A single Dras‐Kohistan‐Ladakh arc revealed by volcaniclastic records

Andjić, G., Zhou, R., Jonell, T. N. and Aitchison, J. C. (2022) A single Dras‐Kohistan‐Ladakh arc revealed by volcaniclastic records. Geochemistry, Geophysics, Geosystems, 23(3), e2021GC010042. (doi: 10.1029/2021GC010042)

Abstract

Tectonic interpretations of arc remnants in the Himalayan orogen remain uncertain, despite their important implications for the overall convergence history between India and Eurasia. Provenance results from deep‐water volcaniclastic rocks of the Indus Suture Zone in Ladakh provide new constraints on the Mesozoic tectonic evolution of the Dras and Kohistan‐Ladakh arcs. Detrital zircon (DZ) U‐Pb ages and whole‐rock geochemistry of the fault‐bounded Upper Cretaceous Nindam and Paleocene Jurutze formations present age patterns and compositions that are consistent with those of the Dras and Kohistan‐Ladakh arcs, respectively. The combination of DZs of the Nindam and Jurutze formations with the igneous zircons of the Dras and Kohistan‐Ladakh arcs shows similar age distributions that support a Late Jurassic to Paleocene tectonic connection between all these units. We argue that the secular trends in geochemical composition of DZs and volcaniclastic material are consistent with the magmatic evolution of one convergent margin, which shifted from a primitive to a mature stage during the Late Cretaceous. The recognition of a single Dras‐Kohistan‐Ladakh arc sets the stage for reevaluating competing scenarios of the Mesozoic evolution of the India–Eurasia convergent system. We find that the most likely scenario is that of a Jurassic arc formed above a south‐dipping intraoceanic subduction zone and accreted to Eurasia during the Early Cretaceous, after which it evolved above a north‐dipping subduction zone.

• Item Type: Articles
• Additional Information: G.A. thanks the Swiss SNF for funding his postdoctoral fellowship (no. 178098) at the University of Queensland.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Jonell, Dr Tara
• Authors: Andjić, G., Zhou, R., Jonell, T. N., and Aitchison, J. C.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Journal Name: Geochemistry, Geophysics, Geosystems
• Publisher: American Geophysical Union
• ISSN: 1525-2027
• ISSN (Online): 1525-2027
• Published Online: 06 March 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Geochemistry, Geophysics, Geosystems 23(3): e2021GC010042
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.5281/zenodo.5705286