Late Triassic to Middle Jurassic magmatism in the Eastern Pontides(NE Türkiye):Evidence for divergent double subduction of Paleo-Tethys lithosphere  

作　　者：Yener Eyuboglu Ze Liu Dicheng Zhu Nilanjan Chatterjee Liangliang Zhang Jincheng Xie Francis O.Dudas 

机构地区：[1]Department of Geological Engineering,Karadeniz Technical University,61080 Trabzon,Turkey [2]State Key Laboratory of Geological Processes and Mineral Resources,and School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China [3]Department of Earth,Atmospheric and Planetary Sciences,Massachusetts Institute of Technology,Cambridge,MA 02139,USA

出　　处：《Geoscience Frontiers》2025年第1期65-90,共26页地学前缘(英文版)

基　　金：supported by Karadeniz Technical University Research Foundation(FBA-2017-7286 and FBA-2023-10635);National Natural Science Foundation of China(42103038);Open Research Project from the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(GPMR201815).

摘　　要：The Meso-Cenozoic geodynamic evolution of northern Türkiye remains a subject of debate primarily due to a lack of systematic geological,geochemical,geochronological,and geophysical investigations.This paper presents comprehensive geochronological and geochemical data on the Late Triassic andesite porphyry,andesite breccia and quartz diorite porphyry,and the Middle Jurassic diabase,and amphibole-poor and amphibole-rich andesite porphyry fromÇevrepınar Igneous Complex(Gümüşhane)in the southern part of the Eastern Pontides Orogenic Belt(EPOB),a well-preserved continental arc in the Alpine-Himalayan orogen.Zircon U-Pb geochronology indicates crystallization ages of∼208-202 Ma(Rhaetian)for the Late Triassic rocks and∼175-172 Ma(Aalenian)for the Middle Jurassic rocks.Whole-rock geochemical and Sr-Nd-Pb isotopic data,and zirconεHf(t)data indicate that both the Late Triassic and the Middle Jurassic rocks originated by low-degree melting of a spinel lherzolite lithospheric mantle source modified by subduction-related fluids and/or melts.Based on the new and published data,we suggest that the Late Triassic to Middle Jurassic arc magmatism in EPOB occurred as a result of southward subduction of the Paleo-Tethys oceanic lithosphere beneath the northern margin of Gondwana-Land.Late Triassic to Jurassic arc magmatism and basin evolution occurred synchronously in the northern and southern peripheries of the present-day Eastern Black Sea Basin,indicating divergent double subduction of the Paleo-Tethys oceanic lithosphere beneath the northern margin of Gondwana and southern margin of Laurasia during the Early Mesozoic.

关 键 词：Arc magma Pontides PALEO-TETHYS Divergent double subduction Mesozoic Oceanic lithosphere 

分 类 号：P58[天文地球—岩石学]