Abstract:
Structural cross sections constrained with seismic reflection, borehole, Landsat, and surface geology in the foreland of the Sulaiman lobe provides data on the style and evolution of a specific foreland structures. Seismic reflection profiles show about 10 km thick stratigraphic section at the deformation front. Nearly all of the stratigraphic section is detached from the crystalline basement, suggesting a deep decollement at the base of the wedge. Structural uplift of 4-8 km is observed in the seismic reflection profiles, without emergent thrusts in the foreland. This is interpreted to be related to passive-roof duplex style of deformation. Duplex sequence is consists of Jurassic and older strata with a floor thrust (decollement) at the base of the section and a roof thrust (passive backthrust) in thick Cretaceous shales. Three cross sections across the foreland show the structural variations from: (1) two broad (half-wavelength about 25 km), low amplitude (1-1. 5 km) folds in front of the duplex; (2) a small wavelength (about 3. 5), low amplitude (about 1 km) fault-propagation fold ahead of a broad fold and the duplex; and(3) a duplex respectively at the deformation front. This data suggests chronology of foreland structures from a fault-propagation fold to a broad concentric bucklefold to a duplex.
Page(s):
1-17
DOI:
DOI not available
Published:
Journal: Pakistan Journal of Hydrocarbon Research, Volume: 3, Issue: 2, Year: 1991