Provenance change of sediment input in the northeastern foreland of Pamir related to collision of the Indian Plate with the Kohistan-Ladakh arc at around 47 Ma

Abstract

The Pamir plateau forms a prominent tectonic salient that marks the western end of the Himalayan orogen containing several terranes that were accreted to Eurasia from the Late Paleozoic to Cenozoic. A detailed knowledge of the tectonic evolution of the Pamir salient during the Cenozoic is important for our understanding of the intracontinental deformation in the western Himalaya. Although the tectonic evolution of the Pamir salient has long been studied, the timing of collision between the Indian Plate and the Kohistan-Ladakh arc is still a matter of debate. We present new U-Pb ages and Hf isotopes of detrital zircons, magnetic fabrics, and stable isotopes from the foreland basin on the northeastern margin of the Pamir that indicate a change in sediment provenance started at about 47 Ma. Sediments in the southwest Tarim Basin were partially derived from the uplifted and eroded Karakoram and Kohistan terranes created by the collision between the Indian Plate and the Kohistan-Ladakh arc at circa 47 Ma, as a result of northward thrusting and propagation of the Indian Plate under Eurasia.

Indentation of the Pamirs with respect to the northern margin of Tibet: Constraints from the Tarim basin sedimentary record

“…Later application of magnetostratigraphic dating to the parallel section exposed along the Gez River [ Sun and Jiang , ] led those authors to reinterpret Bershaw's data in light of their new age constraints. A more comprehensive provenance data set has since been produced by Sun et al [], although we note the uncertainty in the age of this section, as summarized above.…”

Provenance and tectonic setting of Early Eocene Sohnari Member of Laki Formation from southern Indus Basin of Pakistan

“…A group who did Paleomagnetism studies agreed on ~20–65 Ma collision had occurred between the India–Asia plates (Besse, Courtillot, Pozzi, Westphal, & Zhou, ; Dupont‐Nivet, Lippert, Van Hinsbergen, Meijers, & Kapp, ; Klootwijk, Gee, Peirce, Smith, & McFadden, ; Patriat & Achache, ; Patzelt, Li, Wang, & Appel, ; Van Hinsbergen et al, ; Yi, Huang, Chen, Chen, & Wang, ). Sedimentologists concluded the ~34–70 Ma time of collision (Aitchison, Ali, & Davis, ; Beck et al, ; Hu, Sinclair, Wang, Jiang, & Wu, ; Rowley, ; Sun et al, ; Wang et al, 2011; Zhang, Willems, Ding, Gräfe, & Appel, ; Zhuang et al, ). Petrologists' investigations indicated ~31–57 Ma collisional time (Bouilhol, Jagoutz, Hanchar, & Dudas, ; de Sigoyer et al, ; Guillot et al, ; Leech, Singh, Jain, Klemperer, & Manickavasagam, ; St‐Onge, Rayner, & Searle, ; White, Ahmad, Lister, Ireland, & Forster, ).…”

“…As stated in the recent review of Wang et al (2014), there are four groups of geoscientists who investigated the collisional time of India-Asia plates. A group who did Paleomagnetism studies agreed on~20-65 Ma collision had occurred between the India-Asia plates (Aitchison, Ali, & Davis, 2007;Beck et al, 1995;Hu, Sinclair, Wang, Jiang, & Wu, 2012;Rowley, 1996;Sun et al, 2016;Wang et al, 2011;Zhang, Willems, Ding, Gräfe, & Appel, 2012;Zhuang et al, 2015). Petrologists' investigations indicated~31-57 Ma collisional time (Bouilhol, Jagoutz, Hanchar, & Dudas, 2013;de Sigoyer et al, 2000;Guillot et al, 2008;Leech, Singh, Jain, Klemperer, & Manickavasagam, 2005;St-Onge, Rayner, & Searle, 2010;White, Ahmad, Lister, Ireland, & Forster, 2012).…”

Ridge‐spotting: A new test for Pacific absolute plate motion models

“…[] noted that the global Eocene event expresses itself in a reduction in global RMS velocities from about 6 to 4–5 cm yr −1 . IBM subduction initiation is only slightly predated by a major collisional event, namely the onset of collision between India and Eurasia, recorded by a 47 Ma change in sediment provenance on the northeastern margin of the Pamir [ Sun et al ., ], a major slowdown in spreading rates between India and Eurasia around 47 Ma [ Cande and Patriat , ], and contemporaneous plate fragmentation along the central Indian Ridge [ Matthews et al ., ]. This collision may therefore provide the primary driving force for the global Eocene reorganization, with Izanagi‐Pacific ridge subduction and IBM subduction mainly affecting circum‐Pacific plate‐mantle dynamics.…”