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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Ch. Venkateswara Rao ¹, B. Nagamalleswara Rao ¹, C. Kasipafhi ¹, K. Vasudev ¹, K. V. V. Saiyanarayana ², R Kaladhar ¹, G. Satyanarayana ¹, D. Markandfya Rao ¹

Affiliations
1 Department of Geology,Geophysics Andhra University, Visakhapatnam - 530 003, IN
2 Department of Geology, Geoengineering Andhra University, Visakhapatnam - 530 003, IN

Abstract

Forty eight Geoelecti ical soundings (GES) were earned out on Alluvium (Al), sandstones of Rajahmundiy (RS) ot uppei Miocene, Tnupati (TS) of Juiassic and Deccan Tiaps (DT) of Eocene ages to delineate aquifeis around Rajahmundiy, East Godavaii Distnct GES show H,K,A and K A type representing three to four layered sub suitacelitho units Based on prehminaiy pump tests and lesistivity study, the aieacun bedemaicated into thiee groundwatet zones RS having 3 to 40 m thickness with lesistivity range of 2 6 to 63 Qm giving yield of 24000-1,13100 I ph. and aieas ot TS thickness 2 4 to 11 m with lesistivity range ot 3 3 to 57 Qm with yield of above 39600-49500 lph which are consideied as good potential zones The highly weathered DT, having thickness of 5 4 to 30 m with resistivity lange ot 1 32 to 10 Q.m have modeiate yield of 34000 38400 lph Based on the geoelectrical and hydiogeological studies ot the area ten sites weie recommended foi tube/boie well dulling with expected yield of 45420 68130 lph.

Keywords

Hydtogeology, Geoelectrical sounding, Sandstone, Deccan tiap, Rajahmundry, Andhra Pradesh.

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I. V. Reddy ¹, M. S. Reddy ¹, G. Satyanarayana ¹, V. K. K. kalluraya ¹

Affiliations
1 Geological Survey of India, Hyderabad, IN

Abstract

New finds of oligomictic conglomerate at the base of Culcheru Quartzite near Venganamala and at the base of Nagari Quartzite at Gadikota are reported. It is proposed that the Nagari Quartzite and Pullampet Formation arc unconformably overlain by Bairenkonda Quartzite and Cumbum Formation, thereby necessitating a stratigraphic revision of thc Nallamalai Group.

Keywords

Conglonierate Horizon, Stratigraphy, Cuddapah Basin, Andhra Pradesh.

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