The Overmaraat-Gol alkaline pluton in Northern Mongolia: U-Pb age and preliminary implications for magma sources and tectonic setting

Autor: Andrey E. Izokh, Richard E. Ernst, Andrey V. Vishnevskii, I. F. Gertner, V. V. Vrublevskii
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Minerals. 2019. Vol. 9, № 3. P. 170 (1-13)
Minerals
Volume 9
Issue 3
Minerals, Vol 9, Iss 3, p 170 (2019)
Popis: A new Wenlockian zircon U&ndash
Pb age (~426 Ma) of the Overmaraat-Gol nepheline syenite (foyaite, juvite) pluton in the SW Lake Hovsgol area (Northern Mongolia) prompts a long history of alkaline magmatism in the western Central Asian Orogenic Belt, exceeding the duration of the Devonian and Permian&ndash
Triassic events. The LILE and HFSE patterns of pluton samples analyzed by X-ray fluorescence (XRF) and inductively coupled plasma (ICP-MS) methods indicate intrusion in a complex tectonic setting during interaction of a mantle plume with accretionary-collisional complexes that previously formed on the active continental margin. As a result, the parent magma had a heterogeneous source with mixed mantle (PREMA and EM) and crustal components. This source composition is consistent with Nd&ndash
Sr isotope ratios of the Overmaraat-Gol alkaline rocks, from &minus
0.1 to &minus
1.2 &epsilon
Nd(t) and from ~0.706 to 0.707 87Sr/86Sr(t).
Databáze: OpenAIRE