structural and stratigtaphic features within the Tertiary basins of Wyoming. Portions of the Great Divide Basin and adjoining areas in Wyoming have been investigated by applying detailed and region exploration methods to known uranium deposits located within the Red Desert portions of the basin. Geologic field investigations conducted by Bendix Field Engineering Corporaton (Bendix) were restricted to reconnaissance observations made during infrequent visits to the project area by various Bendix personnel. Locations of the most comprehensive field activities are shown in Figure II-1. The principal source fo data for geologic studies of the Red Desert project area has been information and materials furnished by industry. Several hundred holes have been drilled by various groups to delineate the uranium deposits. Results from Bendix-drilled holes at selected locations within the project area are summarized in Table II-1. Additional details and gross subsurface characteristics are illustrated in cross sections; pertinent geologic features are illustrated in plan maps. Related details of continental sedimentation that pertain to the Wyoming Basins generally, and the project area specificially, are discussed in subsections of this Geologic Studies sectiongic Studies section

228

Shallow seismic reflection profiles and geological structure in the Benton Hills, southeast Missouri  

Science.gov (United States)

During late May and early June of 1993, we conducted two shallow, high-resolution seismic reflection surveys (Mini-Sosie method) across the southern escarpment of the Benton Hills segment of Crowleys Ridge. The reflection profiles imaged numerous post-late Cretaceous faults and folds. We believe these faults may represent a significant earthquake source zone. The stratigraphy of the Benton Hills consists of a thin, less than about 130 m, sequence of mostly unconsolidated Cretaceous, Tertiary and Quaternary sediments which unconformably overlie a much thicker section of Paleozoic carbonate rocks. The survey did not resolve reflectors within the upper 75-100 ms of two-way travel time (about 60-100 m), which would include all of the Tertiary and Quaternary and most of the Cretaceous. However, the Paleozoic-Cretaceous unconformity (Pz) produced an excellent reflection, and, locally a shallower reflector within the Cretaceous (K) was resolved. No coherent reflections below about 200 ms of two-way travel time were identified. Numerous faults and folds, which clearly offset the Paleozoic-Cretaceous unconformity reflector, were imaged on both seismic reflection profiles. Many structures imaged by the reflection data are coincident with the surface mapped locations of faults within the Cretaceous and Tertiary succession. Two locations show important structures that are clearly complex fault zones. The English Hill fault zone, striking N30??-35??E, is present along Line 1 and is important because earlier workers indicated it has Pleistocene Loess faulted against Eocene sands. The Commerce fault zone striking N50??E, overlies a major regional basement geophysical lineament, and is present on both seismic lines at the southern margin of the escarpment. The fault zones imaged by these surveys are 30 km from the area of intense microseismicity in the New Madrid seismic zone (NMSZ). If these are northeast and north-northeast oriented fault zones like those at Thebes Gap they are favorably oriented in the modern stress field to be reactivated as right-lateral strike slip faults. Currently, earthquake hazards assessments are most dependent upon historical seismicity, and there are little geological data available to evaluate the earthquake potential of fault zones outside of the NMSZ. We anticipate that future studies will provide evidence that seismicity has migrated between fault zones well beyond the middle Mississippi Valley. The potential earthquake hazards represented by faults outside the NMSZ may be significant.

Palmer, J.R.; Hoffman, D.; Stephenson, W.J.; Odum, J.K.; Williams, R.A.

1997-01-01

229

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

International Nuclear Information System (INIS)

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

230

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)

231

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

Science.gov (United States)

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

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

2014-05-01

232

Structural analysis of vibroacoustical processes  

Science.gov (United States)

The method of automatic identification of acoustical signals, by means of the segmentation was used to investigate noises and vibrations in machines and mechanisms, for cybernetic diagnostics. The structural analysis consists of presentation of a noise or vibroacoustical signal as a sequence of segments, determined by the time quantization, in which each segment is characterized by specific spectral characteristics. The structural spectrum is plotted as a histogram of the segments, also as a relation of the probability density of appearance of a segment to the segment type. It is assumed that the conditions of ergodic processes are maintained.

Gromov, A. P.; Myasnikov, L. L.; Myasnikova, Y. N.; Finagin, B. A.

1973-01-01

233

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

234

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

235

Stereological analysis of spatial structures  

DEFF Research Database (Denmark)

The thesis deals with stereological analysis of spatial structures. One area of focus has been to improve the precision of well-known stereological estimators by including information that is available via automatic image analysis. Furthermore, the thesis presents a stochastic model for star-shaped three-dimensional objects using the radial function. It appears that the model is highly fleksiblel in the sense that it can be used to describe an object with arbitrary irregular surface. Results on the distribution of well-known local stereological volume estimators are provided.

Hansen, Linda Vadgård

2011-01-01

236

The Beaverhead impact structure, SW Montana and Idaho: Implications for the regional geology of the western U.S.  

Energy Technology Data Exchange (ETDEWEB)

The Beaverhead impact structure in SW Montana and Idaho is an allochthonous fragment of a large impact structure ({approximately} 100 km diameter) that was transported some distance eastward during the Cretaceous Sevier orogeny. It is the first tectonic fragment of a large impact structure identified in the geologic record. The present evidence for impact consists of shatter cones, pseudotachylites, and planar deformation features in quartz. The age of the impact is not well constrained but is estimated to be Neoproterozoic to Cambrian (1000-500 Ma). The Beaverhead impact event must have created other features that may be preserved, elsewhere in western Montana and Idaho. These include proximal and distal ejecta (which may be misinterpreted as diamictites and/or tuff horizons) and other fragments of the crater floor containing shatter cones and pseudotachylite. A large circular gravity, magnetic and topographic anomaly, which could be the root of the impact structure, has been identified near Challis, Idaho. An enigmatic lithic tuff, identified in drill cores from the Challis area and an intraformational quartzite breccia in the Leaton Gulch area may be impact-related deposits, but no definitive evidence of shock metamorphism has been observed in these materials. The discovery of more pieces of the Beaverhead puzzle, as well as the recognition of other large impacts in the geologic record, are likely once the regional geologic community grows to accept the incidence of such events and becomes more familiar with the features of shock metamorphism in the field. To that end, the community of geologists in this area should integrate the Beaverhead structure into their research and teaching curriculum.

Fiske, P.S.; Hargaves, R.B.

1994-03-17

237

Glycosphingolipid structural analysis and glycosphingolipidomics.  

Science.gov (United States)

Sphingosines, or sphingoids, are a family of naturally occurring long-chain hydrocarbon derivatives sharing a common 1,3-dihydroxy-2-amino-backbone motif. The majority of sphingolipids, as their derivatives are collectively known, can be found in cell membranes in the form of amphiphilic conjugates, each composed of a polar head group attached to an N-acylated sphingoid, or ceramide. Glycosphingolipids (GSLs), which are the glycosides of either ceramide or myo-inositol-(1-O)-phosphoryl-(O-1)-ceramide, are a structurally and functionally diverse sphingolipid subclass; GSLs are ubiquitously distributed among all eukaryotic species and are found in some bacteria. Since GSLs are secondary metabolites, direct and comprehensive analysis (metabolomics) must be considered an essential complement to genomic and proteomic approaches for establishing the structural repertoire within an organism and deducing its possible functional roles. The glycosphingolipidome clearly comprises an important and extensive subset of both the glycome and the lipidome, but the complexities of GSL structure, biosynthesis, and function form the outlines of a considerable analytical problem, especially since their structural diversity confers by extension an enormous variability with respect to physicochemical properties. This chapter covers selected developments and applications of techniques in mass spectrometric (MS) that have contributed to GSL structural analysis and glycosphingolipidomics since 1990. Sections are included on basic characteristics of ionization and fragmentation of permethylated GSLs and of lithium-adducted nonderivatized GSLs under positive-ion electrospray ionization mass spectrometry (ESI-MS) and collision-induced mass spectrometry (CID-MS) conditions; on the analysis of sulfatides, mainly using negative-ion techniques; and on selected applications of ESI-MS and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to emerging GSL structural, functional, and analytical issues. The latter section includes a particular focus on evolving techniques for analysis of gangliosides, GSLs containing sialic acid, as well as on characterizations of GSLs from selected nonmammalian eukaryotes, such as dipterans, nematodes, cestodes, and fungi. Additional sections focus on the issue of whether it is better to leave GSLs intact or remove the ceramide; on development and uses of thin-layer chromatography (TLC) blotting and TLC-MS techniques; and on emerging issues of high-throughput analysis, including the use of flow injection, liquid chromatography mass spectrometry (LC-MS), and capillary electrophoresis mass spectrometry (CE-MS). PMID:16413319

Levery, Steven B

2005-01-01

238

Reactor neutron activation analysis of geological samples and a comparison with other non-nuclear analytical techniques  

International Nuclear Information System (INIS)

The status of neutron activation analysis (NAA) in geological research is discussed. The technique was developed as far back as the beginning of the 1970s, though since then no improvement in detectable elements or accuracy has taken place. Approximately 40 elements can be analysed by instrumental activation analysis. By applying radiochemical separation, the number of elements that can be analysed increases to almost 70. Compared with other analytical methods used in geological research, activation analysis has some unique features. It thus continues to have a strong position in basic geochemical research. About half of all the publications dealing with basic research includes activation analysis determinations. In routine geochemical surveys and mineral exploration, NAA is much less frequently used. However, a few examples of geochemical surveys, especially for uranium, but also gold and other elements, can be found in the literature. (author). 48 refs, 8 tabs

239

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

240

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

241

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

242

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

243

Instrumental neutron activation analysis of Moroccan geological samples using the k0-standardization method  

International Nuclear Information System (INIS)

Instrumental neutron activation analysis (INAA) for traces and major elements of several geological samples from 'Zgounder' region in Morocco was performed utilizing the k0-standardization method. Sample irradiation has been done by the 250 kW Triga Mark II reactor at Jozef Stefan Institute in Slovenia. Due to its accuracy, sensitivity and specificity, the k0-standardization method is the most suitable method for non-destructive multielement analysis mainly for trace elements in rocks. It requires an accurate knowledge of the parameters of the irradiation facilities and other instrumentation parameters. It is an absolute standardization method, where the absolute nuclear data are replaced by a nuclear constant, the k0-factor, determined experimentally with high accuracy. More than 40 elements were determined using about 30-second short and about 7-hour long irradiations. Gamma-rays emitted from the irradiated samples have been determined by a high purity germanium detector. Accuracy was assessed using the standard reference material AGV-1. This was less than 1% for major elements and about 5% for traces. (author)

244

Crustal structure of the Western Carpathians and Pannonian Basin: Seismic models from CELEBRATION 2000 data and geological implications  

Science.gov (United States)

During the CELEBRATION 2000 seismic experiment, the Western Carpathians and Pannonian basin region was investigated by a dense system of deep seismic sounding profiles. In this paper, we present the results of modeling refracted and reflected waves employing 2D ray tracing for seven interlocking profiles that were jointly modeled and interpreted with the constraint that the models match at the crossing points of the profiles. The resulting P-wave velocity models reveal complex structures in the crust and large variations in the depth of the Moho discontinuity (˜25-45 km). In the southern part of the area, the relatively thin Pannonian basin crust consists of 3-7 km thick sediments and two crustal layers with velocities of 5.9-6.3 km/s in the upper crust and 6.3-6.6 km/s in the lower crust. In the central region, the upper crust of the ALCAPA (Alpine-Carpathian-Pannonian) microplate contains a high velocity body of Vp ? 6.4 km/s, which spatially corresponds with the Bükk Composite Terrane. The total thickness of the ALCAPA crust is 1-2 km greater than in the adjacent Tisza-Dacia microplate. To the north in the area of the Trans-European suture zone (TESZ) and Carpathian foredeep, we observe a 10-20 km thick upper crust with low velocity ( Vp ? 6.0 km/s). Sub-Moho velocities have average values of 7.8-8.0 km/s for the Pannonian basin, while in the Western Carpathians, the TESZ and the East European Craton (EEC) area, they are slightly higher (8.0-8.1 km/s). Lower velocities beneath the ALCAPA and Tisza-Dacia microplates could be caused by compositional variations and the significantly higher surface heat flow. Beneath some profiles, reflectors in the lithospheric mantle were found sub-parallel to the Moho but 10-20 km below it. Our integrated geophysical and geological analysis indicates that the observed structure was created by collision of two lithospheric plates with only a moderate degree of convergence. The northern plate consists of older European tectonic units of the EEC and TESZ. However, the southern one consists of younger tectonic units of the Western Carpathians and the back-arc Pannonian basin that generated the ALCAPA and Tisza-Dacia microplates. We interpret the complex present day structure to be the result of the soft continental collision between the ALCAPA and Tisza-Dacia microplates and the south margin of the European plate, which was mainly followed by the extensional process beneath the back-arc Pannonian basin.

Janik, Tomasz; Grad, Marek; Guterch, Aleksander; Vozár, Jozef; Bielik, Miroslav; Vozárova, Anna; Heged?s, Endre; Kovács, Csaba Attila; Kovács, István; Keller, G. Randy; Celebration 2000 Working Group

2011-08-01

245

Gravity analyses for the crustal structure and subglacial geology of West Antarctica, particularly beneath Thwaites Glacier  

Science.gov (United States)

The West Antarctic Ice Sheet (WAIS) is mostly grounded in broad, deep basins (down to 2.5 km below sea level) that are stretched between five crustal blocks. The geometry of the bedrock, being mostly below sea level, induces a fundamental instability in the WAIS through the possibility of runaway grounding line retreat. The crustal environment of the WAIS further influences the ice sheet's fast flow through conditions at the ice-bedrock boundary. This study focuses on understanding the WAIS by examining the subglacial geology (such as volcanoes and sedimentary basins) at the ice-bedrock boundary and the continent's deeper crustal structure- primarily using airborne gravity anomalies. The keystone of this study is a 2004-2005 aerogeophysical survey over one of the most negative mass balance glaciers on the continent: Thwaites Glacier (TG). The gravity anomalies derived from this dataset- as well as gravity-based modeling and spectral crustal boundary depth estimates- reveal a heterogeneous crustal environment beneath the glacier. The widespread Mesozoic rifting observed in the Ross Sea Embayment (RSE) of West Antarctica extends beneath TG, where the crust is ˜27 km thick and cool. Adjacent to TG, spectrally-derived shallow Moho depths for the Marie Byrd Land (MBL) crustal block can be explained by thermal support from warm mantle. I assemble here new compilations of free-air and Bouguer gravity anomalies across West Antarctica (from both airborne and satellite datasets) and re-interpret the extents of West Antarctic crustal block and their boundaries with the rift system. Airy isostatic gravity anomalies reveal that TG is relatively sediment starved, in contrast to the sediment-rich RSE. TG's fast flow velocities could be sustained in this sediment poor environment if higher heat flux in MBL was providing an ample source of subglacial melt water to the glacier. The isostatic anomalies also indicate that TG's outlet rests on a bedrock sill that will impede future grounding line retreat (up to ˜100 km) and temporarily stabilize the glacier.

Diehl, Theresa Marie

246

Quantification of rock heterogeneities by structural geological field studies combined with laboratory analyses  

Science.gov (United States)

Heterogeneous rock properties in terms of layering and complex infrastructure of fault zones are typical in sedimentary successions. The knowledge of in-situ mechanical rock properties is crucial for a better understanding of processes such as fracturing and fluid transport in fractured reservoirs. To estimate in situ rock properties at different depths it is important to understand how rocks from outcrops differ from rocks at depth, for example due to alteration and removal of the overburden load. We aim at quantifying these properties by performing structural geological field studies in outcrop analogues combined with laboratory analyses of outcrop samples and drill-cores. The field studies focus on 1) fault zone infrastructure and 2) host rock fracture systems in two different study areas with different lithologies, the North German and the Bristol Channel Basin. We analyse quantitatively the dimension, geometry, persistence and connectivity of fracture systems. The field studies are complemented by systematic sampling to obtain the parameters Young's modulus, compressive and tensile strengths and elastic strain energy (also referred to as destruction work) from which we estimate rock and fracture toughnesses. The results show that in rocks with distinctive layering fractures are often restricted to individual layers, that is, stratabound. The probability of arrest seems to depend on the stiffness contrast between two single layers as well as on the thickness of the softer layer. The results also show that there are clear differences between fault zones in the different lithologies in terms of damage zone thicknesses and fracture system parameters. The results of laboratory analyses show that the mechanical properties vary considerably and for many samples there are clear directional differences. That is, samples taken perpendicular to layering commonly have higher stiffnesses and strengths than those taken parallel to layering. We combine the results of laboratory analyses and field measurements to specify the mechanical heterogeneities of typical sedimentary rocks and of the mechanical units of fault zones. The results from drill-core sample analyses are then compared with the results from the outcrop samples. Another approach is to analyse how rock mechanical properties correlate with petrographic properties (e.g., mineral content, cementation, fabric) to use this knowledge to extrapolate the data to depth. Acknowledgements The authors appreciate the support of 'Niedersächsisches Ministerium für Wissenschaft und Kultur' and 'Baker Hughes' within the gebo research project (http://www.gebo-nds.de). The project "Fracture propagation and reservoir permeability in limestone-marl alternations" is funded by the Deutsche Forschungsgemeinschaft (German Research Foundation, http://www.dfg.de).

Reyer, Dorothea; Afsar, Filiz; Philipp, Sonja

2013-04-01

247

Maps Showing Geology and Shallow Structure of Eastern Rhode Island Sound and Vineyard Sound, Massachusetts  

Science.gov (United States)

This report presents results of marine studies conducted by the U.S. Geological Survey (USGS) during the summers of 1975 and 1976 in eastern Rhode Island Sound and Vineyard Sound (fig. 1) located off the southeastern coast of Massachusetts. The study was made in cooperation with the Massachusetts Department of Public Works and the New England Division of the U.S. Army Corps of Engineers. It covered an area of the Atlantic Inner Continental Shelf between latitude 41 deg 12' and 41 deg 33'N, and between longitude 70 deg 37' and 71 deg 15'W (see index map). Major objectives included assessment of sand and gravel resources, environmental impact evaluation both of offshore mining of these resources and of offshore disposal of solid waste and dredge spoil material, identification and mapping of the offshore geology, and determination of the geologic history of this part of the Inner Shelf. A total of 670 kilometers (km) of closely spaced high-resolution seismic-reflection profiles, 224 km of side-scan sonar data, and 16 cores totaling 90 meters (m) of recovered sediment, were collected during the investigation. This report is companion to geologic maps published for Cape Cod Bay (Oldale and O'Hara, 1975) and Buzzards Bay, Mass. (Robb and Oldale, 1977).

O'Hara, Charles J.; Oldale, Robert N.

1980-01-01

248

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

249

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

250

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

251

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

252

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)

253

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

254

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

255

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

256

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)

257

Bedrock geologic and structural map through the western Candor Colles region of Mars  

Science.gov (United States)

The Candor Colles are a population of low, conical hills along the southeast flank of Ceti Mensa, in west Candor Chasma, within the Valles Marineris system of Mars (fig. 1). Ceti Mensa and the adjacent Candor Mensa are mounds of layered sedimentary deposits and are the most prominent landforms within west Candor Chasma. Prior to the arrival of the Mars Reconnaissance Orbiter (MRO) in orbit around Mars in 2006 (Zurek and Smrekar, 2007), geologic maps of the area utilized the relatively low resolution Viking Orbiter photomosaics (20–150 m/pixel). Geologic maps covering west Candor Chasma were created at scales of 1:15,000,000 for the western equatorial region of Mars (Scott and Tanaka, 1986), 1:2,000,000 for the Valles Marineris region (Witbeck and others, 1991), and 1:500,000 for the far eastern part of west Candor Chasma (Mars Transverse Mercator quadrangle–05072; Lucchitta, 1999). 

Okubo, Chris H.

2014-01-01

258

Maps Showing Geology and Shallow Structure of Western Rhode Island Sound, Rhode Island  

Science.gov (United States)

This report presents the results of a high-resolution, seismic-reflection, and sidescan-sonar survey conducted in western Rhode Island Sound south of Narragansett Bay (fig. 1 inset) by the U.S. Geological Survey in 1980. The study defines the geologic framework of the Atlantic Inner Continental Shelf between lat. 41 deg 09' and 41 deg 32'N and long. 71 deg 07' and 71 deg 37'W. A total of 580 kilometers (km) of seismic-reflection profiles and 580 km of sidescan sonographs was collected aboard the RV Neecho. Trackline spacing was 1 to 2 km at the mouth of Narragansett Bay, and dip lines were 2 km apart with widely spaced strike lines in Rhode Island Sound (fig. 1). The maps in this report adjoin those for eastern Rhode Island Sound and Vineyard Sound, Massachusetts, of O'Hara and Oldale (1980).

Needell, Sally W.; O'Hara, Charles J.; Knebel, Harley J.

1983-01-01

259

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

Science.gov (United States)

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

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

1991-01-01

260

Safety analysis of engineered barrier in geologic disposal of high-level waste, (1)  

International Nuclear Information System (INIS)

This reports represents analysis conditions for performance assessment of engineered barrier system of geologic disposal. The conditions for both far field and near field were analyzed by appropriate simulation models and the main results are as follows. 1) Far field conditions: By considering the initial stress state in rock formation and the mechanical stability of the disposal tunnel, the repository were assumed to be located at 500 m in depth. The application of the NATM drilling method can be possible if the rock axial compressibility is more than 250 kg/cm2. 2) Near filed conditions: Assuming glass solidified waste, dimensions of overpack and disposal pit filled with buffer material were critically determined through analyses of corrosion life, groundwater flow, temperature distribution, and radiation filed. 3) Dominant nuclides: The nuclides to be determined were selected by a simple analytical migration model in far field. The model took into account sorption effect of medium and the results were converted to the relative hazard by accounting ALI values. The maximum hazard for each nuclide under pesimistic condition (instantaneous discharge, less sorption) indicates the followings are dominant; 99-Tc, 126-Sn, 79-Se, 93-Zr, 135-Cs for FP and 241-Am, 243-Am, 239-Pu, 240-Pu, 242-Pu, 237-Np, 245-Cm, 246-Cm for TRU. (author)

261

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

OpenAIRE

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

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

2011-01-01

262

‘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

2013-01-01

263

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

264

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

265

NADM Conceptual Model 1.0 -- A Conceptual Model for Geologic Map Information  

Science.gov (United States)

Executive Summary -- The NADM Data Model Design Team was established in 1999 by the North American Geologic Map Data Model Steering Committee (NADMSC) with the purpose of drafting a geologic map data model for consideration as a standard for developing interoperable geologic map-centered databases by state, provincial, and federal geological surveys. The model is designed to be a technology-neutral conceptual model that can form the basis for a web-based interchange format using evolving information technology (e.g., XML, RDF, OWL), and guide implementation of geoscience databases in a common conceptual framework. The intended purpose is to allow geologic information sharing between geologic map data providers and users, independent of local information system implementation. The model emphasizes geoscience concepts and relationships related to information presented on geologic maps. Design has been guided by an informal requirements analysis, documentation of existing databases, technology developments, and other standardization efforts in the geoscience and computer-science communities. A key aspect of the model is the notion that representation of the conceptual framework (ontology) that underlies geologic map data must be part of the model, because this framework changes with time and understanding, and varies between information providers. The top level of the model distinguishes geologic concepts, geologic representation concepts, and metadata. The geologic representation part of the model provides a framework for representing the ontology that underlies geologic map data through a controlled vocabulary, and for establishing the relationships between this vocabulary and a geologic map visualization or portrayal. Top-level geologic classes in the model are Earth material (substance), geologic unit (parts of the Earth), geologic age, geologic structure, fossil, geologic process, geologic relation, and geologic event.

North American Geologic Map Data Model (NADM) Steering Committee Data Model Design Team

2004-01-01

266

Capabilities of LIBS for analysis of geological samples at stand-off distances in a Mars atmosphere  

Energy Technology Data Exchange (ETDEWEB)

The use of LIBS for stand-off elemental analysis of geological and other samples in a simulated Mars atmosphere is being evaluated. Analytical capabilities, matrix effects, and other factors effecting analysis are being determined. Through funding from NASA's Mars Instrument Development Program (MIDP), we have been evaluating the use of LIBS for future use on landers and rovers to Mars. Of particular interest is the use of LIBS for stand-off measurements of geological samples up to 20 meters from the instrument. Very preliminary work on such remote LIBS measurements based on large laboratory type equipment was carried out about a decade ago. Recent work has characterized the capabilities using more compact instrumentation and some measurements have been conducted with LIBS on a NASA rover testbed.

Cremers, D. A. (David A.); Wiens, R. C. (Roger C.); Ferris, M. J. (Monty J.); Brennetot, R. (Rene); Maurice, S. (Sylvestre)

2002-01-01

267

Analysis of scenario development methods and practice of high level radioactive waste geological disposal  

International Nuclear Information System (INIS)

The scenario development is the key step in HLW geological disposal. The features, events and processes (FEPs) should be first considered. The FEPs can be sorted and grouped to form scenario. It is very useful and have reference value for the developing the FEPs of HLW geological disposal in a conceptual and planning stage in China by introducing the FEPs established and sorted methods. (authors)

268

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)

269

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)

270

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

271

The fire assay preconcentration of the platinum group elements for the neutron activation analysis of geological materials  

International Nuclear Information System (INIS)

This paper describes the work that has been carried out using neutron activation analysis (NAA) to develop a rapid and reliable method for the determination of the platinum group elements (PGE: Pt, Pd, Ir, Ru, Rh, Os) and Au in geological, environmental and industrial samples. The method is based on the now established method of preconcentration with fire assay, followed by NAA of the separated PGE and Au. Recent developments have seen improvements in the technique to eliminate losses due to dissolution procedures, and complete recovery of the elements prior to analysis. The method is now being used to validate inductively coupled plasma-mass spectrometry methods for analysis of the PGE

272

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

273

The nappe structure's geologic character and ore-controlling effect of mountain-Xiang ore-field in middle part of Jiangxi province  

International Nuclear Information System (INIS)

On the base of analyzing the nappe structure's geologic distribution, it roundly discusses the nappe structure's geologic character, and systematically summarizes the effect on uranium mineralization of the nappe structure. The nappe structure not only creates the self-contained 3D structure network system, including transmitting, transiting, shifting and reserve, but also trains a combine Interchange structure of the multilayer structure and the lithologic characters difference, at the same time which forms a close, half-close lithologic characters. Those structure applies such as pipe, screen and the store space for the liquid ore transport, moreover it protects the uranium mine. Depends on all of this, concluding the fields of uranium mineralization of the nappe structure, and the enrichment law. (authors)

274

Geological structure of Osaka basin and characteristic distributions of structural damage caused by earthquake; Osaka bonchi kozo to shingai tokusei  

Energy Technology Data Exchange (ETDEWEB)

The paper investigates relations between the damage caused by the Hyogo-ken Nanbu earthquake and the deep underground structures. A characteristic of the earthquake damage distribution is that the damage concentrated near faults. Most of the damages were seen on the side of faults` relatively falling rather than right above the faults and of their slightly slanting to the seaside. Distribution like this seems to be closely related to underground structures. Therefore, a distribution map of the depth of basement granite in Osaka sedimentary basin was drawn, referring to the data on basement rock depth obtained from the distribution map of gravity anomaly and the result of the survey using the air gun reflection method. Moreover, cubic underground structures were determined by 3-D gravity analysis. The result was concluded as follows: when observing the M7 zone of the low land, in particular, where the damage was great from an aspect of gravity anomaly, the basement rock below the zone declined near the cliff toward the sea, which indicates a great possibility of its being a fault. There is a high possibility that the zone suffered mostly from the damage caused by focusing by refraction and total reflection of seismic wave rays. 3 refs., 8 figs.

Nakagawa, K.; Shiono, K.; Inoue, N.; Senda, S. [Osaka City University, Osaka (JP. Faculty of Science); Ryoki, K. [Osaka Polytechnic Collage, Osaka (Japan); Shichi, R. [Nagoya University, Nagoya (Japan). Faculty of Science

1996-05-01

275

Structural-geological models of the Ketzin CO2 storage pilot site used for site evaluation, dynamic reservoir simulations, and monitoring purposes  

Science.gov (United States)

The saline aquifer of the Stuttgart Formation (Upper Triassic) is used for a carbon dioxide (CO2) storage research project at Ketzin, about 25 km west of Berlin (Germany). The structural and lithological site characterization relies on a comprehensive data set, consisting of former exploration data (hydrocarbon and natural gas storage exploration) and of the recent exploration, production, and monitoring data acquired at the CO2 pilot site. The quality of the data in terms of resolution and documentation is variable, covering also different scales. We present an overview of the structural and lithological characterization of the Ketzin CO2 pilot site that is based on the evolution of the geological models prepared for storage site development and site operation. In order to be able to assess risk elements, especially in the early regulatory and permitting stages of the project, the geological model building concentrated on two scales: Firstly, the site scale (called geo-model, comprising the reservoir and its overburden), and, secondly, the reservoir scale, using a higher resolution. The reservoir scale was applied to the target horizon of the CO2 storage (the Triassic Stuttgart Formation) and the Quaternary to Tertiary layers, presenting the near-surface groundwater system. The first geo-models illustrate the geological setting of the Ketzin site as a part of a salt-anticlinal structure based on seismic legacy data. These models were used to give first estimates on the deep natural groundwater flow and to establish pre-drilling profiles, but could not give reliable information on the existence and distribution of faults. Nevertheless, the estimated bed boundaries of the Stuttgart Formation served as an input for the construction of the first reservoir models of the Stuttgart Formation which were used to illustrate the expected variability and heterogeneity in rock properties. The target formation is lithologically very heterogeneous, reflecting a complex fluviatile facies distribution pattern: sandy rocks of the channel facies are embedded in muddy rocks of the floodplain facies. The facies distribution and its hydraulic parameterization were modeled using a stochastic approach. After the processing of the 3D seismic data acquired in 2005, and the drilling of three boreholes in Ketzin in 2007, the need of a re-interpretation of the geological models was given to account for the higher resolution of the new input data. In the revised models it was possible to map the main faults at the site with good accuracy. In addition, seismic facies analysis was performed by applying a spectral decomposition technique to the 3D seismic data. Thereby, subsurface features could be identified, which may indicate to some degree the distribution of the fluvial channel facies of the reservoir formation. This data was then also used to guide the stochastic reservoir modeling of the Stuttgart Formation. In addition, the interpretation of seismic CO2 monitoring data gives further evidence of the mean CO2 distribution in the subsurface and could partly guide the structural interpretation. This data enables a local deterministic refinement of the stochastic reservoir model. Finally, another well drilled into the storage formation in 2012 serves as an additional input to the geological models.

Norden, Ben; Kling, Christian; Frykman, Peter; Krawczyk, Charlotte M.

2013-04-01

276

Structural geology of Ordos basin mineralization and mineralization of uranium deposits in the Huianbao region, west of Ordos basin  

International Nuclear Information System (INIS)

The thesis discussed the geotectonic setting of west Ordos Basin, classification of tectonic units, geology of west fault-fold belt and structural feature in Majiatan region. The stable tectonic region was overall guidance thoughts and ideas for the uranium deposits in the structure relative activities region. Based on exploration and research of uranium geology for many years, the over-thrust nappe belt was favorable region for uranium mineralization. Two oxidation layers which the ancient oxidation was red and oxidation alteration was yellow existed in this region, the uranium ore was controlled on by two oxidation layers. Early red oxidized sandstone was experienced post-reformation such as thrust pushover, lifting, erosion, superimposed depth and separation of block fault. Late yellow oxidation which tended to inherit the early red oxidation and carry on the superposition modification distributed both wings of anticline. The thesis was to summarized the uranium features and metallogenic regularity, which has some guidance for uranium deposits in the basin. (authors)

277

Relation of geological structure to seismicity at Pahute Mesa, Nevada Test Site  

International Nuclear Information System (INIS)

Some of the abundant and unique geological and seismological data acquired at the Nevada Test Site is integrated with the objectives of (1) resolving some of the ambiguity in explanations of the source of aftershocks of nuclear explosions, and (2) demonstrating the value of using detailed geological and seismological data to infer realistic source parameters of earthquakes. The distribution of epicenters of aftershocks from nuclear explosions at Pahute Mesa suggests that they are related to faults or intersections of faults in the buried ring-fracture zones of calderas rather than to the conspicuous basin-and-range faults exposed at the surface. Histograms of fault length show clearly that faults in a basin-and-range regime differ significantly in length, median length, and distribution of length from faults in a caldera regime. A histogram of fault lengths derived from magnitudes of aftershocks shows both the median and distribution characteristics of caldera faults rather than of basin-and-range faults. Cumulative frequency-fault length-squared plots also show differences in the two fault regimes, and have slopes, herein called bf slopes, of --0.89 for caldera and basin-and-range faults, respectively. The bf slopes are similar to the average slope of a cumulative frequency-strain plot for aftershocks rather than to the b slopes for cumulative frequency-magnitude plots. Although the significance of b and bf slopes and differences between them are not resolved clearlynces between them are not resolved clearly, it is concluded that the fault length and strain data reflect dimensions of seismic sources rather than energy of seismic events. The principal conclusion of the investigation is that the most obvious geology of a seismically active area may not provide the proper basis for inferring seismic-source parameters. (U.S.)

278

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

279

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.

280

Using high-resolution aeromagnetic data to recognise and map intra-sedimentary volcanic rocks and geological structures across the Cretaceous middle Benue Trough, Nigeria  

Science.gov (United States)

Recently acquired high-resolution aeromagnetic data over the Cretaceous middle Benue Trough of Nigeria have been analysed employing various edge-enhancement (magnetic derivative) methods: vertical derivatives, total horizontal derivative, analytic signal, and total horizontal derivative of tilt derivative. The study was aimed at mapping intra-sedimentary volcanic rocks and their areal extents/distribution as well as delineating geological structures, their structural trends and tectonic implications. The magnetic derivative anomaly maps produced in this project greatly enhanced the high amplitude, short-wavelength (high wavenumber) anomalies associated with the surface/near-surface intra-sedimentary volcanic rocks and associated geological structures. The maps show that volcanic rocks of Late Cretaceous to Palaeocene age are much more widespread than implied by surface geological mapping, with an areal extent of greater than 12,000 km2 in the relatively shallow subsurface. The results also highlight some known and several previously unknown geological lineaments. Rose (azimuth-frequency) plots of orientations of geological structures show trends being predominantly NE-SW, NW-SE and ESE-WNW with minor ENE-WSW and N-S trends. These main groups of structural trends are associated with the Brasiliano/Pan-African orogeny (600 ± 200 Ma) and likely predate rifting of the Gondwana supercontinent. They may have been enhanced during continental break-up in Late Jurassic to Early Cretaceous.

Anudu, Goodluck K.; Stephenson, Randell A.; Macdonald, David I. M.

2014-11-01

281

Geologic Constraints on Modeling of Complex-Crater Collapse: Data from the Chesapeake Bay Impact Structure, Virginia  

Science.gov (United States)

Numerical models of complex impact-crater collapse frequently invoke Bingham fluids as the rheologic model for the behavior of rocks and sediments surrounding the transient crater during gravity-driven collapse. Acoustic fluidization is increasingly relied on by modelers to produce the necessary reduction in overburden pressure at depth that leads to the transient viscous flow of the Bingham fluid. Geologic and geophysical field studies of the buried, 90-km-wide, late Eocene Chesapeake Bay impact structure (CBIS) (Virginia Coastal Plain) provide constraints for model parameters. The target protolith of the CBIS consisted of Proterozoic and Paleozoic crystalline rocks overlain by hundreds of meters of Cretaceous and Tertiary sediments. The USGS-NASA Langley corehole (Hampton, Va.) and an adjacent high-resolution seismic-reflection survey, both located inside and near the outer margin of the CBIS, reveal the vertical variation in impact disruption within the sedimentary section outside the collapsed transient crater. The observed sediment responses to the impact and their vertical distance above crystalline rock are: deepest fluidization of susceptible sands (68 m); deepest downward infiltration of dissociated Tertiary sediments into Cretaceous sediments (183 m); deepest widespread fluidization, widespread downward infiltration of Tertiary sediments into Cretaceous section, and authigenic resedimentation (198 m); deepest occurrence of sparse shocked ejecta (350 m); inferred position of spall ejection (missing Tertiary sediments) (357 m); base of allogenic resurge deposits (357 m); and top of impactites (391 m). Preliminary analysis of additional cores suggests that these horizons become absolutely and stratigraphically deeper toward the crater's center. The general upward increase in disruption of the impact-modified sedimentary section likely reflects the role of overburden pressure in increasing the Bingham yield stress with depth. The seismic survey shows pervasive high- to moderate-angle, small-offset faults in the impact-modified sedimentary section. In the Langley core, faults of this type have slickenside striae that record normal dip-slip movement. We infer that these faults began as tensile fractures produced early in the impact process that served to reduce the strength of rocks and sediments in the vicinity of the impact. There is a predictable lithologic control on the effects of fluidization and fracturing in this heterogeneous sedimentary section. Water-saturated, better sorted sands were most susceptible to fluidization, whereas clay layers were fractured into clasts and megaclasts that retained their internal cohesion.

Gohn, G. S.; Powars, D. S.; Bruce, T. S.; Quick, J. E.; Catchings, R. D.

2002-05-01

282

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)

283

Analysis of the effects of geological and geomorphological factors on earthquake triggered landslides using artificial neural networks (ANN)  

Science.gov (United States)

The occurrence of landslide is the result of the interaction of complex and diverse environmental factors. The geomorphic and geologic features, rock types and vegetative cover are important base factors of landslide occurrence. However, determining the relationship between these factors and landslide occurrence is very difficult using conventional mathematical analysis. The use of an advanced computing technique for this kind of analysis is very important. Artificial neural network (ANN) has recently been included in the list of analytical tools for a wide range of applications in the natural sciences research fields. One of the advantages of using ANN for pattern recognition is that it can handle data at any measurement scale ranging from nominal, ordinal to linear and ratio, and any form of data distribution (Wang et al., 1995). In addition, it can easily handle qualitative variables making it widely used in integrated analysis of spatial data from multiple sources for predicting and classification. This study focuses on the definition of the relationship between geological factors and landslide occurrence using artificial neural networks. The study also focuses on the effect of the DTMs (e.g. ASTER DTM, ALSM, digitized from paper map and digital photogrammetric measurement data). The main aim of the study is to generate landslide susceptibility index map using the defined relationship using ANN. Landslide data in the Chuetsu region were used in this research. The 2004 earthquake triggered many landslides in the region. The initial results of the study showed that ANN is more accurate in defining the relationship between geological and geomorphological factors and landslide occurrence. It also determined the best combination of geological and geomorphological factors that is directly related to landslide occurrence.

Kawabata, D.; Bandibas, J.

2007-12-01

284

Large coil test structural analysis  

International Nuclear Information System (INIS)

The International Fusion Superconducting Magnet Test Facility (IFSMTF) at Oak Ridge National Laboratory (ORNL) is being utilized for testing of 2.5 x 3.5-m bore superconducting 8-T magnets produced by four international agencies (U.S., Euratom, Japan, and Switzerland). The definitive tests in the design configuration, six coils arranged in a compact torus, will begin in late 1985. Partial-array tests involving one US coil and the Japanese coil were completed in the fall of 1984. This presentation describes structural analysis using NASTRAN, with symmetry and superelement techniques, to predict the IFSMTF test stand and coil responses to various combinations of in-plane and out-of-plane loading conditions for both the partial-array and six-coil test configurations. Comparison to partial-array displacement and strain measurements are presented and discussed. Six-coil results and their utilization for determining safe levels of operation of the system are likewise discussed

285

Three-Dimensional Geologic Model of Complex Fault Structures in the Upper Seco Creek Area, Medina and Uvalde Counties, South-Central Texas  

Science.gov (United States)

This multimedia report shows and describes digital three-dimensional faulted geologic surfaces and volumes of the lithologic units of the Edwards aquifer in the upper Seco Creek area of Medina and Uvalde Counties in south-central Texas. This geologic framework model was produced using (1) geologic maps and interpretations of depositional environments and paleogeography; (2) lithologic descriptions, interpretations, and geophysical logs from 31 drill holes; (3) rock core and detailed lithologic descriptions from one drill hole; (4) helicopter electromagnetic geophysical data; and (5) known major and minor faults in the study area. These faults were used because of their individual and collective effects on the continuity of the aquifer-forming units in the Edwards Group. Data and information were compared and validated with each other and reflect the complex relationships of structures in the Seco Creek area of the Balcones fault zone. This geologic framework model can be used as a tool to visually explore and study geologic structures within the Seco Creek area of the Balcones fault zone and to show the connectivity of hydrologic units of high and low permeability between and across faults. The software can be used to display other data and information, such as drill-hole data, on this geologic framework model in three-dimensional space.

Pantea, Michael P.; Cole, James C.; Smith, Bruce D.; Faith, Jason R.; Blome, Charles D.; Smith, David V.

2008-01-01

286

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

287

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

288

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

Science.gov (United States)

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 (234m)Pa the second daughter product of (238)U. PMID:21924803

Landsberger, S; Kapsimalis, R

2013-03-01

289

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

290

A radiochemical neutron activation analysis method of osmium and ruthenium in geological and environmental samples  

International Nuclear Information System (INIS)

A radiochemical separation procedure has been set up. Os and Ru of 10-9 level in geological and environmental samples were distilled with KMnO4, collected in Na2S + NaOH solution and co-precipitated with CuS. In this procedure Rb, Sc, Hf, Ca, Ta, Fe, Cr, Co, Ir, Pt, Sb and Se have no interference. The chemical yields of Os and Ru were more than 90% and 95%, respectively. It is effective for determining Os and Ru in geological and environmental samples

291

The application of geological computer modelling systems to the characterisation and assessment of radioactive waste repositories  

International Nuclear Information System (INIS)

The deep disposal of radioactive waste requires the collection and analysis of large amounts of geological data. These data give information on the geological and hydrogeological setting of repositories and research sites, including the geological structure and the nature of the groundwater. The collection of these data is required in order to develop an understanding of the geology and the geological evolution of sites and to provide quantitative information for performance assessments. An integrated approach to the interpretation and provision of these data is proposed in this paper, via the use of computer systems, here termed geological modelling systems. Geological modelling systems are families of software programmes which allow the incorporation of site investigation data into integrated 3D models of sub-surface geology

292

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

Science.gov (United States)

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

Carter, W. D. (principal investigator)

1975-01-01

293

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

294

Some new understanding on the characteristics of geological structure and uranium metallogenetic prospect on both sides of the Shandianhe down-faulted zone  

International Nuclear Information System (INIS)

On the basis of the systematic work in the field and at the laboratory, the metallogenetic prognosis map (1:100000) of geological structures and uranium metallogenetic prospect on both sides of the Shandianhe down-faulted zone is compiled. According to this, the regional setting of metallogenesis is emphatically expounded and some new understanding is presented. After the detailed study on the characteristics of geological structures on both sides of the Shangdianhe down-faulted zone, the metallogenetic prospective area are selected and the further prospecting targets in the area are suggested

295

Seismic and structural geology constraints to the selection of CO2 storage sites—The case of the onshore Lusitanian basin, Portugal  

Science.gov (United States)

The Lusitanian sedimentary basin, in Portugal, has a complex tectonic history and a seismic activity determined by its proximity to the Eurasian-Nubian tectonic plate boundary. Seismic activity and geological structure impose serious constraints to the selection of CO2 storage sites. This article focuses on the constraints imposed by active seismicity, geological structure and, as a direct consequence of the latter, by the hydrogeology and geothermal framework on the identification of onshore CO2 storage sites in deep saline aquifers of the Lusitanian basin (central and north sectors).

Pereira, Nadine; Carneiro, Júlio F.; Araújo, Alexandre; Bezzeghoud, Mourad; Borges, José

2014-03-01

296

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)

297

The spectral analysis and information extraction for small geological target detection using hyperion image  

Science.gov (United States)

Imaging spectroscopic technique has been used for the mineral and rock geological mapping and alteration information extraction successfully with many reasonable results, but it is mainly used in arid and semi-arid land with low vegetation covering. In the case of the high vegetation covering, the outcrop of the altered rocks is small and distributes sparsely, the altered rocks is difficult to be identified directly. The target detection technique using imaging spectroscopic data should be introduced to the extraction of small geological targets under high vegetation covering area. In the paper, we take Ding-Ma gold deposit as the study area which located in Zhenan country, Shanxi province, the spectral features of the targets and the backgrounds are studied and analyzed using the field reflectance spectra, in addition to the study of the principle of the algorithms, some target detection algorithms which is appropriate to the small geological target detection are introduced. At last, the small altered rock targets under the covering of vegetation in forest are detected and discriminated in imaging spectroscopy data with the methods of spectral angle mapper (SAM), Constrained Energy Minimization (CEM) and Adaptive Cosine Estimator (ACE). The detection results are reasonable and indicate the ability of target detection algorithms in geological target detection in the forest area.

Li, Qingting; Wei, Xinxin; Zhang, Bing; Yan, Shouxun; Liu, Xiang

2008-12-01

298

Effect of geological carbon sources on eddy covariance measurements: analysis and possible correction approaches  

Science.gov (United States)

A recent set of studies carried out in the SE of Spain highlighted the need to consider geological carbon sources when estimating the net ecosystem carbon balance (NECB) of terrestrial ecosystems located in areas potentially affected by geofluid circulation. In this study we present the mechanisms and propose a new methodology using physical parameters of the atmospheric boundary layer to quantify the CO2 coming from deep origin. To test our approach, we compare NECB estimates with seasonal patterns of soil CO2 efflux and vegetation activity measured by satellite images (NDVI) over two-year period at this site (2007/2008). According with the eddy covariance measurements the alpha grass ecosystem was a net carbon source (93.7 and 145.0 g C m-2, for the years 2007 and 2008, respectively) particularly as a result of large amounts of carbon released over the dry period. This relevant CO2 emission (reaching up to 15 umol m-2 s-1) was however not related to ecosystem activities as confirmed by measurements of soil CO2 efflux using chambers (ca. 0.5 umol m-2 s-1) and plant productivity that was minimal during this period. A simple correction based on a linear relationship between NECB and wind speed for different stability conditions and wind sectors has been used to estimate the geological flux FGEO and subtracted it from the NECB to obtain the biological flux FBIO. We then partitioned FBIO into gross primary productivity and ecosystem respiration and proved that, after removing FGEO, ecosystem and soil respiration followed similar temporal patterns. The annual contribution of the geological component to NECB was 49.6 and 46.7 % for the year 2007 and 2008, respectively. Therefore, potential contribution of geological carbon sources should be tested and quantified in those ecosystems located in areas with potential natural emission of geologic gases to the surface. References: REY A., BELELLI MARCHESINI L., WERE A., SERRANO ORTIZ P., ETIOPE G., PAPALE D, DOMINGO F., PEGORARO E. (2012). Wind as a main driver of the net ecosystem carbon balance of a semiarid Mediterranean steppe in the South East of Spain. GLOBAL CHANGE BIOLOGY, vol. 18, p. 539-554 REY A., ETIOPE G., BELELLI-MARCHESINI L., PAPALE D, VALENTINI R. (2012). Geologic carbon sources may confound ecosystem carbon balance estimates: Evidence from a semiarid steppe in the southeast of Spain. JOURNAL OF GEOPHYSICAL RESEARCH. BIOGEOSCIENCES, vol. 117 REY A., BELELLI-MARCHESINI L., ETIOPE G., PAPALE D., CANFORA E., VALENTINI R., PEGORARO E. (2013) Partitioning the net ecosystem carbon balance of a semiarid steppe into biological and geological carbon components. BIOGEOCHEMISTRY, (in review)

Papale, D.; Rey, A.; Belelli-Marchesini, L.; Etiope, G.; Pegoraro, E.

2013-12-01

299

Seismic analysis of sliding structures  

International Nuclear Information System (INIS)

To limit the seism 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, stiffness,...)

300

System analysis methods for geological repository of high level radioactive waste in granite  

International Nuclear Information System (INIS)

Taking Beishan granite site as an example, this paper proposes the conceptual and structural design of repository for high level radioactive waste at first. Then the function, structure, environment and evolution of the repository are described by the methodology of system analysis. Based on these designs and descriptions, a calculation model for the repository is developed with software GoldSim. At last, this calculation model is applied to emulate the space-time distribution of repository radiotoxicity, to analyze the sensitivity of parameters in the model, to optimize the design parameters, and to predict and assess the repository performance. The results of this study can provide technical supports for resources allocation and coordination of R and D projects. (authors)

301

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

302

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

303

Mathematical Statistics in the Geology  

OpenAIRE

During the last period is modern geology oriented toward intensive utilisation of mathematical methods. Utilisation of these methods was conditioned by complicated structure of geological bodies, which resulted from interaction of a couple of factors. In the period of projection, realisation and evaluation of geological works one meet many problems of description of a character of geological data. These problems ? very often trivial ? arise from the poor knowledge of the principles of stati...

Bliš?an Peter

1999-01-01

304

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

305

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

306

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

307

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)

308

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

309

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

310

Structural Analysis of Steel Structures under Fire Loading  

Directory of Open Access Journals (Sweden)

Full Text Available This paper focuses on the structural analysis of a steel structure under fire loading. In this framework, the objective is to highlight the importance of the right choice of analyses to develop, and of the finite element codes able to model the resistance and stiffness reduction due to the temperature increase. In addition, the evaluation of the structural collapse under fire load of a real building is considered, paying attention to the global behavior of the structure itself. 

C. Crosti

2009-01-01

311

The 3-D structural geology of the PRZ [Potential Repository Zone]. Supplementary proof of evidence  

International Nuclear Information System (INIS)

Supplementary Proof of Evidence by an expert witness is presented in support of the case by Friends of the Earth (FOE) against the proposed construction by UK Nirex Ltd of an underground Rock Characterisation Facility (RCF) at a site in the Sellafield area. The RCF is part of an investigation by Nirex into a suitable site for an underground repository for the disposal of radioactive waste. The objections were raised at a Planning Inquiry in 1995. Various points raised by a Nirex witness in connection with earlier evidence to the Inquiry by FOE are addressed. This evidence dealt with the need for an accurate hydrogeological model of the Potential Repository Zone (PRZ) and the perceived inadequacies of the Nirex approach. The issues addressed in this supplementary evidence are: disagreements over 3D seismic surveys; inconsistencies in the Nirex geological interpretation; the evolution of interpretation of the PRZ; the oil exploration analogy; site potential; the need for deterministic models; and the selective use of information. (2 figures; 1 table). (UK)

312

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

313

Dynamic analysis program for frame structure  

International Nuclear Information System (INIS)

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

314

Analysis of piezoelectric structures and devices  

CERN Document Server

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

Chen, Weiqiu; Wang, Ji

2013-01-01

315

Determination of WYTTENBACH correction factors in neutron activation system dedicated to trace element analysis of geological samples  

International Nuclear Information System (INIS)

Elemental abundances determined by neutron activation usually result from comparisons of gamma-ray intensities in samples (unknown concentrations) and standards (known concentrations). If the samples and standardshave large differences in gamma-ray intensity, significant errors arise from coincidence losses resulting from pulse pile-up. The resolving times (the Wyttenbach factor of 2?/?) of four semiconductor germanium detectors coupled to three different multichannel analyzers used for routine activation analysis are determined with and without pile-up rejector. The errors caused by pulse pile-up in trace element abundance determination of different geological samples are tabulated. (author) 8 refs.; 2 figs.; 2 tabs

316

Comparative analysis of the impact of geological activity on astronomical sites of the Canary Islands, Hawaii and Chile  

CERN Document Server

An analysis of the impact of seismic and volcanic activity was carried out at selected astronomical sites, namely the observatories of El Teide (Tenerife, Canary Islands), Roque de los Muchachos (La Palma, Canary Islands), Mauna Kea (Hawaii) and Paranal (Chile) and the candidate site of Cerro Ventarrones (Chile). Hazard associated to volcanic activity is low or negligible at all sites, whereas seismic hazard is very high in Chile and Hawaii. The lowest geological hazard in both seismic and volcanic activity was found at Roque de los Muchachos observatory, in the island of La Palma.

Eff-Darwich, A; Rodriguez-Losada, J A; de la Nuez, J; Hernandez-Gutierrez, L E; Romero-Ruiz, M C

2009-01-01

317

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)

318

Analysis of the processes defining radionuclide migration from deep geological repositories in porous medium  

International Nuclear Information System (INIS)

Due to the danger of exposure arising from long-lived radionuclides to humans and environment, spent nuclear fuel (SNF) and high level waste (HLW) are not allowed to be disposed of in near surface repositories. There exists an international consensus that such high level and long-lived radioactive wastes are best disposed of in geological repositories using a system of engineered and natural barriers. At present, the geological repository of SNF and HLW has not been realized yet in any country but there is a lot of experience in the assessment of radionuclide migration from deep repositories, investigations of different processes related to the safety of a disposal system. The aim of this study was to analyze the processes related to the radionuclide migration from deep geological repositories in porous medium such as SNF matrix dissolution, release mechanism of radionuclides from SNF matrix, radionuclide solubility, sorption, diffusive, advective transport of radionuclides from the canister and through the engineered and natural barriers. It has been indicated that SNF matrix dissolution, radionuclide solubility and sorption are sensitive to ambient conditions prevailing in the repository. The approaches that could be used for modeling the radionuclide migration from deep repositories in porous medium are also presented. (author)

319

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

Science.gov (United States)

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

Lee, K. (principal investigator)

1976-01-01

320

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

OpenAIRE

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...

Mendes M.; -l, Mari J.; Hayet M.

2013-01-01

321

Analysis of Geologic CO2 Sequestration at Farnham Dome, Utah, USA  

Science.gov (United States)

The Farnham Dome in east-central Utah is an elongated, Laramide-age anticline along the northern plunge of the San Rafael uplift and the western edge of the Uinta Basin. We are helping design a proposed field demonstration of commercial-scale geologic CO2 sequestration, including injection of 2.9 million tons of CO2 over four years time. The Farnham Dome pilot site stratigraphy includes a stacked system of saline formations alternating with low-permeability units. Facilitating the potential sequestration demonstration is a natural CO2 reservoir at depth, the Jurassic-age Navajo formation, which contains an estimated 50 million tons of natural CO2. The sequestration test design includes two deep formations suitable for supercritical CO2 injection, the Jurassic-age Wingate sandstone and the Permian-age White Rim sandstone. We developed a site-specific geologic model based on available geophysical well logs and formation tops data for use with numerical simulation. The current geologic model is limited to an area of approximately 6.5x4.5 km2 and 2.5 km thick, which contains 12 stacked formations starting with the White Rim formation at the bottom (>5000 feet bgl) and extending to the Jurassic Curtis formation at the top of the model grid. With the detail of the geologic model, we are able to estimate the Farnham Dome CO2 capacity at approximately 36.5 million tones within a 5 mile radius of a single injection well. Numerical simulation of multiphase, non- isothermal CO2 injection and flow suggest that the injected CO2 plume will not intersect nearby fault zones mapped in previous geologic studies. Our simulations also examine and compare competing roles of different trapping mechanisms, including hydrostratigraphic, residual gas, solubility, and mineralization trapping. Previous studies of soil gas flux at the surface of the fault zones yield no significant evidence of CO2 leakage from the natural reservoir at Farnham Dome, and thus we use these simulations to evaluate what factors make this natural reservoir so effective for CO2 storage. Our characterization and simulation efforts are producing a CO2 sequestration framework that incorporates production and capacity estimation, area-of-review, injectivity, and trapping mechanisms. Likewise, mitigation and monitoring strategies have been formulated from the site characterization and modeling results.

Lee, S.; Han, W.; Morgan, C.; Lu, C.; Esser, R.; Thorne, D.; McPherson, B.

2008-12-01

322

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

323

Optical analysis of thermal induced structural distortions  

Science.gov (United States)

The techniques used for the analysis of thermally induced structural distortions of optical components such as scanning mirrors and telescope optics are outlined. Particular attention is given to the methodology used in the thermal and structural analysis of the GOES scan mirror, the optical analysis using Zernike coefficients, and the optical system performance evaluation. It is pointed out that the use of Zernike coefficients allows an accurate, effective, and simple linkage between thermal/mechanical effects and the optical design.

Weinswig, Shepard; Hookman, Robert A.

1991-01-01

324

Incorporating Content Structure into Text Analysis Applications  

OpenAIRE

Information about the content structure of a document is largely ignored by current text analysis applications such as information extraction and sentiment analysis. This stands in contrast to the linguistic intuition that rich contextual information should benefit such applications. We present a framework which combines a supervised text analysis application with the induction of latent content structure. Both of these elements are learned jointly using the EM a...

Sauper, Christina Joan; Haghighi, Aria; Barzilay, Regina

2010-01-01

325

Determination of iridium at low levels (sub ng g-1) in geological materials by neutron activation analysis  

International Nuclear Information System (INIS)

The analysis of the platinum group elements (PGE: Ru, Rh, Pd, Os, Ir and Pt) in geological materials is difficult, due to the low concentrations of these elements (ng g-1 or sub ng g-1) and their heterogeneous distribution in many geological matrices. The determination of PGE has attracted great interest due not only to the increasing utilization of these elements in modern industry, but also to the information that these elements can provide on mantle processes. The determination of very low amounts of iridium is particularly important on account of some anomalous concentrations of iridium in sedimentary rock samples, related to the impact of an extraterrestrial object responsible for extinctions at the Cretaceous-Tertiary (K-T) boundary. In the present paper, a radiochemical neutron activation method for the determination of iridium in geological materials is presented. The procedure consisted of thermal neutron irradiation of about 500 mg of the sample, followed by sintering with sodium peroxide, precipitation with tellurium and high resolution gamma-ray spectrometry with a hyper-pure Ge detector. The accuracy and precision of the procedure were evaluated by analysis of the certified reference material SARM-7 (South Africa Bureau of Standards) and W-1 (USGS). The detection limit for the analytical conditions employed was 0.004 ng g-1. The procedure was applied to the reference materials TDB-1 and WGB-1 (CANMET), which present provisional values for Ir, and to the reference materials GXR-3, GXR-5 and GXR- 6 (USGS), which do not present information values for Ir. This work is a contribution to Ir values in these reference materials. As an example of application of the method to real samples, the developed procedure was employed in the determination of iridium in basalts from Parana basin, collected in Bom Guara do Sul, Santa Catarina, provided by the Geosciences Institute of the University of Campinas. (author)

326

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

327

Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California  

Energy Technology Data Exchange (ETDEWEB)

The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California, from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characcterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the accoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of drilling were most useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet.

Galbraith, R.M.

1978-05-01

328

Geological and geophysical analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California  

Energy Technology Data Exchange (ETDEWEB)

The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the acoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of drilling were most useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet.

Galbraith, R.M.

1978-05-01

329

Geological structures and seismicity in foothills of western Taiwan and their implications of deformation in fold-and-thrust belt  

Science.gov (United States)

Characteristics of seismicity in the frontal part of an ongoing mountain-building belt can be tied to geological structural style to give some crucial information concerning the deformation of the belt. In this study, we address variation in fault plane solutions of strike-slip fault in the foothills of western Taiwan. We first describe the characteristics of structural settings on the surface in the subsurface to illustrate the differences and define the boundary between the inner and outer foothills. We then delineate variation in characteristics of seismicity in the foothills. The correspondence between the geological structure and the seismicity is demonstrated in the final. The foreland tectonics of western Taiwan can be divided into three domains: the structures of the pre-orogenic extensional tectonics, the outer part of the fold-and-thrust belt, in which low-angle thrusts mingle with high-angle reactivated normal faults, and the inner part of the belt characterized by imbricate low-angle thrusts. Pre-existing normal faults have altered the local maximum compressive stress field and trajectory of evolving thrust and strongly affected the features of the low-angle thrusts, forming orocline of the fault-and-thrust belt. The outer part of fault-and-thrust belt in northwestern Taiwan is characterized by two settings of thrust and accompanied fold, one trending ENE-WSW, representing reactivated structures of pre-existing normal faults, and the other trending NNE-SSW, parallel to the main strike of the fold-and-thrust belt. The trend of structural settings in the inner foothills is parallel to that of the fold-and-thrust belt. In the central and southern parts of western Taiwan, very few settings that trend ENE-WSW appear in the outer foothills; almost all of them remain as normal fault features. However, some of the active faults in western Taiwan may be strongly related with the reactivated normal fault, with right-lateral slip component, and occur in the frontal area of the fold-and-thrust belt or even beneath the low angle thrust. Most of the hypocenters of earthquake are located at the depth shallower than 15-20 kilometers. In the inner foothills of northwestern and central Taiwan, the resolved maximum stress axes from one set of strike-slip fault planes mainly strike NW-SE, normal to that of the fold-and-thrust belt. The orientation changes counterclockwise and then clockwise from north to south, in correspondence to the orocline of the belt. In the inner foothills of southernmost part of the study area, the resolved maximum stress axes trend obliquely at the strike of the fault-and-thrust belt. Nonetheless, one set of strike-slip fault planes are nearly parallel to the local tear faults. On the other hand, the orientation of strike-slip fault planes in the outer foothills and coastal plane strikes variably and might reflect different structural styles in different segments of the belt. Some of strike-slip fault planes might be related to the reactivated normal faults. The others might correspond to the remote stress field transmitted into the outer foothills. The coincidence between the strike of fault plane solution and that of structural setting in different parts of the foothills in northwestern Taiwan suggests that two distinct processes of mountain-building, normal fault reactivation and low angle thrusting, have been happening in different belts since the beginning of tectonics that eventually result in the structural features in the foothills today.

Yang, Kenn-Ming; Rau, Ruey-Juin; Yang, Chia-Hsun; Yang, Tzu-Ruei; Huang, Shiuh-Tsann; Mei, Wen-Wei; Wu, Jong-Chang; Tang, Yi-Jin

2013-04-01

330

Geological-economic analysis on the exploration of backup resources for depleted mines in Lujing uranium ore-field, central-southern China  

International Nuclear Information System (INIS)

With the geological-economic evaluation program for pithead heap-leaching mining uranium deposits developed by the authors and the data of column-leaching tests and the geological reserve, the geological-economic evaluation is made to the residual geological reserves of both Lujing and Huangfengling deposit, and the geological reserves of Yangjiaonao deposit of the depleted mines in Lujing uranium ore-field, central-southern China. The results of static analysis on these reserves show that the residual geological reserves of both Lujing and Huangfengling deposit belong to sub-profitable type, but the ones of Yangjiaonao deposit is profitable with 26.56% tax-before profit. 1 tU profitable type of ore from Yangjiaonao deposit can use 2.40-3.79 tU subprofitable type of ores from Lujing and Huangfengling deposit. In order to solving the problem on scarcity of backup resources of the depleted mines in Lujing uranium ore-field and using the existing sub-profitable type of geological reserves, it is suggested that the high grade of profitable type of deposits should be explored around the exhausting mines so that the production of the mines could be profitable by the pithead heap-leaching mining method with arrangement groups of both sub-profitable and profitable type of ores. (authors)

331

Robustness Analysis of Kinetic Structures  

DEFF Research Database (Denmark)

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

Kirkegaard, Poul Henning; SØrensen, John Dalsgaard

2009-01-01

332

Geologic Maps and Structure Sections of the southwestern Santa Clara Valley and southern Santa Cruz Mountains, Santa Clara and Santa Cruz Counties, California  

Science.gov (United States)

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (scvmf.ps, scvmf.pdf, scvmf.txt), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineates map units that are identified by general age and lithology following the stratigraphic nomenclature of the U.S. Geological Survey. The scale of the source maps limits the spatial resolution (scale) of the database to 1:24,000 or smaller.

McLaughlin, R.J.; Clark, J.C.; Brabb, E.E.; Helley, E.J.; Colon, C.J.

2001-01-01

333

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

334

Okinawa, Japan: Geologic Battleground  

Science.gov (United States)

One of our main goals as instructors, particularly in introductory courses, is to impart students with an appreciation of how geology has influenced the course of human events. Despite the apparent accessibility of such topics, communicating this in a lively, relevant, and effective way often proves difficult. We use a series of historical events, the Pacific island hopping campaign of WWII, to engage students in an active, guided inquiry exercise to explore how terrain and the underlying geology of an area can shape historical events. Teams of students are assigned the role of planning either the defense or occupation of Okinawa Island, in the Ryukyu arc, in a theoretical version of the 1945 conflict. Students are given a package of information, including geologic and topographic maps, a list of military resources available to them at the time, and some historical background. Students also have access to "reconnaissance" images, 360o digital panoramas of the landscape of Okinawa, keyed to their maps. Each team has a week to plan their strategies and carry out additional research, which they subsequently bring to the table in the form of a written battle plan. With an instructor as arbiter, teams alternate drawing their maneuvers on a map of the island, to which the other team then responds. This continues one move at a time, until the instructor declares a victor. Throughout the exercise, the instructor guides students through analysis of each strategic decision in light of the island's structure and topography, with an emphasis on the appropriate interpretation of the maps. Students soon realize that an understanding of the island's terrain literally meant the difference between life and death for civilians and military participants alike in 1945. The karst landscape of Okinawa posed unique obstacles to both the Japanese and the American forces, including difficult landing sites, networks of natural caves, and sequences of hills aligned perpendicular to the length of the island and to American troop movement. This unique topography forced innovative tactics ranging from reverse slope defense to "blowtorch and corkscrew" offense in response. During this exercise, students apply their map-reading and interpretation skills, as well as their critical analysis abilities; the historical context, in turn, provides motivation to refine those skills. Sun Tzu wrote that all warfare is based on deception. What we hope to communicate to students with this activity is that much of warfare, and, more broadly, the way humans interact with the world, is inherently and undeniably based on geology.

Waymack, S. W.; Carrington, M. P.; Harpp, K. S.

2005-12-01

335

Geological events play a larger role than Pleistocene climatic fluctuations in driving the genetic structure of Quasipaa boulengeri (Anura: Dicroglossidae).  

Science.gov (United States)

Paleoclimatic and paleogeological events have been identified as being the two main drivers of genetic structuring in extant organisms. We used a montane stream-dwelling frog, Quasipaa boulengeri, to explore the relative roles played by these drivers on species in southern China, a region needing thorough studies. We detected four major matrilines, and no broadly distributed haplotypes occurred. The complex orogenesis of south-western China drove matrilineal divergence in Q. boulengeri into highly structured geographical units. These matrilines subsequently persisted in situ with stable populations rather than undergoing expansions during glacial cycling. The unification of the upper and middle Yangtze River in the Three Gorges mountain region mediated downstream colonization of this frog. Analyses identified geological events as playing a larger role than climatic fluctuations in driving the population history of Q. boulengeri. Nuclear allele analyses indicated gene flow; this maintained genetic cohesion of the species. South-eastern Sichuan Basin was identified as the area of secondary contact for several matrilines, and this area deserves further study and special protection. PMID:23216961

Yan, Fang; Zhou, Weiwei; Zhao, Haitao; Yuan, Zhiyong; Wang, Yunyu; Jiang, Ke; Jin, Jieqiong; Murphy, Robert W; Che, Jing; Zhang, Yaping

2013-02-01

336

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

International Nuclear Information System (INIS)

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

337

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

338

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-09-15

339

Journal of Geology  

Science.gov (United States)

From the University of Chicago Press's Journals Division, the Journal of Geology is currently available online free of charge (note: subscription fees may soon apply, but no initiation date is provided). This first-rate technical journal, which publishes "research and theory in geophysics, geochemistry, sedimentology, geomorphology, petrology, plate tectonics, volcanology, structural geology, mineralogy, and planetary sciences" has been in print form since 1893. All of the 1999 issues of the Journal of Geology electronic edition are available here. Internet users can access full-text articles with internal links to references and figures (html, .pdf. .ps).

340

Glossary of Geology  

Science.gov (United States)

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

Jackson, Julia A.

341

Bedrock Geology Mapping Exercise  

Science.gov (United States)

This field mapping and map-making exercise is a capstone project for a course on Geological Maps. Over a weekend (~12 hours of field work), students collect lithologic and structural data from outcrops scattered over a one square mile area. Back in the classroom, students digitally compile their field data (outcrop, structure measurements, traverse locations) into ArcMAP. They infer geologic linework (faults and contacts) and units from this data in ArcMAP and then export these data layers into Illustrator. In Illustrator, they add ancillary map components (a cross section, description of map units, correlation diagram, map symbol legend,...) to create a final map at a 1:10,000 scale. Their maps are printed out on 11"x17" paper and saved as a pdf file. This exercise helps the students to appreciate how field data is collected and how these geologic facts are interpretively organized into a four-dimensional picture that is a geologic map.

Jim Miller

342

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

International Nuclear Information System (INIS)

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

343

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)

344

Lithospheric Structure and Tectonics of Taiwan From Tomography, Relocated Seismicity and Geology  

Science.gov (United States)

Taiwan is a classic example of oblique arc-continent collision, which gives a progressive view of the collision process evolution in space and time. It is also a classic example of reversal of subduction polarity associated with the collision. When studying the tectonic evolution of Taiwan, we can thus trade space for time: direct observations of the current tectonic configuration can be used to infer past configurations, and predict future ones. Until recently, the 3-D geometry of the region of subduction polarity reversal has been matter of speculation because of the lack of direct imaging. We can now define the present 3-D geometry in detail by taking advantage of the most recent work on global and crustal tomography and on earthquake relocation and combining it with surface geology. The upper 10-15 km of crust consist of an accretionary wedge, composed mainly of deformed continental margin. The wedge is fully decoupled from the rest of the lithosphere below by a major detachment and forms a typical fold-and-thrust belt. The detachment is clearly visible in both the seismicity and the crustal tomography. The accretionary wedge and the lithosphere below it accommodate plate convergence differently. The wedge shortens substantially by faulting and folding, resulting in a fast-growing orogen with typical thin-skinned tectonics. The lithosphere below the detachment instead consumes plate convergence by subduction and by large-scale lithospheric folding around a single hinge line, with limited internal deformation. The shallow plate interface between Eurasia and Philippines coincides for most of its extent with the main detachment level of the Eurasian plate. This interface changes from relatively shallow-dipping in the south (Manila trench) to vertical (south-central Taiwan) to overturned (north-central Taiwan). The Eurasian Moho is similarly folded, but it does not overturn. East of the N-S plate interface, the oceanic Philippine Sea plate dips northward as it subducts under continental Eurasia, with the two subduction systems being in quasi-orthogonal stable kinematic configuration. We hypothesize that (1) once arc-continent collision occurs, convergence is taken up by faulting and folding of Eurasia above the detachment, with the Philippines plate acting as a soft indenter at crustal levels, and by subduction of the delaminated Eurasian continental lithosphere below the detachment, and that (2) the continuing westward migration of the fold hinge of the Eurasian lithosphere, necessary to allow delamination of the lithosphere, results in deactivation of compression in the overlying wedge, in crustal stretching with formation of a delamination Moho, and in insertion of mantle at shallow depths. The visible consequence at the surface is the collapse of the orogen. Delamination also requires the presence of a southwestward-propagating vertical lithospheric tear, which marks the northern end of the subducting Eurasian slab. The surface projection of the southern tip line of the vertical tear is currently located offshore Guanyin, in NW Taiwan.

Carena, S.; Suppe, J.; Wu, Y.

2012-12-01

345

Utah Geology  

Science.gov (United States)

Utah Geological Survey's Web site, Utah Geology, offers a variety of interesting geological information about the state. Good descriptions, illustrations, and photographs can be accessed on earthquakes and hazards, dinosaurs and fossils, rocks and minerals, oil and energy, and more. For example, the Rocks and Minerals page contains everything from how to stake a mining claim to downloadable summaries of mineral activity in the state. There is quite a bit of information within the site, and anyone interested in geology will find themselves exploring these pages for quite a while.

346

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

347

Grimsel test site: structural geology and water flow-paths in the migration shear-zone  

International Nuclear Information System (INIS)

The shear-zone in the ventilation tunnel at VT 420 at the Grimsel Test Site (GTS) is a direct continuation of the migration shear-zone AU 96 that is being used for hydraulic and tracer migration experiments. A thick drill-core (diameter 20 cm) was taken from the VT 420 location such that the fragile structures in the central fault breccia remained largely intact. After several hardening steps, thin-sections were produced for all three main deformation planes of the deformation ellipsoid (i.e. parallel/perpendicular to the cleavage and stretching lineation). Vacuum impregnation with fluorescent resin allowed the pore-space to be observed microscopically. The report contains information concerning the ductile shear-zone, brittle deformation, quantitative porosimetry, extrapolation of observed structures to larger scales, implications for water flow and transport, and suggestions for revised conceptual models. 23 figs., 5 tabs., 33 refs

348

Sedimentary dynamics and structural geology of pre-rift deposits of the interior basin of Gabon  

Science.gov (United States)

Recent studies combining field data (facies and paleocurrent analyses, structural surveys), sub-surface data (core analyses, well logs, seismic sections) and palynological data provide insight into the sedimentary dynamics of pre-rift deposits of the interior basin of Gabon and their structural and paleoclimatic setting. These sedimentary deposits belong to the Noya, Agoula and M'vone series of Late Precambrian to Jurassic age. Although these deposits are potential sources of petroleum, they are partly known because of poor outcrop in a wet equatorial climate, low density and uneven distribution of exploration wells and poor seismic survey coverage. The pre-rift deposits reflect fluvial-lacustrine and glacial continental sedimentation, punctuated by many sedimentary gaps and episodes of erosion, and were affected by Late Precambrian extensional faulting indicated by NNE-SSW oriented tilted blocks. This Precambrian extensional faulting was reactivated during subsequent tectonic episodes, and most notably during the Early Cretaceous rifting phase.

Mbina Mounguengui, M.; Lang, J.; Guiraud, M.; Jocktane, O.

2002-08-01

349

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

350

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

OpenAIRE

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 decr...

Vaher, Rein; Sliaupa, Saulius; Shogenova, Alla; Shogenov, Kazbulat; Pomeranceva, Raisa

2009-01-01

351

Geologic structure between the Murray fracture zone and the Transverse Ranges  

Science.gov (United States)

The Murray fracture has been thought to extend ashore into the Transverse Ranges of California, but a geophysical study shows no evidence of structural continuity between these features. Instead, basement morphology typical of the Murray fracture zone ends where its known magnetic and bathymetric expression dies out. Similarly, east-west Transverse Range structures change direction so that they are parallel to the northwest trend of the coast rather than crossing the continental shelf and slope. The lack of continuity suggests an independent development of the Transverse Ranges since at least mid-Tertiary time along an older structural trend continuous with the Murray fracture zone. Possibly a fundamental lineament in the crust, an extension of the Murray, inactive since at least the mid-Tertiary, provided a convenient trend for development of the Transverse Ranges in response to deformation along the San Andreas fault system. The Murray fracture zone is thought by some authors to be a transform-fault. The transform-fault hypothesis alleviates some difficulties that arise in explaining the origin of the zone by transcurrent faulting but equivalent uncertainties seem to accompany the newer explanation. ?? 1969.

von, Huene R.

1969-01-01

352

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

353

US Geological Survey nutrient preservation experiment : experimental design, statistical analysis, and interpretation of analytical results  

Science.gov (United States)

This report describes the experimental details and interprets results from a study conducted by the U.S. Geological Survey (USGS) in 1992 to assess the effect of different sample-processing treatments on the stability of eight nutrient species in samples of surface-, ground-, and municipal-supply water during storage at 4 degrees Celsius for about 30 days. Over a 7-week period, splits of filtered- and whole-water samples from 15 stations in the continental United States were preserved at collection sites with sulfuric acid (U.S. Environmental Protection Agency protocol), mercury (II) chloride (former U.S. Geological Survey protocol), and ASTM (American Society for Testing and Materials) Type I deionized water (control) and then shipped by overnight express to the USGS National Water Quality Laboratory (NWQL). At the NWQL, the eight nutrient species were determined in splits from each of the 15 stations, typically, within 24 hours of collection and at intervals of 3, 7, 14, 22, and 35 days thereafter. Ammonium, nitrate plus nitrite, nitrite, and orthophosphate were determined only in filtered-water splits. Kjeldahl nitrogen and phosphorus were determined in both filtered-water and whole-water splits.

Patton, Charles J.; Gilroy, Edward J.

1999-01-01

354

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

355

Analysis on fractal-like behaviour expected for migration of radionuclides in geologic sorbing media  

International Nuclear Information System (INIS)

In earlier work, we showed that within nonhomogeneous sorbing media the desorption process becomes fractal-like. In migration of radionuclides in geologic media, the adsorption is an essential factor retardating the migration. Moreover, geologic media is inherently nonhomogeneous. It is therefore probable that the migration is significantly influenced by the fractal-like feature. Based on this idea, we have analyzed migration behaviours by employing a new model and compared the results with those obtained using conventional models. The nuclides migrate in the media with the flow of ground water being continually trapped on adsorption sites and released (desorbed) to the flow. The concept of the overall residence-time distribution function for nuclides on the adsorption sites is introduced in the new model. This function obeys the power form, ?t-1-? (? > 0), for sufficiently large t (t denotes time). The migration behaviours predicted by our theory are qualitatively different from those by conventional theories, and the details of the differences are greatly dependent on the exponent ?. In particular, the migration behaviour in cases of 0 < ? < 1 is characterized by far larger retardation effects. (author)

356

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

357

Coalification analysis as a tool for regional geology in the Northern Eifel (Rhenish Massif, Germany)  

Energy Technology Data Exchange (ETDEWEB)

This study is a compilation of regional coalification work which was done in association with geological mapping in the northern part of the Eifel mountains (Devonian, Western Germany). The results are documented and interpreted by using different kinds of two-dimensional presentations: (1) a lateral coalification map, (2) a vertical coalification/stratigraphical height diagram (pseudoborehole), (3) a model cross-section explaining isochronous deviations in coalification.The map shows the highest level of coalification is not restricted to the oldest Palaeozoic strata but includes some sections of Lower Devonian age. The lines of equal coalification cross-geological strata lines that means there is a component of coalification not conformable with simple burial influence.With the help of a pseudoborehole diagram the areal gradient development in different stages of rank is discussed as well as local rapid coalification changes.In a cross-section from the Eifel North-South Zone to the flank of the Venn Anticline, the burial and coalification development is explained by a hypothetical Eifelian sedimentation trough, which marks the time of maximal burial of Lower Devonian strata.Petrophysical influences on coalification of pelitic sediments and the age of coalification are discussed.

Ribbert, K.-H.; Vieth, A. [Geologischer Dienst NRW, Postfach 100 763, D-47 707 Krefeld (Germany)

2005-04-12

358

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

359

Numerical Analysis of Thermal Remediation in 3D Field-Scale Fractured Geologic Media.  

Science.gov (United States)

Thermal methods are promising for remediating fractured geologic media contaminated with volatile organic compounds, and the success of this process depends on the coupled heat transfer, multiphase flow, and thermodynamics. This study analyzed field-scale removal of trichloroethylene (TCE) and heat transfer behavior in boiling fractured geologic media using the multiple interacting continua method. This method can resolve local gradients in the matrix and is less computationally demanding than alternative methods like discrete fracture-matrix models. A 2D axisymmetric model was used to simulate a single element of symmetry in a repeated pattern of extraction wells inside a large heated zone and evaluate effects of parameter sensitivity on contaminant recovery. The results showed that the removal of TCE increased with matrix permeability, and the removal rate was more sensitive to matrix permeability than any other parameter. Increasing fracture density promoted TCE removal, especially when the matrix permeability was low (e.g., groundwater in fractured material, with the interaction between them being considered. Boiling was initiated in the center of the upper part of the heated region and expanded toward the boundaries. This boiling process resulted in a large increase in the TCE removal rate and spread of TCE to the vadose zone and the peripheries of the heated zone. The incorporation of extraction wells helped control the contaminant from migrating to far regions. After 22?d, more than 99.3% of TCE mass was recovered in the simulation. PMID:25040727

Chen, Fei; Falta, Ronald W; Murdoch, Lawrence C

2014-07-18

360

Seismic analysis of sliding structure  

International Nuclear Information System (INIS)

Some components of industrial plants are just sitting on their support, then during a seism, sliding may occur between the structure and its support, inducing a nonlinear behaviour. After having briefly recalled the method to integrate the motion equations of a sliding structure, this paper will be devoted to a numerical approach of the seismic behaviour of the polar crane of a Nuclear Power Plant. The crane is represented by its first eigenmodes and the sliding is modelized by nonlinear links. The influence on the response of various hypothesis like identical motion of the contact points and the number of modes contained in the modal base, are investigated

361

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%, respectively. The average permeability is, respectively, 311, 251, and 12 mD. Devonian sandstone has an average porosity of 26% and permeability in the range of 0.5–2 D. Prospective Cambrian structural traps occur only in Latvia. The 16 largest ones have CO2 storage capacity in the range of 2–74 Mt, with total capacity exceeding 400 Mt. The structural trapping is not an option for Lithuania as the uplifts there are too small. Another option is utilization of CO2 for enhanced oil recovery (EOR. The estimated total EOR net volume of CO2 (part of CO2 remaining in the formation in Lithuania is 5.6 Mt. Solubility and mineral trapping are a long-term option. The calculated total solubility trapping capacity of the Cambrian reservoir is as high as 11 Gt of CO2 within the area of the supercritical state of carbon dioxide.

Vaher, Rein

2009-12-01

362

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.

363

ERTS-1 imagery of eastern Africa: A first look at the geological structure of selected areas  

Science.gov (United States)

The author has identified the following significant results. Imagery of the African rift system resolves the major Cainozoic faults, zones of warping, and associated volcanism. It also clearly depicts the crystal grain of the Precambrian rocks where these are exposed. New structural features, or new properties of known features such as greater extent, continuity, and linearity are revealed by ERTS-1 imagery. This applies, for example, to the NE-SW fracture zones in Yemen, the Aswa mylonite zone at the northern end of the Western Rift, the Nandi fault of western Kenya, the linear faults of the Elgeyo escarpment in the Gregory Rift, and the hemibasins of warped Tertiary lavas on the Red Sea margin of Yemen, matching those of Ethiopian plateau-Afar margin. A tentative scheme is proposed, relating the effect on the pattern of Cainozoic faulting of the degree of obliquity to Precambrian structural trend. It is particularly noteworthy that, even where the Precambrian grain determines the rift faulting to be markedly oblique to the overall trend of the rift trough, for example, in central Lake Tanganyika, the width of the trough is not significantly increased. Some ground mapped lithological boundaries are obscure on ERTS-1 imagery.

Mohr, P. A. (principal investigator)

1972-01-01

364

Analysis of composite structural elements  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: The themes of the study are composite structural components. For this purpose have been designed and built several research positions.Design/methodology/approach: Using different structural materials to build new device components requires multiple tests of the components. Research posts were designed in the advanced graphical program CAx Siemens NX 7.5. Analysed samples were made from the glass fibre, aramid and carbon of various weights. Due to the specific use of composite materials it focuses on the elements in the form of plates and flat bars. For the examination of experimental strain gauge technique was used bead, the force sensor and displacement sensor. The experimental methods were compared with computer simulation using the FEM.Findings: The aim of this study was to determine the basic material constants and a comparison of the experimental method and the method of computer simulation.Research limitations/implications: Change the number of layers and how to connect the laminate with the steel plate changes mechanical properties of the structural component.Practical implications: The ultimate result will be knowledge on the different forms of laminates, such as material properties, the stresses in all layers, strain and comparing the results obtained by two methods.Originality/value: The expected outcome of the study will be the composition and method of joining composite laminate with a steel plate to the possible application in the repair and construction of structural elements of freight wagons.

A. Baier

2010-12-01

365

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

Directory of Open Access Journals (Sweden)

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

Vavrek Pavol

1999-12-01

366

Geological heritage of Morocco  

International Nuclear Information System (INIS)

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

367

Structural analysis of impeller for SMART MCP  

International Nuclear Information System (INIS)

The structural integrity of the MCP impeller is important for the safe and reliable operation of the SMART, since the impeller is operated for long period inside the reactor under high pressure and high temperature. In this study, an analysis model to evaluate the structural integrity of axial pump impeller has been developed and the stress state in the impeller of SMART MCP has been calculated for the applied centrifugal and hydraulic forces. The structural integrity of the impeller has been demonstrated by comparing the analysis results with the allowable stresses. The modal analysis of the impeller has been also performed to investigate the possibility of the resonances of the impeller blades with the rotational frequencies. As a means to reduce the time required for the analysis, a cyclic symmetric analysis model with optimum boundary conditions is proposed by comparing the results from full model analyses

368

Nondestructive assay of fluorine in geological and other materials by instrumental photon activation analysis with a microtron  

Science.gov (United States)

Reliable determination of low concentrations of fluorine in geological and coal samples is difficult. It usually requires tedious decomposition and dissolution of the sample followed by chemical conversion of fluorine into its anionic form. The present paper examines possibilities of non-destructive determination of fluorine, mainly in minerals, rocks and coal, by instrumental photon activation analysis (IPAA) using the MT-25 microtron. The fluorine assay consists of counting the positron-electron annihilation line of 18F at 511 keV, which is a product of the photonuclear reaction 19F(?, n)18F and a pure positron emitter. The assay is complicated by the simultaneous formation of other positron emitters. The main contributors to interference in geological samples are from 45Ti and 34mCl, whereas those from 44Sc and 89Zr are minor. Optimizing beam energy and irradiation-decay-counting times, together with using interfering element calibration standards, allowed reliable IPAA determination of fluorine in selected USGS and CRPG geochemical reference materials, NIST coal reference materials, and NIST RM 8414 Bovine Muscle. In agreement with the published data obtained by PIGE, the results of the F assay by IPAA have revealed erroneous reference values provided for the NIST reference materials SRM 1632 Bituminous Coal and RM 8414 Bovine Muscle. The detection limits in rock and coal samples are in the range of 10-100 ?g g-1.

Krausová, Ivana; Mizera, Ji?í; ?anda, Zden?k; Chvátil, David; Krist, Pavel

2015-01-01

369

Geological Processes Affecting the Thermal Structures of Shallow Seafloor: An Example from offshore SW Taiwan  

Science.gov (United States)

Fluid migration pattern is important for understanding the structural features of a mountain belt and for hydrocarbon exploration. However, these patterns are difficult to measure on the seafloor. Using phase properties of the gas hydrates, we studied the fluid flow patterns offshore southwestern Taiwan. Seismic explorations in this region show wide spreading bottom-simulating-reflectors (BSR), which is interpreted as the bottom of the gas hydrate stability zone. It provides us an opportunity to study possible fluid flow patterns at several hundred meters sub-bottom depths of the marine sediments. First, we used BSR-based geothermal gradient patterns to derive 1D vertical fluid flow models by analyzing the Péclet numbers. We found the regional fluid flow rates ranges from 6 cm/yr to 43 cm/yr, then we also discovered several prospect sites to examine the fluid migration pattern in the environs of active, passive and deformation front. Next, we forward 2D steady-state temperature fields of these sites to account for the topographic effects to compare with the BSR-based temperature. The discrepancy between the 2D conductive thermal model and the BSR-based temperature was interpreted as a result of fluid migration. And furthermore, we built 3D steady-state temperature fields, for comparing with BSR-based temperatures, to detail describe the regional temperature discrepancy with the structure evolution in 3D seismic data. We discovered our interpreted fluid migration patterns are consistent with the regional structure. The BSR-based temperatures in Yung-An Ridge, which is in active margin, are higher than the conduction model near faults and chimney zones, we interpret that it is possible active dewatering inside the accretionary prism to allow fluid to migrate upward here. For the upper reach of Peng-Hu Canyon, which is across deformation front, we found the disequilibrium temperature field probably induced by the recently landslide. For the Formosa Ridge in passive margin, the BSR-based temperatures are colder than the theoretical model, especially on the flanks. We suggested that cold seawater is moving into the ridge from the flanks, cooling the ridge, and then some of the fluid is expelled at the ridge top. On the sum, the shallow temperature fields are strongly affected by 2D or 3D topographic effects, but we can still gain much information regarding fluid flow patterns through modeling. The new method we proposed will be helpful on assess the risk or value on energy exploration.

Chen, Liwen; Chi, Wu-Cheng; Wu, Shao-Kai; Liu, Char-Shine; Lu, Chia-Yu

2014-05-01

370

Yellowstone Geology  

Science.gov (United States)

This Yellowstone National Park website provides geological information about the Park. Links include geologic highlights, hydrothermal features, reports by park geologists, and scientists' talks (videos). A wide array of information can be found on these links and the webpage is expanding as more topics are added.

Yellowstone National Park

371

Structural analysis and stress evaluation system for steel structures: ADAMS  

International Nuclear Information System (INIS)

In order to perform the structural analysis and stress evaluation for frame structures in the nuclear power plants, ADAMS (AIJ Design Analysis and Modules System) has been developed by the addition of the following functions to the ICES-STRUDL system. 1. Load combination and stress evaluation on the basis of specifications for designing steel structure (issued by the Architecture Institute of Japan). 2. Combination of load and stress evaluation of piping support on the basis of the regulations of Ministry of International Trade and Industry. 3. Addition of other functions than that described above. ADAMS enables structural analysis and stress evaluation exactly and efficiently not only for a large scale structure such as the pipe whip protection structure installed inside of the primary containment vessel for many loading cases but also for a large number of structures such as piping support. This system can be applied not only to nuclear power plant but also other plants such as boilers and chemical plants. (author)

372

Structural analysis of the central Columbia Plateau utilizing radar, digital topography, and magnetic data bases  

International Nuclear Information System (INIS)

Interest in the Hanford site (Washington) as a nuclear production, power, and waste disposal site has led to generation of a vast quantity of geophysical and remote sensing data sets of the central Columbia Plateau. To data, these various studies, including at least 13 independent magnetic linear and image lineament studies, have not been adequately correlated. Therefore, these studies provide a unique opportunity to compare and contrast the viability of the different geophysical and remote sensing techniques. The geology of the central Columbia Plateau is characterized by subdued topography and limited outcrop, with most of the exposure concentrated in localized folded/faulted mountains (the Yakima folds) and along river canyons. In order to efficiently compare lineament data bases, we have written an automated computer routine that correlated lineaments that are within a user specified distance of each other. The angle between their trends has to be less than an input maximum separation angle. If more than two lineament maps exist for the area, the analyst may also specify the minimum number of times each structure must be seen. The lineament correlation routine was applied to data bases of all aeromagnetic linears as well as lineaments seen on radar and a digital elevation model DEM image. Geologic structures align with a set of three-dimensional planar structures identified with our Geologic Spatial Analysis (GSA) system. The GSA analysis is based upon computer automated detection of valley bottoms as defined by a DEM

373

Thermal Modeling and Performance Analysis of Interim Dry Storage and Geologic Disposal Facilities for Spent Nuclear Fuel  

International Nuclear Information System (INIS)

Thermal models are constructed and analyses are performed of aluminum-based spent nuclear fuel (Al-SNF) in interim dry storage and geologic disposal configurations. Two models are developed, referred to as the interim storage model and the codisposal waste package (WP) model. Time-dependent source terms of Al-SNF forms and the defense high-level waste (DHLW) canisters are also developed for thermal performance analysis of the geologic codisposal WP.The interim storage model is a three-dimensional conduction-convection conjugate model to investigate the natural convection cooling of a sealed dry storage canister with vertical orientation in a dry storage vault. The analysis is made for various decay heat sources (equivalent to 25 to 35 kW/m3) using various boundary conditions around the canister wall and with backfilled nitrogen or helium gas. Based on the data obtained from the Savannah River Site experimental work and available from the literature, an improved dimensionless correlation for the external heat transfer of the canister by the airflow crossing normal to the staggered tubes is developed.The codisposal WP model considers heat transfer driven by conduction and convection processes combined with radiation for the thermal performance study of an enclosed WP containing one Al-SNF canister and five DHLW glass canisters. Two-dimensional analysis for a representative cross-sectional area of the codisposal WP is performed because each component has a larperformed because each component has a large aspect ratio of package length to diameter and the package is laid down horizontally in a drift tunnel repository. The results showed that the codisposal disposition options for the helium- and air-filled WPs satisfied the present waste acceptance criteria for the WP design under the reference conditions

374

GLay: community structure analysis of biological networks  

OpenAIRE

Summary: GLay provides Cytoscape users an assorted collection of versatile community structure algorithms and graph layout functions for network clustering and structured visualization. High performance is achieved by dynamically linking highly optimized C functions to the Cytoscape JAVA program, which makes GLay especially suitable for decomposition, display and exploratory analysis of large biological networks.

Su, Gang; Kuchinsky, Allan; Morris, John H.; States, David J.; Meng, Fan

2010-01-01

375

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

Energy Technology Data Exchange (ETDEWEB)

Our proposed work on high resolution/high fidelity seismic imaging focused on three general areas: (1) development of new, more efficient, wave-equation-based propagators and imaging conditions, (2) developments towards amplitude-preserving imaging in the local angle domain, in particular, imaging methods that allow us to estimate the reflection as a function of angle at a layer boundary, and (3) studies of wave inversion for local parameter estimation. In this report we summarize the results and progress we made during the project period. The report is divided into three parts, totaling 10 chapters. The first part is on resolution analysis and its relation to directional illumination analysis. The second part, which is composed of 6 chapters, is on the main theme of our work, the true-reflection imaging. True-reflection imaging is an advanced imaging technology which aims at keeping the image amplitude proportional to the reflection strength of the local reflectors or to obtain the reflection coefficient as function of reflection-angle. There are many factors which may influence the image amplitude, such as geometrical spreading, transmission loss, path absorption, acquisition aperture effect, etc. However, we can group these into tw