Journal of Petroleum Geology, Vol.14,
No.4, pp. 365-386, 1991
©Copyright 2000 Scientific Press,
Ltd.
OIL SOURCE ROCK POTENTIAL OF
THE LACUSTRINE JURASSIC SIM UUJU FORMATION, WEST KOREA BAYBASIN
Part I:
Oil source rock correlation and environment of deposition
M. S. Massoud*, S. D. Killops**, A. C.
Scott* and D. Mattey*
* Department of Geology,
** Chemistry Department, Royal
Holloway and Bedford New College. University of London, Egham,
Surrey. TW20 0EX.
Abstract
The offshore West Korea Bay (WKB) Basin is
one of several NE-SW rift basins which formed over thin
continental crust in Korea and eastern China during the Late
Mesozoic and Early Cenozoic, and is characterised by a
two-layered structure, with a Cenozoic basin superposed on a
pre-Tertiary basin. Paraffinic oils recovered from Mesozoic and
Tertiary sandstone intervals are thought to have been generated
from different source beds. The Sim Uuju Formation consists
mainly of fluvially-derived shales and sandstones deposited in a
large, open, fresh-water, deep, tectonic lake, which occupied
wide sub-basins formed by normal faults under a semi-humid
climate, as a result of initial rifting during the Upper
Jurassic. A probable source bed (400- to 500-m thick) has been
geochemically located in the basinal offshore area of the Sim
Uuju sequence penetrated by Well 606. The Jurassic bed could be
considered as a potential source for the Mesozoic oil, provided
that it contains the right type and amount of organic matter
which has reached the stage of oil generation.
