Journal of Petroleum Geology, Vol.8,
No.2, pp. 129-148, 1985
©Copyright 2000 Scientific Press,
Ltd.
OIL AND GAS ACCUMULATIONS IN
OVERTHRUST BELTS -- I
J.C. Pratsch+
+ Sohio Petroleum Co., 13711
Butterfly Lane, Houston, Tx. 77079, USA.
The second part of this paper will appear in the July 1985 issue.
Abstract
Overthrust belts are zones of high crustal
mobility leading to major vertical and lateral movements of rock
units. They developed throughout the geologic history of the
Earth. Their preferred habitat is the active continental margin,
but intra-oceanic and intra-continental occurrences are common.
Oil- and gasfields exist only in small portions of the known
overthrust belts; their distribution is closely related to the
present existence of generative depocenters. Preservation of
hydrocarbon fields formed prior or during thrusting is rare; most
oil- and gasfields in overthrust belts have been formed after the
major thrust deformation. Definition of present effective
depocenters and prediction of preferred lateral and vertical
hydrocarbon migration are the main parameters in any basin
evaluation or "play" definition, in overthrust belts as
well as in normal basins.