Interpretation of seismic reflection data across the Himalayan foreland thrust belt in Pakistan
Approximately 5000 km of Pakistan government and industry seismic reflection profiles have been incorporated into studies of the active collisional foreland of the western Himalaya. From south to north, the profiles reveal a gently north-dipping detachment zone separating Precambrian basement of the Indian shield from southward thrusted Phanerozoic strata. At its leading edge, the detachment lies within an Eocambrian evaporite sequence at the base of the section in the Salt Range and southern Potwar Plateau. Strata of the Punjab plains south of the Salt Range can be traced northward on the seismic profiles 25 kilometers beneath the Salt Range thrust. Beneath the north flank of the Salt Range, the reflection data reveal a large normal fault offsetting the top of the basement. This normal fault caused thrusts to ramp upsection, exposing Paleozoic and Mesozoic strata in the Salt Range. Farther north, strata within the southern Potwar Plateau have been transported at least 25 kilometers, but have undergone little internal deformation. In the northern Potwar Plateau, strata within the upper thrust plate are complexly folded and faulted, perhaps indicating that the Eocambrian evaporite sequence is missing or less effective than a decoupling zone beneath the thicker overthrust section. At the north end of the seismic control, the detachment remains at a low angle beneath approximately nine km of allochthonous sedimentary rocks. A continuation of seismic coverage as a deep crustal profile is needed to study the northward continuation of the detachment and its relations to more interior thrust faults, including the Main Boundary and Main Mantle thrusts.
- Research Organization:
- Oregon State Univ., Corvallis (USA)
- OSTI ID:
- 6197395
- Report Number(s):
- CONF-8510489-
- Journal Information:
- Geol. Soc. Am., Abstr. Programs; (United States), Vol. 17; Conference: 98. annual meeting of the Geological Society of America, Orlando, FL, USA, 28 Oct 1985
- Country of Publication:
- United States
- Language:
- English
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Development of the Himalayan frontal thrust zone: Salt Range, Pakistan
Structure and evolution of the northern Potwar deformed zone, Pakistan
Related Subjects
GEOLOGIC FAULTS
MAPPING
PAKISTAN
PLATE TECTONICS
SEISMIC SURVEYS
BASEMENT ROCK
HIMALAYAS
OROGENESIS
ASIA
DEVELOPING COUNTRIES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
MOUNTAINS
SURVEYS
TECTONICS
580203* - Geophysics- Geophysical Survey Methods- (1980-1989)
580201 - Geophysics- Seismology & Tectonics- (1980-1989)