Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Rm. Ramanathan ¹

Affiliations
1 Department of Geology, Annamalai University, Annamalainagar, IN

Abstract

Seasonal quantitative distributions of the species of the living benthic foraminifera forming the greater part of the foraminiferal population in the Vellar estuary, South India have been studied. Recorded physico-chemical factors have played an important role in controlling the relative abundances of this microfauna. Estuarine foraminiferal assemblage in general shows a quantitative increase with increasingly marine conditions.

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Rm. Ramanathan ¹

Affiliations
1 Department of Geology, Annamalai University, Annamalainagar, IN

Abstract

Seasonal differences in the abundance of the benthic Foraminifera of the estuary are shown to be related to the standardized nomenclature of the sediment types relative to sand silt and clay.

The area with almost sandy substrate in November 1967 yields the lowest foraminiferal number due to the strongest currents caused by the floods observed in October 1967. The finest sediments and weaker currents are associated with the higher foraminiferal numbers in March and April 1968.

The most accommodative substrate for a higher foraminiferal number is found to be silty-clayey-sand, in which silt is dominating over clay.

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