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Ashok Babu, G.
- Thinning of Granitic-Gneissic Crust below Uplifting Hyderabad Granitic Region of the Eastern Dharwar Craton (South Indian Shield): Evidence from AMT/CSAMT Experiment
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Authors
Affiliations
1 National Geophysical Research Institute, (Council of Scientific & Industrial Research), Uppal Road, Hyderabad - 500 007, IN
1 National Geophysical Research Institute, (Council of Scientific & Industrial Research), Uppal Road, Hyderabad - 500 007, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 74, No 6 (2009), Pagination: 697-702Abstract
Hyderabad granitic region (HGR) forms one of the most unusual geotectonic segment of the south Indian shield. Analysis of multiparametric geological, geophysical and IGS-GPS studies have earlier suggested that this region is neotectonically uplifting at a rapid rate. We propose that consequent to such uplift, only a thin veneer of surface granitic layer now remains. In order to quantitatively examine the thickness of highly resistive granitic-gneissic crust below HGR, a audio-magnetotelluric (AMT)/controlled source AMT (CSAMT) experiment was conducted at three separate locations, situated about 50 km east of Hyderabad. The study reveals a maximum thickness of 5.5 to 6.0 km for the granitic - gneissic crust beneath HGR, which is underlain by thick low resistive exhumed intermediate (granulitic ?) crust. This finding is in sharp contrast to that of a thick granitic-gneissic crust (15-20 km) usually found in comparable late Archaean terrains elsewhere.Keywords
Hyderabad Granitic Region, Audio-Magnetotellurics, Uplift, Resistive Crust, Granitic-Gneiss, Granulites, Crustal Velocity, Dharwar Craton.
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- Environmental Impact on Groundwater of Maheshwaram Watershed, Ranga Reddy District, Andhra Pradesh
Abstract Views :185 |
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Authors
Affiliations
1 National Geophysical Research Institute, Hyderabad - 500 007, IN
2 Geology Department, Osmania University, Hyderabad - 500 007, IN
1 National Geophysical Research Institute, Hyderabad - 500 007, IN
2 Geology Department, Osmania University, Hyderabad - 500 007, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 77, No 6 (2011), Pagination: 539-548Abstract
Maheshwaram watershed is situated in Ranga Reddy district of at a distance of about 30 km south of Hyderabad. The watershed has an area of 53 km2 and has hard rock aquifers with semi-arid climate. The study area has been expanding at a fast pace and now has the distinction of being one of the fastest growing urban centers, facing the problem of groundwater depletion and quality deterioration due to the absence of perennial source of surface water and also due to over exploitation. Human activities involving industrial and agricultural development and the inadequate management of land and water resources have, directly or indirectly resulted in the degradation of environment viz. water and soil.
In the present study chemical analysis of groundwater samples of the study area, collected in pre- and post-monsoon has been carried out. The analysed data is utilized to characterize the hydro chemical process dominant in the area. Various classification methods such as Piper, Back and Hanshaw, Wilcox, U.S. Salinity Laboratory are employed to critically study the geochemical characteristics of groundwater.