Abstract:

Maantang formation is of marine limestone,argillite and siltstone,while Xiaotangzi formation is mainly composed of delta-front deposit of tran sition zone from marine to land,rich in marine and terrigenous plant fossils.In the past,they were considered as one of the major source beds in northwestern Sichuan.On the basis of analyses by various mordern apparatus,the author made a study of geochemical features of kerogen in these two formations,we concluded that both of the two formations had been hydrocarbon-generating,but neither of them is a good source rock.In comparison between the two,Maantang formation is better than Xiaotangzi fomation.