From Rodinian passive margin to .i.peri./i.-Siberian continental arc: Evidence from the multiphase Neoproterozoic–early Paleozoic magmatic record of the Zavkhan Block in the Mongolian Collage

0572541 - GLÚ 2024 RIV NL eng J - Článek v odborném periodiku
Soejono, I. - Janoušek, V. - Peřestý, V. - Schulmann, K. - Svojtka, Martin - Hanžl, P. - Hora, J. M. - Míková, J. - Štípská, P. - Guy, A. - Collett, S. - Otgonbaatar, D.
From Rodinian passive margin to peri-Siberian continental arc: Evidence from the multiphase Neoproterozoic–early Paleozoic magmatic record of the Zavkhan Block in the Mongolian Collage.
Gondwana Research. Roč. 121, September (2023), s. 344-367. ISSN 1342-937X. E-ISSN 1878-0571
Institucionální podpora: RVO:67985831
Klíčová slova: Zircon dating * Whole-rock geochemistry * Zavkhan Block * Rodinia * Paleogeography * Microcontinent tectonics
Obor OECD: Geology
Impakt faktor: 6.1, rok: 2022
Způsob publikování: Omezený přístup
https://www.sciencedirect.com/science/article/pii/S1342937X23001314?via%3Dihub

Geochronological and geochemical study of the Neoproterozoic–early Paleozoic magmatic record was carried out in two sections of the Zavkhan Block, one of the largest continental fragments within the Mongolian Collage of the Central Asian Orogenic Belt. Our results show that two distinct magmatic events occurred in both studied domains, the Late Tonian (c. 840–800 Ma) and the Cambro–Ordovician (c. 510– 470 Ma). Based on the variable geochemical signatures and two-stage Nd model ages (TDM Nd:2stg=1.4–3.0 Ga), the late Tonian magmatism included both mantle-derived magmas that suffered a crustal contamination as well as partial melts of a heterogeneous continental crust that ranged from Paleo- to Mesoproterozoic (felsic metaigneous rocks or immature metagreywackes) to Neoarchean–Paleoproterozoic (metabasalts or metatonalites). The Cambro–Ordovician basic–acidic magmatism (TDM Nd:2stg=1.3–2.2 Ga) reflected interplay between two components, mafic juvenile (depleted-mantle-derived) and felsic, generated by anatexis of Tonian, mainly metabasic crust. The late Tonian (c. 840–800 Ma) magmatic activity is interpreted as result of intracontinental rifting, whereas the Cambro–Ordovician (c. 510–470 Ma) magmatism is linked to a continental magmatic-arc system. The comparison of the data from the Zavkhan Block with other microcontinents of the Mongolian Collage shows that most of them experienced an identical two-stage magmatic evolution. The first stage is interpreted as a result of the Rodinia break-up, whereas the second one was associated with inception of the Paleo-Pacific Plate subduction. Based on similarities in the magmatic record, we conclude that the Mongolian Collage microcontinents were located at the Rodinia periphery, as a part of either the Siberian or Tarim cratons. They were separated in the late Tonian, established a passive margin and drifted towards southern Siberia, where they recorded arc magmatism related to the Cambro–Ordovician subduction of the Paleo-Pacific Plate.
Trvalý link: https://hdl.handle.net/11104/0344926