Record Details
Structure and evolution of the Dhurnal oil field, northern Potwar deformed zone, Pakistan
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Structure and evolution of the Dhurnal oil field, northern Potwar deformed zone, Pakistan |
| Names |
Jaswal, Tariq Majeed
(creator) Lillie, Robert J. (advisor) |
| Date Issued | 1990-03-14 (iso8601) |
| Note | Graduation date:1990 |
| Abstract | The North Potwar Deformed Zone (NPDZ) is part of the active foreland fold-and- thrust belt of the Salt Range and Potwar Plateau (SR/PP) in northern Pakistan. About 500 km of seismic reflection profiles are integrated with surface geologic and drilling data to examine the structure of the NPDZ, in general, and the history of deformation of the Dhurnal oil field, in particular. The seismic lines suggest that the overall structure of the eastern NPDZ is a duplex structure developed beneath a passive roof thrust. The roof thrust is generated from a tipline in the Murree Formation of Miocene age, while the sole thrust is initiated from the same Eocambrian evaporite zone that extends 80 km southward beneath the Soan syncline and Salt Range. The Dhurnal oil field structure is a pop-up at the southern margin of the NPDZ, developed beneath the passive roof thrust. The passive roof thrust crops out just north of Dhurnal on the steep, northern limb of the Soan syncline. An overstep passive roof thrust (Sakhwal fault) is interpreted west of Dhurnal, which developed due to southward progression of the deformation front beneath the earlier passive roof thrust. Very gentle basement dip and almost zero topographic slope in the NPDZ suggest that the Eocambrian salt provides effective decoupling at the present position of the NPDZ. The strong deformation in the NPDZ appears to have developed farther north, in an area where the evaporites may be lacking. Since 2 Ma the NPDZ moved farther south over the evaporites without any further deformation, while erosion removed any former topographic slope. Restoring a balanced cross-section suggests the minimum shortening across the NPDZ is about 69 km. Assuming that this shortening occurred in the time interval from 5.1 to 2.0 Ma, the shortening rate is 22 mm/yr. This is about 50% of the 40-50 mm/yr convergence rate of the Eurasian and Indian plates. |
| Genre | Thesis/Dissertation |
| Topic | Geology, Structural -- Pakistan |
| Identifier | http://hdl.handle.net/1957/38890 |
