Repeated magmatic buildup and deep "hot zones" in continental evolution: The Cadomian crust of Iran

Moghadam H., Li Q. L., Griffin W. L., Stern R. J., Ishizuka O., Henry H., ...Daha Fazla

EARTH AND PLANETARY SCIENCE LETTERS, cilt.531, 2020 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 531
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.epsl.2019.115989
  • Dergi Adı: EARTH AND PLANETARY SCIENCE LETTERS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), Artic & Antarctic Regions, Chemical Abstracts Core, Communication Abstracts, Compendex, Environment Index, Geobase, INSPEC, Metadex, Pollution Abstracts, Civil Engineering Abstracts
  • Karadeniz Teknik Üniversitesi Adresli: Hayır

Özet

The generation and differentiation of continental crust by arc magmatism is strongly influenced by episodes of high magmatic flux ("flare-ups"). Magmatic flare-ups encourage the development of deep crustal hot zones where magmatic differentiation and density stratification combine to form the upper felsic and lower mafic continental crust. Such processes, which are responsible for the construction of continental arc crust, are prolonged events, which build a similar to 30-40 km arc crust over tens of million years (similar to 100 Myr). New zircon U-Pb data reveal that the construction of Cadomian crust from NE Iran occurred over similar to 15 +/- 0.3 Myr. However, compiled zircon U-Pb ages reveal a prolonged magmatic flareup of similar to 45 Myr: similar to 570 to 525 Ma. Basement outcrops in NE Iran expose lower- and upper crust that show how magmatic-geochemical differentiation occurred deep beneath a Cadomian continental arc in a crustal hot zone. Isotopic data for igneous rocks produced during this 45 Myr episode reveal interactions between mantle-derived melts and old continental crust. Synthesis of new and published data indicates that this type of interaction is common during periods of high magmatic fluxes. Our results indicate that differentiation of mafic melts in the lower crust during prolonged magmatic flare-ups plays a key role in building a stratified continental crust. Crown Copyright (C) 2019 Published by Elsevier B.V. All rights reserved.