The genesis of coal from the viewpoint of coal petrology

Recognition of peat depositional environments in coal: A review

Coal facies interpretations based on lithotype and maceral variations in Lower Cretaceous (Gates Formation) coals of western Canada

Origin of inertinite-rich coals of Australian cratonic basins

It has been long recognized that fine-grained sediments of both siliciclastic and carbonate compositions are the principal source rocks of petroleum. The common coincidence of significant, and often high, content of organic matter within such sediments, as first comprehensively documented by Trask and Wu (1930), provided the initial clue and support for this now generally accepted opinion.

Deposition of petroleum source rocks

Petrographic composition of coal seams is discussed in connection with the rate of subsidence in some Australian sedimentary basins. Cyclic variation of floor/dirt band --> vitrinite-rich coal --> vitrinite-poor coal --> dirt band/roof can be seen within a seam. Coal seams deposited under unstable conditions are composed of incomplete cycles which lack vitrinite-poor coal, and so are rich in vitrinite, while coal seams deposited under stable conditions are composed of a few complete cycles, and are relatively poor in vitrinite. Such a contrast between coal seams can be seen within a sedimentary basin such as the Sydney Basin in Australia. Coal seams in "shelf sediments" on the stable basement rocks are, for the same reason, much poorer in vitrinite than those deposited under more variable conditions.

M. Shibaoka

Papers

Coal petrology and the formation of coal seams in some Australian sedimentary basins