铁岭灰岩晶包有机质的甾萜烷在高温高压条件下演化特征  

Evolution characteristics of steranes and terpanes in crystal-enclosed organic matter in Tieling limestone under high-temperature and high-pressure

作　　者：解启来[1] 范善发[1] 周中毅[1] 

机构地区：[1]中国科学院广州地球化学研究所,广州510640

出　　处：《地球化学》1999年第6期596-604,共9页Geochimica

基　　金：国家自然科学基金!49572125

摘　　要：铁岭灰岩模拟产物的残留烃中，甾萜烷的含量很高，伽马蜡烷含量较高，三环萜烷和四环萜烷含量较低，几乎不含脱甲基藿烷系列。残余晶包有机质仍保持着模拟实验前晶包有机质的甾萜烷分布特征，即三环萜烷和四环萜烷含量较高，脱甲基藿烷系列高于正常藿烷，甾烷仍保持着降解前原貌。残留烃、残余晶包有机质和原岩晶包有机质的甾萜烷特征对比表明，实验过程中残留烃的甾萜烷是由干酪根和晶包有机质共同产生的，但以干酪根为主。同时也说明，干酪根热降解形成的甾萜烷没有加入到残余的晶包有机质中去，晶包有机质保持着独特的热演化进程。压力影响甾烷的异构化程度，高压下的C29ααα甾烷20S／（20R＋20S）和ββ／（αα+ββ）比值较低压同温度下的低，压力对萜烷异构体参数影响不明显。The residual hydrocarbons generated from the kerogen of Tieling limestone contain abun-dant pentacyclic triterpanes and steranes, lower contents of tetracyclic terpanes and rare25-norhopane. The residual crystal-enclosed organic matter maintains the original distributioncharacteristics of steranes and terpanes before the simulating experiments, having high contentsof tricyclic and tetracyclic terpanes, high ratios of 25-norhopanes to regular hopanes andmarkedly degradational steranes. The comparison of the residual hydrocarbons, the residualcrystal-enclosed organic matter and the original crystal-enclosed organic matter indicates thatthe steranes and terpanes in the residual hydrocarbons are produced mainly by kerogen andslightly by the residual crystal-enclosed organic matter, that the steranes and terpanes generatedfrom the kerogen do not mix into the residual crystal-enclosed organic matter, and that thecrystal-enclosed organic matter remains distinctive evolution process. Furthermore, pressureinfluences C29-sterane isomerization ratios and makes the ratios of 20S/ (20S + 20R) and ββ/(αα+ββ) lower in high pressure than that in low pressure- However, pressure influencesterpane isomerization ratios slightly.

关 键 词：灰岩 晶包有机质 甾萜烷 高温高压 模拟实验 

分 类 号：P593[天文地球—地球化学] P618.130.2[天文地球—地质学]