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

M. Ramkumar ¹, P. Sudha Rani ¹, M. S. Gandhi ¹, M. Pattabhi Ramayya ¹, V. Rajani Kumari ¹, K. V. S. Bhagavan ¹, A. S. R. Swamy ¹

Affiliations
1 Delta Studies Institute, Andhra University, Visakhapatnam - 530 003, IN

Abstract

Textural data of the sediments of Godavari delta indicate the control of energy over grain size and other statistical parameters. These parameters also explain the regional energy conditions, which are indicative of many sub-environments. The prime environmental factors viz. transportation, deposition and preservation vary in time and space, which in turn, produce variability as well as shared nature of grain size characteristics. Many sub-environments have similar depositional/energy regimes making their distinction a difficult task. It is also established that only groups of environments could be delineated, rather than individual environments, based on manual observations and discriminant plots of textural data.

Keywords

Texture, Grain Size, Statistics, Sedimentary Environments, Godavari Delta.

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M. S. Gandhi ¹, J. Seetharamaiah ¹, P. Bhanu Murty ¹

Affiliations
1 Delta Studies Institute, Andhra University, Visakhapatnam - 530 003, IN

Abstract

A simple but very effective and inexpensive indigenous method of vibracoring has been developed for acquisition of continuous cores in subaqueous environments at water depths of below 2m. The principal components are the following: 3.5 HP concrete vibrator, irrigation PVC tube, tripod and pulley. The entire system weighs 50 kg. and approximately costs about Rs.25,000/-. This system was operated successfully in the transitional sedimentary environments of the East Coast deltas by collecting around 100 cores averaging to 2 m in length. Sediments ranging from clay to coarse sand have been recovered using this system. Percentage of recovery was usually 60 to 100 and distortion of delicate sedimentary structures was generally minor.

Keywords

Vibracoring, Deltaic Environments, Andhra Pradesh.

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