DISTRIBUTION OF MINOR ELEMENTS IN THE SHELF AND DEEP-SEA SEDIMENTS OFTHE NORTHERN ARABIAN SEA

Results on the distribution of minor elements (Cu, Ni, Cr, Co, Pb and V) in the surficial sediments of the northern Arabian Sea (latitude 15 -20-degrees-N, longitude 65-73-degrees-30'E) are presented. Based on t he texture of the sediments and the distribution of clay minerals, the study area is divided into three regions: (1) the inner shelf, of sil ty-clay enriched with montmorillonite; (2) the outer shelf, dominated by sand and illite; and (3) the deep sea, consisting of clayey silt. E xcept for Pb, all elements showed relative enrichment in the inner she lf and deep sea when compared with outer-shelf sediments, in accordanc e with their texture and grain size parameters. Metal/Al ratios indica te their occurrences in both lithogenous and non-lithogenous fractions . Most of these elements are detrital in origin and are primarily pres ent in montmorillonite, illite, amphiboles, pyroxenes, garnets, feldsp ars and ilmnite. Adsorption on Fe-Mn oxides and incorporation in authi genic minerals, such as anatase, are the other possible sources of the se trace elements in the sediments.