Petrography of the Shuitian bitumen deposit, Hunan Province, China

Solid bitumen vein deposits were mined until recently in Shuitian, Hunan Province, China. The Shuitian bitumen veins occur in Lower Cambrian black siltstones beneath the pre-Cretaceous unconformity. The H/C ratio of the bitumen is very low, suggesting that the bitumen is very mature and can be classified as impsonite. The carbon in both the bitumen and the host rock is completely aromatic. The minerals associated with the bitumen are quartz, calcite, pyrite and barite. Two kinds of vanadium-bearing mineral inclusions, montroseite and roscoelite, occur within the bitumen. It can be deduced that the vein must have formed within the interval from Caledonian Orogeny to Cretaceous sedimentation, although there is not enough evidence to indicate the exact timing of the vein formation.