The influence of bottom water oxygenation and reactive iron content on sulfur incorporation into bitumens from Jurassic marine shales

Abstract

Sulfur isotope studies of bitumens (dichloromethane-extractable) from Jurassic marine shales indicate that most sulfur is derived, at least initially, from diagenetic sulfate reduction. Under euxinic or semi-euxinic onditions sulfur incorporation in the Jet Rock and Posidonienschiefer bitumens appears to post-date formation of most syngenetic pyrite but occurs contemporaneously with the formation of small concentrations of later pyrite, relatively depleted in 32S. -from Authors