Journal of Petroleum Geology, Vol.2, No.2, pp. 199-218, 1979

©Copyright 2000 Scientific Press, Ltd.

EPISODES OF SOURCE-SEDIMENT DEPOSITION (1)+

F. K. North*

*Carleton University, Ottawa, Canada.

+Part 2: "The Episodes in Individual Close-up" and the Specific References for Parts 1 and 2 will appear in Vol. 2, No. 3.

Abstract

The very unequal distribution of prolific oil basins, in both space and time, is due less to capricious preservation of the oil than to the relative rarity of rich, effective source sediments. There appear to have been only four intervals during which effective source sediments achieved geographically widespread deposition: Frasnian-Famennian (360-340 m.y), Westphalian-Kungurian (310-250 m.y), Kimmeridgian-Campanian (150-70 m.y.), and Oligocene-Middle Miocene (35-12 m.y.). Association with major orogenies (plate reorganizations) involves short but important time lags. Each reorganization involved the creation of a latitudinal (east-west) ocean, flanked on north and south by plates carrying continents which were themselves discontinuously surrounded by new mountains (some of which constituted microplates).