Sediment chemistry of Kau Bay, Halmahera (Eastern Indonesia)

Abstract

Kau Bay is a 470-m-deep basin separated from the Pacific Ocean by a shallow sill, the top of which is 40 m below sea level. The presence of this sill restricts water circulation. The lack of substantial ventilation results in anoxic sediments, the chemistry of which has been studied. Using statistical techniques we recognize five factors that influence the chemistry of Kau Bay sediments: an aluminosilicate, a carbon-sulphur, a biogenic carbonate, an authigenic carbonate and a detrital mineral factor. We relate the depth distribution of these factors to diagenetic, sedimentological and ecological processes occurring in and outside Kau Bay.