TERPENOID COMPOUNDS IN AN IMMATURE SOURCE ROCK

There are abundant terpeooid compounds in terrestrial immature source rocks of our country. A sample taken from Tertiary immature source rocks is analysed by GC-MS. It is identified that more than 20 terpenoid compounds in the sample, which are rarely observed in low-mature or mature source rocks. The identified compounds are as follows: The peak A is a C19 tricyclic terpane related to abietic acid and is thought to represent an evidence for the contribution of higher plant materials, the peak B, D, E are C24 saturared tetracyclic terpanes, and their m. w. are 330. The peak G belongs to C30 triterpene. The peak H is a mixed one which includes C29 and C30 triterpenes and C30 triterpane. The peak I belongs to a terpenoid compound also and is not clear in its structure. The peak K1 is a neohop-13 ( 18 )-ene. The peak K2 is identified as a terpenoid compound with unknown stucture. The peak Ks is also a mixed one which includes C29 17α(H) norhopane, C30 triterpene and Cso triterpane. The peak L is mixed one too and consists of C29 17β ( H ) normortane and neohop-12-ene. The other peaks such as N. 0, P, R are the triterpanes which are common components in low mature or mature source rocks and crude oils.