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

P. Sreenivasa Rao ¹, T. Yeruku Naidu ¹, G. Satyanarayana ¹

Affiliations
1 Andhra University, Department of Geology, Waltair 530 003, IN

Abstract

Benthic foraminifera from surface sediments of Nizampatnam Bay were studied to determine modern distribution of important assemblages. Q-mode factor analysis of the data distinguished four significant factor assemblages that account for 91.9% of the information given in original data matrix. These assemblages are: 1. Asterorotalia, 2. Quinqueloculina and Spiroloculina, 3. Ammonia and Ammobaculites, 4. Amphistegina. These assemblages show response to environmental variables such as substrate and organic matter content. Abundance of Asterorotalia and Ammonia assemblages (factors I and III) probably reflects organic enrichment of fine sediments in the bay. Quinqueloculina and Amphistegina assemblages (factors II and IV) are found in the sandy substrate in the form of reworked fauna.

Keywords

Palaeontology (General), Marine Geology, East Coast of India, Foraminifera, Nizampatnam Bay, Andhra Pradesh.

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T. Yeruku Naidu ¹, S. Kamalakaram ¹, R. Kaladhar ¹

Affiliations
1 Department of Geology, Andhra University, Visakhapatnam - 530 003, A.P., IN

Abstract

The Goguleru creek is a supralittoral brackish water creek located between Krishna and Godavari Delta in coastal Andhra Pradesh. The creek is divisible into the two domains of drain and lagoon. R-Mode cluster analysis was carried out on benthic foraminiferal total population for the months of December 1988 (Winter) and May 1989 (Summer) and four and three major biofacies were recognized respectively. Two of the biofacies are dominated by agglutinated forms while the others are dominated by Ammonia and Asterorotalia. The distribution of these biofacies corresponds to characteristic sub-Environments present in the creek, such as marshy, brackish and open-Sea near shore/Beach. Such studies may help to recognize similar paleoenvironments.

Keywords

Recent Benthic Foraminifera, Biofacies, Environmental Significance, Goguleru Creek, Coastal Andhra Pradesh.

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