对赤道中东太平洋和赤道西太平洋4个柱状样中有机碳、可溶有机质(即氯仿沥青“A”)及其族组成(总烃、饱和烃、芳烃、非烃)、某些生物标志物(正构烷烃、类异戊二烯烃和萜类)分布特征进行物性和源性的地球化学对比研究,并对它们的共性和差异性进行了探讨。结果表明:它们的共性是非烃含量高,而饱和烃和芳烃含量低,饱和烃与芳烃的比值小,类异戊二烯含量高,样品的碳优势指数CPI值为0.812-1.380,Ts/Tm的比值在0.99-1.50,反映了检测出的分子化石经历了一定的成岩作用改造,具有低成熟烃特点。4个站位的有机质都处于低演化阶段,演化程度大小为WP02-1〉ES0103〉W2001-2〉MP2001-01。由于物性、源性以及沉积环境的差异,正构烷烃的特征可以分为两类:MP2001-01柱样沉积物中正构烷烃谱图呈双峰型分布,前低碳峰群以nC17和nC18为主峰,后高碳峰群以nC27和nC29为主峰,nC2-3/nC2+4为0.631-0.950,表征了主要以海洋低等菌藻类和陆地高等植物两种混合来源;而W2001-2,ES0103和WP02-1三个站位的谱图呈单峰型,并以与水生大型植物有关的C25为主峰(nC25为主峰,nC24次之,个别为nC23)的中等碳链长占优势,nC2-3/nC2+4为0.081-0.234,表明正构烷烃主要来源是海洋水生大型植物,藻类对这些海域低熟烃的形成作出了巨大贡献。这3个站位Pr/Ph为0.215-0.901,反映出这些站位处于强还原、还原或少数弱氧化环境,还原环境在低熟烃形成和保存过程中发挥了重要作用。
Chloroform bitumen"A", saturated-hydrocarbon, arene, nonhydrocarbons, n-alkannes isoprenoids and terpenoids of samples of four stations from the equatorial Pacific area were analyzed by the gas chromatography method. The result showed that the content of nonhydrocarbon was higher than those of saturated-hydrocarbon and arene, and the value of saturated-hydrocarbon/arene was relatively lower. The order of evolvement was WP02--1〉 ES0103 〉 W2001--2 〉 MP2001--01. All of the samples could be divided into two groups according to the character of n-alkanes. The characteristic of one group was single peak form with high-carbon. The range of CPI and nC23^-/nC24^+ was 0. 812-1. 380 and 0. 081-0. 234, respectively. These indicated that the source of the n-alkanes was mainly aquatic higher macrophytes origin. The other group of n-alkanes come of both lower thalloses and terrigenous origin according to their CPI with 0. 983- 1. 382 and nC23^-/nC24^+ with 0. 631-0. 950, and double peaks of gas chromatography. All the samples we studied were low-mature hydrocarbon and reductive environment played an important role in the formation and preservation of low-mature hydrocarbon.