The detailed study of structural and tectonic history indicates several episodes of deformation, which caused repeated folds, faults, joints and fracture systems. The basement rocks are overlain by red soil, lateritic soil, clayey soil, river alluvium and coastal alluvium, black, red and red sandy soils of thickness ranging from 1 m to 1.5 m in most places. The area is underlain by the peninsular gneissic terrain of India. Sediments of Miocene were also deposited and identified as the Warkalai sandstones. Also, the sands of recent origin are noticed along the coast.. Penisular Gneisses occupy the largest area in the study places. The basement of the study area consists of charnockite, granite gneiss, Leptinite, Leptinite Gneiss, Peninsular Gneiss, Laterite, Warkalai Sandstone, Variegated Clay, River Alluvium etc.
Most of the wells used for irrigation are shallow and partially penetrating because once a considerable depth of water column is reached, farmers stop further deepening of wells.
Study on Hydrographs indicate that the groundwater table tends to rises during October and December to reach peak and starts receding from February onwards to the end of August to September. However a slight raising trend is seen during July because of Southwest monsoon rain.
Key words: Geological Parameters ,Coastal Area ,Arabian Sea , South Tamilnadu, India etc
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