(Table 1) Lipid and kerogen content at DSDP Leg 64 Holes

Diatomaceous mud and an organically-rich claystone from holes at Sites 474 and 476 at the mouth of the Gulf of California were analyzed by organic geochemical methods to characterize their organic matter. The lipids of all three samples are primarily marine autochthonous, with the exception of Sample 474-5-3, 105-107 cm, which also contains some vascular plant wax. Based on the lipid composition, the sediment was deposited mainly under oxic environmental conditions. The kerogens were aliphatic and autochthonous marine. Two lignite fragments were also analyzed, and the data indicate that they are driftwood that absorbed marine bitumen from the surrounding sediment during coalification.针对加利福尼亚湾口474与476站位钻孔中的硅藻土泥样及富有机质黏土岩，采用有机地球化学方法开展分析以表征其有机质特征。本次分析的全部3个样品中，除474-5-3样（层位105~107cm）外，其余样品的脂类物质均以海源自生成分为主；该异常样品还含有部分维管植物蜡质。基于脂类组成特征，可推断该套沉积物主要沉积于氧化环境条件下。干酪根类型以脂肪族为主，同样属于海源自生有机质。此外还对2块褐煤碎屑进行了分析，结果显示其为漂木，在煤化作用过程中吸收了周围沉积物中的海相沥青。