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

V. Sharma ¹, Surender Singh ¹

Affiliations
1 Department of Geology, University of Delhi, Delhi-110007, IN

Abstract

A study of the radiolarian assemblage from the Sawai Bay Formation (Early Pliocene) exposed in Car Nicobar bland shows the presence of age diagnostic radiolarian taxa. Based on the radiolarian zonation applicable for the tropical Indian Ocean, three radiolarian zones are identified in this formation. These, in ascending order, are: Phormostichoartus doliolum zone, P. fistula zone and Stichocorys peregrina Zone. The radiolarian events (first and last appearances) recognised in the Car Nicobar sequences are discussed in relation to those in the Central Indian Ocean Basin. The proposed radiolarian zones are correlated with the previously proposed planktonic foraminiferal zone in the study area, and an htegrated biostratigraphic scheme is presented.

Keywords

Car Nicobar, Pliocene, Radiolarian Zonation, Micropaleontology, Northeast Indian Ocean.

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Hsin Yi Ling ¹, V. Sharma ², Surender Singh ², D. Mazumdar ², A. K. Mahapatra ²

Affiliations
1 Department of Geology, Northern Illinois University, DeKalb, Illinois 601 15, US
2 Department of Geology, University of Delhi, Delhi-110 007, IN

Abstract

Radiolarians from seven samples of ejected sediments of mud volcanoes of Baratang Island in the Andaman Sea provide additional evidence for the presence of Cretaceousand MiddIe Eocene strata beneath the island. A general NNE-SSW alignment of the mud volcanoes suggests the structural control for their occurrence due to regional tectonics.

Keywords

Radiolaria, Mud Volcanoes, Cretaceous, Eocene, Andaman Sea, Indian Ocean

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