Structural styles in rift basins: Interpretation methodology and examples from Southeast Asia
- Texaco Inc., Houston, TX (United States)
The authors present graphical solutions to the extensional fault-related folding equations of Xiao and Suppe (1992), simplifying the prediction of normal fault location or rollover geometry from subsurface data. These equations also predict the extent of bed thinning and elongation in hanging wall strata. They have derived new equations that relate change in fault slip across a fault bend to fault geometry. Applying these equations in seismic interpretation makes it easier to (1) construct balanced cross-sections, (2) account for the slip observed, and (3) determine the growth history of extensional fault-related folds. They have applied these concepts to several southeast Asian rift basins in Malaysia, Myanmar, Indonesia, and Thailand. These basins were formed by early Tertiary crustal extension, producing rollover structures in which sediment supply generally did not keep up with subsidence. These under-filled, internally drained depressions periodically contained lakes, providing the environment for deposition of organic-rich strata that ultimately became hydrocarbon source rock. Typically, the main basin bounding faults dip 35-55[degrees] near their upper terminations and flatten to become subhorizontal. Synthetic and antithetic secondary faults are usually present. Late compaction faulting often propagates upward from major extensional faults and may reactivate the upper portions of these faults. In many basins, late compression produced inversion structures. By applying the concepts of extensional fault-related folding to these basins, they can (1) explain observed geometries, (2) predict poorly imaged geometries, (3) predict the location of source and reservoir facies, and (4) determine the timing of faulting relative to deposition of source and reservoir rocks.
- OSTI ID:
- 7017409
- Report Number(s):
- CONF-940803-; CODEN: AABUD2
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (United States), Vol. 78:7; Conference: American Association of Petroleum Geologists (AAPG) international conference and exhibition, Kuala Lumpur (Malaysia), 21-24 Aug 1994; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
03 NATURAL GAS
ASIA
SEDIMENTARY BASINS
GEOLOGIC HISTORY
BURMA
EXPLORATION
GEOLOGIC FAULTS
NATURAL GAS DEPOSITS
PETROLEUM DEPOSITS
RESERVOIR ROCK
RIFT ZONES
SOURCE ROCKS
DEVELOPING COUNTRIES
GEOLOGIC DEPOSITS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
MINERAL RESOURCES
RESOURCES
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration