A methodology is described for understanding the interaction of karstic aquifers with allogenic rivers, where little information is available. This methodology includes conventional hydrogenology methods tracer tests ...A methodology is described for understanding the interaction of karstic aquifers with allogenic rivers, where little information is available. This methodology includes conventional hydrogenology methods tracer tests and measurements of flow into, out of and circulating within the karstic system. The method is designed to understand the hydrogeological behaviour of a river in sufficient detail, given a short study period. The methodology is applied to a karstic system in Spain, obtaining useful, quantitative results for a hydrological year, such as an estimate of the water balance, differentiation between autogenic and allogenic natural recharge, relationship and connection between the river and the aquifer, and measurements of infiltration capacity in watercourses under different hydrological situations. The paper deals with a useful example that could be applied to other rivers and aquifers where few data are available. It can be applied to aquifers under a natural regime and Mediterranean climate.展开更多
Mapping from remote sensing has become more effective in the field of geology, mainly in lithological discrimination and identification of hydrothermal alteration zones. The use of this technique consists in obtaining...Mapping from remote sensing has become more effective in the field of geology, mainly in lithological discrimination and identification of hydrothermal alteration zones. The use of this technique consists in obtaining information about the rock mass and the main ones existing in the inaccessible areas. Satellite data from the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) sensor represent a favorable potential for detecting the spectral signatures of mineral zones and identifying their nature. These data are more reliable in places where the climate is arid with less abundant vegetation, as at the Oumjrane-Boukerzia mining district. This region which is part of the Eastern Anti-Atlas, is composed of several mineralized veins which still require detailed studies and exploration by the technique of remote sensing. In this work we applied several processing techniques on ASTER imagery such as Colored Composition, Principal Component Analysis and Ratio Bands. The use of the reports of the specialized Bands makes it possible to identify some hydrothermal alteration minerals within the mining district of Oumjrane Boukerzia. These minerals are represented mainly by iron oxides and hydroxides (Hematite, jarosite, limonite and goethite), carbonate minerals (dolomite, calcite), clay minerals (Illite, kaolinite and chlorite) and quartz minerals. This work allows us to produce a map of hydrothermal alteration zones which can be used as a valuable reference in the strategy of mining exploration for the base metals (Cu, Pb, Zn and Ba), in the mining district of Oumjrane-Boukerzia and in the entire Eastern Anti-Atlas.展开更多
文摘A methodology is described for understanding the interaction of karstic aquifers with allogenic rivers, where little information is available. This methodology includes conventional hydrogenology methods tracer tests and measurements of flow into, out of and circulating within the karstic system. The method is designed to understand the hydrogeological behaviour of a river in sufficient detail, given a short study period. The methodology is applied to a karstic system in Spain, obtaining useful, quantitative results for a hydrological year, such as an estimate of the water balance, differentiation between autogenic and allogenic natural recharge, relationship and connection between the river and the aquifer, and measurements of infiltration capacity in watercourses under different hydrological situations. The paper deals with a useful example that could be applied to other rivers and aquifers where few data are available. It can be applied to aquifers under a natural regime and Mediterranean climate.
文摘Mapping from remote sensing has become more effective in the field of geology, mainly in lithological discrimination and identification of hydrothermal alteration zones. The use of this technique consists in obtaining information about the rock mass and the main ones existing in the inaccessible areas. Satellite data from the ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) sensor represent a favorable potential for detecting the spectral signatures of mineral zones and identifying their nature. These data are more reliable in places where the climate is arid with less abundant vegetation, as at the Oumjrane-Boukerzia mining district. This region which is part of the Eastern Anti-Atlas, is composed of several mineralized veins which still require detailed studies and exploration by the technique of remote sensing. In this work we applied several processing techniques on ASTER imagery such as Colored Composition, Principal Component Analysis and Ratio Bands. The use of the reports of the specialized Bands makes it possible to identify some hydrothermal alteration minerals within the mining district of Oumjrane Boukerzia. These minerals are represented mainly by iron oxides and hydroxides (Hematite, jarosite, limonite and goethite), carbonate minerals (dolomite, calcite), clay minerals (Illite, kaolinite and chlorite) and quartz minerals. This work allows us to produce a map of hydrothermal alteration zones which can be used as a valuable reference in the strategy of mining exploration for the base metals (Cu, Pb, Zn and Ba), in the mining district of Oumjrane-Boukerzia and in the entire Eastern Anti-Atlas.
