IDENTIFICATION OF A NOVEL SPECIES OF HEXACYLIC A ROMATIC HOPANOIDS AND DISCUSSION OF THEIR GEOCHEMICAL SIGNIFICANCE

Beazohopanoid series(C₃₁-C₃₅)have been studied and a new species-C₃₁ben- zohopane(CZB-norbenzohopane)was first identified in black mud-stones from 6 core samples in Jugi Basia(Lower Cretaceous Strata).They are particularly abun- dant in carbonaceous shales,which representative of acid medium in marsh enviro- meat, Though assumed to be formed in the early stage of diagenesis, from bacterial Cas hopanoid precusors, they might also be reserved in the later stage(up to the depth of 3700m).Two possible evolution mechnisms were proposed and the remark- able phenominon that the high concentration of benzohopanoids matches the low ra- do of Ts/Tm was observed, The ratio of C₃₁benzohopane/hopanes can be a new indicator of organic maturity,