Petrogenesis and Tectonic Implications of Yemaquan Monzogranite from North Altyn
Zheng Kun
Wu Cailai
Gao Yuanhong
Guo Wenfeng
Chen Hongjie
Wu Di
Gao Dong
Abstract：Yemaquan monzogranite pluton is the largest outcrop in North Altyn,with a medium-coarse grain and porphyritic texture.This paper aims to discuss the genesis and diagenesis environment of the monzogranite,and the tectonic evolution of North Altyn.Thus,it is necessary to study petrology,geochemistry,zircon U-Pb chronology and Hf isotope of the pluton. The zircon U-Pb age data suggest that the monzogranite was generated at 450—453 Ma.The rock shows significant features of I-type granite with high ratio of Na2O/K2O(1.72—2.29),aluminum saturation index(A/CNK=0.99—1.10)and negative correlation between P2O5% and SiO2%.The REE pattern shows depletion of HREE,relative enrichment of LREE,and slightly negative Eu anomaly.In the primitive mantle-normalized trace-element diagram,the rock shows strong enrichment of Rb,Ba,Th,U,K and depletion of Nb,Ta,P,Ti.The values ofεHf(t)range in 5.52—10.75.The two-stage model ages (tDM2)vary from 0.75 to 1.09 Ga.These characteristics indicate that the source rock was formed from the juvenile crust (basites).Considering the regional tectonic setting,it is concluded that the monzogranite was generated by partial melting of the basites at the root of the orogenic belt in the syn-collision to post-collision environment.
Keywords：monzogranitegeochemistryU-Pb chronologyHf isotopic characteristicspetrogenesisNorth Altyn
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：12( 1266-1277 )