Zircon LA-ICP-MS U-Pb Age and Island-Arc Origin of the Bayanhua Gabbro in the Hegenshan Suture Zone, Inner Mongolia  

作　　者：WANG Jinfang LI Yingjie LI Hongyang 

机构地区：[1]School of Natural Resources,Hebei Geo University

出　　处：《Acta Geologica Sinica(English Edition)》2017年第6期2316-2317,共2页地质学报（英文版）

基　　金：funded by the National Natural Science Foundation of China (grant No.41502211);the China Geological Survey (grants No.1212011120701 and 1212011120711);Hebei Province Education Department (grant No.ZC20165013)

摘　　要：Objective The Bayanhua Nb-enriched gabbro is newly discovered in the Diyanmiao-Meilaotewula SSZ-type ophiolitic m61ange belt of the Hegenshan suture zone, Inner Mongolia. Nb-enriched arc gabbros are usually believed to result from partial melting of the mantle wedge peridotites metasomatized by slab melts derived from the subducting oceanic slab, which represent arc magmatic markers of the oceanic subduction zone. However, whether the Hegenshan ocean basin of the Paleo-Asian Ocean was in its subduction stage in the Early Permian requires further study for a final conclusion, and what is the evolution process of the oceanic subduction and lithospheric mantle of the Hegenshan suture zone remains speculative for the lack of further definitely petrological and chronological evidence and constraints. Therefore, this study carried out zircon LA-ICP-MS U-Pb geochronology and geochemistry on the Bayanhua Nb-enriched gabbro to discuss its origin, in order to provide new evidence for the tectonic evolution of the Hegenshan suture zone of the eastern Central Asian Orogenic Belt.Objective The Bayanhua Nb-enriched gabbro is newly discovered in the Diyanmiao-Meilaotewula SSZ-type ophiolitic m61ange belt of the Hegenshan suture zone, Inner Mongolia. Nb-enriched arc gabbros are usually believed to result from partial melting of the mantle wedge peridotites metasomatized by slab melts derived from the subducting oceanic slab, which represent arc magmatic markers of the oceanic subduction zone. However, whether the Hegenshan ocean basin of the Paleo-Asian Ocean was in its subduction stage in the Early Permian requires further study for a final conclusion, and what is the evolution process of the oceanic subduction and lithospheric mantle of the Hegenshan suture zone remains speculative for the lack of further definitely petrological and chronological evidence and constraints. Therefore, this study carried out zircon LA-ICP-MS U-Pb geochronology and geochemistry on the Bayanhua Nb-enriched gabbro to discuss its origin, in order to provide new evidence for the tectonic evolution of the Hegenshan suture zone of the eastern Central Asian Orogenic Belt.

关 键 词：Zircon LA-ICP-MS U-Pb Age and Island-Arc Origin of the Bayanhua Gabbro Inner Mongolia 

分 类 号：P588.124[天文地球—岩石学]