Sample records for argillite

  1. Generic Argillite/Shale Disposal Reference Case

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    Zheng, Liange; Colon, Carlos Jové; Bianchi, Marco; Birkholzer, Jens


    Radioactive waste disposal in a deep subsurface repository hosted in clay/shale/argillite is a subject of widespread interest given the desirable isolation properties, geochemically reduced conditions, and widespread geologic occurrence of this rock type (Hansen 2010; Bianchi et al. 2013). Bianchi et al. (2013) provides a description of diffusion in a clay-hosted repository based on single-phase flow and full saturation using parametric data from documented studies in Europe (e.g., ANDRA 2005). The predominance of diffusive transport and sorption phenomena in this clay media are key attributes to impede radionuclide mobility making clay rock formations target sites for disposal of high-level radioactive waste. The reports by Hansen et al. (2010) and those from numerous studies in clay-hosted underground research laboratories (URLs) in Belgium, France and Switzerland outline the extensive scientific knowledge obtained to assess long-term clay/shale/argillite repository isolation performance of nuclear waste. In the past several years under the UFDC, various kinds of models have been developed for argillite repository to demonstrate the model capability, understand the spatial and temporal alteration of the repository, and evaluate different scenarios. These models include the coupled Thermal-Hydrological-Mechanical (THM) and Thermal-Hydrological-Mechanical-Chemical (THMC) models (e.g. Liu et al. 2013; Rutqvist et al. 2014a, Zheng et al. 2014a) that focus on THMC processes in the Engineered Barrier System (EBS) bentonite and argillite host hock, the large scale hydrogeologic model (Bianchi et al. 2014) that investigates the hydraulic connection between an emplacement drift and surrounding hydrogeological units, and Disposal Systems Evaluation Framework (DSEF) models (Greenberg et al. 2013) that evaluate thermal evolution in the host rock approximated as a thermal conduction process to facilitate the analysis of design options. However, the assumptions and the

  2. Ten years of Toarcian argillite - carbon steel in situ interaction

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    Dauzeres, Alexandre [IRSN, PRP-DGE/SRTG/LETIS, BP 17, 92262 Fontenay-aux-Roses cedex (France); Maillet, Anais [IRSN, PRP-DGE/SRTG/LETIS, BP 17, 92262 Fontenay-aux-Roses cedex (France); UMR CNRS 7285, IC2MP, Batiment B35 - 5, avenue Albert Turpain, 86022 Poitiers cedex (France); Gaudin, Anne [UMR CNRS 6112, LPGN, 2 rue de la Houssiniere, BP 92208, 44322 Nantes cedex 3 (France); El Albani, Abderrazak; Vieillard, Philippe [UMR CNRS 7285, IC2MP, Batiment B35 - 5, avenue Albert Turpain, 86022 Poitiers cedex (France)


    In situ interaction experiments over periods of 2, 6, and 10 years between Toarcian argillite and carbon steel discs were carried out in the Tournemire Underground Research Laboratory (URL), yielding a dataset of the materials' geochemical evolution under conditions representative of the future geological disposal of high-level long-lived radioactive wastes. The carbon steel discs were exposed to corrosion due to trapped oxygen. The corrosion rates indicate that the oxidizing transient lasted between 2 and 6 years. A systematic dissolution of calcium phases (Ca-smectite sheets in I/S and calcite) was observed in the iron diffusion halos. The iron release induced mineralogical dissolution and precipitation reactions, which partly clogged the argillite porosity. (authors)

  3. Complexation of europium(III) by organic extracts from Callovo-Oxfordian argillites

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    Brevet, L.; Grasset, L.; Ambles, A. [Univ. de Poitiers, Synthese et Reactivi te des Substances Naturelles, CNRS UMR 6514, 86022 Poitiers (France); Reiller, P.; Claret, F.; Amekraz, B.; Moulin, C. [CEA, CE Saclay, CEA/DEN/DANS/DPC/SECR, Labo ratoire de Speciation des Radionucleides et des Molecules, F-91191 Gif-sur-Yvette (France)


    The complexation behaviour of organic extracts obtained after acid alteration of Callovo-Oxfordian argillites toward europium (III) is studied in time resolved laser induced spectrofluorimetry. The presence of fluoride ions in one extract, originated from the dissolution of remaining silicates in HCl/HF, precludes the correct study. Nevertheless, the dialysis of the extract at 500 Da permits to obtain a clearer evolution of the complexation pattern. The fluorescence spectrum and decay are strikingly different the ones obtained on alkaline degradation products of the Callovo-Oxfordian argillite, and resemble more to a small organic molecule pattern.

  4. Hydraulic Monitoring of Low-Permeability Argillite at the Meuse/Haute Marne Underground Research Laboratory (United States)

    Delay, Jacques; Cruchaudet, Martin

    ANDRA (Agence Nationale pour la Gestion de Déchets Radioactifs) has developed an electromagnetic permanent gauge (EPG) for long term monitoring of pore pressures in low permeability Callovo-Oxfordian argillites. The EPG is a pressure gauge that is permanently cemented into a borehole with no wire or tubing connections. The EPG transmits its data electromagnetically through the rock. Improvements in batteries have extended the life of the EPG to six years or more. Data from EPG installations in two holes near ANDRAs underground laboratory provide information on hydraulic conductivity and head. The heads in the argillites of the laboratory site are higher than heads in the two encasing carbonate units. These anomalous overpressures provide evidence for the very low permeability of the rock. Possible mechanisms for the overpressure include osmotic flows due to chemical potential gradients or delayed responses to the evolution of the regional groundwater hydrodynamics.

  5. Elastoplastic damage modelling of argillite in partially saturated condition and application (United States)

    Jia, Y.; Song, X. C.; Duveau, G.; Su, K.; Shao, J. F.

    This paper presents an elastoplastic damage model for argillites in unsaturated and saturated conditions. A short resume of experimental investigations is presented in the first part. Based on experimental data and micromechanical considerations, a general constitutive model is proposed for the poromechanical behavior of argillite in both saturated and unsaturated conditions. The proposed model is formulated within the framework of poroplasticity and continuum damage mechanics. Main features observed in experimental data are taken into account, in particular the elastic degradation due to microcracks, coupling between plastic deformation and induced damage, influence of water saturation on plastic flow and damage evolution, as well as variation of permeability with induced damage. The performance of the model is examined by comparing numerical simulation with test data in representative load paths. Finally, the model is applied to a hydromechanical coupling analysis of a cavity subjected to excavation and ventilation.

  6. Modeling Cl{sup -} concentration and δ{sup 37}Cl profiles in pore water across a 250 m-thick indurated argillite at the Tournemire URL (France)

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    Le Gal La Salle, Corinne; Rebeix, Romain; Lancelot, Joel [Universite de Nimes / Site GIS - 30035 Nimes cedex 01 (France); Aix-Marseille Universite, CEREGE UMR7330, 13545 Aix en Provence (France); Matray, Jean-Michel [IRSN, BP17 - 92262 Fontenay-aux-Roses Cedex (France); Bensenouci, Fethic [IRSN, BP17 - 92262 Fontenay-aux-Roses Cedex (France); IDES, UMR CNRS 8148 Universite Paris-Sud - 91405 Orsay Cedex (France); Michelot, Jean-Luc [IDES, UMR CNRS 8148 Universite Paris-Sud - 91405 Orsay Cedex (France); Dauzeres, Alexandre; Wittebroodt, Charles [IRSN, BP17 - 92262 Fontenay-aux-Roses Cedex (France); Frape, Shaun; ShouakarStash, Orphane [University of Waterloo, 200 University Avenue. West Waterloo, Ontario N2L 3G (Canada)


    Dissolved chloride in argillite pore water has been studied as a natural analogue for radionuclides potentially released from radioactive waste disposal. The Tournemire URL intersects impervious and compacted argillite. A previously obtained chloride concentration profile of intact rock is symmetric with a maximum concentration of 0.6±0.1 g/L, compared to 19 g/L for the original connate seawater. Dissolved chloride shows high δ{sup 37}Cl values, ranging between +6 and +80/00 vs. SMOC. The modeled profile considers diffusive exchange between connate seawater and meteoric freshwater. Transport parameters were obtained by radial diffusion experiments. Numerical modeling was performed with the coupled reactive-transport code Hytec. Simulations suggest a diffusive-exchange time of 85±10 Ma for Cl, which correlates with a major erosional period. Simulated δ{sup 37}Cl values between 1.002 and 1.003 agree with observed pore water δ{sup 37}Cl. This study strongly suggests that the dissolved chloride profile in the argillites results from diffusive exchange and indicates that unfractured argillites can provide good confinement. (authors)

  7. Sr, C and O isotopes as markers of alkaline disturbances in the Toarcian argillites of the Tournemire experimental platform (France). Case of a 15-years old engineered analogue. (United States)

    Techer, I.; Boulvais, P.; Bartier, D.; Tinseau, E.


    In France, the concept of a geological disposal of high-activity and long-period nuclear wastes requires the use of concrete and cement-bearing materials as building structures or as waste containment packages, in conjunction with clayey barriers (e.g., compacted bentonite as an engineered barrier and/or argillite-type rocks as a geological barrier). Hydrolysis of cementitious phases is however known to produce hyper-alkaline pore fluids with pH ranging from 10 to 13.5 that will be in disequilibrium with the geological setting environment (argillite pore-water pH around 8). The disturbance of clayey rocks in contact with such materials is thus an important task in safety assessment studies of deep geological storage. This concerns the knowledge of mineral / solution paths but also the spatial extent of the alkaline plume into the clayey material. Experimental and modelling approaches were performed this last decade to answer these questions. In addition to these approaches, natural or engineered contexts in which a clayey formation has been in contact with cementitious materials can be considered as analogues of a deep geological storage for the study of argillite /cement interaction. Such contexts can be found in the IRSN Tournemire experimental platform in Aveyron (France). This platform is based on a tunnel, excavated between 1882 and 1886 through Domerian marls and Toarcian argillites, which is dedicated since 1990 to multidisciplinary research programs. In the frameworks of these programs, exploration boreholes were realized from the basement of the tunnel in the 1990 years. The boreholes were then filled with concrete and cement that are presently in contact with the Toarcian argillites for 15-20 years. One of this borehole - DM borehole - was overcored in 2005 in order to collect the Toarcian argillites in contact with the cement and the concrete. Mineralogical, petrographic and microstructural analyses have argued for a clear disturbance of the Toarcian

  8. Determination of hydraulic properties of the Callovo-Oxfordian argillite at the bure site: Synthesis of the results obtained in deep boreholes using several in situ investigation techniques (United States)

    Distinguin, Marc; Lavanchy, Jean-Marc

    Since 1991, ANDRA ( Agence Nationale pour la gestion des Déchets Radioactifs - National Radioactive Waste Management Agency) has been performing research on the possibility of geologic disposal of high level radioactive waste. In 1999, Andra began constructing an Underground Research Laboratory at Bure, a site located on the border of the Meuse-Haute-Marne departments, 300 km East of Paris. The laboratory is investigating the Callovo-Oxfordian argillite, a 130 m thick middle Jurassic stratum, at a depth of about 420 m. Argillite is a clay-rich sedimentary rock with low-permeability. Between 1994 and 2004, Andra collected from deep boreholes an impressive wealth of data covering a wide range of geosciences. This paper focuses on the hydraulic data related to argillite, including the results from short-term hydraulic packer tests and long-term monitoring of the formation pressures. Three types of tools are used on the site for investigations in deep boreholes. The first one is a conventional packer test tool used in the petroleum industry and adapted for hydrogeological purposes. The main objective is to determinate the permeability of the formation through short-term tests (24-72 h) at about 10 regular intervals. The two other types of tool are permanent monitoring devices. The electromagnetic pressure gauge (EPG) is totally isolated from the surface perturbations. There are no electric or hydraulic lines to the surface and the borehole is cemented. The advantage of this tool is that the formation almost recovers its initial pressure, avoiding disturbances from surface. Although the multi-packer equipment, installed in an open borehole can be affected by surface perturbations, it is used to measure pressure at different isolated levels in the same borehole ( i. e., 11 chambers in one borehole). Evaluations of the formation pressure (freshwater head) and hydraulic conductivity have been performed for all intervals investigated (19 short-term packer tests and 15 long

  9. Simulation of anions diffusion in Callovo-Oxfordian argillite by description of the rock microstructure; Modelisation de la diffusion des anions dans l'argilite du Callovo-oxfordien par description de la microstructure de la roche

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    Diaz, N. [CEA Saclay, Dept. de Physico-Chimie (DEN/DANS/DPC/SECR), 91 - Gif sur Yvette (France)


    The Callovo-Oxfordian argillite has been proposed as host rock for deep underground radioactive wastes storage. The aim of this study is to determine the report of effective diffusion coefficients De(anion)/De(water) at the micrometer scale considering the spatial distribution of minerals in the rock. (A.L.B.)

  10. Modelling of the mechanical behaviour and damage of clay-stones: application to the East argillite; Modelisation du comportement mecanique des argiles raides avec prise en compte de l'endommagement: application aux argilites de l'Est

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    Aublive-Conil, N


    The storage in deep geological formation is one of the solutions retained by France for the management of highly long life radioactive waste. The retained host rock is a clay-stone named East argillite located in the departments of Meuse and Haute-Marne. A thermodynamic formulation is used to propose a rheological model, which reproduces the mechanical behavior of clay-stones. Initially, an anisotropic damage plastic model was formulated in order to describe material degradations. Then, the damage plastic model is reformulated in order to taken into account the damage influence on the hydraulic behavior of porous material. The numerical simulations correctly reproduce the mechanical behavior of East Argillites but also the anisotropy of the hydraulic behavior introduced by the damage effect. (author)

  11. Contributions to micromechanical model of the non linear behavior of the Callovo-Oxfordian argillite; Contributions a la modelisation micromecanique du comportement non lineaire de l'argilite du callovo-oxfordien

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    Abou-Chakra Guery, A


    This work is performed in the general context of the project of underground disposal of radioactive waste, undertaken by the French National Radioactive Waste Management Agency (ANDRA). Due to its strong density and weak permeability, the formation of Callovo-Oxfordian argillite is chosen as one of possible geological barriers to radionuclides. The objective of the study to develop and validate a non linear homogenization approach of the mechanical behavior of Callovo-Oxfordian argillites. The material is modelled as a composite constituted of an elasto(visco)plastic clay matrix and of linear elastic or elastic damage inclusions. The macroscopic constitutive law is obtained by adapting the incremental method proposed by Hill. The derived model is first compared to Finite Element calculations on unit cell. It is then validated and applied for the prediction of the macroscopic stress-strain responses of the argillite at different geological depths. Finally, the micromechanical model is implemented in a commercial finite element code (Abaqus) for the simulation of a vertical shaft of the underground laboratory. This allows predicting the distribution of damage state and plastic strains and characterizing the excavation damage zone (EDZ). (author)

  12. 修水碳硅泥岩型铀矿特征及资源潜力分析%Characteristics and Resource Potential of Arbonaceous-siliceous-argillitic Rock-hosted Uranium Deposits in Xiushui Area

    Institute of Scientific and Technical Information of China (English)

    胡茂梅; 杨松; 邵飞; 刘守坚; 梁发辉; 邓军


    修水碳硅泥岩型铀矿主要有保峰源、董坑、大椿、白土、洞下矿床,矿床集中分布于修水复向斜中,构成修水矿化集中区,该矿化集中区位于修水-宁国-开化碳硅泥岩成矿带西端,是我国重要的碳硅泥岩型铀矿主产地,具有优越的区域铀成矿地质条件.通过铀矿调查评价工作,分析厘定了研究区岩性岩相、构造、岩相古地理、铀源等条件,明确了灯影组、王音铺组碳硅泥岩建造为研究区主要铀源层、赋矿层,新发现了观音堂组中的工业铀矿体.以铀成矿地质条件、铀矿化特征分析为重点,预测铀资源潜力.%The arbonaceous-siliceous-argillitic rock-hosted uranium deposits mainly include Baofengyuan, Dongkeng,Dachun, Daitu,Dongxia in Xiushui area,which are concentrated in Xiushui synclinorium, and formed into mineralization concentration area which is located in western of the Xiushui - Ningguo - Kaihua carbonaceous-siliceous-argillitic rock in metallogenic- belt, it is the main origin of carbonaceous-siliceous-argillitic rock type u-ranium deposits in our country, we have carried out by the uranium survey and evaluation work, an analysis on the area of lithology and facies, structure, lithofacies palaeogeography, uranium source conditions, clearled the Dengying Formation, Wang Yin Pu group of carbonaceous-siliceous-argillitic rock construction for regional uranium source, host strata, found a new industrial uranium ore body in Buddism godness Guanyin hall group.This page is based on the geological conditions of uranium metallogenesis, uranium mineralization characteristics analysis to predict the potential of uranium resources.

  13. Modelling the effective diffusion coefficient of anions in Callovo-Oxfordian argillite knowing the microstructure of the rock; Modelisation predictive de la migration des anions par description de la microstructure de la roche: application a l'argilite du Callovo-Oxfordien

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, N.


    After having presented the issue of radioactive waste storage, the concept of geological storage and its application in the Meuse/Haute-Marne underground laboratory, and described the Callovo-Oxfordian geological formation and the argillite transport properties, this research thesis aims at developing a prediction of these properties at a macroscopic scale for water and anions. A first part presents the different experimental means implemented to acquire the diffusion coefficients for the studied materials (Callovo-Oxfordian argillite and purified Puy illite), and the spatial organisation of minerals by LIBS probe-based mapping to highlight a relationship between rock microstructure and its transport macroscopic properties. The next part presents the models which have been developed at the nanometer and micrometre scale to predict the diffusion coefficients. Experimental results are then compared with computed values

  14. Microbial investigations in Opalinus clay from Mont Terri and in Callovo-Oxfordian argillite from Meuse/Haute-Marne; Caracterisation microbiologique de l'argile a opalinus du Mont Terri et de l'argilite du callovo-oxfordien de Meuse/Haute-Marne

    Energy Technology Data Exchange (ETDEWEB)

    Poulain, S


    The subject of this Ph.D. thesis deals with research achieved in the context of the Axis 2 of the law Bataille voted on December 30, 1991 about the possibility of building a deep geological repository for medium or high activity and long living nuclear waste. Nearby such a site, some microorganisms may influence the mobility of radionuclides coming from the waste canisters. This work consisted in looking for autochthonous microorganisms in the Opalinus clay formation from Mont Terri (Switzerland) and in the Callovo-Oxfordian argillite from Meuse/Haute-Marne (France). Microbial Investigations in these unknown unperturbed environments suggested very low microbial densities in the clayey sediments. However, new bacterial species could be isolated from those samples. In addition, a part of the allochthonous population, which has been introduced by air and human activity, could be identified in the Meuse/Haute-Marne underground research laboratory. (author)

  15. DR Argillite Disposal R&D at LBNL

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Liange [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kim, Kunhwi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Xu, Hao [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    Within the Natural Barrier System (NBS) group of the Used Fuel Disposition (UFD) Campaign at the Department of Energy’s (DOE) Office of Nuclear Energy LBNL’s research activities have focused on understanding and modeling EDZ evolution and the associated coupled processes and impacts of high temperature on parameters and processes relevant to performance of a clay repository to establish the technical base for the maximum allowable temperature. This report documents results from some of these activities. These activities address key Features, Events, and Processes (FEPs), which have been ranked in importance from medium to high, as listed in Table 7 of the Used Fuel Disposition Campaign Disposal Research and Development Roadmap (FCR&D-USED-2011-000065 REV0) (Nutt, 2011). Specifically, they address FEP 2.2.01, Excavation Disturbed Zone, for clay/shale, by investigating how coupled processes affect EDZ evolution; FEP 2.2.05, Flow and Transport Pathways; and FEP 2.2.08, Hydrologic Processes, and FEP 2.2.07, Mechanical Processes, and FEP 2.2.09, Chemical Process—Transport, by studying near-field coupled THMC processes in clay/shale repositories. The activities documented in this report also address a number of research topics identified in Research & Development (R&D) Plan for Used Fuel Disposition Campaign (UFDC) Natural System Evaluation and Tool Development (Wang 2011), including Topics S3, Disposal system modeling – Natural System; P1, Development of discrete fracture network (DFN) model; P14, Technical basis for thermal loading limits; and P15 Modeling of disturbed rock zone (DRZ) evolution (clay repository).

  16. Coupled THMC study of the Bure clay argillite; Etude du comportement couple THMC des argiles raides

    Energy Technology Data Exchange (ETDEWEB)

    Haxaire, A.; Djeran-Maigre, I. [Institut National des Sciences Appliquees (INSA), Laboratoire de Genie Civil et d' Ingenierie (LGCIE), 69 - Villeurbanne (France); Millard, A. [CEA Saclay (SEMT/LM2S), 91 - Gif sur Yvette (France)


    To study the thermo-hydro-mechanical and chemical (THMC) behaviour of the so-called argilite of the East, a model based on the thermodynamics of porous media is proposed. A dissolution is studied and two analyses of responses of the argilite are computed with Cast3M. The case study is made of a cylindrical sample of argilite. The influence of a chemical reaction on the suction is shown. The paper ends with a discussion of the further improvements of the model. (authors)

  17. Field examination of shale and argillite in northern Nye County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Connolly, J. R.; Woodward, L. A.; Emanuel, K. M.; Keil, K.


    Thirty-two locales underlain by clay-rich strata ranging from Cambrian Pioche Shale to Mississippian Chainman Shale and equivalents were examined in northern Nye County, Nevada. The text of the report summarizes data for each stratigraphic unit examined. Checklists for tabulating field data at each locale are included in an appendix. Working guidelines used to evaluate the locales include a minimum thickness of 150 m (500 ft) of relatively pure clay-rich bedrock, subsurface depth between 150 m (500 ft) and 900 m (3000 ft), low topographic relief, low seismic and tectonic activity, and avoidance of areas with mineral resource production or potential. Field studies indicate that only the Chainman Shale, specifically in the central and northern parts of the Pancake Range, appears to contain sites that meet these guidelines.

  18. Investigation of Coupled Processes and Impact of High Temperature Limits in Argillite Rock

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    Zheng, Liange [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kim, Kunhwi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Houseworth, Jim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    The focus of research within the UFD Campaign is on repository-induced interactions that may affect the key safety characteristics of an argillaceous rock. These include thermal-hydrological-mechanical-chemical (THMC) process interactions that occur as a result of repository construction and waste emplacement. Some of the key questions addressed in this report include the development of fracturing in the excavation damaged zone (EDZ) and THMC effects on the near-field argillaceous rock and buffer minerals and petrophysical characteristics, particularly the impacts of induced temperature rise caused by waste heat.

  19. Water Retention Capacity of Argillite from the VE Test - Phase II at Mont Terri: Effect of Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Fernandez, A. M.; Melon, A. M.


    The VE (ventilation) test carried out at the Mont Terri underground laboratory in Switzerland intended to evaluate in situ the behaviour of a consolidated clay formation when subjected to alternate periods of flow of wet and dry air during several months. For that, a 10-m gallery was excavated in the Opalinus Clay formation and carefully instrumented. Before and after a second ventilation phase boreholes were drilled. Samples were taken from the drill cores and were analysed from mineralogical and geochemical points of view. Also, the retention curves of these samples were determined in the laboratory following drying paths performed under free volume conditions at 20 degree centigrade, what is the content of this report. Although there are not large differences in the WRC of samples taken from different boreholes, at different distances from the gallery wall or before or after ventilation, those samples taken near the gallery wall and after ventilation tend to show a higher water retention capacity. This has been correlated to the higher salinity of the pore water of these samples, what increases their osmotic suction. This effect is attenuated towards high suctions. (Author) 10 refs.

  20. New experimental approach for studying diffusion through an intact and unsaturated medium: a case study with Callovo-Oxfordian argillite. (United States)

    Savoye, Sébastien; Page, Jacques; Puente, Céline; Imbert, Christophe; Coelho, Daniel


    The diffusion of tritiated water and anionic species was studied in an unsaturated core of Callovo-Oxfordian claystone, which is a potential host-rock for disposal of high-level radioactive wastes. The diffusion parameters in such conditions were determined using modified through-diffusion cells in which the suction is generated by the osmosis process. This specific device leads to values of saturation degree ranging from 81% to 100%. The results show that the diffusion through unsaturated samples is clearly slower than that in fully saturated samples, with steady-state fluxes decreasing by a factor up to 7 for tritium and up to 50 for anionic species. While tritium porosity values follow volumetric water contents (from 21 to 16%), the porosity accessible to anionic species significantly decreases (from 7.5 to 0.7%). Such diffusive behaviors have been modeled by means of a modified Archie's law, taking into account a critical water saturation below which no tracer can percolate. These results indicate that the largest pores, which are initially affected by dehydration, would play an important role on the connectivity of the porous medium. This would especially affect anionic species diffusion behavior because they are constrained to diffuse into the largest pores first.

  1. Metal corrosion and argillite transformation at the water-saturated, high-temperature iron-clay interface: A microscopic-scale study

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, Michel L. [Department of Physics and Chemistry, CEA - Laboratory for the Reactivity of Surfaces and Interfaces, DPC/SCP/LRSI, CEN Saclay, Bat. 391, F-91191 Gif-sur-Yvette Cedex (France); UMR 8587 ' LAMBE' , Universite d' Evry-Val d' Essonne, 91 025 Evry (France)], E-mail:; Bataillon, Christian [CEA - Laboratory for the Study of Aqueous Corrosion, DPC/SCCME/LECA, CEN Saclay, Bat. 458, F-91191 Gif-sur-Yvette Cedex (France); Benhamida, Keltoum; Blanc, Cecile; Menut, Denis; Lacour, Jean-Luc [Department of Physics and Chemistry, CEA - Laboratory for the Reactivity of Surfaces and Interfaces, DPC/SCP/LRSI, CEN Saclay, Bat. 391, F-91191 Gif-sur-Yvette Cedex (France)


    In this study, microscopic and spectroscopic techniques (scanning electron microscopy coupled with energy-dispersive X-ray analysis, Raman microspectroscopy, micro X-ray fluorescence spectroscopy, micro X-ray fine structure adsorption spectroscopy, and micro laser-induced breakdown spectroscopy) were combined to decipher the chemical and mineralogical properties of a saturated Fe-clay interface reacted at 90 deg. C and 50 bar for 8 months. The results collectively confirm the presence of a corrosion layer and a clay transformation layer. The corrosion layer is made of a magnetite-containing internal sublayer and a Fe-phyllosilicate external sublayer enriched in Na, with traces of goethite presumably resulting from sample reaction with air. The clay transformation layer is made of predominantly Ca-rich siderite (FeCO{sub 3}). It is depleted in Al and K, suggesting dissolution of rock-forming minerals. The corroded thickness determined from the amount of Fe in corrosion and transformation layers and assuming zero porosity equals 19 {+-} 9 {mu}m. These data indicate that the interfacial clay was transformed by dissolution of calcite and clay minerals and precipitation of siderite close to the original surface. Silica released upon clay dissolution diffused into the corrosion layer and coprecipitated with oxidized Fe to form Fe-phyllosilicate.

  2. Hydrogeological Investigations in Deep Wells at the Meuse/Haute Marne Underground Research Laboratory (United States)

    Delay, Jacques; Distinguin, Marc

    ANDRA (Agence Nationale pour la Gestion de Déchets Radioactifs) has developed an integrated approach to characterizing the hydrogeology of the carbonate strata that encase the Callovo-Oxfordian argillite at the Meuse/Haute-Marne Laboratory site. The argillites are difficult to characterize due to their low permeability. The barrier properties of the argillites can be inferred from the flow and chemistry properties of the encasing Oxfordian and Dogger carbonates. Andras deep hole approach uses reverse air circulation drilling, geophysical logging, flow meter logging, geochemical sampling, and analyses of the pumping responses during sampling. The data support numerical simulations that evaluate the argillites hydraulic behaviour.

  3. Multiscale Study of the Nonlinear Behavior of Heterogeneous Clayey Rocks Based on the FFT Method (United States)

    Jiang, Tao; Xu, Weiya; Shao, Jianfu


    A multiscale model based on the fast Fourier transform (FFT) is applied to study the nonlinear mechanical behavior of Callovo-Oxfordian (COx) argillite, a typical heterogeneous clayey rocks. COx argillite is modeled as a three-phase composite with a clay matrix and two types of mineral inclusions. The macroscopic mechanical behavior of argillite samples with different mineralogical compositions are satisfactorily predicted by unified local constitutive models and material parameters. Moreover, the numerical implementation of the FFT-based nonlinear homogenization is easier than direct homogenization, such as the FEM-based homogenization, because it automatically satisfies the periodic boundary condition.

  4. Experimental study and modelling of physico-chemical mechanisms of clay-concrete interactions in the radioactive waste geological disposal context; Etude experimentale et modelisation des mecanismes physico-chimiques des interactions beton-argile dans le contexte du stockage geologique des dechetsradioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Dauzeres, A.


    These research works are carried out as part of the radioactive wastes geological disposal feasibility study. The current option developed by Andra, includes several cementitious materials in contact with the surrounding Callovo-Oxfordian (COX) (an argillite). Concretes and argillite present very different pore solutions (ionic concentrations and pH). Controlled by the concentrations differences, the aqueous species diffusion in the solids generates chemical and physical disturbances. This study is based on experimental, analytical and numerical works, in order to identify the mechanisms controlling the clayey environment influence on cementitious materials. (author)

  5. Large scale geological characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Guillemot, D.; Yven, B.; Lefranc, M.; Trouiller, A.; Geraud, Y.; Esteban, L. [Andra - Agence Nationale pour la Gestion des Dechets Radioactifs, 92 - Chatenay Malabry (France); Marache, A.; Riss, J.; Denis, A. [Bordeaux-1 Univ., CDGA (GHYMAC), Talence (France); Yven, B.; Trouiller, A. [Andra - Agence Nationale pour la Gestion des Dechets Radioactifs, Service Milieu Geologique, 92 - Chatenay Malabry (France); Lefranc, M.; Beaudoin, B.; Chiles, J.P. [Ecole des Mines de Paris, Centre de Geosciences, 77 - Fontainebleau (France); Ravenne, C. [Institut Francais du Petrole, 92 - Rueil Malmaison (France); Bouchez, J.L.; Esteban, L.; Siqueira, R. [Toulouse Univ., 31 (France); Toulouse and GdR CNRS FORPRO, 31 (France); Esteban, L. [Strasbourg Univ., EOST, 67 (France); Now at Geological Survey of Canada-Pacific, Sidney, B.C. (Canada)


    This session gathers 4 articles dealing with: the seismic imaging of the variability in the Callovo-Oxfordian argillite (D. Guillemot, B. Yven); the identification of homogeneous zones from well logging measurements by statistical tools (A. Marache, J. Riss, A. Denis, B. Yven, A. Trouiller); the geostatistical characterization of Callovo-Oxfordian clay variability from high resolution log data (M. Lefranc, B. Beaudoin, J.P. Chiles, D. Guillemot, C. Ravenne, A. Trouiller); and the Magnetic properties, magnetic mineralogy and fabric of the argillites of the Meuse/Haute-Marne URL (J.L. Bouchez, L. Esteban, Y. Geraud, A. Trouiller, R. Siqueira)

  6. Hydrogen transfer experiments and modelization in clay rocks for radioactive waste deep geological repository; Experimentation et modelisation du transfert d'hydrogene a travers des argiles de centre de stockage de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Boulin, P


    Gases will be generated by corrosion of high radioactive waste containers in deep geological repositories. A gas phase will be generated. Gas pressure will build up and penetrated the geological formation. If gases do not penetrate the geological barrier efficiently, the pressure build up may create a risk of fracturing and of creation of preferential pathways for radionuclide migration. The present work focuses on Callovo-Oxfordian argillites characterisation. An experiment, designed to measure very low permeabilities, was used with hydrogen/helium and analysed using the Dusty Gas Model. Argillites close to saturation have an accessible porosity to gas transfer that is lower than 0,1% to 1% of the porosity. Analysis of the Knudsen effect suggests that this accessible network should be made of 50 nm to 200 nm diameter pores. The permeabilities values were integrated to an ANDRA operating model. The model showed that the maximum pressure expected near the repository would be 83 bar. (author)

  7. Investigations of Near-Field Thermal-Hydrologic-Mechanical-Chemical Models for Radioactive Waste Disposal in Clay/Shale Rock

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.H.; Li, L.; Zheng, L.; Houseworth, J.E.; Rutqvist, J.


    Clay/shale has been considered as potential host rock for geological disposal of high-level radioactive waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of radioactive waste. Figure 1-1 presents the distribution of clay/shale formations within the USA.

  8. Precambrian age of the Boston Basin: New evidence from microfossils (United States)

    Lenk, C.; Strother, P.K.; Kaye, C.A.; Barghoorn, E.S.


    A Vendian (Late Proterozoic Z) age has been determined for the Boston Basin by comparison of a microflora from the Cambridge Argillite with other late Precambrian assemblages. The microfossils, which include Bavlinella cf. faveolata, are preserved as petrifactions in pyrite. This age designation for the sedimentary rocks of the Boston Basin should allow for the reinterpretation of the structure of the basin and its regional correlations. Copyright ?? 1982 AAAS.

  9. A study on sintering of ceramic bricks made from waste coal (United States)

    Stolboushkin, A. Yu; Ivanov, A. I.; Syromyasov, V. A.; Fomina, O. A.


    The results of the study on phase transformations and structure formation during firing of bricks made from wastes of coaly argillite processing. The effect of firing temperature on the processes of mineral formation and changes in the quantitative content of amorphous phase and brick porosity was defined. It was found that at 950-1050 °C the sintering takes place providing a solid brick structure.

  10. Clays in radioactive waste disposal


    Delage, Pierre; Cui, Yu-Jun; Tang, Anh-Minh


    Clays and argillites are considered in some countries as possible host rocks for nuclear waste disposal at great depth. The use of compacted swelling clays as engineered barriers is also considered within the framework of the multi-barrier concept. In relation to these concepts, various research programs have been conducted to assess the thermo-hydro-mechanical properties of radioactive waste disposal at great depth. After introducing the concepts of waste isolation developed in Belgium, Fran...

  11. Submarine fan sedimentation at a convergent margin: the cretaceous mangapokia formation, New Zealand (United States)

    Barnes, Philip M.


    The middle Cretaceous Mangapokia Formation (Pahaoa Group) near Te Awaiti, southeast North Island, New Zealand, consists of indurated, poorly fossiliferous, alternating sandstone and argillite, minor conglomerate, grit, pebbly-sandstone, and pebbly-mudstone (terrigenous sedimentary assemblage), and minor basalt, coloured argillite, chert, and micritic limestone (ocean-floor assemblage). Seven lithofacies are distinguished in the sedimentary assemblage on the basis of lithology, bed thickness and geometry, sand/mud ratio, grain size and internal sedimentary features. Facies 1 (10-15% of total exposure), which includes all sediments coarser than sand grade, comprises seven subfacies as follows: lenticular and erosive beds of coarse-grained (Subfacies 1Ai), medium-grained (Subfacies 1Aii) and fine-grained (Subfacies 1Aiii) predominantly clast-supported conglomerate, grit (Subfacies 1Aiv) and pebbly-sandstone (Subfacies 1Av) displaying numerous types of graded bedding and sedimentary structures, were all deposited predominantly from high-concentration turbidity currents or bed-load inertia flows. Minor chaotic sand or mud matrix-supported conglomerate lenses (Subfacies 1Bi), and beds which show clear evidence of post-depositional remobilisation (Subfacies 1Bii), represent debris flow deposits. Thick lenses of sandstone and minor argillite interbeds (Facies 2) were deposited from large-volume inertia flows, possibly grainflows. Facies 3, the most common lithofacies, consists of laterally more extensive, medium thickness, graded beds of alternating sandstone and argillite with rare Bouma sequences. These deposits are proximal turbidites which accumulated in environments more distal than Facies 1 and 2. Thin-bedded (Facies 4) and very thin-bedded (Facies 5) alternating sandstone and argillite, and argillite-dominated sequences with minor interbedded sandstone (Facies 6) were deposited in interchannel depressions, on channel levees, or in areas distant from high

  12. Evaluation of Used Fuel Disposition in Clay-Bearing Rock

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F.; Weck, Philippe F.; Sassani, David Carl; Zheng, Liange; Rutqvist, Jonny; Steefel, Carl I.; Kim, Kuhhwi; Nakagawa, Seiji; Houseworth, James; Birkholzer, Jens T.; Caporuscio, Florie Andre; Cheshire, Michael; Rearick, Michael; McCarney, Mary K.; Zavarin, Mavrik; Benedicto, Ana; Kersting, Annie B.; Sutton, Mark.; Jerden, James L.; Frey, Kurt E.; Copple, Jacqueline M.; Ebert, William L.


    Radioactive waste disposal in shale/argillite rock formations has been widely considered given its desirable isolation properties (low permeability), geochemically reduced conditions, anomalous groundwater pressures, and widespread geologic occurrence. Clay/shale rock formations are characterized by their high content of clay minerals such as smectites and illites where diffusive transport and chemisorption phenomena predominate. These, in addition to low permeability, are key attributes of shale to impede radionuclide mobility. Shale host-media has been comprehensively studied in international nuclear waste repository programs as part of underground research laboratories (URLs) programs in Switzerland, France, Belgium, and Japan. These investigations, in some cases a decade or more long, have produced a large but fundamental body of information spanning from site characterization data (geological, hydrogeological, geochemical, geomechanical) to controlled experiments on the engineered barrier system (EBS) (barrier clay and seals materials). Evaluation of nuclear waste disposal in shale formations in the USA was conducted in the late 70’s and mid 80’s. Most of these studies evaluated the potential for shale to host a nuclear waste repository but not at the programmatic level of URLs in international repository programs. This report covers various R&D work and capabilities relevant to disposal of heat-generating nuclear waste in shale/argillite media. Integration and cross-fertilization of these capabilities will be utilized in the development and implementation of the shale/argillite reference case planned for FY15. Disposal R&D activities under the UFDC in the past few years have produced state-of-the-art modeling capabilities for coupled Thermal-Hydrological-Mechanical-Chemical (THMC), used fuel degradation (source term), and thermodynamic modeling and database development to evaluate generic disposal concepts. The THMC models have been developed for shale

  13. Mass Transfer and Porous Media (MTPM)

    Energy Technology Data Exchange (ETDEWEB)

    Rotenberg, B.; Marry, V.; Malikova, N.; Vuilleumier, R.; Giffaut, E.; Turq, P.; Robinet, J.C.; Diaz, N.; Sardini, P.; Goutelard, F.; Menut, D.; Parneix, J.C.; Sammartino, S.; Pret, D.; Coelho, D.; Jougnot, D.; Revil, A.; Boulin, P.F.; Angulo-Jaramillo, R.; Daian, J.F.; Talandier, J.; Berne, P.; Cochepin, B.; Trotignon, L.; Bildstein, O.; Steefel, C.; Lagneau, V.; Van der Lee, J.; Birchall, D.J.; Harrington, J.F.; Noy, D.J.; Sellin, P.; Bildstein, O.; Piault, E.; Trotignon, L.; Montarnal, P.; Deville, E.; Genty, A.; Le Potier, C.; Imbert, C.; Semete, P.; Desgree, P.; Fevrier, B.; Courtois, A.; Touze, G.; Sboui, A.; Roberts, J.E.; Jaffre, J.; Glaus, M.A.; Rosse, R.; Van Loon, L.R.; Matray, J.M.; Parneix, J.C.; Tinseau, E.; Pret, D.; Mayor, J.C.; Ohkubo, T.; Kikuchi, H.; Yamaguchi, M.; Alonso, U.; Missana, T.; Garcia-Gutierrez, M.; Patelli, A.; Siitari-Kauppi, M.; Leskinen, A.; Rigato, V.; Samper, J.; Dewonck, S.; Zheng, L.; Yang, Q.; Naves, A.; Dai, Z.; Samper, J.; Wolfsberg, A.; Levitt, D.; Cormenzana, J.L.; Missana, T.; Mingarro, M.; Schampera, B.; Dultz, S.; Riebe, B.; Samper, J.; Yang, Q.; Genty, A.; Perraud, D.; Poller, A.; Mayer, G.; Croise, J.; Marschall, P.; Krooss, B.; Matray, J.M.; Tanaka, T.; Vogel, P.; Lavanchy, J.M.; Enssle, C.P.; Cruchaudet, M.; Dewonck, S.; Descostes, M.; Blin, V.; Radwan, J.; Poinssot, C.; Mibus, J.; Sachs, S.; Devol-Brown, I.; Motellier, S.; Tinseau, E.; Thoby, D.; Marsal, F.; DeWindt, L.; Tinseau, E.; Pellegrini, D.; Bauer, A.; Fiehn, B.; Marquardt, Ch.; Romer, J.; Gortzen, A.; Kienzler, B


    This session gathers 48 articles (posters) dealing with: interlayer / micro-pore exchange of water and ions in clays: a molecular dynamics study; the multi-scale characterisation of mineral and textural spatial heterogeneities in Callovo-Oxfordian argilite and its consequence on solute species diffusion modelling; the diffusion of ions in unsaturated clay rocks: Theory and application to the Callovo- Oxfordian argillite; the porous media characterization with respect to gas transfer in Callovo Oxfordian argillite; the predictions on a 2-D cementation experiment in porous medium: intercomparison on the Comedie project; the large-scale gas injection test (LASGIT) at the Aespoe hard rock laboratory in Sweden; simulating the geochemical coupling between vitrified waste, canister and near-field on the alliances platform; toward radionuclide transport calculations on whole radioactive waste disposal with CAST3M platform; the experimental study of the water permeability of a partially saturated argillite; a mixed hexahedral finite elements for Darcy flow calculation in clay porous media; the diffusive properties of stainless steel filter discs before and after use in diffusion experiments with compacted clays; the structural organization of porosity in the Opalinus clay at the Mont Terri Rock Laboratory under saturated and unsaturated conditions; the evaluation of pore structure in compacted saturated Bentonite using NMR relaxometry; diffusion coefficients measurement in consolidated clays: a combination of micro-scale profiling and solid pore structure analyses; the numerical interpretation of in-situ DIR diffusion experiments on the Callovo- Oxfordian clay at the Meuse/Haute-Marne URL the identification of relative conductivity models for water flow and solute transport in unsaturated compacted Bentonite; diffusion experiments in Callovo- Oxfordian clay from the Meuse/Haute-Marne URL, France: experimental setup and data analyses; the transport in organo

  14. Sources and fate of xenoliths in the Wooley Creek batholith-a geochemical perspective (United States)

    Barnes, C. G.; Coint, N.; Rämö, O. T.; Barnes, M. A.


    The Wooley Creek batholith (WCb) is a tilted plutonic complex that intrudes three host terranes: a structurally lower ophiolitic mélange of the Rattlesnake Creek terrane (RCt) is overlain by volcanogenic metasediments of the western Hayfork arc sequence (wHt), which is in turn overlain by chert-argillite mélange of the eastern Hayfork terrane (eHt). Xenoliths and screen-like zones are widespread and encompass metaperidotite, amphibolite, semipelitic migmatitic schist and gneiss, quartz-rich rock types, and calc-silicate rocks (some migmatitic). Because the batholith is tilted, identification of xenolith sources is important in reconstructing the magmatic system and interpreting modes of emplacement. However, aside from ultramafic rocks (from the RCt), lithologic discrimination of xenolith sources is complicated by the presence of argillitic rocks in all three terranes and mafic (meta) volcanic and volcaniclastic rocks in the RCt and wHt. On a geochemical basis, the mafic host rock types are readily distinguished because wHt samples contain high Sr contents (>400 ppm) compared to mafic RCt samples. One metabasic xenolith contains high Sr contents (~980 ppm) consistent with an origin from the wHt, and several contain ca. 300 ppm Sr, which is compatible with an origin from the RCt. In contrast, the argillitic host rocks show considerable compositional overlap; however, some eHt samples contain high Ba contents (>1500 ppm) and the (negative) slopes of REE patterns generally decrease from eHt to wHt to RCt samples. Epsilon Nd values for metabasic rocks from the RCt range from +5.8 to +9.3 and values for the wHt are +6.7 and +5.5 for argillitic and metavolcanic rocks, respectively. Argillites from the RCt vary in ɛNd from +4.2 to -8.9 and argillites from the eHt have ɛNd from -10 to -22. In the batholith, ALL of the metasedimentary xenoliths for which Nd isotope data are available have ɛNd residual during partial melting. In contrast, metasedimentary xenoliths from

  15. Creep and damage in argillaceous rocks: microstructural change and phenomenological modeling; Fluage et endommagement des roches argileuses: evolution de la microstructure et modelisation phenomenologique

    Energy Technology Data Exchange (ETDEWEB)

    Fabre, G


    The underground radioactive waste disposal far exceeds the period of exploitation of common civil engineering works. These specific projects require to predict the irreversible deformations over a large time scale (several centuries) in order to assess the extension and to forecast the evolution of the EDZ (Excavation Damage Zone) around the cavity. In this study, the viscosity of three sedimentary argillaceous rocks has been studied under different conditions of uniaxial compression: static or cyclic creep tests, monotonic and quasistatic tests, performed across various strata orientations. Argillaceous rocks are studied as a possible host layer for radioactive waste disposals. Indeed, they present some of the physical characteristics and mechanical properties, which are essential for being a natural barrier: low permeability, high creep potential and important holding capacity of radioactive elements. The purpose of the experimental study was to shed some light over the mechanisms governing the development of delayed deformations and damage of argillaceous rocks. It relates three rocks: an argillite from East of France, a Tournemire argillite and a marl from Jurassic Mountains. On atomic scale, viscoplastic deformations are due to irreversible displacements of crystalline defects, called dislocations. The experimental study was also supplemented with observations on thin sections extracted from the argillite and marl samples using a SEM. The aim was to identify the mechanisms responsible for the time-dependent behaviour on a microstructural scale. Analytical simulations of the mechanical behaviour of the three rocks gave parameters used in different viscoplastic models. The best modeling was obtained with the viscoplastic model which takes account of the development of volumetric strains and of the damage anisotropy. (author)

  16. Experimental study and modeling of the propagation of an alkaline concentration wave coming from a cement matrix an passing through the argilite of the Meuse / Haute-Marne laboratory; Etude experimentale et modelisation de la propagation d'une onde de concentration alcaline issue d'une matrice cimentiere a travers l'argilite du site du laboratoire Meuse / Haute-Marne

    Energy Technology Data Exchange (ETDEWEB)

    Roussel, Th


    The propagation of an alkaline wave through a clay rock has been investigated- The wave is generated by a cementitious matrix through the Callovo-Oxfordian argillite of the Meuse Haute-Marne Laboratory (-480 m depth). The argillite itself is composed of quartz, micas, calcite and an interstratified l/S. In order to characterise the interactions between the alkaline fluid and the argillaceous medium, dynamic column experiments have been carried out. The originality of the investigation methodology consists in exploiting the data generated from the breakthrough curves as well as from the characterisation of the solids extracted from the columns. Two types of processes having totally different reaction times have hence been thoroughly studied: - Fast surface adsorption and condensation reactions: On the one hand cation adsorption reactions by site ionisation have been characterised. They are responsible of the buffering effect of the clays. On the other hand an original reaction of calcium compound condensation in the interlayer space of the swelling clays has been revealed. These processes have been modelled and their simulations with the IMPACT calculation code showed that the models elaborated were very satisfying. - Strongly kinetically limited dissolution/precipitation reactions: The main primary phases dissolved are quartz and interstratified l/S. The precipitation of secondary phases are mainly C(A)SH and zeolites. After the injection of an alkaline fluid for 6 months at 60 deg C, the argillite is strongly amorphized but only 20 to 30% of the quartz and the interstratified I/S are dissolved. Therefore, dissolution kinetics of the primary phases and the solubility products of the main secondary phases have been determined. (author)

  17. M4FT-16LL080302052-Update to Thermodynamic Database Development and Sorption Database Integration

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences; Wolery, T. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Akima Infrastructure Services, LLC; Atkins-Duffin, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Global Security


    This progress report (Level 4 Milestone Number M4FT-16LL080302052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Argillite Disposal R&D Work Package Number FT-16LL08030205. The focus of this research is the thermodynamic modeling of Engineered Barrier System (EBS) materials and properties and development of thermodynamic databases and models to evaluate the stability of EBS materials and their interactions with fluids at various physico-chemical conditions relevant to subsurface repository environments. The development and implementation of equilibrium thermodynamic models are intended to describe chemical and physical processes such as solubility, sorption, and diffusion.

  18. Ability of High-Resolution Resistivity Tomography to Detect Fault and Fracture Zones: Application to the Tournemire Experimental Platform, France (United States)

    Gélis, C.; Noble, M.; Cabrera, J.; Penz, S.; Chauris, H.; Cushing, E. M.


    The Experimental Platform of Tournemire (Aveyron, France) developed by IRSN (French Institute for Radiological Protection and Nuclear Safety) is composed of a tunnel excavated in an argillite formation belonging to a limestone-argillite-limestone subhorizontal sedimentary sequence. Subvertical secondary fault zones were intercepted in argillite using drifts and boreholes in the tunnel excavated at a depth of about 250 m located under the Larzac Plateau. A 2D 2.5 km baseline large-scale electrical resistivity survey conducted in 2007 allowed detecting in the upper limestones several significantly low electrical resistivity subvertical zones (G élis et al. Appl Geophys 167(11): 1405-1418, 2010). One of these discontinuities is consistent with the extension towards the surface of the secondary fault zones identified in the argillite formation from the tunnel. In an attempt to better characterize this zone, IRSN and MINES ParisTech conducted a high-resolution electrical resistivity survey located transversally to the fault and fracture zones. A 760-m-long profile was acquired using two array geometries and take-outs of 2, 4 and 8 m, requiring several roll-alongs. These data were first inverted independently for each take-out and then using all take-outs together for a given array geometry. Different inverted 2D electrical resistivity models display the same global features with high (higher than 5000 Ωm) to low (lower than 100 Ωm) electrical resistivity zones. These electrical resistivity models are finally compared with a geological cross-section based on independent data. The subvertical conductive zones are in agreement with the fault and fracture locations inferred from the geological cross-section. Moreover, the top of a more conductive zone, below a high electrical conductive zone and between two subvertical fault zones, is located in a more sandy and argillaceous layer. This conductive zone is interpreted as the presence of a more scattered fracture zone

  19. An experimental study of electrical and dielectric properties of consolidated clayey materials; Etude experimentale des proprietes electriques et dielectriques des materiaux argileux consolides

    Energy Technology Data Exchange (ETDEWEB)

    Comparon, L


    This study is devoted to the electrical and dielectric properties of consolidated clays. A better understanding of the conduction and polarization phenomena in clays is necessary to better interpret in situ measurements in terms of water saturation and texture. An experimental study was carried out on synthetic clay samples (kaolinite and smectite) compacted with various water contents, porosities and mineralogical compositions, on a large frequency range, using three laboratory setups. The electrical properties of natural argillites (from ANDRA) were then investigated. We found that the response of the synthetic samples is mainly controlled by water content on the whole frequency range; two polarization phenomena were observed, which were related to the Maxwell-Wagner polarization and the electrical double layer polarization around the clay particles. The electrical response of argillites is more complex; it is controlled by water content but also by the microstructure of the rock. In these rocks, the electrical and dielectric anisotropies are high; anisotropy was also measured for the synthetic clays. The existing models explain the high frequency limit of the dielectric permittivity of the clayey materials, but the low frequency part of the spectra ({<=}1 MHz) needs theoretical developments. (author)

  20. Quaternary deposits and weathered bedrock material as a source of dangerous radon emissions in Estonia

    Directory of Open Access Journals (Sweden)

    Petersell Valter


    Full Text Available The risk of dangerous radon emissions in Estonia is high, being among the highest in Europe. In almost 33 per cent of Estonian land area, the content of radon in soil-contained air exceeds the safe limit for unrestricted construction (50 kBq/m3. In such high radon-risk areas the concentration of radon in soil-contained air ranges from 50 to 400 kBq/m3, in a few cases reaching up to 2,100 kBq/m3 exceeding the permitted level for residential areas. The situation is particularly serious in the northernmost part of the country, where uranium-rich graptolite argillite (Dictyonema shale and the Obolus phosphorite are close to ground surface and their particles are constituent parts of Quaternary deposits. Radon emissions from bedrock have been investigated in detail, but to date Quaternary strata as a source of radon emissions are poorly studied. According to our measurements the highest concentrations of radon are related to tills containing clasts and fines of graptolite argillite and phosphorite. Glacial deposits include also granitoidal material, containing U, Th and K, which have been transported by glaciers from the outcrop areas of crystalline basement rocks in Finland and the Gulf of Finland. Due to weathering, outwash and repeated redeposition other genetic types are poorer in radioactive elements and they are weaker sources of radon.

  1. Eleana near-surface heater experiment final report

    Energy Technology Data Exchange (ETDEWEB)

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


    This report summarizes the results of a near-surface heater experiment operated at a depth of 23 m in argillite within the Eleana Formation on the Nevada Test Site (NTS). The test geometrically simulated emplacement of a single canister of High-Level Waste (HLW) and was operated at a power level of 2.5 kW for 21 days, followed by 3.8 kW to 250 days, when the power was turned off. Below 85 to 100{sup 0}C, there was good agreement between modeled and measured thermal results in the rock and in the emplacement hole, except for transient transport of water in the heater hole. Above 100{sup 0}C, modeled and measured thermal results increasingly diverged, indicating that the in-situ rock-mass thermal conductivity decreased as a result of dehydration more than expected on the basis of matrix properties. Correlation of thermomechanical modeling and field results suggests that this decrease was caused by strong coupling of thermal and mechanical behavior of the argillite at elevated temperatures. No hole-wall decrepitation was observed in the experiment; this fact and the codrrelation of modeled and measured results at lower temperatures indicate that there is no a priori reason to eliminate argillaceous rocks from further consideration as a host rock for nuclear wastes.

  2. Discovery of the copper deposits with features of the Keweenawan type in the border area of Yunnan and Guizhou provinces

    Institute of Scientific and Technical Information of China (English)

    朱炳泉; 胡耀国; 张正伟; 常向阳


    There existed intense Cu anomaly on the northeastern side of the geochemical boundary with NW strike in the border area between the Yunnan and Guizhou provinces. Through field observation, ore bodies of high-grade native coppers have been found. The copper mineralization was constrained by the ancient volcanic vents of Permian basalt eruption and the overlain strata of carbonaceous argillites. Native coppers with flaky, net veined and impregnated occurrences, fine-grained tenorites and massive chalcocites widely occur in volcanic breccias, tuffs, carbonaceous-siliceous argillites and siliceous bitumen rocks with bed thickness of about 15-80 m. Cu contents vary from 0.5% to 20%. The copper mineralization was tightly related to actinolite-tremolitization, zeolitization and bituminization and involved in extensive reduction environments. Continental flood basalts erupted in mantle plume environments usually have high Cu concentrations (~170 ×10-6 in the Emeishan basalts), which provided a copper source of mineralization. Thus, metallogenesis of the native copper deposits in the Yunnan-Guizhou border area is tightly associated with intensive crust-mantle and organic-inorganic interactions. The tremolitization and chalcocitization indicate that the metallogenic temperatures are in a range of 400-100℃. The geologic background and characteristics of ore and alteration for the native copper deposits in this area are somewhat similar to those of the Keweenawan native copper deposit in Michigan, USA.

  3. Can clays ensure nuclear waste repositories? (United States)

    Zaoui, A; Sekkal, W


    Research on argillite as a possible host rock for nuclear waste disposal is still an open subject since many issues need to be clarified. In the Underground Research Laboratories constructed for this purpose, a damaged zone around the excavation has been systematically observed and characterized by the appearance of micro-fissures. We analyse here -at nanoscale level- the calcite/clay assembly, the main constituents of argillite, under storage conditions and show the fragility of the montmorillonite with respect to calcite. Under anisotropic stress, we have observed a shear deformation of the assembly with the presence of broken bonds in the clay mineral, localised in the octahedral rather than the tetrahedral layers. The stress/strain curve leads to a failure strength point at 18.5 MPa. The obtained in-plane response of the assembly to perpendicular deformation is characterized by smaller perpendicular moduli Ez = 48.28 GPa compared to larger in-plane moduli Ex = 141.39 GPa and Ey = 134.02 GPa. Our calculations indicate the instability of the assembly without water molecules at the interface in addition to an important shear deformation.

  4. Textural and stable isotope studies of the Big Mike cupriferous volcanogenic massive sulfide deposit, Pershing County, Nevada. (United States)

    Rye, R.O.; Roberts, R.J.; Snyder, W.S.; Lahusen, G.L.; Motica, J.E.


    The Big Mike deposit is a massive sulphide lens entirely within a carbonaceous argillite of the Palaeozoic Havallah pelagic sequence. The massive ore contains two generations of pyrite, a fine- and a coarse-grained variety; framboidal pyrite occurs in the surrounding carbonaceous argillite. Coarse grained pyrite is largely recrystallized fine-grained pyrite and is proportionately more abundant toward the margins of the lens. Chalcopyrite and sphalerite replace fine-grained pyrite and vein-fragmented coarse-grained pyrite. Quartz fills openings in the sulphide fabric. S-isotope data are related to sulphide mineralogy and textures. Isotopically light S in the early fine-grained pyrite was probably derived from framboidal biogenic pyrite. The S-isotope values of the later coarse-grained pyrite and chalcopyrite probably reflect a combination of reduced sea-water sulphate and igneous S. Combined S- and O-isotope and textural data accord with precipitation of fine-grained pyrite from a hydrothermal plume like those at the East Pacific Rise spreading centre at lat. 21oN. The primary material was recystallized and mineralized by later fluids of distinctly different S-isotope composition. -G.J.N.

  5. Elastic Properties of Sedimentary Rocks (United States)

    Melendez Martinez, Jaime

    Sedimentary rocks are an important research topic since such rocks are associated to sources of ground water as well as oil, gas, and mineral reservoirs. In this work, elastic and physical properties of a variety of sedimentary samples that include glacial sediments, carbonates, shales, one evaporite, and one argillite from a variety of locations are investigated. Assuming vertical transverse isotropy, ultrasonic compressional- and shear-waves (at 1 MHz central frequency) were measured as a function of confining pressure on all samples with the exception of glacial samples which were tested assuming isotropy. Tensile strength tests (Brazilian test) were also carried out on selected glacial samples and, in addition, static-train measurements were conducted on shales and argillite samples. Lithological and textural features of samples were obtained through thin section techniques, scanning electron microscopy images and micro-tomography images. X-ray diffraction and X-Ray fluorescence provided the mineralogical oxides content information. Porosity, density, and pore structure were studied by using a mercury intrusion porosimeter and a helium pycnometer. The wide range of porosities of the studied samples (ranging from a minimum of 1% for shales to a maximum 45% for some glacial sediments) influence the measured velocities since high porosity sample shows an noticeable velocity increment as confining pressure increases as a consequence of closure of microcracks and pores, unlike low porosity samples where increment is quasi-lineal. Implementation of Gassmann's relation to ultrasonic velocities obtained from glacial samples has negligible impact on them when assuming water saturated samples, which suggests that state of saturation it is no so important in defining such velocities and instead they are mainly frame-controlled. On the other hand, velocities measured on carbonate and evaporite samples show that samples are at best weak anisotropic, thus the intrinsic

  6. Evaluation of Used Fuel Disposition in Clay-Bearing Rock

    Energy Technology Data Exchange (ETDEWEB)

    Jove-Colon, Carlos F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Weck, Philippe F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hammond, Glenn Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kuhlman, Kristopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zheng, Liange [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kim, Kunhwi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Houseworth, James [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cheshire, Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Palaich, Sarah [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Norskog, Katherine E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wolery, Thomas J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jerden, James L. [Argonne National Lab. (ANL), Argonne, IL (United States); Copple, Jacqueline M. [Argonne National Lab. (ANL), Argonne, IL (United States); Cruse, Terry [Argonne National Lab. (ANL), Argonne, IL (United States); Ebert, William L. [Argonne National Lab. (ANL), Argonne, IL (United States)


    Deep geological disposal of nuclear waste in clay/shale/argillaceous rock formations has received much consideration given its desirable attributes such as isolation properties (low permeability), geochemically reduced conditions, slow diffusion, sorbtive mineralogy, and geologically widespread (Jové Colón et al., 2014). There is a wealth of gained scientific expertise on the behavior of clay/shale/ argillaceous rock given its focus in international nuclear waste repository programs that includes underground research laboratories (URLs) in Switzerland, France, Belgium, and Japan. Jové Colón et al. (2014) have described some of these investigative efforts in clay rock ranging from site characterization to research on the engineered barrier system (EBS). Evaluations of disposal options that include nuclear waste disposition in clay/shale/argillaceous rock have determined that this host media can accommodate a wide range of waste types. R&D work within the Used Fuel Disposition Campaign (UFDC) assessing thermal effects and fluid-mineral interactions for the disposition of heat-generating waste have so far demonstrated the feasibility for the EBS and clay host rock to withstand high thermal loads. This report represents the continuation of disposal R&D efforts on the advancement and refinement of coupled Thermal-Hydrological-Mechanical-Chemical (THMC), hydrothermal experiments on clay interactions, used fuel degradation (source term), and thermodynamic modeling and database development. The development and implementation of a clay/shale/argillite reference case described in Jové Colón et al. (2014) for FY15 will be documented in another report (Mariner et al. 2015) – only a brief description will be given here. This clay reference case implementation is the result of integration efforts between the GDSA PA and disposal in argillite work packages. The assessment of sacrificial zones in the EBS is being addressed through experimental work along with 1D reactive

  7. Modelling glass alteration in an altered argillaceous environment (United States)

    Bildstein, O.; Trotignon, L.; Pozo, C.; Jullien, M.


    The long term behaviour of materials such as glass, steel and clay has been investigated in the context of deep geological disposal of radioactive wastes. The interactions between vitrified wastes, canister corrosion products (CPs) and clay are studied using a modified version of the reaction-transport code Crunch, especially looking at pH changes and possible cementation at the interface with the clayey materials. These perturbations may indeed affect the lifetime of glass matrix in deep repositories, e.g., high pH enhances the rate of glass alteration. This work focuses on the argillite of Bure. The calculations were performed at 323 K with a glass alteration rate switching from a high initial rate to a residual rate according to the sorption capacity of CPs. The time at which this sorption capacity is saturated is crucial to the system in terms of wastes package lifetime. The results show that the glass alteration imposes a high pH value at the interface with CPs and clay: up to a value of 9.2, compared to 7.3 which is the initial pH value in the argillite. Experimental data show that the rate of glass alteration is much higher in such pH conditions. For a R7T7-type glass, the rate is about five times higher at pH 9 than at pH 7. This pH perturbation migrates through the clayey domain as a result of the migration of mobile elements such as boron and sodium, and despite the existence of strong pH buffers in the argillite. The cementation of porosity at the interface between glass and clay is predicted by the model due to the massive precipitation of iron corrosion products and glass alteration products. At this point of the evolution of the system, the pH starts to decrease and the alteration rate of the glass could be significantly reduced. This porosity clogging effect is difficult to confirm by experiments especially since existing data on short term experiments tend to show a pervasive precipitation of silica in the domain instead of a localized precipitation

  8. Coupled transport phenomena in a clay from a Callovo-Oxfordian formation; Phenomenes de transport couples dans les argiles du Callovo-Oxfordien

    Energy Technology Data Exchange (ETDEWEB)

    Paszkuta, M


    Low permeability materials containing clay play an important role in practical life and natural environment. Indeed, the ability of clay soils to act as semi permeable membranes, that inhibit the passage of electrolytes, is of great interest. The major objective of this thesis is to evaluate the transport properties of natural clays and in particular coupled transports when a pressure gradient, an electrical field, a concentration gradient and a temperature gradient interact. The material is a compact argillite extracted in East France from a Callovo-Oxfordian formation which was supplied to us by ANDRA. NaCl was used as the main solute. Two series of experiments were performed to measure permeability, diffusion, conductivity, the electro-osmotic coefficient and the Soret coefficient. (author)

  9. Soils on overburden dumps in the forest-steppe and mountain taiga zones of the Kuzbass (United States)

    Bragina, P. S.; Tsibart, A. S.; Zavadskaya, M. P.; Sharapova, A. V.


    The properties of the soils forming on coal dumps significantly depend on the properties of the parent rocks and the technology of creating the dumps. In the forest-steppe and mountain taiga zones of the Kuznetsk Coal Basin, argillites, siltstones, and sandstones are the overburden and enclosing rocks. They are responsible for the alkaline reaction and the same microelement composition in almost all the soils studied. The nonselective formation of the dumps and the predominance of the coarse fraction in the rocks composing the dumps is a cause of the wide distribution of petrozems and humus petrozems on their surface. The presence of a great amount of coal particles in the substrates and the incorrect planning of the dumps may be the reasons for their self-ignition, which can change the composition of polycyclic aromatic hydrocarbons in the soils of the dumps.

  10. Isotopic indication to source of ore materials and fluids of the Wangfeng gold deposit in Tianshan: A case study of metallogenesis during collisional orogenesis

    Institute of Scientific and Technical Information of China (English)

    陈华勇; 鲍景新; 张增杰; 刘玉琳; 倪培; 凌洪飞


    The Wangfeng gold deposit is one of the five most important gold deposits in the Tian-shan. Studies of its metallogenic time, space, geodynamic background, ore feature and ore fluid have proved that the deposit formed in the late Paleozoic continental collision, and consequently is a suitable delegate to probe mineralizing regularities during collisiona! orogenesis. Isotopic studies including O, D, C, S, Pb and Sr reveal ore materials derived from sedimentary association (including carbonate and sulfate), which further refers to the Hercynian carbonate-silicolite-argillite formation north to Wangfeng camp. At the end of Paleozoic, the southward intracontinental subduction of Hercynian synthem along the Hongwuyueqiao fault down to the Central Tianshan terrane induced large-scale fluidization which extracted and out-transported ore materials from Hercynian synthem upto shallow fair positions, and finally resulted in the formation of the Wangfeng deposit. This study excludes the possibility of other tecton

  11. Very slow creep tests on salt samples

    Directory of Open Access Journals (Sweden)

    de Greef V.


    Full Text Available Long-term creep tests have been performed on rock-salt and argillite samples under very small uniaxial loadings (σ = 0.02 to 0.1 MPa . To minimize the effects of temperature variations, testing devices were set in a mine where temperature fluctuations are of the order of one-hundredth of a degree Celsius. The mechanical loading was provided by dead weights. The deformations were measured through special displacement sensors with a resolution of ∆ε = 10-8. Strain rates as small as έ = 7 × 10-13s-1 were measured. These tests allow rock-sample creep to be investigated at very small strain rates. The tests also prove that extrapolation of constitutive laws at very small rates is often incorrect.

  12. Plasto-damage modelling for semi-brittle geomaterials

    Directory of Open Access Journals (Sweden)

    Alizadeh Ali


    Full Text Available This paper presents an elastoplastic damage model for constitutive modelling of semi-brittle geomaterials showing two irreversible mechanisms. On one hand, the model deals with the plastic behaviour of a porous medium by a new variant of Barcelona Basic Model. On the other hand, the model combines the micromechanical definition of damage and phenomenological concepts in the framework of Continuum Damage Mechanics (CDM for damage modelling. A second order tensorial damage variable is adopted for the model. Damaged effective stress variables are employed for formulation of elastoplastic behaviour laws and the plastic yield surface is a damage dependent one. The model has been validated by comparing the numerical results with experimental results of argillites.

  13. Peralkaline- and calc-alkaline-hosted volcanogenic massive sulfide deposits of the Bonnifield District, East-Central Alaska (United States)

    Dusel-Bacon, Cynthia; Foley, Nora K.; Slack, John E.; Koenig, Alan E.; Oscarson, Robert L.


    Volcanogenic massive sulfide (VMS) Zn-Pb-Cu-Ag-Au deposits of the Bonnifield mining district formed during Late Devonian-Early Mississippian magmatism along the western edge of Laurentia. The largest deposits, Dry Creek and WTF, have a combined resource of 5.7 million tonnes at 10% Zn, 4% Pb, 0.3% Cu, 300 grams per tonne (g/t) Ag, and 1.6 g/t Au. These polymetallic deposits are hosted in high field strength element (HFSE)- and rare-earth element (REE)-rich peralkaline (pantelleritic) metarhyolite, and interlayered pyritic argillite and mudstone of the Mystic Creek Member of the Totatlanika Schist Formation. Mystic Creek metarhyolite and alkali basalt (Chute Creek Member) constitute a bimodal pair that formed in an extensional environment. A synvolcanic peralkaline quartz porphyry containing veins of fluorite, sphalerite, pyrite, and quartz intrudes the central footwall at Dry Creek. The Anderson Mountain deposit, located ~32 km to the southwest, occurs within calc-alkaline felsic to intermediate-composition metavolcanic rocks and associated graphitic argillite of the Wood River assemblage. Felsic metavolcanic rocks there have only slightly elevated HFSEs and REEs. The association of abundant graphitic and siliceous argillite with the felsic volcanic rocks together with low Cu contents in the Bonnifield deposits suggests classification as a siliciclastic-felsic type of VMS deposit. Bonnifield massive sulfides and host rocks were metamorphosed and deformed under greenschist-facies conditions in the Mesozoic. Primary depositional textures, generally uncommon, consist of framboids, framboidal aggregates, and spongy masses of pyrite. Sphalerite, the predominant base metal sulfide, encloses early pyrite framboids. Galena and chalcopyrite accompanied early pyrite formation but primarily formed late in the paragenetic sequence. Silver-rich tetrahedrite is a minor late phase at the Dry Creek deposit. Gold and Ag are present in low to moderate amounts in pyrite from all of

  14. Technological demonstrators. Researches and studies on the storage and disposal of long living intermediate level and high level radioactive wastes; Les demonstrateurs technologiques. Recherches et etudes sur le stockage et l'entreposage des dechets de haute activite et de moyenne activite a vie longue

    Energy Technology Data Exchange (ETDEWEB)



    This brochure presents the technological demonstrators made by the French national agency of radioactive wastes (ANDRA) and exhibited at Limay (Yvelines, France). These demonstrators, built at scale 1, have been an essential support to the establishment of the 'Dossier 2005' which demonstrates the feasibility of a reversible disposal of long living-intermediate level and high level radioactive wastes in the Callovo-Oxfordian argillite of Meuse-Haute Marne. Two type of demonstrators were built: demonstrators of storage containers for long living-intermediate level wastes and for spent fuels, and dynamic demonstrators for containers handling. This brochure presents these different demonstrators, their characteristics and the results of their tests. (J.S.)

  15. The Mesozoic rift basins of eastern North America: Potential reservoir or Explorationist's folly

    Energy Technology Data Exchange (ETDEWEB)

    Pyron, A.


    Mesozoic rift basins are found on the East Coast of North America from Georgia to Nova Scotia. The basins formed as a result of extensional activity associated with the breakup of Pangaea. The internal geometry of the basins includes a depositional sequence ranging from coarse fanglomerates to fine-grained siltstones and argillites. Since these Mesozoic rift basins were first studied, they have not been considered to be likely spots for hydrocarbon accumulations. Recently, geologists have reconsidered these Mesozoic basins and have developed a more synergistic approach that suggests that many of these rift basins might be suitable targets for exploration. By analogy, these Mesozoic basins are correlative to similar basins in northwestern Africa, where significant reserved of oil and natural gas have been developed. The similarity between the productive basins in northwestern Africa and the Mesozoic basins of North America and their proximity to major markets provides sufficient rationale to further investigate these basins.

  16. Experimental characterization of the hydro-mechanical behaviour of Meuse/Haute-Marne argilites; Caracterisation experimentale du comportement hydromecanique des argilites de Meuse/Haute-Marne

    Energy Technology Data Exchange (ETDEWEB)

    Escoffier, S


    Within the framework of a feasibility study of underground radioactive waste repository the experimental characterization of the coupled behavior of the host layer is of first importance. This work concerns the experimental characterization in laboratory of the poro-elastic behavior of argillite which constitutes the host layer of the future underground laboratory of ANDRA located at the limit of the Meuse/Haute-Marne. The theoretical approach is the Mechanics of Porous Media defined by Coussy [1991] which has the advantage of providing a formulation of the behavior laws using measurable parameters in laboratory. The difficulties or the feasibility of the characterization tests of these rocks coupled behavior are related to their very low permeability which requires an adaptation of the experimental devices initially used on more permeable rocks. Initially a synthesis on the knowledge of the poro-elastic parameters of Meuse/Haute-Marne argillite is given. Thereafter a first approach of the use of the studies of sensitivity as tools of decision-making aid is proposed. The experimental difficulties encountered by the various experimenters are illustrated by the diversity of the experimental choices, the test duration or by the results disparity. Because of economic, political and ecological stake, the studies of sensitivity could make it possible to direct the experimental efforts by giving indications on the dominating parameters in the coupled behavior of a rock. In the second time after the presentation of the test results of physical characterization 3 types of tests are described: permeability test (pulse test), determination of Biot coefficient under odometric loading and isotropic drained test. The complexity of these tests is related to the attack of the experimental limits. They are presented in detail: theoretical recalls, experimental set up, experimental protocol, unfolding and test results. (author)

  17. Analysis of the Fractures pattern at the Chingshui geothermal field, Taiwan (United States)

    Lu, C.; Lo, W.; Song, S.


    Magma chambers in the shallow crust and shallow intrusive igneous rock result in a high heat flow and geothermal gradient. Hot springs, one of geothermal potential phenomena, is widely distributed in Taiwan, especially in the Slate Belt and Tananao Complex of Central Range. The Slate Belt is mainly composed of meta-sandstone, argillite and slate, which have high porosity for geothermal source reservoirs. While the Tananao Complex is composed of phyllite, schist, gneiss, limestone and amphibolites, which have low porosity, but heat flow can conduct along cleavages, Joints, and other fractures. The purpose of this study is to delineate the fracture pattern and geothermal structure by field geologic survey and joints analysis. The rocks cropping out in the mapped area belong mainly to the Lushan Formation of Miocene age, which can be divided into two members: Chingshuihu member and Jentse member in ascending order. The Chingshuihu member is composed of slate or phyllite with thin beds of metasandstone. The Jentse member is composed of alternation of argillite and metasandstone. The geothermal reservoir of the Chingshui geothermal field might be related to the fault damage zone of the Chingshuihsi fault and Xiaonanao fault. Linking damage zones were caused by the interaction and linkage of fault segments in the geothermal field and developed a wide range of fracture patterns that depend on the nature of the interaction between the two fault segments. The fault damage zone and high porosity of sandstone resulted in well geothermal reservoir. The information obtained from the field geologic survey and Joint analysis indicate that the joint systems could be divided into four sets in terms of the strike and dip. Further, the geothermal reservoir is confined to a zone that extends 800m in width along N30E, 1km in length, and has an 80 dip toward SE. The main geothermal field is found in the NW of the reservoir; this area is located between the Chingshuihsi fault and

  18. Semipermeability Evolution of Wakkanai Mudstones During Isotropic Compression (United States)

    Takeda, M.; Manaka, M.


    Precise identification of major processes that influence groundwater flow system is of fundamental importance for the performance assessment of waste disposal in subsurface. In the characterization of groundwater flow system, gravity- and pressure-driven flows have been conventionally assumed as dominant processes. However, recent studies have suggested that argillites can act as semipermeable membranes and they can cause chemically driven flow, i.e., chemical osmosis, under salinity gradients, which may generate erratic pore pressures in argillaceous formations. In order to identify the possibility that chemical osmosis is involved in erratic pore pressure generations in argillaceous formations, it is essential to measure the semipermeability of formation media; however, in the measurements of semipermeability, little consideration has been given to the stresses that the formation media would have experienced in past geologic processes. This study investigates the influence of stress history on the semipermeability of an argillite by an experimental approach. A series of chemical osmosis experiments were performed on Wakkanai mudstones to measure the evolution of semipermeability during loading and unloading confining pressure cycles. The osmotic efficiency, which represents the semipermeability, was estimated at each confining pressure. The results show that the osmotic efficiency increases almost linearly with increasing confining pressure; however, the increased osmotic efficiency does not recover during unloading unless the confining pressure is almost relieved. The observed unrecoverable change in osmotic efficiency may have an important implication on the evaluation of chemical osmosis in argillaceous formations that have been exposed to large stresses in past geologic processes. If the osmotic efficiency increased by the past stress can remain unchanged to date, the osmotic efficiency should be measured at the past highest stress rather than the current in

  19. Geologic Map of the Weaverville 15' Quadrangle, Trinity County, California (United States)

    Irwin, William P.


    terrane is faulted against the west edge of the Central Metamorphic terrane, and its northerly trend is disrupted by major left-lateral offsets along generally west-northwest-trending faults. The serpentinized peridotite-gabbro complex that forms the western base of the terrane is the Permian North Fork ophiolite, which to the east is overlain by broken formation of mafic-volcanic rocks, red chert, siliceous tuff, argillite, minor limestone, and clastic sedimentary rocks. The chert and siliceous tuff contain radiolarians of Permian and Mesozoic ages, and some are as young as Early Jurassic (Pliensbachian). Similar Pliensbachian radiolarians are found in Franciscan rocks of the Coast Ranges. The Eastern Hayfork terrane is broken formation and melange of mainly chert, sandstone, argillite, and various exotic blocks. The cherts yield radiolarians of Permian and Triassic ages but none of clearly Jurassic age. Limestone bodies of the Eastern Hayfork terrane contain Permian microfaunas of Tethyan affinity. The Western Hayfork terrane, exposed only in a small area in the southwestern part of the quadrangle, consists dominantly of mafic tuff and dark slaty argillite. Sparse paleontologic data indicate a Mesozoic age for the strata. The terrane includes small bodies of diorite that are related to the nearby Wildwood pluton of Middle Jurassic age and probably are related genetically to the stratified rocks. The terrane is interpreted to be the accreted remnants of a Middle Jurassic volcanic arc. Shortly after intrusion by Shasta Bally batholith (approx. 136 Ma), much of the southern half of the Weaverville quadrangle was overlapped by Lower Cretaceous, dominantly Hauterivian, marine strata of the Great Valley sequence, and to a lesser extent later during Oligocene and (or) Miocene time by fluvial and lacustrine deposits of the Weaverville Formation. This map of the Weaverville Quadrangle is a digital rendition of U.S. Geological Survey Miscellaneous Field

  20. Effect of desaturation and re-saturation on shale in underground galleries; Effets de la desaturation et de la resaturation sur l'argilite dans les ouvrages souterrains

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Q.T


    The aim of this thesis is to characterize by experimental and numerical approaches the hydric, mechanical and hydro-mechanical effects due to the desaturation and re-saturation of the Eastern argillite, host rock of the Bure site, future underground radioactive waste disposal facility. Experimental and numerical approaches for the characterization of hydric transfers in argilites are presented. A simple identification method is proposed which uses the determination of the linearized hydric diffusivity from weight measurements performed on samples (thin tubes and plates) submitted to humidity steps according to a desaturation-re-saturation cycle. The hydric transfer is nonlinear. In order to interpret this phenomenon, a non-linear numerical model is established which takes into account the physical phenomena (hydraulic conduction, vapor diffusion, phase change..). The evolution of the physical and mechanical behaviour of the argillaceous rock with respect to the imposed humidity is then analyzed according to a desaturation-re-saturation cycle by successive steps. The hydric deformation, the velocity of ultrasonic waves propagation, the elastic properties, the rupture characteristics and the delayed phenomena depend on the hydric state of the material. The desaturation and re-saturation influence on a scale model of tunnel is analyzed. Thick tubes parallel or perpendicular to the stratification are used to show up the anisotropy of the rock. These tubes are submitted to hydric loads by blowing air with variable hygrometry through their center hole. A nonlinear poro-elastic model is used to interpret the anisotropic hydro-mechanical phenomena observed. It is shown that hydric loads can lead to the rupture of test samples which follow the anisotropic directions of the rock and which can be interpreted by the hydro-mechanical model as a violation of a rupture criterion in total pulling stress. Finally, numerical calculations for the phenomena generated by desaturation

  1. Modelling iron clay interactions in deep geological disposal conditions (United States)

    Bildstein, O.; Trotignon, L.; Perronnet, M.; Jullien, M.

    In the context of deep geological disposal of high level radioactive wastes, the interactions between iron and clay-rich materials may lead to adverse transformations of clay minerals with a potential loss of confining properties such as swelling and capacity to exchange cations. Such transformations have been experimentally observed at temperatures starting at ca. 80 °C, where smectites contained in a mixture of bentonite and iron powder are transformed into iron-rich serpentine-type minerals. The reaction-transport code CRUNCH is used to investigate the iron-clay interactions at 50 °C over a period of 10,000 years, which are the conditions considered here to represent the mean temperature value and the expected timescale for the corrosion stage. The aim is to predict the nature and quantity of corrosion product, calculate the chemistry of water (essentially the pH) and the mineralogical transformation in the system containing the canister, an optional engineered barrier (bentonite) and the host-rock (argillite). The results of the calculations show that at the interface with the canister, where steel corrosion occurs, the iron is partly immobilized by the precipitation of iron oxides (essentially magnetite) and small amounts of siderite. The pH stabilizes at high values, between 10 and 11, at this location. In the bentonite or the argillite in contact with the container, the primary clay minerals are destabilized and iron-rich serpentine-like minerals precipitate as observed in the experiments (cronstedtite and berthierine). These minerals show low cation exchange and swelling capacities. The results also show that the interactions between iron and clay may lead to significant porosity changes in the system. A reduction of the porosity is predicted at the surface of the steel canister, due to the precipitation of iron oxides. Porosity increase is predicted in the clay material due to the dissolution of the primary clay minerals. The effect of these porosity

  2. Hydro-mechanical processes

    Energy Technology Data Exchange (ETDEWEB)

    Laouafa, F.; Kazmierczak, J.B. [Institut National de l' Environnement Industriel et des Risques (INERIS), Parc Technologique ALATA, 60 - Verneuil en Halatte (France); Armand, G. [Agence Nationale pour la Gestion des Dechets Radioactifs, Lab. de Souterrain de Meuse/Haute-Marne, 55 - Bure (France); Vaunat, J. [Catalonia UPC- Technical Univ., Barcelona (Spain); Jobmann, M.; Polster, M. [DBETEC- DBE Technology GmbH, Peine (Germany); Su, K.; Lebon, P.; Plas, F.; Armand, G.; Abou-Chakra Guery, A.; Cormery, F.; Shao, J.F.; Kondo, D. [ANDRA - Agence Nationale pour la Gestion des Dechets Radioactifs, 92 - Chatenay Malabry (France); Souley, M. [Institut National de l' Environnement Industriel et des Risques (INERIS), 54 - Nancy (France); Coll, C.; Charlier, R.; Collin, F.; Gerard, P. [Liege Univ., Dept. ArGEnCo (Belgium); Xiang Ling, Li [ESV EURIDICE, SCK.CEN, Belgian Nuclear Research Centre, Mol (Belgium); Collin, F. [Liege Univ., Charge de Recherches FNRS (Belgium); Pellet, F.L.; Fabre, G. [University Joseph Fourier, Laboratory 3S-R, 38 - Grenoble (France); Garcia-Sineriz, J.L.; Rey, M. [AITEMIN - Asociacion para la Investigacion y Desarrollo Industrial de los Recursos Naturales, Madrid (Spain); Mayor, J.C. [ENRESA - Empresa Nacional des Residuos Radioactivos, Madrid (Spain); Castellanos, E.; Romero, E.; Lloret, A.; Gens, A. [Catalunya Univ. Politecnica, UPC (Spain); Villar, M.V. [CIEMAT - Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain); Chambon, R. [Laboratoire 3S, UJF-INPG-CNRS, 38 - Grenoble (France); Czaikowski, O.; Lux, K.H. [Clausthal Univ. of Technology, Professorship for Waste Disposal and Geomechanics, Clausthal-Zellerfeld (Germany); Van Geet, M.; Bastiaens, W.; Volckaert, G.; Weetjens, E.; Sillen, X. [SCK-CEN, Waste and Disposal dept., Mol (Belgium); ONDRAF/NIRAS, Brussel (Belgium); Imbert, Ch. [CEA Saclay, Dept. de Physico-Chimie (DPC/SCCME/LECBA), 91 - Gif sur Yvette (France)] [and others


    This session gathers 13 articles dealing with: three-dimensional and time stepping modelling of the whole Meuse/Haute-Marne ANDRA URL (F. Laouafa, J.B. Kazmierczak, G. Armand, J. Vaunat, M. Jobmann, M. Polster); a constitutive model for a deep argillaceous rock using Hoek-Brown criteria (K. Su, C. Chavant, M. Souley); the long term behaviour of the Boom clay: influence of viscosity on the pore pressure distribution (C. Coll, R. Charlier, X.L. Li, F. Collin); the microstructural changes induced by viscoplastic deformations in argillaceous rocks (F.L. Pellet, G. Fabre, K. Su, P. Lebon); the engineered barrier experiment at Mont Terri rock laboratory (J.L. Garcia-Sineriz, M. Rey, J.C. Mayor); the chemical influence on the Hydro-Mechanical behaviour of high-density FEBEX bentonite (E. Castellanos, M.V. Villar, E. Romero, A. Lloret, A. Gens); the influence of water exchanges on the gallery convergence (P. Gerard, R. Charlier, R. Chambon, F. Collin); a new method for ageing resistant storage of argillaceous rock samples to achieve reproducible experimental results even after long intermediate storage times (O. Czaikowski, K.H. Lux); the installation and evaluation of a large-scale in-situ shaft seal experiment in Boom clay the RESEAL project M. Van Geet, W. Bastiaens, G. Volckaert, E. Weetjens, X. Sillen, A. Gens, M.V. Villar, Ch. Imbert, M. Filippi, F. Plas); the hydro-Mechanical response of the Callovo-Oxfordian mud-stone around a deep vertical drift (J. Vaunat, B. Garitte, A. Gens, K. Su, G. Armand); the sensitivity of total stress to changes in externally applied water pressure in KBS-3 buffer bentonite (J.F. Harrington, D.J. Birchall, P. Sellin); the comparison of the poro-elastic behavior of Meuse/Haute Marne and Tournemire argillites: effect of loading and saturation states (E. Bemer, A. Noiret, F. Homand, A. Rejeb); and the multi-scale modelling of the argillites mechanical behaviour (A. Abou-Chakra Guery, F. Cormery, K. Su, J.F. Shao, D. Kondo)

  3. The Baling group/Bannang Sata group of the Malay/Thai Peninsula (United States)

    Burton, C. K.

    The Baling formation of eastern Kedah and northern-most Perak, Peninsular Malaysia has long been proposed for group rank. This proposal is adopted here although it is still not possible to formalize fully this rock unit. The Baling group extends across the international frontier into Thailand (as the Bannang Sata group) where it evidently attains its maximum development, at least in terms of areal extent, but it has not yet been studied in detail in that country. The Baling consists of arenite and carbonate of the Papalut quartzite below, and black siliceous argillite, with minor calcareous rocks, of the Kroh formation, above. A thick sequence of rhyolitic pyroclastic rocks (the Grik tuff) occurs around the passage between two foregoing formations in the Grik area of Perak. Review of age criteria and regional relationships indicates that the Papulut is closely related to a (?) Mid Cambrian to Lower Ordovician shelf sequence in parts of the coastal tract of NW Peninsular Malaysia and the adjacent portion of Thailand (Jerai formation, Machinchang Formation, Tarutao Formation). Minor amounts of acid pyroclastic rocks in all these rock units are correlated with the initial phase of the Grik tuffs. The Kroh formation is part of a hitherto unrecognised but widespread association of Mid Palaeozoic black shale facies including the Mahang Formation to the west and the upper part of the Foothills group ("Bentong group") to the east and southeast. This facies seems to have been initiated in the Ordovician and is characterized by Lower to Mid Silurian and Lower Devonian graptolites, the latter accompanied in the Baling and Mahang by numerous Lower to Mid Devonian tentaculites. No fossils of uppermost Wenlock, Ludlow or Pridoli ages have been determined in these rocks. Counter to earlier palaeogeographic reconstructions no evidence of a confining sill or barrier or contemporary subduction zone can be detected within the outcrop of this black siliceous argillite association. If

  4. Reconnaissance geologic map of the Dubakella Mountain 15 quadrangle, Trinity, Shasta, and Tehama Counties, California (United States)

    Irwin, William P.; Yule, J. Douglas; Court, Bradford L.; Snoke, Arthur W.; Stern, Laura A.; Copeland, William B.


    The Dubakella Mountain 15' quadrangle is located just south of the Hayfork quadrangle and just east of the Pickett Peak quadrangle. It spans a sequence of four northwest-trending tectonostratigraphic terranes of the Klamath Mountains geologic province that includes, from east to west, the Eastern Hayfork, Western Hayfork, Rattlesnake Creek, and Western Jurassic terranes, as well as, in the southwest corner of the quadrangle, part of a fifth terrane, the Pickett Peak terrane of the Coast Ranges geologic province. The Eastern Hayfork terrane is a broken formation and melange of volcanic and sedimentary rocks that include blocks of limestone and chert. The limestone contains late Permian microfossils of Tethyan faunal affinity. The chert contains radiolarians of Mesozoic age, mostly Triassic, but none clearly Jurassic. The Western Hayfork terrane is an andesitic volcanic arc that consists mainly of agglomerate, tuff, argillite, and chert, and includes the Wildwood pluton. That pluton is related to the Middle Jurassic (about 170 Ma) Ironside Mountain batholith that is widely exposed farther north beyond the Dubakella Mountain quadrangle. The Rattlesnake Creek terrane is a highly disrupted ophiolitic melange of probable Late Triassic or Early Jurassic age. Although mainly ophiolitic, the melange includes blocks of plutonic rocks (about 200 Ma) of uncertain genetic relation. Some scattered areas of well-bedded mildly slaty detrital rocks of the melange appear similar to Galice Formation (unit Jg) and may be inliers of the nearby Western Jurassic terrane. The Western Jurassic terrane consists mainly of slaty to phyllitic argillite, graywacke, and stretched-pebble conglomerate and is correlative with the Late Jurassic Galice Formation of southwestern Oregon. The Pickett Peak terrane, the most westerly of the succession of terranes of the Dubakella Mountain quadrangle, is mostly fine-grained schist that includes the blueschist facies mineral lawsonite and is of Early

  5. Disappearance of Sea Floor of the Paleo-asian Ocean: Geological Evidence from the Dong Ujimqin, Inner Mongolia, China (United States)

    Zhou, Z.; Zhang, T.; Wang, B.; Yu, Y.


    It is well accepted that the Central Asian Orogenic Belt (CAOB) formed by the Paleozoic collision of the Siberia and the North China plates and the simultaneous closure of the Paleo-Asian Sea, but the location of the suture zone is still very debatable. Three proposed hypotheses of where the suture zone is are: Solonker-Sonid Zuoqi-Hegenshan, Ophiolite belt along Solonker-Xar Moron River, and the Main Mongolian Lineament in Mongolia. Our mapping, geochronology and geochemistry work in Dong Ujimqin (about 240 km to the NE of Hegan Shan) support the third hypothesis the best. Paleozoic stratigraphy in the research area was studied in detail. From Ordovician to middle Permian, local stratigraphy from bottom to top includes: Ordovician echinodermmeta fossil bearing crystalline limestone, sandstone and argillite; Middle Devonian coarse grained sandstone and argillite; Lower Middle Permian interlayerred sandstone and siltstone. There is an angular unconformity between the Middle Devonian and the overlying Permian strata. The Permian strata contain fossils of Cathaysia flora which include Cladophlebis sp.1,Cladophlebis sp. 2, Pterophyllum daihoense Kawasaki, Calamites suckowiiBrongniart, Sphenopteris sp., Cladophlebis nystroemii Halle, Cladophlebis ozakii Yabe et Oishi, Emplectopteris triangularis Halle, Lepidophylloides sp., Mariopteris hallei (Stockmans et Mathieu), Cladophlebis manchuica (Kawasaki). Structurally, Ordovian strata thrust over the Middle Devonian from NW to SE, and the Middle Devonian thrust over Upper Devonian from NW to SE too. The strike of the axial plane of the folds associated with the thrusts is NE. Two Carboniferous magmatic belts were discovered in the research area. U-Pb zircon geochronology using LA-ICP-MS gave ages of 325-326Ma and 298-311Ma for the North and South belts respectively. The magamatic activities moved from NW to SE. Whole rock, trace element and REE geochemistry tell us that all these magmatic rocks are of syn

  6. Tracing sources of crustal contamination using multiple S and Fe isotopes in the Hart komatiite-associated Ni-Cu-PGE sulfide deposit, Abitibi greenstone belt, Ontario, Canada (United States)

    Hiebert, R. S.; Bekker, A.; Houlé, M. G.; Wing, B. A.; Rouxel, O. J.


    Assimilation by mafic to ultramafic magmas of sulfur-bearing country rocks is considered an important contributing factor to reach sulfide saturation and form magmatic Ni-Cu-platinum group element (PGE) sulfide deposits. Sulfur-bearing sedimentary rocks in the Archean are generally characterized by mass-independent fractionation of sulfur isotopes that is a result of atmospheric photochemical reactions, which produces isotopically distinct pools of sulfur. Likewise, low-temperature processing of iron, through biological and abiotic redox cycling, produces a range of Fe isotope values in Archean sedimentary rocks that is distinct from the range of the mantle and magmatic Fe isotope values. Both of these signals can be used to identify potential country rock assimilants and their contribution to magmatic sulfide deposits. We use multiple S and Fe isotopes to characterize the composition of the potential iron and sulfur sources for the sulfide liquids that formed the Hart deposit in the Shaw Dome area within the Abitibi greenstone belt in Ontario (Canada). The Hart deposit is composed of two zones with komatiite-associated Ni-Cu-PGE mineralization; the main zone consists of a massive sulfide deposit at the base of the basal flow in the komatiite sequence, whereas the eastern extension consists of a semi-massive sulfide zone located 12 to 25 m above the base of the second flow in the komatiite sequence. Low δ56Fe values and non-zero δ34S and Δ33S values of the komatiitic rocks and associated mineralization at the Hart deposit is best explained by mixing and isotope exchange with crustal materials, such as exhalite and graphitic argillite, rather than intrinsic fractionation within the komatiite. This approach allows tracing the extent of crustal contamination away from the deposit and the degree of mixing between the sulfide and komatiite melts. The exhalite and graphitic argillite were the dominant contaminants for the main zone of mineralization and the eastern

  7. Morphogenetic features of soils in the Cat Tien National Park, southern Vietnam (United States)

    Khokhlova, O. S.; Myakshina, T. N.; Kuznetsov, A. N.; Gubin, S. V.


    Morphogenetic features of soils on the selected plots in the Cat Tien National Park in southern Vietnam have been studied with the use of a set of morphological, analytical, and instrumental methods. The lithological factor and topographic position play the leading role in the development of the particular genetic soil features. The soils can be subdivided into four groups according to these factors. The soils developing from volcanic deposits with a predominance of tephra can be classified as thin clayey brown tropical soils (Dystric Skeletic Rhodic Cambisols (Clayic)), and the soils developed from less weathered colluvial derivatives of basalts with some admixture of tephra can be classified as dark-humus clayey tropical soils (Skeletic Greyzemic Umbrisols (Clayic)). Very poor soils developed from the eluvium of argillites are classified as thin weakly developed clayey tropical soils (Dystric Regosols (Clayic)). The soils forming from the alluvial sediments of different textures are classified as alluvial loamy sandy soils (Dystric Fluvisols (Arenic, Drainic)) and as alluvial clay loamy soils (Eutric Fluvisols (Episiltic, Endoclayic)).

  8. Clay Generic Disposal System Model - Sensitivity Analysis for 32 PWR Assembly Canisters (+2 associated model files).

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Edgar [Argonne National Lab. (ANL), Argonne, IL (United States)


    The Used Fuel Disposition Campaign (UFDC), as part of the DOE Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technology program (FCT) is investigating the disposal of high level radioactive waste (HLW) and spent nuclear fuela (SNF) in a variety of geologic media. The feasibility of disposing SNF and HLW in clay media has been investigated and has been shown to be promising [Ref. 1]. In addition the disposal of these wastes in clay media is being investigated in Belgium, France, and Switzerland. Thus, Argillaceous media is one of the environments being considered by UFDC. As identified by researchers at Sandia National Laboratory, potentially suitable formations that may exist in the U.S. include mudstone, clay, shale, and argillite formations [Ref. 1]. These formations encompass a broad range of material properties. In this report, reference to clay media is intended to cover the full range of material properties. This report presents the status of the development of a simulation model for evaluating the performance of generic clay media. The clay Generic Disposal System Model (GDSM) repository performance simulation tool has been developed with the flexibility to evaluate not only different properties, but different waste streams/forms and different repository designs and engineered barrier configurations/ materials that could be used to dispose of these wastes.

  9. M4FT-16LL080303052-State of Knowledge for Colloid Facilitated Radionuclide Transport and Update on Actinide Diffusion in Bentonite Backfill

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences; Joseph, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences


    This progress report (Level 4 Milestone Number M4FT-16LL080303052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Disposal R&D Activity Number FT-16LL080303051 and Crystalline International Collaborations Activity Number FT-16LL080303061. The focus of this research is the interaction of radionuclides with Engineered Barrier System (EBS) and host rock materials at various physico-chemical conditions relevant to subsurface repository environments. They include both chemical and physical processes such as solubility, sorption, and diffusion. The colloid-facilitated transport effort focused on preparation of a draft manuscript summarizing the state of knowledge and parameterization of colloid-facilitated transport mechanisms in support of reactive transport and performance assessment models for generic crystalline repositories. This draft manuscript is being submitted as a level 3 milestone with LANL as the primary author. LLNL’s contribution to that effort is summarized only briefly in the present report. A manuscript summarizing long-term U(VI) diffusion experiments through bentonite backfill material was recently accepted for publication; the contents of that manuscript are summarized in the present report. The Np(IV) diffusion experiments were started mid-year and are ongoing. The completion of these experiments is planned for early FY17. Our progress in quantifying Np(IV) diffusion in bentonite backfill is summarized in the present report. Our involvement with the NEA TDB project was summarized in a recent Argillite Disposal activity report. It is not included in this report.

  10. Physical-Property Measurements on Core samples from Drill-Holes DB-1 and DB-2, Blue Mountain Geothermal Prospect, North-Central Nevada (United States)

    Ponce, David A.; Watt, Janet T.; Casteel, John; Logsdon, Grant


    From May to June 2008, the U.S. Geological Survey (USGS) collected and measured physical properties on 36 core samples from drill-hole Deep Blue No. 1 (DB-1) and 46 samples from drill-hole Deep Blue No. 2 (DB-2) along the west side of Blue Mountain about 40 km west of Winnemucca, Nev. These data were collected as part of an effort to determine the geophysical setting of the Blue Mountain geothermal prospect as an aid to understanding the geologic framework of geothermal systems throughout the Great Basin. The physical properties of these rocks and other rock types in the area create a distinguishable pattern of gravity and magnetic anomalies that can be used to infer their subsurface geologic structure. Drill-holes DB-1 and DB-2 were spudded in alluvium on the western flank of Blue Mountain in 2002 and 2004, respectively, and are about 1 km apart. Drill-hole DB-1 is at a ground elevation of 1,325 m and was drilled to a depth of 672 m and drill-hole DB-2 is at a ground elevation of 1,392 m and was drilled to a depth of 1522 m. Diameter of the core samples is 6.4 cm. These drill holes penetrate Jurassic and Triassic metasedimentary rocks predominantly consisting of argillite, mudstone, and sandstone; Tertiary diorite and gabbro; and younger Tertiary felsic dikes.

  11. DOE-Managed HLW and SNF Research: FY15 EBS and Thermal Analysis Work Package Status.

    Energy Technology Data Exchange (ETDEWEB)

    Matteo, Edward N. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)


    This report examines the technical elements necessary to evaluate EBS concepts and perform thermal analysis of DOE-Managed SNF and HLW in the disposal settings of primary interest – argillite, crystalline, salt, and deep borehole. As the disposal design concept is composed of waste inventory, geologic setting, and engineered concept of operation, the engineered barrier system (EBS) falls into the last component of engineered concept of operation. The waste inventory for DOE-Managed HLW and SNF is closely examined, with specific attention to the number of waste packages, the size of waste packages, and the thermal output per package. As expected, the DOE-Managed HLW and SNF inventory has a much smaller volume, and hence smaller number of canister, as well a lower thermal output, relative to a waste inventory that would include commercial spent nuclear fuel (CSNF). A survey of available data and methods from previous studies of thermal analysis indicates that, in some cases, thermo-hydrologic modeling will be necessary to appropriately address the problem. This report also outlines scope for FY16 work -- a key challenges identified is developing a methodology to effectively and efficiently evaluate EBS performance in each disposal setting on the basis of thermal analyses results.

  12. Extractant efficiency in the solubilization of alternative sources of potassium

    Directory of Open Access Journals (Sweden)

    Daniele Nogueira dos Reis


    Full Text Available Knowledge of a rock’s composition allows for inferences regarding several properties, ranging from its physical characteristics to its solubility. This study aimed to evaluate the use of different extractants to solubilize the K present in rocks as a potential source of nutrients and the effects of extractant contact time and temperature on rock solubilization. Samples of two rocks and a mineral concentrated from a granitic rock were treated with ammonium dihydrogen phosphate (NH4(H2PO4, calcium dihydrogen phosphate (Ca(H2PO42, sodium hydroxide (NaOH and water (control. Sample-extractant treatments were performed using a water bath shaker at temperatures of 25 and 50°C for periods of 3, 7, 10, 20, and 30 days. The amounts of K extracted from rocks using the extractants were in the following order: NH4H2PO4>Ca(HPO42>NaOH>water. The sequence of K release (ppm based on the rocks studied was as follows: nepheline syenite>green banded argillite>concentrated biotite. Increasing the extractant contact time and temperature enhanced the solubilized K content.

  13. Exploration of the Rotokawa geothermal field, Taupo volcanic zone, New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Browne, P.R.L. (Univ. of Auckland (New Zealand))


    The Rotokawa geothermal field is located 7 km east of Wairakei, New Zealand, and has been investigated for its sulphur resources and power potential over the past 50 years. Exploration of the field has slow and mostly unsystematic. The depths of the drill holes are less than 50 m until 1964. Since 1965 the exploration has been carried out systematically. Three, one and four exploration wells were drilled in 1965-66, 1977, and 1984-86 respectively. Finding Jurassic greywackes and argillites at a depth of 2200 m below a thick (ca. 900 m)sequence of two pyroxene andesite lava flows had an important significance, because the Jurassic rocks are the basement rocks for the North Island. The Rotokawa geothermal field represents an important resource with an assessed potential of 49 MW (proven), 100 MW (probable) and 200 MW (possible), though these figures are considered to be probably optimistic. Further exploratory drilling is needed. The main development problems at this stage are: (1) encountering good subsurface permeability, (2) identifying and combating corrosive CO{sub 2}-rich fluids, (3) determining the most favorable reinjection conditions; this is a problem, ironically enhanced by the hot temperature and the consequently high silica contents of the thermal fluids, (4) establishing an acceptable development plan for the field which accommodates the requirements of both the sulphur mining interests, the power producers, and especially the Ngati Tahu maori owners of the land. 24 refs., 2 figs., 2 tabs.

  14. Mineralogy, Geochemistry and Stable Isotope Studies of the Dopolan Bauxite Deposit, Zagros Mountain, Iran

    Directory of Open Access Journals (Sweden)

    Somayeh Salamab Ellahi


    Full Text Available The Dopolan deposit is a Mediterranean-type bauxite located in the Zagros Fold-Thrust Zone, Iran. This deposit consists of five lithological members including iron-rich, clay-rich, oolitic, pisolitic and organic matter-containing bauxites. The mineralogy of the deposit includes diaspore, boehmite, and kaolinite, nacrite, with minor pyrite, anatase and rutile. Geochemical studies show that light rare earth elements (LREEs are enriched relative to heavy rare earth elements (HREEs in all members, supporting an authigenic origin. Mass changes based on Ti as an immobile element indicate that conventionally-immobile elements (Al, Nb, Ta, Zr, Hf are enriched in situ in the residual units, whereas mobile elements (K, Ca, Si were depleted during bauxitization. This study shows that the Khaneh–Kat argillitic dolomite is the likely parent rock. The δ18O (7.63‰to 9.35‰ and D values (49.91‰to 66.49‰ for kaolinite in the bauxite samples suggest equilibration with meteoric waters which supports a supergene origin. Bauxitization occurred in a warm climate with relatively constant isotopic composition suggesting climate stability during the development of bauxite horizons and remobilization of Al (with formation of secondary boehmite. The δ13C values of calcite (7.3‰ in the bauxite support the idea that the Khaneh–Kat Formation has experienced post-depositional isotope exchange with meteoric waters during the karstification process.

  15. Thermo-hydro-mechanical processes in the nearfield around a HLW repository in argillaceous formations. Vol. II. In-situ-investigations and interpretative modelling. May 2007 to May 2013

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang; Czaikowski, Oliver; Komischke, Michael; Wieczorek, Klaus


    Deep disposal of heat-emitting high-level radioactive waste (HLW) in clay formations will inevitably induce thermo-hydro-mechanical-chemical disturbances to the host rock and engineered barriers over very long periods of time. The responses and resulting property changes of the natural and engineered barriers are to be well understood, characterized, and predicted for assessing the long-term performance and safety of the repositories. In accordance with the R and D programme defined by the German Federal Ministry of Economics and Technology (BMWi), GRS has intensively performed site-independent research work on argillaceous rocks during the last decade. Most of the investigations have been carried out on the Callovo-Oxfordian argillite and the Opalinus clay by par-ticipation in international research projects conducted at the underground research laboratories at Bure in France (MHM-URL) and Mont-Terri in Switzerland (MT-URL). The THM-TON project, which was funded by BMWi under contract number 02E10377, in-vestigated the THM behaviours of the clay host rock and clay-based backfill/sealing materials with laboratory tests, in situ experiments and numerical modelling.

  16. Isotopic (U-Pb, Nd) and geochemical constraints on the origins of the Aileu and Gondwana sequences of Timor (United States)

    Boger, S. D.; Spelbrink, L. G.; Lee, R. I.; Sandiford, M.; Maas, R.; Woodhead, J. D.


    Detrital zircon U-Pb age data collected from the argillitic sedimentary rocks of the Timorese Aileu Complex and Gondwana Sequence indicate that both units were derived from a common source containing 200-600 Ma, 900-1250 Ma and 1450-1900 Ma zircon. The modally most significant age population within this range of ages dates to c. 260 Ma. The observed spectrum of ages can be traced to the eastern active margin of Pangaea and its immediate foreland, which today is best exposed along the northeast coast of Australia. Compared to the relative homogeneity of the detrital zircon age data, geochemical and Nd isotopic data show that the mudstones of the Aileu Complex are on average more siliceous, have higher K2O/Na2O, Rb/Sr, Th/Sc and yield notably older Nd TDM model ages when compared to those from the Gondwana Sequence. These data are interpreted to suggest that, although both sequences share a common east Pangaea provenance, they were eroded from different sections of this active margin and deposited in spatially separated basins. The present proximity of these units is a result of their tectonic juxtaposition during the Pliocene to Recent collision between the northern edge of the Indo-Australia plate and the Banda Arc.

  17. M4FT-16LL080303052-State of Knowledge for Colloid Facilitated Radionuclide Transport and Update on Actinide Diffusion in Bentonite Backfill

    Energy Technology Data Exchange (ETDEWEB)

    Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences; Joseph, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.. Physical and Life Sciences


    This progress report (Level 4 Milestone Number M4FT-16LL080303052) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Crystalline Disposal R&D Activity Number FT-16LL080303051 and Crystalline International Collaborations Activity Number FT-16LL080303061. The focus of this research is the interaction of radionuclides with Engineered Barrier System (EBS) and host rock materials at various physico-chemical conditions relevant to subsurface repository environments. They include both chemical and physical processes such as solubility, sorption, and diffusion. The colloid facilitated transport effort focused on preparation of a draft manuscript summarizing the state of knowledge and parameterization of colloid facilitated transport mechanisms in support of reactive transport and performance assessment models for generic crystalline repositories. This draft manuscript is being submitted as a level 3 milestone with LANL as the primary author. LLNL’s contribution to that effort is summarized only briefly in the present report. A manuscript summarizing longterm U(VI) diffusion experiments through bentonite backfill material was recently accepted for publication; the contents of that manuscript are summarized in the present report. The Np(IV) diffusion experiments were started mid-year and are ongoing. The completion of these experiments is planned for early FY17. Our progress in quantifying Np(IV) diffusion in bentonite backfill is summarized in the present report. Our involvement with the NEA TDB project was summarized in a recent Argillite Disposal activity report. It is not included in this report.

  18. Review of potential host rocks for radioactive waste disposal in the southeast United States-Southern Piedmont subregion

    Energy Technology Data Exchange (ETDEWEB)


    A literature study was conducted on the geology of the Southern Piedmont province in the states of Maryland, Virginia, North Carolina, South Carolina, and Georgia. The purpose was to identify geologic areas potentially suitable for containment of a repository for the long-term isolation of solidified radioactive waste. The crystalline rocks of the Southern Piedmont province range in age from Precambrian to Paleozoic, and are predominantly slates, phyllites, argillites, schists, metavolcanics, gneisses, gabbros, and granites. These rock units were classified as either favorable, potentially favorable, or unfavorable as potential study areas based on an evaluation of the geologic, hydrologic, and geotechnical characteristics. No socio-economic factors were considered. Rocks subjected to multiple periods of deformation and metamorphism, or described as highly fractured, or of limited areal extent were generally ranked as unfavorable. Potentially favorable rocks are primarily the high-grade metamorphic gneisses and granites. Sixteen areas were classified as being favorable for additional study. These areas are primarily large igneous granite plutons as follows: the Petersburg granite in Virginia; the Rolesville-Castallia, Churchland, and Landis plutons in North Carolina; the Liberty Hill, Winnsboro, and Ogden plutons in South Carolina; and the Siloam, Elberton, and six unnamed granite plutons in Georgia.

  19. Planation Surfaces on the Tibet Plateau, China

    Institute of Scientific and Technical Information of China (English)


    A planation hypothesis is proposed to explain landform evolution of the Tibet Plateau. A denudation threshold (T), the maximum potential denudation rate for a certain type of rock, is introduced to explain the combined effects of lithology and tectonics on landform evolution. If the tectonic uplifting rate (U) is equal to or less than the threshold rate (U ≤ T), the tectonic uplifting and terrain denudation are in dynamic equilibrium, and landforms are in a steady state. The end product should be planation surfaces whether the original landforms are fiat plains or deeply dissected mountains. If U > T, uplift and denudation are not able to reach a dynamic equilibrium state. The plateau surface is mostly underlain by soft rocks, such as the Mesozoic epimetamorphic argillites and Tertiary sedimentary rocks, while the mountain ranges comprise hard rocks, such as granite, gneiss and limestone. In soft rock regions, hills are low with a relative relief of mostly less than 100m and the slopes are gentle at a gradient of <200. In contrast, hills can maintain steep slopes in hard rock regions. The Tibet Plateau has been under an equilibrium condition between tectonic uplifting and denudation except for the mountain ranges. The plateau might have reached the present altitudes before the Quaternary.

  20. Palaeogeography and palaeoecology of early Floian (Early Ordovician cephalopods from the Upper Fezouata Formation, Anti-Atlas, Morocco

    Directory of Open Access Journals (Sweden)

    B. Kröger


    Full Text Available In the central Anti-Atlas (Morocco, the Early Ordovician succession consists of about 1000 m of fossiliferous argillites and siltstones. The Upper Fezouata Formation (Floian contains a comparatively rich and abundant cephalopod association. A small collection of these cephalopods is described herein for the first time. The cephalopods are interpreted as autochthonous or parautochthonous, representing a fauna, which originally lived nektobenthically in the open water above the sediments or related to the sea bottom. The cephalopod associations of the Upper Fezouata Formation are similar to other contemporaneous assemblages known from higher palaeolatitudes and associated with deeper depositional settings and in siliciclastically dominated deposits. They are composed almost exclusively of slender orthocones, in this case predominantly of Destombesiceras zagorense n. gen., n. sp., which is interpreted as an early discosorid. Bathmoceras australe Teichert, 1939 and Bathmoceras taichoutense n. sp. from the Upper Fezouata Formation are at present the earliest unambiguous occurrences of bathmocerid cephalopods. Epizoans on the shell of a specimen of Rioceras are the earliest evidence of bryozoans growing as potential hitchhikers on cephalopod shells, indicating an early exploitation of a pseudoplanktonic lifestyle in this phylum. doi:10.1002/mmng.201200004

  1. Faults dominant structure? -Seismic images of the subsurface structure for the Ilan geothermal field in Taiwan. (United States)

    Chang, Yu-Chun; Shih, Ruey-Chyuan; Wang, Chien-Ying; Kuo, Hsuan-Yu; Chen, Wen-Shan


    A prototype deep geothermal power plant is to be constructed at the Ilan plain in northeastern Taiwan. The site will be chosen from one of the two potential areas, one in the west and the other in the eastern side of the plain. The triangle-shaped Ilan plane is bounded by two mountain ranges at the northwest and the south, with argillite and slate outcrops exposed, respectively. The Ilan plane is believed situating in a structure extending area at the southwestern end of the Okinawa Trough. Many studies about subsurface structure of the plain have been conducted for years. The results showed that the thickest sediments, around 900 m, is located at the eastern coast of the plain, at north of the largest river in the plain, the Lanyang river, and then became shallower to the edges of the plain. Since the plane is covered by thick sediments, formations and structures beneath the sediments are barely known. However, the observed high geothermal gradient and the abundant hot spring in the Ilan area indicate that this area is having a high potential of geothermal energy. In order to build up a conceptual model for tracing the possible paths of geothermal water and search for a suitable site for the geothermal well, we used the seismic reflection method to delineate the subsurface structure. The seismic profiles showed a clear unconformity separating the sediments and the metamorphic bedrock, and some events dipping to the east in the bedrock. Seismic images above the unconformity are clear; however, seismic signals in the metamorphic bedrock are sort of ambiguous. There were two models interpreted by using around 10 seismic images that collected by us in the past 3 years by using two mini-vibrators (EnviroVibe) and a 360-channel seismic data acquisition system. In the first model, seismic signals in the bedrock were interpreted as layer boundaries, and a fractured metamorphic layer down the depth of 1200m was thought as the source of geothermal water reservoir. In the

  2. Electrical studies at the proposed Wahmonie and Calico Hills nuclear waste sites, Nevada Test Site, Nye County, Nevada (United States)

    Hoover, D.B.; Chornack, Michael P.; Nervick, K.H.; Broker, M.M.


    Two sites in the southwest quadrant of the Nevada Test Site (NTS) were investigated as potential repositories for high-level nuclear waste. These are designated the Wahmonie and Calico Hills sites. The emplacement medium at both sites was to be an inferred intrusive body at shallow depth; the inference of the presence of the body was based on aeromagnetic and regional gravity data. This report summarizes results of Schlumberger VES, induced polarization dipole-dipole traverses and magnetotelluric soundings made in the vicinity of the sites in order to characterize the geoelectric section. At the Wahmonie site VES work identified a low resistivity unit at depth surrounding the inferred intrusive body. The low resistivity unit is believed to be either the argillite (Mississippian Eleana Formation) or a thick unit of altered volcanic rock (Tertiary). Good electrical contrast is provided between the low resistivity unit and a large volume of intermediate resistivity rock correlative with the aeromagnetic and gravity data. The intermediate resistivity unit (100-200 ohm-m) is believed to be the intrusive body. The resistivity values are very low for a fresh, tight intrusive and suggest significant fracturing, alteration and possible mineralization have occurred within the upper kilometer of rock. Induced polarization data supports the VES work, identifies a major fault on the northwest side of the inferred intrusive and significant potential for disseminated mineralization within the body. The mineralization potential is particularly significant because as late as 1928, a strike of high grade silver-gold ore was made at the site. The shallow electrical data at Calico Hills revealed no large volume high resistivity body that could be associated with a tight intrusive mass in the upper kilometer of section. A drill hole UE 25A-3 sunk to 762 m (2500 ft) at the site revealed only units of the Eleana argillite thermally metamorphosed below 396 m (1300 ft) and in part highly

  3. Modeling Coupled Processes in Clay Formations for Radioactive Waste Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui-Hai; Rutqvist, Jonny; Zheng, Liange; Sonnenthal, Eric; Houseworth, Jim; Birkholzer, Jens


    As a result of the termination of the Yucca Mountain Project, the United States Department of Energy (DOE) has started to explore various alternative avenues for the disposition of used nuclear fuel and nuclear waste. The overall scope of the investigation includes temporary storage, transportation issues, permanent disposal, various nuclear fuel types, processing alternatives, and resulting waste streams. Although geologic disposal is not the only alternative, it is still the leading candidate for permanent disposal. The realm of geologic disposal also offers a range of geologic environments that may be considered, among those clay shale formations. Figure 1-1 presents the distribution of clay/shale formations within the USA. Clay rock/shale has been considered as potential host rock for geological disposal of high-level nuclear waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures induced by tunnel excavation. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at Mol site, Belgium (Barnichon et al., 2005) have all been under intensive scientific investigations (at both field and laboratory scales) for understanding a variety of rock properties and their relations with flow and transport processes associated with geological disposal of nuclear waste. Clay/shale formations may be generally classified as indurated and plastic clays (Tsang et al., 2005). The latter (including Boom clay) is a softer material without high cohesion; its deformation is dominantly plastic. For both clay rocks, coupled thermal, hydrological, mechanical and chemical (THMC) processes are expected to have a significant impact on the long-term safety of a clay repository. For

  4. Contact angles at the water-air interface of hydrocarbon-contaminated soils and clay minerals (United States)

    Sofinskaya, O. A.; Kosterin, A. V.; Kosterina, E. A.


    Contact angles at the water-air interface have been measured for triturated preparations of clays and soils in order to assess changes in their hydrophobic properties under the effect of oil hydrocarbons. Tasks have been to determine the dynamics of contact angle under soil wetting conditions and to reveal the effect of chemical removal of organic matter from soils on the hydrophilicity of preparations. The potentialities of static and dynamic drop tests for assessing the hydrophilic-hydrophobic properties of soils have been estimated. Clays (kaolinite, gumbrine, and argillite) have been investigated, as well as plow horizons of soils from the Republic of Tatarstan: heavy loamy leached chernozem, medium loamy dark gray forest soil, and light loamy soddy-calcareous soil. The soils have been contaminated with raw oil and kerosene at rates of 0.1-3 wt %. In the uncontaminated and contaminated chernozem, capillary water capacity has been maintained for 250 days. The contact angles have been found to depend on the degree of dispersion of powdered preparation, the main type of clay minerals in the soil, the presence and amount of oxidation-resistant soil organic matter, and the soil-water contact time. Characteristic parameters of mathematical models for drop behavior on triturated preparations have been calculated. Contamination with hydrocarbons has resulted in a reliable increase in the contact angles of soil preparations. The hydrophobization of soil surface in chernozem is more active than in soils poorer in organic matter. The complete restoration of the hydrophilic properties of soils after hydrocarbon contamination is due to the oxidation of easily oxidizable organic matter at the low content of humus, or to wetting during several months in the absence of the mazut fraction.

  5. Constitutive relationships for elastic deformation of clay rock: Data Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.H.; Rutqvist, J.; Birkholzer, J.T.


    Geological repositories have been considered a feasible option worldwide for storing high-level nuclear waste. Clay rock is one of the rock types under consideration for such purposes, because of its favorable features to prevent radionuclide transport from the repository. Coupled hydromechanical processes have an important impact on the performance of a clay repository, and establishing constitutive relationships for modeling such processes are essential. In this study, we propose several constitutive relationships for elastic deformation in indurated clay rocks based on three recently developed concepts. First, when applying Hooke's law in clay rocks, true strain (rock volume change divided by the current rock volume), rather than engineering strain (rock volume change divided by unstressed rock volume), should be used, except when the degree of deformation is very small. In the latter case, the two strains will be practically identical. Second, because of its inherent heterogeneity, clay rock can be divided into two parts, a hard part and a soft part, with the hard part subject to a relatively small degree of deformation compared with the soft part. Third, for swelling rock like clay, effective stress needs to be generalized to include an additional term resulting from the swelling process. To evaluate our theoretical development, we analyze uniaxial test data for core samples of Opalinus clay and laboratory measurements of single fractures within macro-cracked Callovo-Oxfordian argillite samples subject to both confinement and water reduced swelling. The results from this evaluation indicate that our constitutive relationships can adequately represent the data and explain the related observations.

  6. Timing and characterization of the change in the redox state of uranium in Precambrian surface environments: A proxy for the oxidation state of the atmosphere (United States)

    Pollack, Gerald D.

    The redox-sensitive geochemical behavior of uranium permits the use of Th/U ratios as a geochemical proxy for the oxidation state of the atmosphere and oceans during sedimentary processes. Due to the effects of post-depositional uranium mobility on Th/U ratios during events involving oxygenated fluids, direct measurements of Th/U ratios are often misleading, but the whole rock Pb isotope composition may be used to determine a sample's apparent time-integrated Th/U ratio (kappaa) and the timing associated with the onset of the U-Th-Pb geochemistry. Rare earth element (REE) concentrations were determined by isotope dilution mass spectrometry to evaluate the influence of multiple provenance components and potential mobility of Th, U, and Pb during post-depositional processes on the Th/U ratio. The Pb isotope compositions and REE concentrations were determined for six Paleoproterozoic sedimentary sequences, which were the focus of previous studies involving the timing of the rise of atmospheric oxygen. The Mount McRae Shale, Huronian Supergroup, and Zaonezhskaya Formation have been interpreted as experiencing post-depositional alteration (perhaps associated with orogenic events) due to Pb-Pb ages that are younger than the likely depositional age and observed fractionation of REE in chondrite normalized REE patterns and interelement REE ratios (e.g. La/Nd, La/Yb, Eu/Eu*). Similar geochemical proxies have been interpreted as sedimentary geochemical features of the Timeball Hill Formation, Hotazel Formation, and Sengoma Argillite Formation. This study of Paleoproterozoic sedimentary units constrains the onset of U-Th decoupling, most likely due to the onset of oxidative weathering conditions, began by 2.32 Ga, the latest. Index words. Pb isotopes, Rare earth elements, Th/U ratios, Time-integrated, Atmospheric evolution, Oxygen content of the atmosphere, U-Th decoupling

  7. Seismic properties and effects of hydrothermal alteration on Volcanogenic Massive Sulfide (VMS) deposits at the Lalor Lake in Manitoba, Canada (United States)

    Miah, Khalid H.; Bellefleur, Gilles; Schetselaar, Ernst; Potter, David K.


    Borehole sonic and density logs are essential for mineral exploration at depth, but its limited availability to link rock properties of different ore forming geologic structure is a hindrance to seismic data interpretations. In situ density and velocity logs provide first order control on the reflectivity of various lithologic units. We analyzed borehole logs from 12 drill holes over and around the Lalor VMS deposits geographically located in the northern Manitoba, Canada, in an attempt to characterize lithologic units based on its seismic properties. The Lalor Lake deposit is part of the Paleoproterozoic Flin Flon Belt, and associated with an extensive hydrothermal alteration system. Volcanogenic Massive Sulfide (VMS) zones are distributed in several ore lenses with relatively shallower facies comprise solid to solid sulfides, tend to be disseminated or Stringer sulfides, while deeper lenses are gold and silver enriched and occurred in the highly altered footwall region. Our analysis suggests that massive sulfide and diorite have higher acoustic impedance than other rock units, and can produce useful reflection signatures in seismic data. Bivariate distributions of P-wave velocity, density, acoustic impedance and Poisson's ratio in end-member mineral cones were used for qualitative assessment of the extent of alteration of various lithologic units. It can be inferred that hydrothermal alteration has considerably increased P-wave velocity and density of altered argillite and felsic volcanic rocks in comparison to their corresponding unaltered facies. Amphibole, garnet, kyanite, pyrite, sphalerite and staurolite are the dominant end-member alteration minerals affecting seismic rock properties at the VMS site.

  8. Clay 2001 dossier: progress report on feasibility studies and research into deep geological disposal of high-level, long-lived waste; Dossier 2001 argile: sur l'avancement des etudes et recherches relatives a la faisabilite d'un stockage de dechets a haute activite et a vie longue en formation geologique profonde

    Energy Technology Data Exchange (ETDEWEB)



    A French Act of Parliament passed on 30 December 1991 set out the main areas of research required to prepare solutions for the long-term management of high-level, long-lived radioactive waste. The three avenues of research listed in the Act included a feasibility study of the deep geological disposal of these waste, with responsibility for steering the study given to ANDRA, France National Agency for Radioactive Waste Management. Following government decisions taken in 1998, the study focused on two types of geological medium, clay and granite. The clay formations study is essentially based on results from an underground laboratory sited at the border between the Meuse and Haute-Marne departments, where the Callovo-Oxfordian argillite beds are being investigated. No site has yet been chosen for an underground laboratory for the granite study, so for the time being this will draw on generic work and on research carried out in laboratories outside France. ANDRA has decided to present an initial report on the results of its research programme, publishing a dossier on the work on clay formations in 2001 with a second dossier covering the work on granite due for release in 2002. This dossier is thus a review of the work carried out by ANDRA on the feasibility study into a radioactive waste repository in a clay formation. It represents one step in a process of studies and research work leading up to the submission of a report due in 2005 containing ANDRA conclusions on the feasibility of a repository in the clay formation. (author)

  9. Landscape evolution in relation with occurrence of gravitational slope deformation and catastrophic landslides (United States)

    Tsou, Ching-Ying; Chigira, Masahiro; Matsushi, Yuki; Chen, Su-Chin


    The Central Range of Taiwan is an example of a tectonically active orogen. The topography of a mountainous catchment of the Dahan River in northern side of the Central Range exhibits V-shaped inner valleys where landsliding is the dominant process of hillslope erosion and bedrock rivers are incising into the landscape. We take two approaches including (i) the study of present day morphostructural features of gravitationally deformed slopes and (ii) the study of the relationship between the gravitational slope deformation and fluvial incision to research the linkage of gravitational slope deformations, catastrophic landslides, and landscape evolution for the prediction of potential sites of future landslides. Mapped deep-seated gravitational slope deformations and scars of rainfall-induced rock/debris avalanches imply that their distributions are closely related to three series of convex slope breaks relating to the rejuvenation of topography by a three-phase fluvial incision leaded by three series of knickpoints migration. Many shallow rock/debris avalanches have occurred below the lowest slope break. By contrast, majority of gravitational slope deformations have occurred at the margins of the highest slope break around the paleosurface remnants, suggesting that the rejuvenation caused debuttressing of hillslopes and subsequent stress-release led to large scale slope destabilization, resulting in gravitational slope deformations. Catastrophic landslides in many locations deem to be preceded by gravitational slope deformation of rocks with adverse geological structures, many of which are buckling of alternating beds of sandstone and mudstone, and toppling of argillite and slate. The gravitationally deformed slopes change the topography and remain for a long time, and commonly accompany with some other types of mass movements (e.g. debris flows, rock/debris avalanches, and rockfalls). The results suggest that landslides are strongly controlled by geomorphology and

  10. Summary of national and international fuel cycle and radioactive waste management programs, 1984

    Energy Technology Data Exchange (ETDEWEB)

    Harmon, K.M.; Lakey, L.T.; Leigh, I.W.


    Worldwide activities related to nuclear fuel cycle and radioactive waste management programs are summarized. Several trends have developed in waste management strategy: All countries having to dispose of reprocessing wastes plan on conversion of the high-level waste (HLW) stream to a borosilicate glass and eventual emplacement of the glass logs, suitably packaged, in a deep geologic repository. Countries that must deal with plutonium-contaminated waste emphasize pluonium recovery, volume reduction and fixation in cement or bitumen in their treatment plans and expect to use deep geologic repositories for final disposal. Commercially available, classical engineering processing are being used worldwide to treat and immobilize low- and intermediate-level wastes (LLW, ILW); disposal to surface structures, shallow-land burial and deep-underground repositories, such as played-out mines, is being done widely with no obvious technical problems. Many countries have established extensive programs to prepare for construction and operation of geologic repositories. Geologic media being studied fall into three main classes: argillites (clay or shale); crystalline rock (granite, basalt, gneiss or gabbro); and evaporates (salt formations). Most nations plan to allow 30 years or longer between discharge of fuel from the reactor and emplacement of HLW or spent fuel is a repository to permit thermal and radioactive decay. Most repository designs are based on the mined-gallery concept, placing waste or spent fuel packages into shallow holes in the floor of the gallery. Many countries have established extensive and costly programs of site evaluation, repository development and safety assessment. Two other waste management problems are the subject of major R and D programs in several countries: stabilization of uranium mill tailing piles; and immobilization or disposal of contaminated nuclear facilities, namely reactors, fuel cycle plants and R and D laboratories.

  11. Structural evolution of lamprophyric dikes in Lailai, northeastern coast of Taiwan, deduced from mesoscopic structures in dikes and country rocks (United States)

    You, Cian-Siang; Huang, Wen-Jeng; Lo, Wei; Wang, Tzu-Bin; Chen, Chien-Chih


    Lamprophyric dikes are standing in right-stepping en echelon up to 2.3 meters high within the Oligocene Tatungshan formation on the Lai-Lai wave-cut platform in the northeastern coast of Taiwan. The marine platform composed mainly of argillite is the extension of Hsuehshan range, which has the tallest peak of 3,886 m high in Taiwan. The dikes formed at depth in the late Miocene of 9±1.1 Ma ago are exposed on the marine platform nowadays due to the exhumation and Penglai orogeny resulting from the collision of Eurasian plate and Philippine Sea plate, which began in Pleistocene of 5-6 Ma ago. In consequence, folds, faults, joints and other structures are associated with them. In this study, the distribution of the dikes and fractures were mapped by conducting accurate surveys with a total station theodolite and orthorectifying aerial images taken by an unmanned aerial vehicle in different elevations. Electrical resistivity exploration was performed to decipher the arrangement of the dikes underground and the characteristics of the faults. The associated mesoscopic structures were delineated by mapping at a scale of 1: 40 in the field. We infer that the dikes was formed at depth of approximately 2.4 kilometers according to the thickness of overlaying sedimentary rocks formed from late Oligocene to late Miocene. Thus, it excludes the possibility that fractures existed before the lamprophyric magma intruded into the country rocks. Our observations help restore the original status of the current 19 dike segments. We conclude that the lamprophyric magma forcedly and vertically intruded into the Oligocene rocks and the direction change of maximum principle stress at depth of 2.4 kilometers resulted in three or more right-stepping en-echelon dikes.

  12. Generic Crystalline Disposal Reference Case

    Energy Technology Data Exchange (ETDEWEB)

    Painter, Scott Leroy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chu, Shaoping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Harp, Dylan Robert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Perry, Frank Vinton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    A generic reference case for disposal of spent nuclear fuel and high-level radioactive waste in crystalline rock is outlined. The generic cases are intended to support development of disposal system modeling capability by establishing relevant baseline conditions and parameters. Establishment of a generic reference case requires that the emplacement concept, waste inventory, waste form, waste package, backfill/buffer properties, EBS failure scenarios, host rock properties, and biosphere be specified. The focus in this report is on those elements that are unique to crystalline disposal, especially the geosphere representation. Three emplacement concepts are suggested for further analyses: a waste packages containing 4 PWR assemblies emplaced in boreholes in the floors of tunnels (KBS-3 concept), a 12-assembly waste package emplaced in tunnels, and a 32-assembly dual purpose canister emplaced in tunnels. In addition, three failure scenarios were suggested for future use: a nominal scenario involving corrosion of the waste package in the tunnel emplacement concepts, a manufacturing defect scenario applicable to the KBS-3 concept, and a disruptive glaciation scenario applicable to both emplacement concepts. The computational approaches required to analyze EBS failure and transport processes in a crystalline rock repository are similar to those of argillite/shale, with the most significant difference being that the EBS in a crystalline rock repository will likely experience highly heterogeneous flow rates, which should be represented in the model. The computational approaches required to analyze radionuclide transport in the natural system are very different because of the highly channelized nature of fracture flow. Computational workflows tailored to crystalline rock based on discrete transport pathways extracted from discrete fracture network models are recommended.

  13. A closely-spaced magnetotelluric study of the Ahuachapan-Chipilapa geothermal field, El Salvador

    Energy Technology Data Exchange (ETDEWEB)

    Romo, Jose Manuel; Flores, Carlos; Vega, Raymundo; Vazquez, Rogelio; Flores, Marco A. Perez; Trevino, Enrique Gomez; Esparza, Francisco J.; Garcia, Victor H. [Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Baja California (Mexico); Quijano, Julio E. [Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL), Santa Tecla (El Salvador)


    The distribution of electrical conductivity beneath the Ahuachapan-Chipilapa geothermal area was simulated using 2-D models based on 126 closely-spaced magnetotelluric (MT) measurements. The observed MT response was interpreted as being produced by the superposition of two orthogonal geological structural systems: an approximately E-W regional trend associated with the Central Graben structure, which affects the loner period response, and a local and younger N-S fault system that is responsible for the short-to-intermediate period data. The MT response in the 0.02-10 s range period was used to simulate the conductivity structure within the first 2 km depth. By correlating the low-resistivity zones between twelve 2-D models, maps of the spatial distribution of conductors at three different depth levels were constructed. Three deep conductors were identified, one of the associated with the Ahuachapan reservoir, another apparently related to the Laguna Verde volcano, and a third one controlled by El Tortuguero Graben. The subsurface geometry of these conductivity anomalies suggests that the the Chipilapa and La Labor hot springs are supplied by two separate sources of hot fluids, one coming from the east and the other from the south or southwest. The distribution of the shallow high-conductivity zones agrees with the hydrothermal alteration zones mapped at the surface, suggesting that at shallow levels the argillitization process contributes significantly to the low resistivity. The large number of drillholes and the dense MT site coverage allowed the definition of important correlations between high temperatures and high conductivity, as well as between deep conductivity anomalies and productive wells. On this basis two years for future drilling are proposed. (Author)

  14. Relationship Between Pre-failure and Post-failure Mechanical Properties of Rock Material of Different Origin (United States)

    Tutluoğlu, Levent; Öge, İbrahim Ferid; Karpuz, Celal


    Under compression, gathering data related to the post-failure part of the stress-strain curve requires stiff servo-controlled testing systems. In unconfined conditions, data related to the post-peak region of the intact rock parameters are not common as pre-peak and peak state parameters of stress-strain behavior. For problems involving rock in the failed state around structures, proper choice of plastic constitutive laws and post-failure parameters is important for the modeling of the failed state. The aim is to relate commonly used intact rock parameters of pre-failure (tangent modulus E i and secant modulus E s) and peak strength ( σ ci) states to parameters of the post-failure state under unconfined compression. Post-failure parameters are the drop modulus ( D pf), representing the slope of the falling portion in brittle state, residual strength ( σ cr), and dilatancy angle ( ψ°). Complete stress-strain curves were generated for various intact rock of different origin. Seventy-three post-failure tests were conducted. Samples included in the testing program were chosen to represent rocks of different origin. Specimens of granite, rhyodacite, dunite, quartzite series, glauberite, argillite, marl, and lignite were used in the tests. The results from the pre-failure and peak state testing parts were processed and compared to the post-failure stress-strain parameters. For the estimation of post-failure parameters in terms of the pre-peak and peak states, the functional relations were assessed. It was found that the drop modulus D pf increases with rock strength σ ci, following a power function with an approximate power of two. With an exponential trend, the D pf/ E s ratio increases with decreasing E i/ σ ci ratio. Relations estimating the residual strength and dilatancy from the pre-peak and peak state parameters are in logarithmic and exponential functional forms, respectively.

  15. Modeling the Hydrogeochemical Transport of Radionuclides through Engineered Barriers System in the Proposed LLW Disposal Site of Taiwan - 12082

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wen-Sheng [Hydrotech Research Institute, National Taiwan University, Taipei, Taiwan (China); Liu, Chen-Wuing; Tsao, Jui-Hsuan [Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan (China); Li, Ming-Hsu [Institute of Hydrological and Oceanic Sciences, National Central University, Jhongli, Taiwan (China)


    A proposed site for final disposal of low-level radioactive waste located in Daren Township of Taitung County along the southeastern coast has been on the selected list in Taiwan. The geology of the Daren site consists of argillite and meta-sedimentary rocks. A mined cavern design with a tunnel system of 500 m below the surface is proposed. Concrete is used as the main confinement material for the engineered barrier. To investigate the hydrogeochemical transport of radionuclides through engineered barriers system, HYDROGEOCHEM5.0 model was applied to simulate the complex chemical interactions among radionuclides, the cement minerals of the concrete, groundwater flow, and transport in the proposed site. The simulation results showed that the engineered barriers system with the side ditch efficiently drained the ground water and lowered the concentration of the concrete degradation induced species (e.g., hydrogen ion, sulfate, and chloride). The velocity of groundwater observed at side ditch gradually decreased with time due to the fouling of pore space by the mineral formation of ettringite and thaumasite. The short half-life of Co-60, Sr-90 and Cs-137 significantly reduced the concentrations, whereas the long half-life of I-129(1.57x10{sup 7} years) and Am-241(432 years) remain stable concentrations at the interface of waste canister and concrete barrier after 300 years. The mineral saturation index (SI) was much less than zero due to the low aqueous concentration of radionuclide, so that the precipitation formation of Co-60, Sr-90, I-129, Cs-137 and Am-241 related minerals were not found. The effect of adsorption/desorption (i.e., surface complexation model) could be a crucial geochemical mechanism for the modeling of liquid-solid phase behavior of radionuclide in geochemically dynamic environments. Moreover, the development of advanced numerical models that are coupled with hydrogeochemical transport and dose assessment of radionuclide is required in the future

  16. Analysis of the phenomenon of material expansiveness in tunnels built in anhydrite. Outcomes and experiences

    Directory of Open Access Journals (Sweden)

    del Campo, J. M.


    Full Text Available The serious geotechnical problems arising in many tunnels bored in material giving rise to stability problems as a result of being expansive, makes the water channelizers. These are materials which are easily washed with sulphates dissolving with water causing the massif to become decompressed and to remould, aggravating and transferring the problem beyond the tunnel’s immediate environment. In the particular case of layers of anhydrite between argillite, it also happens that the primary support and subsequent lining must have exceptional strength to resist the pressures the terrain may transmit in the medium to long term. This article describes the most relevant aspects of the hydromechanical behaviour of sulphated soil and rock and presents some experiments, concluding with various aspects associated to the phenomenon of swelling in tunnels and its possible treatment.

    Los graves problemas geotécnicos sucedidos en numerosos túneles europeos excavados en materiales que generan problemas de estabilidad, como consecuencia de su expansividad, los convierten en canalizadores de aguas. Estos materiales son fácilmente lavables al disolverse los sulfatos con el agua, provocando una decompresión y remoldeo del macizo, agravando y trasladando el problema más allá del inmediato entorno del túnel. En el caso particular de presencia de capas de anhidrita entre argilitas, además de la adopción de medidas de sostenimiento y revestimiento especiales, el sostenimiento primario y el revestimiento posterior deben ser excepcionalmente resistentes a las presiones que pueden llegar a transmitir el terreno a medio y largo plazo. En este artículo se describen los aspectos más relevantes de comportamiento hidromecánico de los suelos y las rocas sulfatadas y se presentan algunas experiencias, concluyendo sobre aspectos asociados al fenómeno de hinchamiento en túneles y su posible tratamiento.

  17. Pedogenetic processes and carbon budgets in soils of Queretaro, Mexico (United States)

    García Calderón, Norma Eugenia; Fuentes Romero, Elizabeth; Hernandez Silva, Gilberto


    Pedogenetic processes have been investigated in two different physiographic regions of the state of Querétaro in order to assess the carbon budget of soils, looking into the gains and losses of organic and inorganic carbon: In the mountain region of the natural reserve Sierra Gorda (SG) with soils developed on cretaceous argillites and shales under sub-humid temperate to semi-arid conditions, and in the Transmexican Volcanic Belt (TMVB) with soils developed on acid and intermediate igneous rocks under humid temperate climate in the highlands and semi-arid and subhumid subtropical conditions in the lowlands. The analyses of soil organic carbon (SOC) and soil inorganic carbon (SIC) of the SG region, including additional physical, chemical and mineralogical investigations were based on 103 topsoils in an area of 170 km2. The analyses in the TMVB region were based on the profiles of a soil toposequence from high mountainous positions down to the plains of the lowlands. The results show a SOC accumulation from temperate to semi-arid forest environments, based on processes of humification and clay formation including the influence of exchangeable Ca and the quantity and quality of clay minerals. The turnover rates of SOC and SIC depended largely on the rock parent materials, especially the presence of carbonate rocks. Moreover, we found that the SOC content and distribution was clearly depending on land use, decreasing from forests to agricultural land, such as pasture and cropping areas and were lowest under mining sites. The highest SIC pools were found in accumulation horizons of soils under semi-arid conditions. On all investigated sites SOC decreased the mobility of cations and especially that of heavy metals, such as As, Hg, Sb, Pb, and Cd.

  18. Experimental Simulation of Meteorite Ablation during Earth Entry using a Plasma Wind Tunnel (United States)

    Loehle, Stefan; Zander, Fabian; Hermann, Tobias; Eberhart, Martin; Meindl, Arne; Oefele, Rainer; Vaubaillon, Jeremie; Colas, Francois; Vernazza, Pierre; Drouard, Alexis; Gattacceca, Jerome


    Three different types of rocks were tested in a high enthalpy air plasma flow. Two terrestrial rocks, basalt and argillite, and an ordinary chondrite, with a 10 mm diameter cylindrical shape were tested in order to observe decomposition, potential fragmentation, and spectral signature. The goal was to simulate meteoroid ablation to interpret meteor observation and compare these observations with ground based measurements. The test flow with a local mass-specific enthalpy of 70 MJ kg‑1 results in a surface heat flux at the meteorite fragment surface of approximately 16 MW m‑2. The stagnation pressure is 24 hPa, which corresponds to a flight condition in the upper atmosphere around 80 km assuming an entry velocity of 10 km s‑1. Five different diagnostic methods were applied simultaneously to characterize the meteorite fragmentation and destruction in the ground test: short exposure photography, regular video, high-speed imaging with 10 kHz frame rate, thermography, and Echelle emission spectroscopy. This is the first time that comprehensive testing of various meteorite fragments under the same flow condition was conducted. The data sets indeed show typical meteorite ablation behavior. The cylindrically shaped fragments melt and evaporate within about 4 s. The spectral data allow the identification of the material from the spectra which is of particular importance for future spectroscopic meteor observations. For the tested ordinary chondrite sample a comparison to an observed meteor spectra shows good agreement. The present data show that this testing methodology reproduces the ablation phenomena of meteoritic material alongside the corresponding spectral signatures.

  19. Modeling of excavation induced coupled hydraulic-mechanical processes in claystone

    Energy Technology Data Exchange (ETDEWEB)

    Massmann, Jobst


    Concepts for the numerical modeling of excavation induced processes in claystone are investigated. The study has been motivated by the international discussion on the adequacy of claystone as a potential host rock for a final repository of radioactive waste. The processes, which could impact the safety of such a repository, are manifold and strongly interacting. Thus, a multiphysics approach is needed, regarding solid mechanics and fluid mechanics within a geological context. A coupled modeling concept is therefore indispensable. Based on observations and measurements at an argillaceous test site (the underground laboratory Tournemire, operated by the Institute of Radioprotection and Nuclear Safety, France) the modeling concept is developed. Two main processes constitute the basis of the applied model: deformation (linear elasticity considering damage) and fluid flow (unsaturated one-phase flow). Several coupling phenomena are considered: Terzaghi 's effective stress concept, mass conservation of the liquid in a deformable porous media, drying induced shrinkage, and a permeability which depends on deformation and damage. In addition, transversely isotropic material behavior is considered. The numerical simulations are done with the finite element code RockFlow, which is extended to include: an orthotropic non-linear shrinkage model, a continuum damage model, and an orthotropic permeability model. For these new methods the theory and a literature review are presented, followed by applications, which illustrate the capability to model excavation induced processes in principle. In a comprehensive case study, the modeling concept is used to simulate the response of the Tournemire argillite to excavation. The results are compared with observations and measurements of three different excavations (century old tunnel, two galleries excavated in 1996 and 2003). In summary, it can be concluded that the developed model concept provides a prediction of the excavation

  20. Bedrock geologic map of the northern Alaska Peninsula area, southwestern Alaska (United States)

    Wilson, Frederic H.; Blodgett, Robert B.; Blome, Charles D.; Mohadjer, Solmaz; Preller, Cindi C.; Klimasauskas, Edward P.; Gamble, Bruce M.; Coonrad, Warren L.


    The northern Alaska Peninsula is a region of transition from the classic magmatic arc geology of the Alaska Peninsula to a Proterozoic and early Paleozoic carbonate platform and then to the poorly understood, tectonically complex sedimentary basins of southwestern Alaska. Physiographically, the region ranges from the high glaciated mountains of the Alaska-Aleutian Range to the coastal lowlands of Cook Inlet on the east and Bristol Bay on the southwest. The lower Ahklun Mountains and finger lakes on the west side of the map area show strong effects from glaciation. Structurally, a number of major faults cut the map area. Most important of these are the Bruin Bay Fault that parallels the coast of Cook Inlet, the Lake Clark Fault that cuts diagonally northeast to southwest across the eastern part of the map area, and the presently active Holitna Fault to the northwest that cuts surficial deposits.Distinctive rock packages assigned to three provinces are overlain by younger sedimentary rocks and intruded by widely dispersed latest Cretaceous and (or) early Tertiary granitic rocks. Much of the east half of the map area lies in the Alaska-Aleutian Range province; the Jurassic to Tertiary Alaska-Aleutian Range batholith and derivative Jurassic sedimentary rocks form the core of this province, which is intruded and overlain by the Aleutian magmatic arc. The Lime Hills province, the carbonate platform, occurs in the north-central part of the map area. The Paleozoic and Mesozoic Ahklun Mountains province in the western part of the map area includes abundant chert, argillite, and graywacke and lesser limestone, basalt, and tectonic mélange. The Kuskokwim Group, an Upper Cretaceous turbidite sequence, is extensively exposed and bounds all three provinces in the west-central part of the map area.

  1. Petrology, Magnetic susceptibility, Tectonic setting and mineralization associated with Plutonic and Volcanic Rocks, Eastern Bajestan and Taherabad, Iran

    Directory of Open Access Journals (Sweden)

    Malihe Ghoorchi


    Full Text Available Study area is located in district of Bajestan and Ferdows cities, NE of Iran. Structurally, this area is part of Lut block. The oldest exposed rocks, to the north of intrusive rocks and in Eastern Bajestan, are meta-chert, slate, quartzite, thin-bedded crystalline limestone and meta-argillite. The sedimentary units are: Sardar Formation (Carboniferous, Jamal Formation (Permian, Sorkh Shale and Shotori Formations (Triassic, carbonateous rocks (Cretaceous and lithostratigraphically equivalent to Kerman conglomerate (Cretaceous-Paleocene are exposed in this area. Based on relative age, magmatism in eastern Bajestan and Taherabad started after Late Cretaceous and it has been active and repeated during Tertiary time. At least, three episodes of volcanic activities are recognized in this area. The first stage was mainly volcanic flow with mafic composition and minor intermediate. The second episode was mainly intermediate in composition. The third stage was changed to acid-intermediate in composition. Since the plutonic rocks intruded the volcanic rocks, therefore they may be Oligo-Miocene age. Bajestan intrusive rocks are granite-granodiorite-quartz monzonite. Taherabad intrusive rocks are diorite-quartz diorite- monzonite-latite. Bajestan intrusive rocks are reduced type (ilmenite series and Taherabad intrusive rocks are oxidized type (magnetite series.Based on geochemical analysis including trace elements, REE and isotopic data, Bajestan intrusive rocks formed in continental collision zone and the magma has crustal origin. Taherabad intrusive rocks were formed in subduction zone and magma originated from oceanic crust. Taherabad intrusive rock has exploration potential for Cu-Au and pb.

  2. DECOVALEX-THMC Project. Task C. Excavation Damaged Zone (EDZ) in argillaceous rock at Tournemire site (France). Report of Task C1

    Energy Technology Data Exchange (ETDEWEB)

    Rejeb, A. (comp.) [Inst. of Radioprotection and Nuclear Safety (France); Stephansson, O. (comp.) [GeoForschungsZentrum-Potsdam (Germany); Millard, A. [CEA/IRSN (France); Ziefle, G.; Kohlmeier, M.; Massmann, J.; Zielke, W. [ISEB/BGR (Germany); Uehara, S.; Kobayashi, A.; Chijimatsu, M.; Fujita, T. [KU/JAEA (Japan)


    rocks and in particular the stress field, mechanical properties and hydraulic properties. Thereafter, the EDZ characterization from geological mapping and permeability measurements are presented. The EDZ in the 100 years old tunnel drilled manually and with its reinforcement of limestone blocks is very different from the EDZ observed in drifts excavated with road-headers 3 and 10 years ago. Numerical models have to be developed to predict the extent of the EDZ around the tunnel. The CEA/IRSN team contribution to Task C1 concerns three calculations: a pure mechanical calculation, a coupled hydro-mechanical calculation with saturated rock, and coupled hydro-mechanical calculation with unsaturated rock. The EDZ around the tunnel has been estimated on the basis of a post-processing of the stress calculations, using Mohr-Coulomb failure criterion. These calculations were performed by using the CEA finite element code CASTEM, which can simulate fully coupled THM processes. All the results from the calculations show that an EDZ around the tunnel can only be predicted if we consider mechanical rock properties lower than those measured in laboratory. However, none of the predictions provided the shape and the real extent of the observed EDZ in the tunnel. The evaluation of the EDZ by a simple post-processing technique does not account for the irreversible effect of damage on the mechanical as well as hydraulic behaviour of the argillite. The ISEB/BGR team performed the simulations by using the finite element code Rock Flow. The team simulated three cases where the influence of capillary pressure shows that a change of saturation at the boundary of the tunnel influences an area around the tunnel with time. In the near field of the tunnel, the effect of seasonal fluctuation is high. This result is influenced by the boundary conditions, the permeability and the relation between the capillary pressure and the saturation. Case 2 incorporates the swelling or shrinking of the argillite

  3. 2005 dossier. ANDRA's researches on the geological disposal of high-level and long-lived radioactive wastes. Results and perspectives; Dossier 2005. Les recherches de l'Andra sur le stockage geologique des dechets radioactifs a haute activite et a vie longue. Resultats et perspectives

    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 geologic disposal of high-level and long-lived radioactive wastes in deep geologic formations (argilites and granites). Content: 1 - Research on deep disposal of radioactive waste: general interest task: Legislative framework, ANDRA scientific objectives, Inspections and assessments; 2 - Designing a safe and reversible disposal system: Repository safety, Reversibility: an essential requirement; 3 - Clay Research on a repository in a clay formation, A long research programme, Dossier 2005 Argile; 4 - Meuse/Haute-Marne site clay: Expected properties of the rock formation, Choice of argillite, Meuse/Haute-Marne site, Conclusions from 10 years of research at the Meuse/Haute-Marne site; 5 - Repository installations: Safe and reversible architecture, Disposal of B waste, Disposal of C waste, Possible disposal of spent fuel (CU); 6 - The disposal facility in operation: From waste packages reception to their disposal in cells, Stages of the progressive closure of engineered structures; 7 - Reversible management: Freedom of choice for future generations, Various closure stages; 8 - Long-term evolution of the repository: Apprehending the repository complexity Main evolutions expected, Slow and limited release of radioactive substances; 9 - Repository safety and impact on man: Several evolution scenarios, Normal evolution, Altered evolution; 10 - Granite Research on a repository in a granite formation: A global approach, Scientific co-operations, Dossier 2005 Granite; 11 - Characteristics of French granite formations: What properties are required for a repository?, Different types of granite formations; 12 - Repository installations: Repository design adapted to granite fractures, Clay seals to prevent water flows, Waste disposal packages ensuring long-term leak-tightness, Physical and chemical environment favourable for waste packages, Architecture

  4. Crustal shortening followed by extensional collapse of the Cordilleran orogenic belt in northwestern Montana: Evidence from vintage seismic reflection profiles acquired in the Swan Range and Swan Valley (United States)

    Rutherford, B. S.; Speece, M. A.; Stickney, M. C.; Mosolf, J. G.


    Reprocessing of one 24-fold (96 channel) and four 30-fold (120 channel) 2D seismic reflection profiles have revealed crustal scale reflections in the Swan Range and adjacent Swan River Valley of northwestern Montana. The five reprocessed profiles constitute 142.6 of the 303.3 linear km acquired in 1983-84 by Techo of Denver, Colorado. The four 30-fold profiles used helicopter-assisted dynamite shooting (Poulter method) and the 24-fold profile used the Vibroseis method. Acquisition parameters were state of the art for the time. The Swan Range lies east of the Rocky Mountain Trench and is part of the Cordilleran foreland thrust belt where the Lewis thrust system emplaced a thick slab of Proterozoic Belt Supergroup strata eastward and over Paleozoic and Mesozoic rocks during the Late Cretaceous to early Paleocene Laramide orogeny. Deeply drilled borehole data are absent within the study area; however, we generated a synthetic seismogram from the Arco-Marathon 1 Paul Gibbs well (total depth=5418 m), located approximately 70 km west of the reprocessed profiles, and correlated the well data to surface seismic profiles. Large impedance contrasts in the log data are interpreted to be tholeiitic Moyie sills within the Prichard Formation argillite (Lower Belt), which produce strong reflection events in regional seismic sections and result in highly reflective, east-dipping events in the reprocessed profiles. We estimate a depth of 10 km (3 to 3.5 seconds) to the basal detachment of the Lewis thrust sheet. The décollement lies within Belt Supergroup strata to the west of the Swan River Valley before contacting unreflective, west-dipping crystalline basement beneath the Swan Range--a geometry that results in a wedge of eastward-thinning, autochthonous Belt rocks. Distinct fault-plane signatures from the west-dipping, range-bounding Swan fault--produced by extensional collapse of the over-thickened Cordillera--are not successfully imaged. However, reflections from Cenozoic

  5. Magnetic Properties of Oil-gas-bearing Rocks of The Central Part of Dniper-donetsk Trough (United States)

    Kuderavets, R.; Maksymchuk, V.; Gorodisky, Y.

    Small amplitude positive local delta F anomalies were revealed by the results of high- accuracy magnetic prospecting in the Dniper-Donets trought over a series of oil-gas- bearing structures. Their nature can be explained by lithofacial and epigenetic rock magnetic variations in the oxidized-reduced zones of carbon deposits. Though, there is no trustable experimental data on magnetic properties of rocks in these zones. To study peculiarities of lateral and vertical magnetic perceptability, mineral rock com- position distribution within oil-gas-bearing areas in Dniper-Donetsk trough a series of investigations of these characteristics have been conducted for productive and un- productive holes. In general, the magnetic perceptability of core from 19 holes, near oil-gas deposits and far from theirs as well were determined. A statistic analysis of the obfained cappa values was done, rock mineral composition in some holes was de- termined. The results make it possible to conclude: 1. The cut is composed mainly of terrigenous rocks and is characterized by a slight differentiation by the magnetic perceptability (0-150x10E-5Si) 2. Small values of rock magnetic perceptability (1- 3x10E-5Si) and dispersion for low Visean substage of low carbon with which oil-gas- bearing of the region under study is closely connected were determined. 3. Statistic analysis proved the existence of some types of cappa distribution within the hole in particular it differs within productive and unproductive formations. 4. Larger values of cappa and their dispersion in comparison with analogical deposits in productive formations, were revealed. 5. A series of secondary epigenic minerals: quartz, kaoli- nite, aragonite, ankerite, dolomite, pirite, hematite, siderite was determined in the de- posit zone and out of it. The largest amount of ironminerals (ankerite, pirite, hematite, siderite) was found in terrigeneous rocks (argillite) located over and under carbon de- posits. The analysis of the


    Directory of Open Access Journals (Sweden)

    V. G. Bakhmutov


    Full Text Available Paleomagnetic data are the priority source of information for global paleotectonic reconstructions representing horizontal movements of the crustal blocks. Upon receipt of new paleomagnetic data, kinematic models of the East European platform in the Paleozoic are regularly revised and improved. The article presents results of the paleomagnetic study of sedimentary gray-colored and red beds of the Silurian and Lower Devonian sequences located in the Dniester river basin, Podolia region, SW Ukraine. The study covered 17 outcrops that are stratigraphically correlated with the Wenlock, Ludlow, Pridoli states of the Sillurian and the Lochkovian stage of the Devon. Over 400 samples of grey limestone, argillite, dolomite, red limestone and sandstone were analyzed, and two components of natural remnant magnetization (NRM were revealed. The first component with SSW declination and negative inclination is revealed in the majority of the samples during AF- and T-magnetic cleaning. Its pole positions, that are calculated separately for each series, are trending to the Permian segment of the apparent polar wander path (APWP published by Torsvik et al. [2012] for Baltica / Stable Europe. Considering its chemical origin, this NRM component is related to formation of authigenic minerals due to rock remagnetization. The second component is revealed only in some samples taken from the red beds (during thermal demagnetization in the range of unblocking temperatures from 590 to 690 °С and in few samples of grey limestone (in AF fields from 30 to 70 mT or in the range of unblocking temperatures from 300 to 460 °С. This component has SW declination and positive inclination, goes to the origin of coordinates of the diagrams, and has all the indicators of primary magnetization of sediments. Calculated positions of the poles (0 ºS and 329 ºE for grey limestone of the Tiverskaya series, 2.3 °S and 338.4 °E for red beds of the Dniestrovskaya series, etc. are well

  7. Linking Weathering, Rock Moisture Dynamics, Geochemistry, Runoff, Vegetation and Atmospheric Processes through the Critical Zone: Graduate Student led Research at the Eel River Critical Zone Observatory (United States)

    Dietrich, W. E.


    In the Eel River Critical Zone Observatory lies Rivendell, a heavily-instrumented steep forested hillslope underlain by nearly vertically dipping argillite interbedded with sandstone. Under this convex hillslope lies "Zb", the transition to fresh bedrock, which varies from less than 6 m below the surface near the channel to 20 m at the divide. Rempe and Dietrich (2014, PNAS) show that the Zb profile can be predicted from the assumption that weathering occurs when drainage is induced in the uplifting fresh bedrock under hillslopes by lateral head gradients driven by channel incision at the hillslope boundary. Infiltrating winter precipitation is impeded at the lower conductivity boundary at Zb, generating perched groundwater that dynamically pulses water laterally to the channel, controlling stream runoff. Below the soil and above the water table lies an unsaturated zone through which all recharge to the perched groundwater (and thus all runoff to channels) occurs. It is this zone and the waters in them that profoundly affect critical zone processes. In our seasonally dry environment, the first rains penetrate past the soil and moisten the underlying weathered bedrock (Salve et al., 2012, WRR). It takes about 200 to 400 mm of cumulative rain, however, before the underlying groundwater rises significantly. Oshun et al (in review) show that by this cumulative rainfall the average of the wide-ranging isotopic signature of rain reaches a nearly constant average annual value. Consequently, the recharging perched groundwater shows only minor temporal isotopic variation. Kim et al, (2014, GCA) find that the winter high-flow groundwater chemistry is controlled by relatively fast-reacting cation exchange processes, likely occurring in transit in the unsaturated zone. Oshun also demonstrates that the Douglas fir rely on this rock moisture as a water source, while the broadleaf trees (oaks and madrone) use mostly soil moisture. Link et al (2014 WRR) show that Doug fir declines

  8. Excavation damaged zone

    Energy Technology Data Exchange (ETDEWEB)

    Poulain, S.; Sergeant, C.; Vesvres, M.H.; Simonoff, M.; Lavielle, B.; Thomas, B.; Gilabert, E. [Bordeaux-1 Univ., I and 2/CNRS and GdR FORPRO 0788, Nuclear Analytical and Bioenvironmental Chemistry 33 - Gradignan (France); Poulain, S.; Altmann, S.; Lenoir, N.; Barnichon, J.D.; Wileveau, Y.; Lebon, P. [ANDRA - Agence Nationale pour la Gestion des Dechets Radioactifs, 92 - Chatenay Malabry (France); Le Marrec, C. [Bordeaux-1 Univ., ISTAB, INRA, UMR Oenologie - ISVV, 33 - Talence (France); Vinsot, A.; Dewonck, S.; Wileveau, Y.; Armand, G.; Cruchaudet, P.; Rebours, H.; Morel, J. [Agence Nationale pour la Gestion des Dechets Radioactifs, Lab. de Souterrain de Meuse/Haute-Marne, 55 - Bure (France); Lanyon, G.W. [Fracture Systems Ltd, Tregurrian, Ayr, St Ives, Cornwall (United Kingdom); Marschall, P.; Vietor, T. [NAGRA - National Cooperative for the Disposal of Radioactive Waste, Wettingen (Switzerland); Bourdeau, C.; Dedecker, F.; Billaux, D. [ITASCA Consultants, S.A.S., 69 - Ecully (France); Lenoir, N.; Desrues, J.; Viggiani, G.; Besuelle, P. [Laboratoire 3S-R - Sols Solides Structures-Risques, 38 - Grenoble (France); Bornert, M. [Ecole Polytechnique, LMS - Lab. de Mecanique des Solides, 91 - Palaiseau (France); Arson, C.; Gatmiri, B. [CERMES, Ecole Nationale des Ponts et Chaussees, 77 - Marne-la-Vallee (France); Gatmiri, B. [University of Tehran (Iran, Islamic Republic of); Bernier, F. [ESV EURIDICE GIE - European Underground Research Infrastructure for Disposal of Nuclear Waste in Clay Environment (Belgium); Nussbaum, C.; Mori, O. [Geotechnical Institute Ltd., Fabrique de Chaux, St-Ursanne (Switzerland); Bossart, P. [Swisstopo - Federal Office of Topography, Wabern (Switzerland); Schuster, K.; Alheid, H.J. [BGR - Bundesanstalt fur Geowissenschaften und Rohstoffe, Hannover (Germany); Lavanchy, J.M.; Croise, J.; Schwarz, R. [Colenco Power Engineering AG, Groundwater Protection and Waste Disposal, Baden (Switzerland)] [and others


    This session gathers 13 articles dealing with: autochthonous and colonizing microorganisms in argillaceous underground environments (S. Poulain, C. Sergeant, C. Le Marrec, M.H. Vesvres, A. Vinsot, S. Dewonck, M. Simonoff, S. Altmann); the discrete fracture network modelling of the Hg-a experiment at the Mont Terri rock Laboratory (G.W. Lanyon, P. Marschall, T. Vietor); the discrete modelling of drift behaviour in the Meuse/Haute-Marne URL, France (C. Bourdeau, F. Dedecker, D. Billaux); the fracturing in Callovo-Oxfordian argillite under triaxial compression studied by X-ray microtomography (N. Lenoir, J. Desrues, G. Viggiani, P. Besuelle, M. Bornert, J.D. Barnichon); a general review of the damage models for the EDZ creation (C. Arson, B. Gatmiri); similarities in the Hydro-Mechanical response of Callovo-Oxfordian clay and Boom clay during gallery excavation (Y. Wileveau, F. Bernier); the different geometries of the EDZ fracture networks in the Mont Terri and Meuse/Haute-Marne rock laboratories: Structural approach (C. Nussbaum, Y. Wileveau, P. Bossart, A. Moeri, G. Armand); the characterisation of the Excavation-Damaged Zone in the Meuse/Haute-Marne Underground Research Laboratory (G. Armand, P. Lebon, M. Cruchaudet, H. Rebours, J. Morel, Y. Wileveau); the EDZ characterisation with ultrasonic interval velocity measurements in the Meuse/Haute-Marne URL, performed between depth of 85 m and 504 m (K. Schuster, H.J. Alheid); the clay formation at the Meuse Haute Marne URL: evaluation of the impact of resin filled slots on flow paths characteristics within the EDZ (J.M. Lavanchy, J. Croise, R. Schwarz, G. Armand, M. Cruchaudet); the characterisation and evolution of EDZ by extraction and analyse of noble gases in pore waters in the Meuse/Haute Marne URL site (B. Lavielle, B. Thomas, E. Gilabert); in-situ gas test for the characterisation of Excavation Disturbed Zone at the Meuse/Haute Marne URL (H. Shao, K. Schuster, J. Soennke, V. Braeuer); and the flow and reactive

  9. The Upper Triassic alkaline magmatism of the western Neo-Tethys (Bajo Ebro, NE Spain): age and geodynamic implications (United States)

    Sanz, T.; Lago, M.; Gil, A.; Pocoví, A.; Galé, C.; Ubide, T.; Larrea, P.; Ramajo, J.; Tierz, P.


    A set of mafic rocks crop out in the north-western margin of the Neo-Tethys (eastern Spain and France). These rocks show three common features: 1) they were emplaced into Upper Triassic sediments (Keuper facies), 2) they are mainly basalts and dolerites and show an alkaline geochemical affinity and 3) these magmas rose to their emplacement level through deep fractures; some of the fractures were newly opened as a result of the Triassic extension (Triassic-Liassic rifting), whereas others had been generated during the Permian extension (Lower Permian rifting) and were reopened. Magmatic activity has also been recognized in these areas during the Jurassic, the Cretaceous and the Quaternary. The Bajo Ebro sector (NE Spain) comprises two types of Upper Triassic mafic rocks: 1) massive rocks emplaced as dikes, sills and basaltic lavas (10-12 meters in thickness and up to kilometric in extension) and 2) a wide range of pyroclasts (from ash grains to bombs) forming layers more than 100 meters thick, which are usually interbedded with argillites and carbonates. Protrusions of the sills into the overlying sediments, together with spilitization of the igneous rocks, suggest that the magmas emplaced into unconsolidated sediments. Furthermore, a level of epiclastic-basaltic breccias is recognized overlying the magmatic levels and below the dolostones of the Imón Formation (Rhaetian in age); these breccias are interpreted to represent an erosive episode which affected the magmatic rocks in emerged areas. According to these criteria, these rocks can be considered Upper Triassic (pre-Rhaetian) in age. The basaltic lavas show alkaline mineral assemblages composed of: olivine (Fo79-65), Ti-rich clinopyroxene (Fs3-15, En52-35, Wo50-42), plagioclase (An80-50), Ti-rich magnetite and apatite. Their major and trace element whole rock compositions show contents in SiO2 (41,3-49,3 w.%), Nb/Y (1,5-4,1), Zr/TiO2 (0,0057-0,013), V (157,8-292,1 ppm) and Ti/1000 (11,3-18,53) which indicate

  10. Caracterização dos argilominerais usados em matéria-prima cerâmica, da formação Rio do Rasto, Bacia do Paraná, no município de Turvo, SC Characterization of clay minerals used in the ceramic industry, from Rio do Rasto formation, Paraná basin, exploitation in Turvo, SC, Brazil

    Directory of Open Access Journals (Sweden)

    J. A. Costa


    Full Text Available No sudeste de Santa Catarina existem inúmeras minas de exploração de argilas destinadas à indústria cerâmica da região. Para o conhecimento desta matéria prima foi realizada a caracterização em detalhe de uma frente de lavra em atividade. A exploração é realizada em terrenos sedimentares da Formação Rio do Rasto (Permiano Superior na Bacia do Paraná que afloram como morros testemunho. Foram coletadas quatorze amostras representativas dos níveis desta mina composta de argilitos com intercalação de siltitos de pequena espessura. As amostras foram analisadas por difratometria de raios X pelo método do pó na rocha total e na fração In the southeastern part of Santa Catarina state, Brazil, many mines of clays used as raw material for the ceramic industry are found. A detail study of this material was developed in a mine in activity. The exploitation of clays is held in sedimentary rocks of Rio do Rasto Formation (Upper Permian in the Paraná Basin. The outcrops are in hills testimonies. Fourteen samples were collected and represent the levels of this mine which consisted of argillites with intercalation of slim siltite layer. These samples were analyzed by X-ray diffraction using the powder method and in the fraction < 4 µm. The chemical composition was determined by X-ray fluorescence spectrometer. Petrographic observations in thin section were also performed. Scanning electron microscope images was obtained in samples fragments by secondary electron method. Electron microprobe microanalysis was performed in one thin section. The results showed large vertical variation in the mineralogy and it has been identified three different levels. Up to 2.00 m there is a predominance of smectite. Between 5.50 m 2.00 m the smectite is the main clay mineral, but with significant amounts of illite/mica and above 5.50 m occurs large increase in K-feldspar and detrital mica. Studies in detail by X-ray diffraction (determination of the b

  11. Determination of the thermal conductivity of opalinus clay via simulations of experiments performed at the Mont Terri underground laboratory (United States)

    Mügler, C.; Filippi, M.; Montarnal, Ph.; Martinez, J.-M.; Wileveau, Y.


    Storage in deep geological formations is a potential solution for the management of high-level radioactive wastes. In this context, different types of rocks such as argillite are extensively studied. In the Mont Terri underground laboratory (Switzerland), several experiments have been performed in order to characterize the properties of the opalinus clay. One of these experiments, called HE-C, has consisted in measuring in situ the time evolution of the rock temperature submitted to a heating source. Experimental measurements have shown that the thermal behaviour of the clay was not homogeneous around the borehole where the heater was installed. Furthermore, 3D direct numerical simulations of this experiment performed with the code Cast3M have proved that it was necessary to introduce a new parameter α to model the amount of electric power lost in cables and by air convection inside the metallic tube containing the heater. A numerical simulation-optimization technique has been used to estimate the thermal longitudinal and transverse conductivities ( λ// and λ⊥) of the host rock. It consists in minimizing an objective function that is the sum of the squared differences between measured and calculated temperatures. But this method induced a lot of Cast3M simulations. In order to drastically reduce the CPU time, we used a neural network approximation built from a sample training of 1100 Cast3M simulations. It allowed us to calculate the objective function for 500 000 different values of the triplet ( λ//, λ⊥, α). Finally, we obtained the following values for the thermal conductivities on one side of the borehole, λ// = 1.84 ± 0.04 W m - 1 K - 1 and λ⊥ = 0.55 ± 0.03 W m - 1 K - 1 ; on the other side, λ// = 1.90 ± 0.07 W m - 1 K - 1 and λ⊥ = 1.07 ± 0.09 W m - 1 K - 1 . The estimated thermal conductivities λ⊥ perpendicular to the bedding plane are quite different. It is perhaps caused by the presence of an intensive fractured zone on one side of

  12. A new challenge: in-situ investigation of the elusive nanostructures in wet halite and clay using BIB/FIB-cryo-SEM methods (United States)

    Desbois, G.; Urai, J. L.


    are able to stabilize the in-situ fluids in grain boundaries or pores, preserve the natural structures at nano scale, produce high quality polished cross-sections for high resolution SEM imaging and reconstruct accurately the grain boundary and the pore space networks in 3D by serial cross sectioning. Our first investigations on wet halite and wet clay materials produced unprecedented high quality images of fully preserved fluid-filled pore space as appear in nature. We have thus validated the use of the FIB/BIB-cryo-SEM technology for the in-situ investigations of the elusive structures in wet geomaterials paving the way towards a fuller understanding of how pore geometry can affect physical properties of rocks. [1] Desbois G. And Urai J.L. (submitted). In-situ morphology of meso-porosity in Boom clay (Mol site, Belgium) inferred by the innovative FIB-cryo-SEM method. E-earth. [2] Desbois G., Urai J.L., Burkhardt C., Drury M., Hayles M. and Humbel B. (2008). Cryogenic vitrification and 3D serial sectioning using high resolution cryo-FIB-SEM technology for brine-filled grain boundaries in halite: first results. Geofluids, 8: 60-72 [3] Esteban L., Géraud Y. And Bouchez J.L. (2006). Pore network geometry in low permeability argillites from magnetic fabric data and oriented mercury injections. Geophysical Research Letters, vol. 33, L18311, doi : 10.1029/2006GL026908. [4] Esteban L., Géraud Y. And Bouchez J.L. (2007). Pore network connectivity anisotropy in Jurassic argillite specimens from eastern Paris Basin (France). Physics and Chemistry of the Earth, 32(1) :161-169. [5] Hildenbrand A., Krooss B. M. and Urai J. L. (2005). Relationship between pore structure and fluid transport in argillaceous rocks. Solid Mechanics and Its Applications, IUTAM Symposium on Physicochemical and Electromechanical Interactions in Porous Media, 125 : 231-237, doi : 10.1007/1-4020-3865-8_26. [6] Hildenbrand A. and Urai J.L. (2003) Investigation of the morphology of pore space in mudstones

  13. Petrography, Geochemistry and Proposed Genesis of Ordovician Oolitic Iron Formation Members of the Lashkarak Formation, Eastern Alborz

    Directory of Open Access Journals (Sweden)

    Mansoore Maghsoudloo Mahalli


    Full Text Available Introduction Oolitic iron formations are sedimentary rocks with >5 vol.% oolites and >15 wt.% iron, corresponding to 21.4 wt.% Fe2O3 (Young, 1989; Petranek and Van Houten, 1997; Mucke and Farshad, 2005. In Iran, new iron oolite-bearing members have been identified in the Lashkarak Formation (lower-middle Ordovician in the Abarsej, Dehmola and Simehkuh sections, eastern Alborz (Ghobadi Pour et al., 2011. At present, the mineralogy and geochemistry of these members are not known. Consequently, research reported here was conducted to reveal the mineralogical and geochemical characteristics of Ordovician oolitic iron formationmembers and to discuss their genesis and economic importance. Materials and Analyses Field geology and sampling was carried out to collect 25 samples from the ooliticiron formation members in the Abarsej, Dehmola and Simehkuh section in eastern Alborz. Samples were prepared for polished-thin sections (n=10, XRD analysis (n=15. Whole-rock chemical analysis (n=15 by XRF for major elements and by ICP-ES for trace elements was performed by laboratories at the SarCheshmeh copper mine complex, Kerman, Iran. One sample was analyzed by SEM at the Wales Museum, UK. Results Microscopic studies show that the oolitic iron formation members are hosted by carbonate argillite rocks. They are mainly composed of oolites rather than pisoliths (small bodies somewhat larger and more irregular than oolites, whereas oolites have mainly ellipsoidal forms and locally spherical shapes. Most (6 oolites show banding with a central core. Simple oolites without a core are scarce. Mineralogically, oolites are mainly chamositic and hematitic in composition; goethite, pyrite and glauconite occur in traces and siderite is absent. Quartz, calcite and zircon are accessory minerals which are present in the groundmass. Geochemically, TFeO % of the oolitic iron formation horizons ranges from 8 to 48 % with an average of 21%. The CaO content ranges from 2 to 37% and

  14. 秦岭山阳水沟口组黑色岩系微量元素地球化学及其沉积成矿背景的指示意义%Trace element geochemical characteristics of the Shuigoukou Formation black rock series in Shanyang area of the Qinling Mountains and their indication significance for sedimentation-mineralization

    Institute of Scientific and Technical Information of China (English)

    王立社; 张复新; 侯俊富; 房波; 周燕


    According to field investigation, it is found that the black rock series of Shuigoukou Formation in Shanyang area of the Qinling Mountains is made up of micritic limestone,carbonaceous argillite, claystone, carbonaceous siliceous argillite, carbonaceous limestone and silicalite. Phosphatic nodule and barite are commonly seen in these rocks. The abundances of rare earth elements and some trace elements such as V,Ni,Co,U,Th in the black rock series were measured using ICP-MS method. Some conclusions have been reached; 1) The average concentrations of ore-forming elements (such as V,Mo,Ni,Ba,Pb,Zn,U,Ag,Cu,Cd,Tl,Bi and Cr) are several times to dozen times higher than their crustal abundances), showing that they are rich in the rock series, especially in silicolites and argilloid. Higher content of trace elements and rare earth elements is closely related to phosphorus,TOC and barium. 2)Different concentrations of rare earth elements are connected with different types of rock. The black rock series is usually of the LPvEE -enriched type. 3) The samples are characterized by slight or intermediate negative Ce anomalies (δ Ce =0.40~1.00) and distinct positive Eu anomalies, exclusively with high δ Eu (>2.1). 4)The ratios of U/Th display a large variation from 0.31 to 28.7, the ratios of w (V) /w (V +Ni) ( 0.51~1) and w (Ni) /w (Co) (4.8~49) are relatively high,the ratios of w (Ce) / w (La) (0.68~1.89) are normal, and the average rate of?w (Co) /w (Zn) is 0.21. According to a comparison of these related parameters of PvEE and trace elements with the available data in the references and the La/Yb- Ce/ La and La/Yb - PvEE diagrams, it is suggested that the black rock series of Shuigoukou Formation was formed in the environment of a dry, anoxic and profundal to semi-profundal faulted depression sea basin belonging to a passive continental margin, with the action of hydrothermal fluids.%通过野外调研发现,秦岭造山带山阳地区水沟口组黑色岩系主要由黑

  15. 云南兰坪盆地西缘脉状铜多金属矿床硫、铅同位素组成及成矿示踪%Sulfur and lead isotope compositions and tracing of copper deposits on the western border of the Lanping Basin, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    张锦让; 温汉捷


    云南兰坪盆地西缘脉状铜多金属矿床主要赋存于由砂岩、粉砂岩和页岩组成的碎屑岩建造中.为了查明兰坪盆地西缘脉状铜多金属矿床成矿物质来源,对盆地西缘四个典型脉状铜多金属矿床(科登涧、连城、金满和水泄)的硫、铅同位素的组成进行了分析和对比研究.结果表明,这些矿床的铅同位素组成总体变化较小,且大部分落在盆地沉积地层铅范围内,金满、连城铜矿床可能有部分深源铅的加入.硫同位素特征表明,兰坪盆地西缘脉状铜多金属矿床的硫主要来源于地层硫酸盐的还原作用,其中金满铜矿床和连城铜钼多金属矿床可能有深源硫的混入.各矿床硫同位素不同的特点,除反映各矿床源区硫同位素组成的差异外,可能还与各矿床成矿时不同的物理化学条件(温度、氧逸度、pH值和离子强度等)差异有关.%A large number of vein-type Cu-polymetallic deposits were developed on the western border of the Lanping Basin in western Yunnan Province, which constituted an important Cu-polymetallic mineralization belt. These deposits are hosted in clastic rocks (sandstone, siltite and argillite) of Mesozoic and Cenozoic formation. In order to trace source of ore-forming materials of these deposits, four representative deposits (Jinman, Shuixie, Kedengjian and Liancheng) were selected to analyze sulfur and lead isotopic compositions. Pb isotopic compositions show very narrow variations and mostly fall within the range of the sedimentary rock lead, suggesting that lead in these vein-type Cu-polymetallic deposits is mostly derived from the basement of the basin. However, the Jinman and Liancheng deposits may have deep sources of lead with different Pb isotopic composition. Sulfur isotope analysis show that the reduced sulfur of these vein-type Cu-polymetallic deposits mainly come from the strata sulfate. However, like Pb isotopes, the Jinman and Liancheng deposits have more

  16. Raw materials exploitation in Prehistory of Georgia: sourcing, processing and distribution (United States)

    Tushabramishvili, Nikoloz; Oqrostsvaridze, Avthandil


    Study of raw materials has a big importance to understand the ecology, cognition, behavior, technology, culture of the Paleolithic human populations. Unfortunately, explorations of the sourcing, processing and distribution of stone raw materials had a less attention until the present days. The reasons of that were: incomplete knowledge of the archaeologists who are doing the late period archaeology (Bronze Age-Medieval) and who are little bit far from the Paleolithic technology and typology; Ignorance of the stone artifacts made on different kind of raw-materials, except flint and obsidians. Studies on the origin of the stone raw materials are becoming increasingly important since in our days. Interesting picture and situation have been detected on the different sites and in different regions of Georgia. In earlier stages of Middle Paleolithic of Djruchula Basin caves the number of basalt, andesite, argillite etc. raw materials are quite big. Since 130 000 a percent of the flint raw-material is increasing dramatically. Flint is an almost lonely dominated raw-material in Western Georgia during thousand years. Since approximately 50 000 ago the first obsidians brought from the South Georgia, appeared in Western Georgia. Similar situation has been detected by us in Eastern Georgia during our excavations of Ziari and Pkhoveli open-air sites. The early Lower Paleolithic layers are extremely rich by limestone artifacts while the flint raw-materials are dominated in the Middle Paleolithic layers. Study of these issues is possible to achieve across chronologies, the origins of the sources of raw-materials, the sites and regions. By merging archaeology with anthropology, geology and geography we are able to acquire outstanding insights about those populations. New approach to the Paleolithic stone materials, newly found Paleolithic quarries gave us an opportunities to try to achieve some results for understanding of the behavior of Paleolithic populations, geology and

  17. Metallogeny of The Sierra de Guanajuato Range, Central México (United States)

    Pedro F., Z. D.


    The Sierra de Guanajuato Range (SGR), trending N315° at Central México, is an orographic feature extending over a distance of 80 km. SGR comprises three well defined lithostratigraphic units: (1) a cretaceous basement including an arc-derived terrane named Guanajuato Arc (GA) made of gabbro, diorite and basaltic pillowed lava, and volcano-sedimentary rocks belonging to Arperos fore-arc basin which are geochemically anomalous in Au (0.15 ppm), Ag (3 ppm), Cu (40 ppm), Pb (50 ppm) and Zn (15 ppm); (2) Early Tertiary intrusive rocks, e.g., Comanja Granite which is affected by the presence of tourmalinized (schörl) aplito-pegmatite dykes mineralized with rare earths elements, and (3) Eocene redbeds (1,500-2000 m) and Oligocene-Miocene volcanics cover. The metallogeny of the SGR shows a multiple origin in time and space: volcano-sedimentary, granitic and volcanic, being possible to define three metallogenic epochs: cretaceous, paleocene and oligocene. Cretaceous epoch includes: (a) volcanogenic massive sulphide deposits (VMS) of bimodal-siliclastic type belonging to León-Guanajuato district; wallrock of VMS is made of felsic-internediate volcanics and black argillite; at Los Gavilanes deposit paragenesis is next: chalcopyrite > sphalerite > galena, pyrite > pyrrhotite > marcasite; grade is as follows: Au: .02-.07 g/t; Ag: 157-18.5 g/t; Cu: 2.24-0.81%, Pb: 4.16-0.03%; Zn: 10.35-3.02 %; (b) lens-shaped stratiform bodies of massive pyrite (i. ex., San Ignacio prospect; ˜ 4,000 ton) of exhalative-sedimentary origin with chalcopyrite and sphalerite microveins. Paleocene epoch includes both quartz-cordierite-sanidine veins and replacement bodies of hydrothermal metamorphic filliation (W +Se-Bi, Pb, Zn, Cu), and pyrometasomatic bodies [Cu, Pb, Zn (Ag), W] which genetically are linked to Comanja Granite emplacement. The wallrock at El Maguey mine (35,000 ton; 0.6% WO3) is made of hornfel and the vein (1.8-3.2m width) has a banding structure made of : \\{quartz & K

  18. Ordovician and Silurian Phi Kappa and Trail Creek formations, Pioneer Mountains, central Idaho; stratigraphic and structural revisions, and new data on graptolite faunas (United States)

    Dover, James H.; Berry, William B.N.; Ross, Reuben James


    Recent geologic mapping in the northern Pioneer Mountains combined with the identification of graptolites from 116 new collections indicate that the Ordovician and Silurian Phi Kappa and Trail Creek Formations occur in a series of thrust-bounded slices within a broad zone of imbricate thrust faulting. Though confirming a deformational style first reported in a 1963 study by Michael Churkin, our data suggest that the complexity and regional extent of the thrust zone were not previously recognized. Most previously published sections of the Phi Kappa and Trail Creek Formations were measured across unrecognized thrust faults and therefore include not only structural repetitions of graptolitic Ordovician and Silurian rocks but also other tectonically juxtaposed lithostratigraphic units of diverse ages as well. Because of this discovery, the need to reconsider the stratigraphic validity of these formations and their lithology, nomenclature, structural distribution, facies relations, and graptolite faunas has arisen. The Phi Kappa Formation in most thrust slices has internal stratigraphic continuity despite the intensity of deformation to which it was subjected. As revised herein, the Phi Kappa Formation is restricted to a structurally repeated succession of predominantly black, carbonaceous, graptolitic argillite and shale. Some limy, light-gray-weathering shale occurs in the middle part of the section, and fine-grained locally pebbly quartzite is present at the base. The basal quartzite is here named the Basin Gulch Quartzite Member of the Phi Kappa. The Phi Kappa redefined on a lithologic basis represents the span of Ordovician time from W. B. N. Berry's graptolite zones 2-4 through 15 and also includes approximately 17 m of lithologically identical shale of Early and Middle Silurian age at the top. The lower contact of the formation as revised is tectonic. The Phi Kappa is gradationally overlain by the Trail Creek Formation as restricted herein. Most of the coarser

  19. Investigations on self-sealing of indurated clay - Part of the NF-PRO project. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang; Rothfuchs, T.; Dittrich, J.; Mueller, J.


    The self-sealing potential of the Callovo-Oxfordian argillite and the Opalinus clay was investigated on strongly damaged samples. Gas permeability as a function of the confining stress before and after water resaturation was measured. Not only normally-sized but also large-scale and cylindrical ring-shaped samples were tested. Each test lasted over a time period of 5 to 16 months. The experimental findings are: 1. The permeability of the pre-damaged samples decreased significantly with a concurrent increase of the confining stress due to fracture closure. The permeability measured in radial direction on a hollow sample decreased from 10{sup -15} m{sup 2} at a low confining stress of 1 MPa to 10{sup -21} m{sup 2} at 28 MPa. The compression of the sample led to plastic closure of pre-existing fractures, leading to a significantly lower permeability after unloading. A similar permeability reduction with increasing confining stress was also observed in axial direction, parallel to the bedding plane. But, at low confining stresses below 10 MPa, the axial permeability parallel to the bedding was about one to two orders of magnitude higher than the radial one perpendicular to the bedding. The hydraulic anisotropy vanishes off with increasing the confining stress. 2. The permeability of fractured clay rocks was dominated by the confining stress normal to the fracture plane. This was validated by gas permeability measurements on a large sample (D=260 mm/L=616 mm) with fractures oriented parallel to the sample axis. The increase of the lateral stress from 3 to 18 MPa at 19 MPa axial stress led to a decrease of axial permeability from 10{sup -13} to 10{sup -19} m{sup 2}. 3. The permeability od damaged clay rocks decreased also with time due to the time-dependent compaction of pores and fractures. On the pre-damaged samples, a permeability reduction by a factor of 4 to 8 was observed over two months at a low confining stress of 1.5 MPa. 4. The high swelling potential of the

  20. The geology, geochemistry and emplacement of the Cretaceous—Tertiary ophiolitic Nicoya Complex of the Osa Peninsula, southern Costa Rica (United States)

    Berrangé, J. P.; Thorpe, R. S.


    The Nicoya Complex of the Osa Peninsula is essentially an obducted segment of oceanic crust comprising basaltic lavas and associated intrusive dolerite and gabbro, interstratified with lesser amounts of pelagic limestones, cherts and argillites. The sediments contain a minor clastic component and were deposited on an ocean floor of considerable relief and distant from a major landmass. The extrusive and intrusive basaltic rocks have geochemical affinities to large ion lithophile (LIL) element-enriched oceanic crust, and are interpreted to have formed in a back-arc basin analagous to the Mariana Trough, Lau Basin or Gulf of California. One sample has distinctly different geochemical characteristics and may represent a younger within-plate seamount. In the Late Cretaceous, an E-W-trending intra-oceanic trench/volcanic/back-arc system developed in association with an active southward-dipping subduction zone located south of the present-day southern Central American isthmus. Pelagic sediments and basaltic lavas accumulated in the back-arc over a period of at least 34 Ma spanning the Late Cretaceous and Early Tertiary. During this period there were three major volcanic events dated respectively as Santonian-Campanian (78.0 ± 2 Ma), Palaeocene (60.2 ± 7.6 Ma) and Middle Eocene (44.0 ± 4.4 Ma). Continuing northward movement of the southern plate caused overthrusting of the volcanic arc onto the northern plate and production of a thickened embryonic continental crust. Inferred reorganization of crustal stress in the Late Eocene caused fragmentation of the single ancestral plate into the Caribbean and "East Pacific" plates, with a flipping of the subduction zone accompanying development of the NE-dipping Middle America subduction zone and andesitic volcanism. During the Oligocene, the ancestral East Pacific plate split into the NE-moving Cocos plate and the eastward-moving Nazca plate, separated by the E-W-trending Colón spreading ridge and a series of N

  1. Shale disposal of U.S. high-level radioactive waste.

    Energy Technology Data Exchange (ETDEWEB)

    Sassani, David Carl; Stone, Charles Michael; Hansen, Francis D.; Hardin, Ernest L.; Dewers, Thomas A.; Martinez, Mario J.; Rechard, Robert Paul; Sobolik, Steven Ronald; Freeze, Geoffrey A.; Cygan, Randall Timothy; Gaither, Katherine N.; Holland, John Francis; Brady, Patrick Vane


    This report evaluates the feasibility of high-level radioactive waste disposal in shale within the United States. The U.S. has many possible clay/shale/argillite basins with positive attributes for permanent disposal. Similar geologic formations have been extensively studied by international programs with largely positive results, over significant ranges of the most important material characteristics including permeability, rheology, and sorptive potential. This report is enabled by the advanced work of the international community to establish functional and operational requirements for disposal of a range of waste forms in shale media. We develop scoping performance analyses, based on the applicable features, events, and processes identified by international investigators, to support a generic conclusion regarding post-closure safety. Requisite assumptions for these analyses include waste characteristics, disposal concepts, and important properties of the geologic formation. We then apply lessons learned from Sandia experience on the Waste Isolation Pilot Project and the Yucca Mountain Project to develop a disposal strategy should a shale repository be considered as an alternative disposal pathway in the U.S. Disposal of high-level radioactive waste in suitable shale formations is attractive because the material is essentially impermeable and self-sealing, conditions are chemically reducing, and sorption tends to prevent radionuclide transport. Vertically and laterally extensive shale and clay formations exist in multiple locations in the contiguous 48 states. Thermal-hydrologic-mechanical calculations indicate that temperatures near emplaced waste packages can be maintained below boiling and will decay to within a few degrees of the ambient temperature within a few decades (or longer depending on the waste form). Construction effects, ventilation, and the thermal pulse will lead to clay dehydration and deformation, confined to an excavation disturbed zone within

  2. 塔里木盆地塔中地区奥陶系碳酸盐岩封盖性能%Sealing capacity of the Ordovician carbonate rocks in Tazhong area,the Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    钱一雄; 何治亮; 陈强路; 李慧莉; 路清华; 蔡习尧; 尤东华


    利用5口区探井碳酸盐岩的矿物组成、微孔特征和测井资料等对塔里木盆地塔中地区奥陶系碳酸盐岩封盖性能进行了研究.结果表明,塔中奥陶系良里塔格组和鹰山组位于中成岩A-B亚段和晚成岩A亚段.良里塔格组中颗粒灰岩的突破压力为1.81 ~ 29.76 MPa,突破半径为13.89~77.35 nm,变化较大;泥灰岩的突破压力为14.33 MPa,突破半径为9.77 nm;含泥质条带泥晶灰岩的突破压力为3.15 ~5.41 MPa,突破半径为25.90~44.51 nm.鹰山组灰云岩的突破压力为0.98 ~ 10.35 MPa,突破半径为13.52~142.60 nm.因此,良里塔格组泥灰岩、部分颗粒灰岩及鹰山组云灰岩均有一定的封盖能力,其连续厚度大于5 m,突破压力大于5 MPa,突破半径介于10 ~ 20 nm,孔喉半径小于0.1 μm.塔中鹰山组内分布稳定、厚4~10m的高电阻含云灰岩构成的致密层段可作为局部封盖层,是中1井奥陶系鹰山组上油、下气油气分布的主要原因之一.%Mineral composition, micro-pore characteristics and well-logs from five wells were used to study the sealing capacity of the Ordovician carbonate rocks in Tazhong area,Tarim Basin. The Ordovician Lianglitage and Yingshan formations are at substage A-B of the middle diagenetic stage and substage A of the late diagenetic stage. For the Lianglitage Formation grainstone,the breakthrough pressure (BP) is 1. 81 -29. 76 Mpa,and the threshold radius (TR) is 13. 89 -77. 35 nm,. For the marlstones,the BP is 14. 33MPa and TR is 25. 9 -44. 51 nm. For the micritic limestone with band of argillite, the BP is 0. 98 - 10. 35 Mpa and the TR is 13. 52 - 142. 60 nm. The BP and the TR of the Yingshan Formation limy dolomites are 0. 98 - 10. 35 Mpa and 13. 52 - 142. 60 nm. Thus, the marlstone and partial grainstone of the Lianglitage Formation and the Yingshan Formation dolomite limestone have certain sealing capacity,with thickness over 5 m,BP over 5 Mpa,TR between 10-20 nm,pore throat radium

  3. In-situ stress and fracture characterization for planning of a hydraulic stimulation in the Desert Peak Geothermal Field, NV (United States)

    Hickman, S.; Davatzes, N. C.


    failure could be induced on well-oriented fractures seen in the well once fluid pressures are increased ~2.5 MPa or more above the ambient formation fluid pressure. This includes the intended stimulation interval at 0.9 to 1.1 km depth, which is comprised of rhyolite tuff and argillite at ambient temperatures of ~180 to 195° C. This geomechanical model will be tested during hydraulic stimulation of well 27-15 as part of the Desert Peak EGS Project, which is intended to enhance formation permeability through self-propping shear failure. If this stimulation is successful, then preferential activation of normal faults associated with the current stress state should generate a zone of enhanced permeability propagating to the SSW, in the direction of nearby geothermal injection and production wells, and to the NNE, into an unexploited portion of the field. These results indicate that well 27-15 is a viable candidate for EGS stimulation and complements research by other investigators, including cuttings and core testing, geochemical tracer studies, pressure transient analyses, and micro-seismic monitoring.

  4. Geology of quadrangles H-12, H-13, and parts of I-12 and I-13, (zone III) in northeastern Santander Department, Colombia (United States)

    Ward, Dwight Edward; Goldsmith, Richard; Cruz, Jaime B.; Restrepo, Hernan A.


    A program of geologic mapping and mineral investigation in Colombia was undertaken cooperatively by the Colombian Instituto Nacional de Investigaciones Geologico-Mineras (formerly known as the Inventario Minero Nacional), and the U. S. Geological Survey; by the Government of Colombia and the Agency for International Development, U. S. Department of State. The purpose was to study, and evaluate mineral resources (excluding of petroleum, coal, emeralds, and alluvial gold) of four selected areas, designated Zones I to IV, that total about 70,000 km2. The work in Zone III, in the Cordillera Oriental, was done from 1965 to 1968. The northeast trend of the Cordillera Oriental of Colombia swings abruptly to north-northwest in the area of this report, and divides around the southern end of the Maracaibo Basin. This section of the Cordillera Oriental is referred to as the Santander Massif. Radiometric age determinations indicate that the oldest rocks of the Santander massif are Precambrian and include high-grade gneiss, schist, and migmatite of the Bucaramanga Formation. These rocks were probably part of the Precambrian Guayana Shield. Low- to medium-grade metamorphic rocks of late Precambrian to Ordovician age .include phyllite, schist, metasiltstone, metasandstone, and marble of the Silgara Formation, a geosynclinal series of considerable extent in the Cordillera Oriental and possibly the Cordillera de Merida of Venezuela. Orthogneiss ranging from granite to tonalite is widely distributed in the high- and medium-grade metamorphic rocks of the central core of the massif and probably represents rocks of two ages, Precambrian and Ordovician to Early Devonian. Younger orthogneiss and the Silgara are overlain by Middle Devonian beds of the Floresta Formation which show a generally low but varying degree of metamorphism. Phyllite and argillite are common, and infrequent marble and other calcareous beds are fossiliferous. Except for recrystallization in limestones of !the

  5. Zheltozems of Russia: Micromorphology, clay minerals, and pedogenetic analysis Zheltozems de Rusia: micromorfología, minerales de la arcilla y análisis edafogenético Zheltozems da Russia: Micromorfología, Minerais de Argila e Análise Pedogenética

    Directory of Open Access Journals (Sweden)

    Maria Gerasimova


    Full Text Available Zheltozems (literally "yellow earths" that can be classified as Acrisols, Alisols, or Ultisols, occupy very small areas in Russia; they are strongly modified by human activities. The unchanged profiles are preserved only locally, in particular, in the Sochi arboretum. When compiling the soil map of the arboretum, different Zheltozems were described on gentle and moderately steep slopes and diverse parent materials: calcareous claystone and its heavy-textured derivates. The micromorphology of three characteristic Zheltozem profiles developed on these different parent materials was also studied. The features that they have in common are the following: in all profiles, a specific heavy-textured Bw, or BM 'metamorphic' horizon was identified with a certain set of micromorphological properties: a massive microstructure with fine planes merging into deformed biogenic pores, a monic groundmass with few silt grains that are sometimes oriented, and impregnative iron-oxides pedofeatures. The b-fabric was defined as stipple speckled, poro- and granostriated, locally (monostriated ressembling stress coatings. There are almost no clay coatings except for very few fine internal ones that are light yellow and homogeneous; clay and iron pseudomorphs (alteromorphs occur over some skeleton grains. Many of these properties are related to the clay mineral composition. There are varying quantities of smectites and kaolinite-smectites, whereby the former increase with depth. The presence of expanding minerals is known to contribute to the disintegration of coatings. Remnants of these are observed in typic iron-manganic nodules. In terms of WRB, this horizon is an intergrade between cambic and argic, which is not accounted for in soil diagnostics. As three different Zheltozems are studied in the same area, the following genesis of this specific intergrade can be given. The saprolite in one of the profiles is composed of fragments of weathered calcareous argillites

  6. Reconsideración estratigráfica del Neopaleozoico de los alrededores del dique Los Sauces, La Rioja Stratigraphic reconsideration of the late Paleozoic in the surrounding of the Los Sauces dam, La Rioja

    Directory of Open Access Journals (Sweden)

    E.M. Pieroni


    and sandstone, which are interbedding with black siltstone and mudstone. These fine sediments were mined during last decades as refractory argillite. The Sauces Formation is formed by orange red sandstones and siltstones with a few proportions of conglomerates. Main outcrops of Sauces Formation are present at NNW, NE and SSE side of the valley and isolated outcrops appear as small islands in the modern lake. Some characteristic species of the megaflora collected in the basal and middle sections of the Libertad Formation indicate a Late Carboniferous age. On the other hand palynologic studies performed in samples collected in the Sauces Formation indicate an Early Permian age.

  7. The geology of aluminium phosphates and sulphates of the alunite group minerals: a review (United States)

    Dill, Harald G.


    Aluminium phosphates and sulphates of the alunite supergroup (APS minerals) occur in a wide range of environments of formation covering the metamorphic, igneous and sedimentary realms. Supergene processes, including mineral dressing and dumping when sulphide ores are mined, as well as hypogene alteration are also responsible for the precipitation of APS minerals. In these environments, complex solid solution series (s.s.s.) can form. The general formula of these alunite minerals is AB 3 (XO 4) 2(OH) 6, where A is a large cation (Na, U, K, Ag, NH 4, Pb, Ca, Ba, Sr, REE). B sites are occupied by cations of the elements Al, Fe, Cu and Zn. In nature, the anion (XO 4) x- is dominated by P and S. Mineral dressing and identification of APS minerals often needs a combination of highly sophisticated measures including Atterberg settling methods, XRD, DTA, TGA, TEM-EDX, SEM, EMPA and XRF. In sedimentary rocks APS minerals occur in various rocks and environments of deposition: calcareous, phosphorite-bearing, argillaceous-carbonaceous, arenaceous, coal-bearing environments, in soils and paleosols, in saprolite (bauxites, laterites) and in calcareous-argillaceous sequences hosting Carlin-type SHDG deposits. In igneous rocks, APS minerals may be encountered mainly in acidic through intermediate pyroclastic, volcanic and subvolcanic rocks. They occur in barren volcanic rocks and porphyry-type intrusions that have sparked epithermal Au-Ag-base metal deposits, Au-Sb mineralization, APS-bearing argillite and alunite deposits in their immediate surroundings. Granitic and pegmatitic rocks are rarely host of supergene APS mineralization. During low-grade stage regional metamorphism, peraluminous parent rocks originating from a sedimentary or igneous protolith may also give rise to APS mineralization. Peraluminous parent rocks enriched in S and/or P are a prerequisite for the formation of APS minerals that are stable up to a temperature of 400°C at moderately high fluid pressure of up

  8. Fractionation between inorganic and organic carbon during the Lomagundi (2.22 2.1 Ga) carbon isotope excursion (United States)

    Bekker, A.; Holmden, C.; Beukes, N. J.; Kenig, F.; Eglinton, B.; Patterson, W. P.


    The Lomagundi (2.22-2.1 Ga) positive carbon isotope excursion in shallow-marine sedimentary carbonates has been associated with the rise in atmospheric oxygen, but subsequent studies have demonstrated that the carbon isotope excursion was preceded by the rise in atmospheric oxygen. The amount of oxygen released to the exosphere during the Lomagundi excursion is constrained by the average global fractionation between inorganic and organic carbon, which is poorly characterized. Because dissolved inorganic and organic carbon reservoirs were arguably larger in the Paleoproterozoic ocean, at a time of lower solar luminosity and lower ocean redox state, decoupling between these two variables might be expected. We determined carbon isotope values of carbonate and organic matter in carbonates and shales of the Silverton Formation, South Africa and in the correlative Sengoma Argillite Formation, near the border in Botswana. These units were deposited between 2.22 and 2.06 Ga along the margin of the Kaapvaal Craton in an open-marine deltaic setting and experienced lower greenschist facies metamorphism. The prodelta to offshore marine shales are overlain by a subtidal carbonate sequence. Carbonates exhibit elevated 13C values ranging from 8.3 to 11.2‰ vs. VPDB consistent with deposition during the Lomagundi positive excursion. The total organic carbon (TOC) contents range from 0.01 to 0.6% and δ13C values range from - 24.8 to - 13.9‰. Thus, the isotopic fractionation between organic and carbonate carbon was on average 30.3 ± 2.8‰ ( n = 32) in the shallow-marine environment. The underlying Sengoma shales have highly variable TOC contents (0.14 to 21.94%) and δ13C values (- 33.7 to - 20.8‰) with an average of - 27.0 ± 3.0‰ ( n = 50). Considering that the shales were also deposited during the Lomagundi excursion, and taking δ13C values of the overlying carbonates as representative of the δ13C value of dissolved inorganic carbon during shale deposition, a carbon

  9. Modelling of long term geochemical evolution and study of mechanical perturbation of bentonite buffer of a KBS-3 repository

    Energy Technology Data Exchange (ETDEWEB)

    Marsal, Francois; Pellegrini, Delphine; Deleruyelle, Frederic; Serres, Christophe (French Inst. for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (FR)); Windt, Laurent de (Ecole des Mines de Paris, Paris (FR))


    simulated intrusion of oxidizing waters lead to a limited perturbation, i.e. localized within bentonite near the fracture plane level. Actually, the calculated evolutions are relatively slow, so that in some cases the buffer remains in a transient stage over the whole simulation period and thus could turn heterogeneous in geochemical properties. Regarding the effect of temperature, a heterogeneous evolution is again observed, with moderate to slight dissolution-precipitation reactions either on the inner or outer border of the buffer (warmer and cooler zones) depending on the accessory minerals. These main trends in bentonite geochemical evolutions are in good agreement with the results presented in SR-Can and in Arcos et al., though some discrepancies have been pointed out, that can be explained by differences in modelling input data (mainly regarding log K values). Finally, issues in terms of processes and data would worth being further investigated as they might have a significant influence on bentonite evolutions, such as the thermohydraulic coupling of processes during the initial transient phase or the stability of montmorillonite. PART II: Elements of the SR-Can project relative to piping and erosion phenomena of bentonite components of a KBS-3 repository are analysed with regard to the experience feedback available at IRSN and consisting in experimental results obtained on samples at the UJF-Grenoble between 2000 and 2004. A synthesis of these tests is presented, with a closer attention to the Argillite/Bentonite tests during which phenomena of erosion occurred. The reference evolution of a KBS-3 repository, the resaturation and swelling kinetics of backfills and buffers and the possibility for a buffer to swell upwards the backfill have been considered. According to the reviewed documents, IRSN notes that the SR-Can project tackles the piping and erosion phenomena with local modellings and 'rough estimates', the latter being based on 3 &apos

  10. Reabilitation of degraded area by erosion, using soil bioengineering techniques in Bacanga river basin, Sao Luis City - Maranhao State, Brazil. (United States)

    Teixeira Guerra, A. J.; Rodrigues Bezerra, J. F.; da Mota Lima, L. D.; Silva Mendonça, J. K.; Vieira Souza, U. D.; Teixeira Guerra, T.


    The aim of this paper is to assess the stages of rehabilitation of a degraded site by erosion, in Salina/Sacavém district, São Luís City, considering geomorphologic characteristics and soil bioengineering techniques. This technique has been applied in different situations to rehabilitate degraded areas, with positive results from the use of biodegradable materials (e.g. vegetal fibres, wooden stakes and re-vegetation). These techniques stabilize the soil at low cost and improve the environment. Bioengineering involves the planned and strategic application of selected materials, involving biodegradable materials, often in combination with 'hard engineering' structures constructed from stone, concrete and steel. The settlement of São Luís was established in 1612 and has evolved in distinct phases. Rapid urban growth was associated with industrialization in the second half of the 18th Century. Rapid population and urban growth has intensified problems, compounded by poor planning and improper soil use. São Luís, like many other Brazilian cities, has experienced rapid population growth in recent decades, which has created a series of socio-economic and environmental problems, including accelerated soil erosion. Sacavém is one of these communities where natural and human factors contribute to the severe gully erosion. The local lithology is mainly Tertiary sandstones and, to a lesser extent, shales, argillites and siltstones, all of which belong to the Barreiras Formation. Weathering on these rocks produces erodible soils, including lithosols, latosols, concretionary red/yellow clay soils and concretionary plinthosols. Thus, erodible soils and regolith are subject to high erosion rates, especially on steeper slopes subject to additional human interventions. Furthermore, although regional slopes are quite gentle, there is localized high relative relief. Sacavém vegetation, in the gullied area, consists of brushwood. Secondary mixed forest and brushwood are the

  11. Self-sealing of excavation induced fractures in clay host rock

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chun-Liang [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Braunschweig (Germany)


    Excavation of an underground repository for disposal of radioactive waste in clay formations generates fractures around the openings, which may act as pathways for water transport and radionuclides migration. Because of the favorable properties of the clay rocks such as the rheological deformability and swelling capability, a recovery process of the excavation damaged zone (EDZ) can be expected due to the combined impact of rock compression, backfill resistance, and clay swelling during the post-closure phase. Another important issue is the impact of gases produced from anoxic corrosion of waste containers and other metallic components within the repository. The EDZ may act as a conduit for preferential gas flow, depending on the extent of the recovery process. For the safety assessment of a repository, the self-sealing behaviour and impact on water and gas transport through the EDZ have to be characterized, understood, and predicted. Recently, GRS has extensively investigated these important issues with various kinds of laboratory and in- situ experiments under relevant repository conditions. Test samples were taken from the Callovo-Oxfordian argillite at Bure in France and the Opalinus clay (shaly facies) at Mont Terri in Switzerland. Major findings are summarized as follows. As observed in laboratory and in-situ, the gas permeabilities of the claystones increase with stress-induced damage by several orders of magnitude from the impermeable state up to high levels of 10{sup -12}-10{sup -13} m{sup 2}. When hydrostatic confining stress is applied and increased, the fractures in the claystones tend to close up, leading to a decrease in gas permeability down to different levels of 10{sup -16}-10{sup -21} m{sup 2} at stresses in a range of 10 to 20 MPa. As water enters and flows through fractures, the clay matrix can take up a great amount of the water and expand into the interstices. Consequently, the hydraulic conductivity decreases dramatically by several orders of

  12. Soixante années de recherches en coopération sur l'érosion hydrique et la lutte antiérosive au Maghreb

    Directory of Open Access Journals (Sweden)

    Mohamed Mazour


    erosion damages by saturation of the topsoil than usual rains. In Algeria, A. DEMMAK found that the wadis solid transport is related mainly to the extension in the watersheds of argillite, marl and shale outcrops.Since 1985, a research team of INRF and IRD realised, in Algeria, investigations on SWC techniques efficiency, developed intensive agro-ecosystems valorising better the ground and labour, restored gullies with various sills models and various plants and trees valorising the badlands: they called the system "GCES". In Morocco, teams of ENFI foresters, Rabat University geographers and IRD have described and analysed 30 SWC systems developed by farmers living in the Atlas mountains. IRD with the Faculty of Marrakech developed a methodology using teledetection, rainfall infiltrometer on 1 m2, surface status and GIS in order to spatialise erosion risks and types of SWC managements necessary in a mountainous watershed of 270 km2.

  13. In situ and laboratory investigations of fluid flow through an argillaceous formation at different scales of space and time, Tournemire tunnel, southern France (United States)

    Boisson, Jean-Yves; Bertrand, Lucien; Heitz, Jean-François; Golvan, Yann Moreau-Le


    In the context of a research and development program on waste disposal, an experimental site (Tournemire tunnel, Aveyron, France) was selected by the French Institute for Nuclear Protection and Safety (IPSN) in order to undertake studies on potential fluid flow at different scales of space and time within a 250-m-thick argillaceous formation. The argillite has a low natural water content ( 3-5%) and very low radii access porosity. Diffusion (tritiated water) coefficients (1×10-12 to 2×10-11 m2/s) and hydraulic conductivities derived from different types of laboratory tests (10-14 to 10-13 m/s) are characteristics of a very low-permeable rock. In situ hydraulic tests (including long-term hydraulic-head measurements) were used to obtain values for hydraulic head and hydraulic conductivity at a scale of 1-10 m (10-13 to 10-11 m/s). Despite uncertainties on these data (due to a scale factor, presence of fissures, and possible artefacts due to hydro-chemo-mechanical coupling), it is expected that fluid flow is essentially governed by diffusion processes. Identification of possible natural flows at larger scales of time and space was investigated using natural isotopic tracers from interstitial fluids. Modelling, based on the deuterium profile along the clay formation and assuming pure diffusion processes, provides estimations of possible flow times. However, lack of knowledge concerning the past geological evolution of the site and the possible role of a fracture network do not permit reduction of uncertainties on these estimations at this stage. Résumé. Dans le cadre de son programme de recherche et développement sur les stockages de déchets, un site expérimental (tunnel de Tournemire, Aveyron, France) a été sélectionné par l'Institut de Protection et Sûreté Nucléaire (IPSN) pour conduire des études sur les possibilités de transferts de fluides à différentes échelles de temps et d'espace au sein d'une formation argileuse de 250 m d'épaisseur. L