摘要
本文通过热模拟实验揭示了木质褐煤中综合有机母质与干酪根在热演化过程中形成五环三萜类和８，１４－断藿烷的差异，并探讨了这两类化合物的地球化学意义．综合有机母质生成的五环三萜类数量多、化合物种类也多，干酪根降解生成的数量小、化合物种类也少，８，１４－断藿烷主要由非干酪根物质转化而成，干酪根降解基本上不生成这类化合物。藿烷参数Ｔｓ／Ｔｍ、Ｃ３１αβ２２Ｓ／２２（Ｓ＋Ｒ）、Ｃ３２αβ２２Ｓ／２２（Ｓ＋Ｒ）和８，１４－断藿烷多数Ｃ２７８β（Ｈ）／８α（Ｈ）、Ｃ２８８β（Ｈ）／８α（Ｈ）是良好的热演化指标；藿烯和生物藿烷同时存在或生物藿烷单独存在分别指示未成熟和低成熟。
Pyrolysis was done by two methods, the Y series of experiments showed the process of comprehensive original organic matter evolved and the Z series showed the process of only kerogen evolved. The comprehensive original organic matter was composed of non-kerogen matter and kerogen, so based on the two series of experiments we can study deeply how triterpenoids are generated and how they change.From the result of pyrolysis, this paper showed the differences between the comprehensive original organtic matter generated from both non-kerogen matter and kerogen and from only kerogen, and approached geochemical significance of the triterpenoids.The comprehensive original organic matter generated much more pentacyclic triterpenoids than kerogen did, so most pentacyclic triterpenoids were yielded by the non-kerogen matter.In Z series, there were no 8, 14-secohopanes, it's clear that the kerogen didn't yield 8, 14secohopanes. In Y zeries, when the temperature was 400℃, the pentacyclic triterponoids disappeared but 8, 14-secohopanes remained and were abundant, so the pentacyclic triterpanoids changed into 8, 14-secohopanes in high temperature.Hopanes, hopenes and 8, 14-secohopanes are all able to indicate maturity. At 250℃ hopenes were very abundant, but at 300℃ they disappeared, so they can indicate immaturity.Biohopanes are instable, too, when it was 350℃ they disappeared, so they can indicate lowmaturity. Three hopanes parameters and two 8, 14-secohopane ones were calculated. With the rising of the temperature, the two parameters Ts/Tm and C31αβ22S/22 (S+R) increased slowly in the beginning, but when the temperature exceeded 300℃, the parameters increased quickly;when it changed from 250℃ to 300℃, the parameter C32αβ22S/22 (S+R) remained the same, but when it was higher than 300℃, it increased quickly ; the two 8, 14-secohopanes parameters C278β(H) /So (H) and C288β(H) /8α(H) decreased quickly when it was lower than 300℃, and decreased slowly when it was higher than 300℃. The five Parameters al
出处
《沉积学报》
CAS
CSCD
北大核心
1996年第A00期100-106,共7页
Acta Sedimentologica Sinica
基金
国家科委重点资助项目
关键词
褐煤
木质褐煤
三萜类化合物
热模拟
wood brown coal pentacyclic triterpenoids 8, 14 -secohopane pyrolysis
