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

S. G. D. Sridhar ¹, S. M. Hussain ², P. Periakali ¹, V. Kumar ³

Affiliations
1 Department of Applied Geology, University of Madras, Guindy Campus, Chennai - 600 025, IN
2 Department of Geology, School of Earth and Atmospheric Sciences, University of Madras, Guindy Campus, Chennai - 600 025, IN
3 Department of Geology, National College, Tiruchirappali - 620 001, IN

Abstract

The shallow marine and tropical ostracod taxon Kotoracythere inconspicua(Brady) is encountered from the surface sediments of Indian waters Fifty-Two sediment and bottom water samples were collected over an year, representing the four seasons, in a transect (depth 0-13 m) off Rameswaram, southeast coast of India. Living specimens of this species are found in all the seasons. Systematics and ecology of the species are presented Biogeographically, this taxon has an extremely wide distribution in tropical, littoral zones of all oceans, excepting east Pacific. Its wide geographic distribution is explained through currents and by passive dispersal by ships.

Keywords

Ostracoda, Ecology, Biogeography, Palk Bay, Indian Ocean.

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V. Kumar ¹, D. Srjnivasan ¹

Affiliations
1 Department of Geology, National College, Tiruchirapalli, IN

Abstract

Foraminiferal distribution of the Coleroon i iver estuary, Tamil Nadu is studied by statistical 'Factor Analysis' Fortius study, 56 sediment and bottom water samples were collected from 14 stations, once in thiee months repiesenting foui seasons In ordei to study the relationship between foiaminifera and present day environment, living fonns alone are considered 56 foiaminiferal species belonging to 31 genera have been identified of which 13 are arenaceous agglutinated, 11 aie calcareous porcelaneous and remaining 32 are calcareous perfoiate forms

In the present woi k three assemblages alone are taken since they explain more than 93% of the total variance From factor analysis, it is infeired that there are two distinct assemblage zones in all the seasons The first and dominant assemblage zone is highly loaded in station 5 and is influenced by greater depth, higher salinity values, associated with higher fines (gieatei than 30% silt and clay) and highei CaCO., content of the substrate The second zone is predominant in station 1 and is influenced by the sandy substrate, lesser fines and lesser organic matter of the substrate.

Keywords

Benthic Foraminifera, Factor analysis, Coleroon Estuary, Tamil Nadu.

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