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31.
Hydrochemical signatures of deep groundwater circulation in a part of the Himalayan foreland basin 总被引:2,自引:1,他引:1
Groundwater samples were analyzed from 71 springs and wells as part of a larger study in a region of compressional tectonic
regime. The study site covers the Peshawar basin and surroundings in the Himalayan foreland of Pakistan. The northern portion
is mountainous and the water table is discontinuous in different intermontane valleys, with abundant springs (with normal
and anomalous temperatures and composition). The southern part is divided into isolated basins with a number of drilled (“deep”)
and dug (“shallow”) wells. Hydrochemical signatures of elevated strontium (Sr), SiO2, boron (B)—and the geothermometric signatures—all indicate a deep circulation of the emerging groundwater. Moreover, for
several of the sample sites, water chemical compositions, measured spring and water well temperatures, and reservoir temperatures
calculated for spring waters, all point to origin from deep horizons within the basin. Remarkable proximity of all the thermal
and hydrochemical anomalies to major faults suggests that the waters ascended along these faults from greater depths. The
area is a natural western extension of the Himalayan Geothermal Belt described in earlier literature for the eastern and central
Himalayas. 相似文献
32.
Kamlesh Verma Sanjeeb Bhattacharya A. M. Asim Ansari Prakash K. Srivastava Amit Dharwadkar 《Journal of the Geological Society of India》2014,83(5):532-534
Eleven glacial sediment samples collected from different elevation of Jutulsessen Nunatak, Gjelsvikfjella of East Antarctica were studied for the clay mineralogical analysis using X-ray diffraction technique. The result shows prominent peak at 10, and 3.34 Å suggesting the presence of biotite possibly derived from the catchment where biotite rich granite gneisses are exposed. The detailed investigation on the shape of biotite peak of certain samples shows the signs of alteration of biotite in to a mixed layer containing tri-octahedral smectite (low charge vermiculite). The presence of mixed layer along with the biotite is found to be associated with the samples of lower geomorphic level. The progressive alteration of clay sized biotite to form a mixed layer in the lower horizons of Jutulsessen Nunatak is probably due to the periodic accumulation of melt-water during the austral summer. 相似文献