Middle to late Miocene growth of the North Pamir

Lin Li (1, 2, 3) , Guillaume Dupont-Nivet (1, 4) , Yani Najman (5) , Mustafa Kaya (4) , Niels Meijer (4) , Marc Poujol (1) , Jovid Aminov (6)

1 GR - Géosciences Rennes
2 Rochester Institute of Technology
3 University of Arizona
4 University of Potsdam = Universität Potsdam
5 Lancaster University
6 CAS - Chinese Academy of Sciences [Beijing]

How and when the Pamir formed remains an open question. This study explores Pamir tectonics recorded in a sedimentary section in the eastern Tajik Basin. A prominent lithofacies change that has been recognized regionally is assigned to the middle Miocene (13.5 Ma based on preferred magnetostratigraphic correlation). Closely following this change, detrital zircon U-Pb age spectra and mudstone bulk-rock  Nd values exhibit a sediment source change from the Central to the North Pamir estimated ca. 12 Ma. At the same time, the stable oxygen and carbon isotopic values of carbonate cements show negative and positive shifts, respectively. Combined with previous studies in both the Tajik and Tarim basins, these results suggest that the North Pamir experienced a middle-late Miocene phase of deformation and surface uplift. This supports models proposing middle-late Miocene Pamir tectonism, and climate models implying that coeval Pamir orogenesis deflected Westerly moisture and affected Asian environments.

Keywords: Tajik Basin; Pamir; Lithostratigraphy; Magnetostratigraphy; Provenance; Stable isotopes

Domains: Stratigraphy; Geochemistry; Tectonics

Lin Li, Guillaume Dupont-Nivet, Yani Najman, Mustafa Kaya, Niels Meijer, et al.. Middle to late Miocene growth of the North Pamir. Basin Research, 2022, 34 (2), pp.533-554. ⟨10.1111/bre.12629⟩. ⟨insu-03405280⟩