Informatics Publishing Limited

A. H. M. Ahmad ¹, A. Majid ¹

Affiliations
1 Department of Geology, Aligarh Muslim University, Aligarh - 202 002, IN

Abstract

The Kachchh Basin is a pericratonic rift basin situated at the western margin of the Indian plate. The Habo Dome embodies an important exposure of Bathonian to Kimmergian sediments among the Kachchh Mainland exposures. Based on vertical facies transitions, facies associations were documented: mixed shallow marine (Facies association 1), shoreface and lagoon deposits (Facies association II) and subtidal innershelf below fair weather wave base (Facies association III). The documented facies associations reflect that Habo Dome sediments deposited in a variety of environments from shallow marine to fluvio-deltaic and were strongly influenced by fluctuation of relative sea level. The dominance of floating grains and point contacts in the sandstone indicate that detrital grains do not show much pressure effects as a result of either shallow burial or early cementation. The sandstones were cemented by iron oxide, carbonate and silica in order of abundance. Three types of cements, blocky, rim and fibrous cement occur in the studied limestone representing phreatic, fresh water phreatic and deep burial diagenetic stages. Neomorphism and micritization are common. Both primary and secondary porosity exists in these sediments. Different graphs of porosity versus depth suggest a depth of burial in the range of 615-769 m.

Keywords

Sandstone, Facies Analysis, Depositional Environment, Petrography and Diagenesis, Kachchh, Gujarat.

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A. Majid

Abstract

Both filtered and unfiltered water supply systems exist in the city of Calcutta. Filtered water is meant for drinking purposes and unfiltered water for street watering, fire extinguishing and flushing privies, drains etc. There are a few tube wells up to 6" dia. with pumping arrangement for augmenting filtered water supply in scantly supply areas. During war time 2700 Nos. 1 1/2" dia. tube wells were sunk as an emergency measure of which about 1300 are being maintained to cope with the increased demand for drinking purposes. Private tube wells more or less 500 in number may be found inside premises. Supply of filtered water in the outskirt of the city where there is no water main or the pressure does not reach is made by 10 lorries of 800 gallons capacity. Such supply is nearly 50,000 galls, daily.

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