Graduate Thesis Or Dissertation
 

Structural interpretation of the eastern Sulaiman foldbelt and foredeep, Pakistan

Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/pc289n30z

Descriptions

Attribute NameValues
Creator
Abstract
  • The Sulaiman foldbelt is an active and conspicuous tectonic feature on the northwestern margin of the Indo-Pakistani plate. Seismic reflection data have been combined with surface geological mapping and drillhole data to interpret the structural style and tectonic shortening of the eastern Sulaiman foldbelt and its adjacent foredeep. The data show that the basement is more than 8 km deep near the deformation front and that it deepens towards the west. The foredeep adjacent to the eastern Sulaiman foldbelt is a broad synclinal structure, with a steep western limb; the more gentle eastern limb has monoclinal dips from near zero to 2.5° . Several salt-cored anticlines are observed on the eastern part of the monocline, but the salt structures are lacking in the western foredeep and in the frontal part of the Sulaiman foldbelt. The basal decollement under the Sulaiman lobe lies either in ductile Eocambrian salt, or within a deep zone of other material that undergoes ductile behavior. Near the deformation front, ramps from the basal detachment become flats in lower Triassic and lower Cretaceous shales. A steep and highly elevated zone immediately to the west of frontal folds is interpreted to be underlain by a passive-roof duplex. The culmination wall of this oblique duplex is separated from the overlying roof sequence by a passive-roof thrust in lower Cretaceous shales. The roof-thrust has a back-thrust sense of movement, relative to the forelandward propagating duplex, and may extend obliquely 100 km into the interior of the foldbelt. Fault-propagation and fault-bend folds are present in the frontal portion of the eastern Sulaiman foldbelt. Palinspastic restoration of a balanced cross-section shows 108 km of shortening in the eastern Sulaiman foldbelt east of the Kingri strike-slip fault. The presence of more than 11 km of pre-Neogene strata on top of basement suggests that the Mesozoic rifted margin of the Indian subcontinent may lie beneath the Sulaiman foldbelt. This interpretation is also favored by the presence of ophiolites and flysch deposits overthrusted on late Cretaceous shelf strata.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome) using Capture Perfect 3.0 on a Canon DR-9050C in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items

Thumbnail Title Date Uploaded Visibility Actions
file details HumayonMansoor1990.pdf 2017-08-16 Public Download