Journal of The Geological Society of India 

About: Journal of The Geological Society of India is an academic journal. The journal publishes majorly in the area(s): Groundwater & Metamorphism. Over the lifetime, 4172 publications have been published receiving 36435 citations.

Drastic: A Standardized System to Evaluate Groundwater Pollution Potential using Hydrogeologic Setting

Abstract: DRASTIC is a methodology which allows the pollution potential of any area to be systematically evaluated. The system optimizes the use of existing data and has two major portions: the designation of mappable units, termed hydrogeologic settings, and the superposition of a relative ranking system called DRASTIC. Hydrogeologic settings incorporate the major hydrogeologic factors which are used to infer the potential for to enter groundwater. These factors form the acronym DRASTIC and include depth to water, net recharge, aquifer media, soil media, topography, impact of the vadose zone and hydraulic conductivity of the aquifer. The relative ranking scheme uses a combination of weights and ratings to produce a numerical value, called the DRASTIC Index which helps prioritize areas with respect to pollution potential.

Crustal Structure Along Kavali-Udipi Profile in the Indian Peninsular Shield from Deep Seismic Sounding

Abstract: Deep Seismic Sounding (DSS) studies were initiated for the first time in India under a 3-year Indo-Soviet collaboration agreement starting 1972, along a 600km long roughly ENE-WSW profile which lies near 14°N latitude, extending from Kavali on the east coast of India to Udipi on the west coast. A crustal section is depicted along the Kavali-Udipi profile, showing a large number of reflectors from about 2 km to about 50 km depth. The 600 km long section consists of 17 major blocks, besides a few smaller ones. It is cut up by 15 major deep faults and two major low angle thrusts. In addition there are 5 faults/thrusts extending to intermediate depths. The geological evolution of this part of the shield probably began in Early Proterozoic with the formation of the Dharwar geosyncline between Parnapalle and Agumbe, This was divided into two parts by the uplift of the block where Closepet granites are now exposed. The Dharwars in the eastern part are now almost completely eroded, exposing their basement. The Moho here is at an average depth of 35-36 km, going down to 38 km below Dharmavaram. In the western part, where there is a large thickness of Dharwars still present, Moho is more or less flat at a depth of 38 km, going down to 41 km below Holalkere and rising about 36 km below Chennagiri, The basement of the schist belt here varies from 4 to 7 km in depth. The Cuddapahs must have been deposited starting near Parnapalle eastward due to en-echelon type faulting. Moho goes down from 34km below Parnapalle to 40 km below Duttaluru. The block between Maidukuru and Malepadu subsided later to create a fresh depression in which the Kurnools were deposited. In general, the basement of the Cuddapahs is at a depth of 8-10 km. The Cuddapahs, on their eastern margin, have been subjected to a major low angle thrust.

Structure and tectonics of Kutch Basin, western India, with special reference to earthquakes

Abstract: The Kutch basin is a western margin pericratonic rift basin of India. Nagar Parkar uplift in the north and Kathiawar uplift (Saurashtra horst) in the south respectively along Nagar Parkar and North Kathiawar faults delimit the E-W rift. The Kutch rift was initiated during the Late Triassic break up of the Gondwanaland by the reactivation of primordial faults in the Precambrian Delhi fold belt. The rifting was aborted during Late Cretaceous pre-collision stage of the Indian plate. During post-collision compressive regime of the Indian plate, the Kutch rift basin became a shear zone with strike-slip movements along sub-parallel rift faults. The Kutch Mainland Fault along the rift axis became the active principal fault. Presently, this right lateral strike-slip fault is overstepped by the South Wagad Fault in the eastern part of the basin. The overstep zone between the two wrench faults is a convergent transfer zone undergoing transpressional stress in the strained eastern part of the basin. The epicenters of two big earthquakes as well as the aftershock hypocenters of Bhuj earthquake are located within this zone. The study of the intrusive rocks, rift geometry and seismic tomography indicates presence of a large ultramafic body in the lower crust. An overview of the structural and tectonic evolution of the basin is discussed in the context of earthquakes. Based on structural and detailed depth-wise analysis of aftershock data, a conceptual domino-listric model of Kutch rift is presented here. On the basis of this model, an attempt is made here to explain the dynamics of the earthquake generation in the Kutch basin.

Morphometric Analysis of a Watershed of South India Using SRTM Data and GIS

Abstract: An attempt has been made to study drainage morphometry and its influence on hydrology of Wailapalli watershed, South India. For detailed study we used Shuttle Radar Topographic Mission (SRTM) data for preparing Digital Elevation Model (DEM), aspect grid and slope maps, Geographical information system (GIS) was used in evaluation of linear, areal and relief aspects of morphometric parameters. The study reveals that the elongated shape of the basin is mainly due to the guiding effect of thrusting and faulting. The lower order streams are mostly dominating the basin. The development of stream segments in the basin area is more or less affected by rainfall. The mean Rb of the entire basin is 3.89 which indicate that the drainage pattern is not much influenced by geological structures. Relief ratio indicates that the discharge capability of these watersheds is very high and the groundwater potential is meager. These studies are very useful for planning rainwater harvesting and watershed management.