Deposition model of a Miocene barred wave- and storm-dominated shoreface and shelf, southeastern Malay basin, offshore west Malaysia
The J sandstone is an important hydrocarbon-bearing reservoir in the southeastern part of the Malay basin. The lower and upper members of the J sandstone are composed of shoreface and offshore sediments. The shoreface sequence contains depositional structures characteristic of a barred wave- and storm-dominated shoreface. Each shoreface sequence is laterally associated with a series of stacked offshore bars. Offshore bars can be subdivided into proximal and distal types. Two types of proximal offshore bars have been identified: (1) proximal bars formed largely above fair-weather wave base (inner proximal bars), and (2) proximal bars formed below fair-weather wave base (outer proximal bars). The inner proximal bars are closely associated with the shoreface sequence and are similar to the middle and lower shoreface. The presence of poorly sorted, polymodal, very fine to very coarse-grained sandstone beneath well-sorted crestal sandstones of inner proximal bars suggests that these offshore bars may have been deposited rapidly by storms. The crests of the inner proximal offshore bars were subsequently reworked by fair-weather processes, and the crests of the outer proximal and distal offshore bars were reworked by waning storm currents and oscillatory waves. Thick marine shales overlying offshore bars contain isolated sheet sandstones. Each sheet sandstone exhibits features that may be characteristic of distal storm shelf deposits. 15 figures, 2 tables.
- Research Organization:
- Oxford Univ., England
- OSTI ID:
- 5563526
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Vol. 70:1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Outer shelf storm deposits of Upper Cretaceous Chico Formation, California
Kemik sandstone: inner shelf sand from northeast Alaska
Related Subjects
MALAYSIA
PETROLEUM DEPOSITS
RESERVOIR ROCK
DEPOSITION
GEOLOGIC HISTORY
OFFSHORE SITES
SANDSTONES
SEDIMENTARY BASINS
TERTIARY PERIOD
ASIA
CENOZOIC ERA
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
MINERAL RESOURCES
RESOURCES
ROCKS
SEDIMENTARY ROCKS
020200* - Petroleum- Reserves
Geology
& Exploration