Journal of Geological Society of India 

About: Journal of Geological Society of India is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Geology & Geochemistry. It has an ISSN identifier of 0016-7622. Over the lifetime, 1665 publications have been published receiving 12884 citations.

The Tectonic Framework of Assam

Abstract: A spur of ancient rocks partly covered by gently-dipping Tertiary beds extends from the Shillong Plateau and Mikir Hills north-eastwards beneath the alluvium of Upper Assam. Over this spur the Eastern Himalaya have been thrust southwards and the Naga Hills have been thrust north-westwards. The amount of movement of the overthrust masses cannot be determined but it is suggested that in each case the total displacement may be 150-300 kilometres or even more. The Shillong Plateau is separated from the Surma Valley by a faulted monocline with southerly dips. This fault, the Dauki tear-fault, is now shown to have a probable horizontal displacement of about 250 kilometres, and thus to be a major feature of the tectonic pattern of the Indian sub-continent. The horizontal movement along the Dauki tear-fault detached the Shillong Plateau from the main mass of the Indian Shield. The principal movements occurred late in the Tertiary, mostly in the Pliocene.

Major Ion Chemistry of Groundwater in Delhi Area: Chemical Weathering Processes and Groundwater Flow Regime

Abstract: Groundwater is moderately to highly saline in all parts of Delhi area. No definite explanation has emerged so far about the source of salinity. Study of major ion chemistry of groundwater has been conducted to identify the source of major ions in terms of chemical weathering processes. The chemistry of groundwater is dominated by carbonate weathering. The excess of sodium ion over chloride ion can be attributed to silicate weathering to a certain extent. The groundwater in northern and western parts of the area is primarily alkaline and secondarily saline and in the southern and southwestern parts it is primarily saline and secondarily alkaline. Highly correlated positive linear trend between sodium and chloride indicates mixing of two groundwater bodies with different end member composition (i.e. fresh and saline). Multicomponent mixing may also be taking place within the local flow regimes. The large lateral variation of chloride concentration indicate recharge and discharge zones of local flow regime. Local recharge to the unconfined aquifer is more dominant than recharge from lateral flow. The very high Cl and SO 4 contents in some groundwaters seem to be related to long evaporative and to sulphur oxidising conditions in topographically low area.