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[en] A new tectonic interpretation of the Sainte Victoire Mountain (north of Marseille, south eastern France) is proposed, principally invoking vertical movements and providing evidence which suggests an uplift which may be still active today in the western part. Some new observations confirm our hypothesis. (Author)
[en] he karst, a complex phenomenon, is governed by a number of variables which dictate its genesis and evolution. Among these variables tectonic settings and lithology play the main role. In Cuba, approximately 65% of the territory is occupied by karst. The Sierra de los Organos, part of Cordillera de Guaniguanico, has some of the largest karstic systems in the country. With the aim of demonstrating the relationship between the spatial and morphological development of the underground karstic systems and the geological structure and lithology of the area, several structural and morphological measurements and field observations have been made. These measurements and observations allowing us to conclude that the karstic processes take place mainly in massive, relatively homogeneous and very thick limestone in the Sierra de los Organos. Moreover, these rocks are characterized by both low porosity and a high degree of fracturing. These karstic forms are also conditioned by the existence of various fracturing systems with general NE-SW and NW-SE orientations. Interception of these fracturing systems provides, as expected, areas with the largest volumes of karstic cavities. (Author)
[en] A stratigraphic revision of the latest Cryogenian, Ediacaran and earliest Cambrian of the southwestern Siberian Platform is proposed here. All late Neoproterozoic stratigraphic units fill the Sayan foredeep. The sedimentary record is adscribed to the upper Cryogenian and Ediacaran Oselok Group and the lower Cambrian Ust’-Tagul Formation. They can be subdivided into members with a characteristic fossiliferous content ecology of Dickinsonia.
[es]Se propone a continuación una revisión estratigráfica del Criogénico terminal, el Ediacárico y el Cámbrico temprano en la Platafora Siberiana. Todas las unidades estratigráficas neoproterozoicas tardías llenan la cuenca remanente de Sayan. El registro sedimentario se adscribe al grupo Criogénico terminal y Ediacárico de Oselok y a la formación inferior cámbrica Ust’-Tagul. Se pueden subdividir en miembros a partir de su característico contenido en Dickinsonia.
[en] Two wildcat oil and gas exploration holes drilled in 1991 on the northern edge of the Amargosa Desert penetrated Tertiary and Quaternary sedimentary rocks, alluvium, and basalt, possible Tertiary volcanic or volcaniclastic rocks, and Tertiary (?) and Paleozoic carbonate rocks. The easternmost of the two holes, Felderhoff-Federal 5-1, encountered about 200 feet of alluvium, underlain by 305 feet of basalt breccia and basalt, about 345 feet of probable Tertiary tuffaceous sedimentary rocks, and 616 feet of dense limestone and dolomite of uncertain age. Drill hole 25-1 penetrated 240 feet of alluvium and marl (?), and 250 feet of basalt breccia (?) and basalt, 270 feet of tuff (?) and/or tuffaceous sedimentary rocks, 360 feet of slide blocks (?) and large boulders of Paleozoic carbonate rocks, and 2,800 feet of Paleozoic limestone and dolomite. The two drill holes are located within a northerly trending fault zone defined largely by geophysical data; this fault zone lies along the east side of a major rift containing many small basalt eruptive centers and, farther north, several caldera complexes. Drill hole 25-1 penetrated an inverted paleozoic rock sequence; drill hole 5-1 encountered two large cavities 24-inches wide or more in dense carbonate rock of uncertain, but probable Paleozoic age. These openings may be tectonic and controlled by a regional system of northeast-striking faults
[en] Compilation of lithogeochemical patterns of Rabau Hulu uranium mineralization sector was conducted by studying 252 samples data collected from exploration and evaluation drill holes. The patterns were characterized by chemical composition and mineralogical changes as well as trace elements enrichment. By knowing the patterns, alteration and trace elements halos around uranium minerals can be determined. While alteration halos can be identified by examining the ratio of K2O/Al2O3, MgO/Al2O3 and Fe2O3/MgO in the samples, trace elements halos can be distinguished by the presence of Ni, Co, Cu, Pb, Zn, Mo and V. The Pb and Zn halo identification can be employed as a very effective exploration techniques, respectively. In conclusion, experimental data indicate that the Rabau Hulu sector can be classified into an intensive alteration sector with uranium enrichment in this area. The presence of uranium enrichment outside the kaolinitic zone also suggests preconcentration of uranium through metamorphism. (author). 2 tabs, 8 figs, 4 refs
[en] Due to the complex natural geological conditions, many slope-related geological hazards occur in the Three Gorges Reservoir area in China. This study focuses on the characteristics of landslide development and their underlying mechanisms in this area. A statistical analysis is conducted to determine the characteristics of landslide development in the Wushan area, including the landslide distribution as a function of the elevation, slope, landslide material composition, scale, lithology, boundary conditions, instability mechanism, stratigraphic age, attitude, and sliding direction. The mechanisms of slope instability and the effect on the occurrence of landslides are analyzed. This study provides important reference material for landslide research in the Three Gorges Reservoir area and similar stratigraphic areas.