Occurrence of Upper Oligocene - Lower Miocene Rocks in the Upper Continental Slope, off the Southern Part of Cauvery Basin

Seabed survey off the southern part of Cauvery basin revealed the exposure of well indurated ferruginous fossiliferous limestone in the upper continental slope ESE off Nagapattinam. The presence of benthic foraminifera] fossil viz. Miogypsina sp. assigns Upper Oligocene - Lower Miocene age to the ferruginous limestone. The limestone exposure in the upper continental slope suggests the northeasterly offshore extension of the sub-basin viz., Ramnad - Palk Strait Depression.