Geological Society of America

T283 From Oceanic Subduction to Inter-Continental Collision: Examples of Convergent Margin Processes in Non-Collisional and Collisional Settings (Posters)

Wednesday, 25 September 2019
9:00 AM - 6:30 PM
Hall AB, North Building

EOCENE INTRA-OCEANIC SUBDUCTION SYSTEM OF NEO-TETHYS IN THE ZAGROS, IRAN

Paper number: T283-7
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Songjian Ao Presenting Author
Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, N/A
Wenjiao Xiao
Urumqi
Morteza Khalatbari Jafari
Geological Survey and Mining Exploration of Iran, Tehran, N/A
Brian F. Windley
University of Leicester, Leicester

Abstract

There is much debate about the formation and closure of the Tethys, because the pre-collisional tectonic evolution of Tethyan Ocean is essential in constraining the timing and process of collision between the Eurasian and Arabian continents. Here we present a combined analysis of zircon LA-ICP-MS U-Pb ages and Hf -O isotopes of two ophiolites, the Marivan and the Sardasht from the NW Zagros orogen. Our new data reveal that the Marivan ophiolite has a Late Eocene age (ca. 40.3 Ma), and was probably generated by back-arc extension. However, the Sardasht ophiolite formed in the Early Eocene (ca. 50.6 Ma), probably during initial intra-oceanic subduction. Consequently, we argue that the Tethys Ocean was undergoing incipient intra-oceanic subduction and back-arc extension in the NW Zagros during the Eocene. Accordingly, the collisional orogeny underwent intra-oceanic subduction process and arc accretion before the final continent-continent collision.

Geological Society of America Abstracts with Programs. Vol. 51, No. 5

doi: 10.1130/abs/2019AM-338238

© Copyright 2019 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.