Biostratigraphy of the Middle Eocene Kohat Formation, Himalayan Fold and Thrust Belt, Northern Pakistan

The present structural framework of the Kala Chitta Range evolved through movement between two detachment surfaces. The Precambrian Attock Slates acted as a basal detachment surface above which large scale horizontal compression took place to produce the main structural framework of the Kala Chitta Range. The Middle Eocene argillaceous and gypsiferous Kuldana Formation behaved as the upper detachment surface giving rise to blind thrusts which were later exposed due to the intense erosion of the overlying folded Miocene strata.

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U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland

Solid Earth ◽

10.5194/se-12-2539-2021 ◽

2021 ◽

Vol 12 (11) ◽

pp. 2539-2551

Author(s):

Luca Smeraglia ◽

Nathan Looser ◽

Olivier Fabbri ◽

Flavien Choulet ◽

Marcel Guillong ◽

...

Keyword(s):

Middle Eocene ◽

Regional Scale ◽

Earthquake Hazard ◽

Late Eocene ◽

Passive Margin ◽

Tectonic Activity ◽

Thrust Belt ◽

Fold And Thrust Belt ◽

Earthquake Hazard Assessment ◽

Alpine Foreland

Abstract. Foreland fold-and-thrust belts (FTBs) record long-lived tectono-sedimentary activity, from passive margin sedimentation, flexuring, and further evolution into wedge accretion ahead of an advancing orogen. Therefore, dating fault activity is fundamental for plate movement reconstruction, resource exploration, and earthquake hazard assessment. Here, we report U–Pb ages of syn-tectonic calcite mineralizations from four thrusts and three tear faults sampled at the regional scale across the Jura fold-and-thrust belt in the northwestern Alpine foreland (eastern France). Three regional tectonic phases are recognized in the middle Eocene–Pliocene interval: (1) pre-orogenic faulting at 48.4±1.5 and 44.7±2.6 Ma associated with the far-field effect of the Alpine or Pyrenean compression, (2) syn-orogenic thrusting at 11.4±1.1, 10.6±0.5, 9.7±1.4, 9.6±0.3, and 7.5±1.1 Ma associated with the formation of the Jura fold-and-thrust belt with possible in-sequence thrust propagation, and (3) syn-orogenic tear faulting at 10.5±0.4, 9.1±6.5, 5.7±4.7, and at 4.8±1.7 Ma including the reactivation of a pre-orogenic fault at 3.9±2.9 Ma. Previously unknown faulting events at 48.4±1.5 and 44.7±2.6 Ma predate the reported late Eocene age for tectonic activity onset in the Alpine foreland by ∼10 Myr. In addition, we date the previously inferred reactivation of pre-orogenic strike-slip faults as tear faults during Jura imbrication. The U–Pb ages document a minimal time frame for the evolution of the Jura FTB wedge by possible in-sequence thrust imbrication above the low-friction basal decollement consisting of evaporites.

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Bannu Basin, fold-and-thrust belt of northern Pakistan: Subsurface imaging and its implications for hydrocarbon exploration

Marine and Petroleum Geology ◽

10.1016/j.marpetgeo.2017.05.023 ◽

2017 ◽

Vol 85 ◽

pp. 242-258 ◽

Cited By ~ 2

Author(s):

Ismail Ahmad Abir ◽

Shuhab D. Khan ◽

Gulzar M. Aziz ◽

Shahina Tariq

Keyword(s):

Hydrocarbon Exploration ◽

Subsurface Imaging ◽

Thrust Belt ◽

Northern Pakistan ◽

Fold And Thrust Belt

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Thrust tectonics on Brøggerhalvøya and their relationship to the Tertiary West Spitsbergen Fold-and-Thrust Belt

Geological Magazine ◽

10.1017/s0016756801006069 ◽

2002 ◽

Vol 139 (1) ◽

pp. 47-72 ◽

Cited By ~ 12

Author(s):

K. SAALMANN ◽

F. THIEDIG

Keyword(s):

Middle Eocene ◽

Kinematic Model ◽

Thrust Belt ◽

Fold Belt ◽

Kinematic Evolution ◽

Fold And Thrust Belt ◽

Thrust Tectonics ◽

Tectonic Transport ◽

Thrust Sheets ◽

West Spitsbergen

The Tertiary fold-and-thrust belt on Brøggerhalvøya is characterized by a NE-vergent pile of nine thrust sheets. The sole thrust of the pile is located in Precambrian phyllites and climbs up-section to the northeast. Four lower thrust sheets consisting predominantly of Upper Palaeozoic sediments are overlain by two thrust sheets in the central part of the stack which contain a kilometre-scale syncline and anticline. The fold is cut by juxtaposed thrusts giving rise to the formation of three structurally higher basement-dominated thrust sheets. A multiple-stage kinematic model is proposed including (1) in-sequence foreland-propagating formation of the lower thrust sheets in response to N–S subhorizontal bedding-parallel movements, (2) a change in tectonic transport to ENE and out-of-sequence thrusting and formation of the kilometre-scale fold-structure followed by (3) truncation of the kilometre-scale fold and stacking of the highest basement-dominated thrust sheets by hind-ward-propagating out-of-sequence thrusting. The strain of the thrust sheets is predominantly compressive with the exception of the structurally highest thrust sheets, reflecting a temporal change to a more transpressive regime. Thrusting was followed by (4) N–S extension and (5) W–E extension. Comparison of the structural geometry and kinematic evolution of Brøggerhalvøya with the data reported for the fold belt further south allows us to assume a coeval evolution with the fold belt. A latest Paleocene/Early Eocene age for the main phase of thrusting is suggested for the West Spitsbergen Fold-and-Thrust Belt; the main phases therefore pre-date the separation of Svalbard and Greenland due to right-lateral movements along the Hornsund Fault Zone. The fold belt's temporal evolution followed by the formation of the Forlandsundet Graben can be linked with the plate-kinematic framework in the span between latest Paleocene and Middle Eocene times.

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