研究样品采自太平洋东部W2001-2站位(154°07′42″W,10°30′34″N,水深5102m),以无扰动多管采样方式采样。本文通过研究氯仿沥青"A"、有机质和有机分子与微量元素的关系,探讨了有机质在柱样形成中的作用。结果表明,大致以21-33cm和33-48cm为界线,呈现出系统的变化规律:正构烷烃呈单峰群分布,主碳峰为C25,碳优势指数(carbon preference index,CPI)为0.90-1.26,略显奇偶优势,反映出正构烷烃的母质除了少部分来自海洋菌藻类,主要来自洋底较深处软泥。低的姥鲛烷/植烷(Pr/Ph〈0.81),反映了柱样的强还原环境性质。饱和烃/芳烃比值低,存在大量不饱和烃(非烃+沥青质为49.63%-59.66%),富含有利于早期成烃的特殊组分,并长期处于低演化阶段,以上特征均显示出样品的低成熟特点。研究还表明元素Ti和V与有机碳、氯仿沥青"A"呈正相关性;元素P、Mg和Mn与有机碳、氯仿沥青"A"呈明显负相关性,与非烃也有一定的相关性,这些提供了低成熟度条件下有机质的组成特点及其与化学元素作用的证据。
Core W2001-2 was obtained with a multi-tube sampler in the Eastern Pacific Ocean at water depth of 5102 m(154°07′42″W,10°30′34″N).Chloroform bitumen "A," organic matters and microelements were analyzed in order to investigate the effect of organic matters on sediment diagenesis.The results showed that the distribution of Core W2001-2 presented obvious changes,especially at the lines of 21—33 cm and 33—48 cm.The n-alkanes showed dominance in C25 and distribution in unimodality.The CPI(carbon preference index) value was between 0.90 and 1.26 with a slight odd-even predominance,indicating that organic matters sourced mainly from deeper submarine ooze as well as a little from marine algae.The lower ratios of Pr/Ph(0.81) suggested a strong reducing environments.The characteristics of low contents of saturated hydrocarbon and aromatic hydrocarbon,with high contents of non-hydrocarbon compounds including non-hydrocarbon and asphaltene that amount is in the range of 49.63% to 59.66%,indicated that the property of the sediment was at a low-mature stage.The results also showed that organic matters and chloroform bitumen "A" had a positive relativity to Ti and V,but an inverse relativity to P,Mg and Mn.These relations confirmed the interactions between organic matters and some elements under low-mature conditions.