Strike-slip faulting in a foreland fold-thrust belt, western Salt Range, central Pakistan

Conference · Tue Jan 01 04:00:00 EST 1985 · Geol. Soc. Am., Abstr. Programs; (United States)

OSTI ID:6319372

McDougall, J W

The N15W-trending Kalabagh fault zone (KFZ) is part of the Himalayan frontal fault (HFF) and is nearly orthogonal to active ENE-trending folds and thrust faults associated with Himalayan convergence. The KFZ extends 20 km north of Kalabagh village on the Indus River (NW Salt Range) before bending to the west along several north-dipping reverse faults. Quaternary low-angle thrust displacement appears to be concentrated at the HFF, especially the Salt Range frontal thrust. Siwalik conglomerate and sandstone cut by the KFZ north of the HFF may be as young as Quaternary, however, late Quaternary faulting has not been documented north of the HFF near Kalabagh village. Evidence of right-lateral strike-slip offset along the KFZ is seen in the field along the NNW-trending western edge of the Salt Range and from there north to Shakardarra village. Focal mechanism solutions of earthquakes show right-slip faulting in basement extending from the southernmost surface trace of the KFZ over 150 km farther south in the Punjab plain. Residual gravity anomalies and the strike of an abrupt change in Bouguer gravity values follow the KFZ along the western Salt Range and farther south. The sedimentary sequence exposed east of the KFZ is thought to be decoupled from basement along a detachment surface underlying much of the Potwar Plateau. West of the KFZ, a similar sedimentary sequence may be more strongly coupled to basement. Detachment surfaces involving major displacement probably ramp upsection, creating relatively complex fold and fault geometry on the west side of the KFZ.

• Research Organization: Oregon State Univ., Corvallis (USA)
• OSTI ID: 6319372
• Report Number(s): CONF-8510489-
• Conference Information: Journal Name: Geol. Soc. Am., Abstr. Programs; (United States) Journal Volume: 17
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580201* -- Geophysics-- Seismology & Tectonics-- (1980-1989)
ASIA
CENOZOIC ERA
DEVELOPING COUNTRIES
GEOLOGIC AGES
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC HISTORY
GEOLOGIC STRUCTURES
GEOMETRY
GEOPHYSICAL SURVEYS
GRAVITY SURVEYS
HIMALAYAS
MATHEMATICS
MOUNTAINS
PAKISTAN
QUATERNARY PERIOD
SURVEYS
TECTONICS