GEOCHEMISTY OF BICYCLIC ALKANES IN SEDIMENTS, COAL AND CRUDE OILS

By using GC-MS to analyze the extracts of source rocks, coal and crude oil samples formed in different sedimentary environments in China, New Zealand and Australia, twenty- two compounds of five types of bicyclic alkanes have been dis covered in the samples. This paper makes an exposition of stereochemical structure, abundance and distributive features of these compounds and their relation to sedimentary environments and thermal evolution. Furt- thermore, it demonstrates how the abundance ratios of bicyclic alkanes to steranes and ter- panes, drimane to homodramane and the relative abundance of C_(15),C_(16),C_(12)-C_(14) series of bicyclic- alkane compounds can be used to judge and determine types of oil and gas forming environ- ments (the depositive environments of source rocks from which the oil and gas were formed), characteristics of source rocks and degree of maturation.