Distribution of Phosphate in Sediments of the Northern Half of the Western Continental Shelf of India

Abstract

The study has revealed that (i) P₂O₅ content in the sediments varies from 0.17 to 1.2%, (ii) fine grained sediments of terrigenous origin occupying inner shelf region between Gulf of Cambay and Port Dabhol and greater part of the shelf region north of Gulf of Cambay up to Indus Canyon contain low percentages of phosphate ( 0.2 to 0.3%), typical for normal marine sediments, while the relict zone of the outer shelf region between Gulf of Cambay and a little south of Bombay and the upper Continental slope region contain relatively high content of P₂O₅ and (iii) P₂O₅ content of the acid soluble fractions of the sediments also exhibits a similar trend. These distribution patterns are discussed in relation to the distribution patterns of the sediments and their chemistry and the hydrographic features of the overlying waters. From these studies, it is suggested that the outer shelf region between Gulf of Cambay and a little south of Bombay and the Continental slope region are environmentally favourable for detailed exploration of phosphate.