地质力学学报2016，Vol.22Issue(4)：1049-1061,13.
准噶尔东部早志留世两类花岗岩的岩石成因及构造意义
PETROGENESIS AND TECTONIC IMPLICATIONS OF TWO TYPES EARLY SILURIAN GRANITES IN EAST JUNGGAR
摘要
Abstract
The early Silurian monzogranite and syenogranite are located in the western section of Harlik Mountain with a NWW-trending,which intrude into the Ordovician Tashui Formation (O1-2 t).The LA-ICP-MS zircon U-Pb dating shows their emplacement ages are 438.8 ±2.3 Ma ～435.8 ± 3.1 Ma.The rocks have high contents of silicon (SiO2 =73.0 ～ 77.8％) and potassium (K20 =3.31 ～ 4.26％),and low contents of magnesium (MgO =0.03 ～ 0.59％),with moderate aluminum saturation index (A/CNK =1.02 ～ 1.08),which show that the rocks are high-K calcalkaline,weakly peraluminium series.Monzogranites exhibit strongly fractionated REE patterns with moderate negative Eu anomalies,and they are depleted in Nb,Ta,Ti,P,but enriched in Rb,Ba,K,showing notable fractionated Ⅰ-type granitoids with mafic lower continental crust as a potential magma source.Syenogranites show remarkably depletion of Eu,P,Ti and Sr,and enrichment of Rb,K,Zr and Hf,showing A-type granites affinity,whose magma source maybe the dehydrated felsic upper continental crust.Combined with the stratigraphic unconformity in this region,we propose that the East Junggar is in a post-collisional setting rather than arc-related setting during the early Silurian.The upwelling asthenosphere provided enhanced heat flux and triggered the partial melting of the juvenile crust,and resulted in the generation of various Silurian post-collisional granites in East Jungga.关键词
哈尔里克/志留纪/A型花岗岩/后碰撞Key words
Harlik/Silurian/A-type granite/post-collision分类
天文与地球科学引用本文复制引用
肖典,廖群安,王良玉,赵浩,查雁鸿,赵红伟,尹庭旺,田锦明,刘鸿飞..准噶尔东部早志留世两类花岗岩的岩石成因及构造意义[J].地质力学学报,2016,22(4):1049-1061,13.基金项目
中国地质调查局“特殊地质地貌区填图试点”项目(DD20160060 （）
12120114042801) （）
