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" Structural Architecture and Jurassic to Eocene Chrono-stratigraphic Evolution of the North Suleiman Range, Mughal Kot Gorge, Pakistan "
Ullah, Farman
Tull, James F
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Latin Dissertation
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English
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| Record Number
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1106308
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TLpq2384858987
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| Main Entry
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Tull, James F
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Ullah, Farman
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| Title & Author
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Structural Architecture and Jurassic to Eocene Chrono-stratigraphic Evolution of the North Suleiman Range, Mughal Kot Gorge, Pakistan\ Ullah, FarmanTull, James F
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| College
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The Florida State University
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| Date
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2019
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2019
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| Degree
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Ph.D.
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| Page No
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295
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| Abstract
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The northern Sulaiman Range forms an integral part of the foreland basin chain associated with the western transform border of the Pakistani Himalayas. The study area occupies the easternmost segment of the northern Suleiman Range where regional trends follow a north-south orientation. Towards the west of the study area lies the higher Suleiman fold belt, which is mostly exposed at the level of Mesozoic rocks. East of the higher Suleiman fold belt lies the low Suleiman fold belt region which is developed at the level of Eocene rocks, whereas in the east, the molasse-filled depression of the Suleiman fore deep is located. The sedimentary pile exposed within the study area has recorded a complex tectonic history of the region presenting various stages of evolution of a basin from platform or passive continental margin to various stages of deformation associated with oblique plate collision and ophiolite obduction in the west. The eastern mountain front of the northern Sulaiman Range in the study area is comprised of a foreland-dipping major monocline of the Sulaiman fore deep. The monocline is structurally uplifted along the orogenic front by the East Domanda fault which is a north-south trending and east-dipping regional scale back thrust with concomitant left-lateral wrenching. Current structural mapping and modelling conducted during the geological field work in the eastern frontal parts of northern Sulaiman ranges has revealed the presence of an east-verging fold-thrust system comprised of Mesozoic to Eocene rocks related to east-directed ramping from the basal Jurassic detachment. This structural assemblage as a whole is thrust over by the East Domanda fault, giving rise to a wedge shape geometry to the mountain front in the subsurface. Balancing of geological cross section. In the study area, during the Jurassic the carbonate barrier-inlet shelf platform depositional setting was prevailing from the Bajocian (c. 171.6 Ma)-Callovian (c. 157 Ma) age depositing the Suleman Limestone. A composite stratigraphic Sequence (JSEQ 1) that further constitutes alternate Transgressive-Regressive (TR) systems tracts (TSTJ 1-TSTJ 3; RSTJ I-RSTJ 3) were deposited in a second order cycle. The Middle Jurassic (Bajocian-Callovian) deposition of the carbonate platform sediments are related to the deepening associated with the rift basin in response to the separation of the Indo Madagascar plate from the Afro-Arabian plate. The progressive shallowing may be related to the thermal uplift preceding the Indo-Madagascar separation from the Afro-Arabian plate that have caused the shallowing and ultimately the exposure of the Mid Jurassic platform, resulting in the development of the Sequence Boundary (SB 1). The Cretaceous Kimmeridgian (c. 155 Ma)-Velanginian (c. 136 Ma) Sembar Formation constitute a Sequence (CSEQ 1) during the Transgressive/Regressive Systems Tract (TSTC 1/RSTC 1). The Oxfordian Sequence Boundary (SB 2), the Berriasian Sequence Boundary (SB 3) is found within the Sembar Formation. The Kimmeridgian (c. 155 Ma)-Velanginian (c. 136.4 Ma) deposition of the Sembar Formation in sequence CSEQ 1 is related to the re-deposition of the late Jurassic paleosoles/laterites of the Suleiman Limestone into the clastic dominated platform, indicated by by the belemnite and ammonite fauna. The Cretaceous Coniacian (c. 89.1 Ma)-Companian (c. 70.6 Ma) deposition of the Parh Limestone has occurred in an open-deep marine basin, above the CCD in the second order cycle depositing the Sequence (CSEQ 2). The Houterivian-Turonian Sequence Boundary (SB 3) is manifested by a stratigraphic gap shown by the complete absence of the Goru Formation between the facies of the Sembar Formation in the Sequence (CSEQ 1) and the Parh Formation in the Sequence (CSEQ 2). The Mughal kot Formtion represents the early Masstrichtian 3rd Order cycle, depositing Sequence (CSEQ 3) characterized by debris flow, slumps, and turbidities, with development of storm beds. The Early-Late Maastrichtian Sequence Boundary (SB 4) was developed due to the combined effect of a global sea level fall (Haq et al., 1987), and the non-deposition or erosion of the thermally uplifted basin, coeval with the timing of the obduction of the Daccan Trap/ Waziristan Ophiolites/ and Accretionary prism sediments in the Kirthar Fold Belt in Pakistan. The Pab Sandstone represents a late Masstrichtian age that constrains a 3rd Order cycle. This cycle constitutes the RSTC 3 of CSEQ 3, which was deposited the shallow-moderately deep prograding channels in the swampy-deltaic settings. The Sequence Boundary (SB 5) between the Pab Formation (Sequence CSEQ 4) and the Ranikot Formation (Sequence PSEQ 1) correlates well with the K-T boundary. Regression of Mesozoic seas, in various parts of Pakistan is marked by a period of emergence. The sequence of Ranikot/Dunghan Formation was deposited in the Late Paleocene (Danian; c. 59.2-56 Ma), in a 3rd Order cycle having SEQP 1 deposition during the Late Paleocene (Thanitian; c. 61.6-56 Ma). This was caused by the deepening of the basinal conditions associated with the flexural loading of the Indian plate and also possibly driven by global sea level rise (Haq et al. 1987). The Ghazij Group constitutes the Gahzij /Drug and Baska formations, which were deposited in a 3rd Order cycle during the Early Eocene (Ypressian; c. 56-47.8 Ma). The Kirthar Formation contains age diagnostic larger benthic/planktic foraminifera that suggest a Middle Eocene (Lutetian-Pribonian; c. 47.8-33.9 Ma) age corresponding to the composite Sequence ESEQ 2, deposited in the second order cycle. The early Eocene Ghazij Group (ESEQ 1) and Middle Lutetian Kirthat Formation (ESEQ 2) correspond well with the Eustatic sea level rise that has affected the dynamics of the sedimentary Basins across the Tethys.
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Geology
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