Zircon U-Pb geochronology and geochemistry of Late Devonian?Carboniferous granitoids in NW Iran: implications for the opening of Paleo-Tethys


Mohammadı A., Moazzen M., Lechmann A., Laurent O.

INTERNATIONAL GEOLOGY REVIEW, vol.62, no.15, pp.1931-1948, 2020 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 62 Issue: 15
  • Publication Date: 2020
  • Doi Number: 10.1080/00206814.2019.1675540
  • Journal Name: INTERNATIONAL GEOLOGY REVIEW
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Agricultural & Environmental Science Database, Aquatic Science & Fisheries Abstracts (ASFA), Geobase, INSPEC, Pollution Abstracts
  • Page Numbers: pp.1931-1948
  • Keywords: Granitoid, U-Pb geochronology, rifting, Iran, Palaeo-Tethys, A-TYPE GRANITES, PLASMA-MASS SPECTROMETRY, ICP-MS, LU-HF, MANTLE, EVOLUTION, ZAGROS, SR, ND, MAGMATISM
  • Istanbul Technical University Affiliated: Yes

Abstract

We present zircon U-Pb crystallization ages combined with bulk rock major and trace element geochemistry and Sr-Nd-Pb and zircon in-situ Hf isotopic compositions of the Amand and Moro granitoid intrusions in northwest Iran. The Amand and Moro plutons include granite and syeno-diorite with LA-ICP-MS U-Pb zircon ages of 367 ? 6.8 Ma and 351 ? 1.3 Ma, respectively, representative of Late Devonian-Early Carboniferous magmatic activity in NW Iran. Geochemical characteristics such as typical enrichments in alkalis, Nb, Zr, Ga and Y, depletion in P and Sr and fractionated REE patterns with high Ga/Al ratios and Eu negative anomalies are consistent with A-type magmatic signatures. The granitoids are classified as A(2)-type and within-plate granitoids. The bulk rock geochemistry (enrichments in Th, Nb and, high Th/Yb, Zr/Y ratios) along with low variation of Nd-143/Nd-144((i)) and Sr-87/Sr-86((i)) ratios and positive zircon ?Hf-(t) support the role of a mantle plume component for the evolution of the Amand and Moro A-type granitoids in an extensional tectonic environment. In fitting with wider regional knowledge, this magmatism occurred during Paleo-Tethys opening in northern Gondwana.