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首页|期刊导航|地质学报(英文版)|Geochronology and Geochemistry of the Xingxingxia Triassic A-type Granites in Central Tianshan,NW China:Petrogenesis and Tectonic Implications

Geochronology and Geochemistry of the Xingxingxia Triassic A-type Granites in Central Tianshan,NW China:Petrogenesis and Tectonic ImplicationsOACSTPCD

Geochronology and Geochemistry of the Xingxingxia Triassic A-type Granites in Central Tianshan,NW China:Petrogenesis and Tectonic Implications

英文摘要

The Triassic granitoids in Central Tianshan play a key role in determining the petrogenesis and tectonic evolution on the southern margin of the Central Asian orogenic belt.In this study,we present SHRIMP zircon U-Pb ages,Hf isotopic and geochemical data on the Xingxingxia biotite granite,amazonite granite and granitic pegmatite in Central Tianshan,NW China.Zircon U-Pb dating yielded formation ages of 242 Ma for the biotite granite and 240 Ma for the amazonite granite.These granitoid rocks have high K2O with low MgO and CaO contents.They are enriched in Nb,Ta,Hf and Y,while being depleted in Ba and Sr,showing flat HREE patterns and negative Eu anomalies.They have typical A-type granite geochemical signatures with high Ga/Al(8-13)and TFeO/(TFeO + MgO)ratios,showing an A2 affinity for biotite granite and an A1 affinity for amazonite granite and granitic pegmatite.Zircon εHf(t)values of the granitoids are 0.45-2.66,with Hf model ages of 0.99-1.17 Ga.This suggests that these A-type granites originated from partial melting of the lower crust.We propose that Xingxingxia Triassic A-type granites formed under lithospheric extension from post-orogenic to anorogenic intraplate settings and NE-trending regional strike-slip fault-controlled magma emplacement in the upper crust.

HUANG Zengbao;LI Xiyao;ZHAO Hao;LU Qing

Geological Survey of Gansu Province,Lanzhou 735000,ChinaKey Laboratory of Submarine Geosciences and Prospecting Techniques,MOE and College of Marine Geosciences,Ocean University of China,Qingdao,Shandong 266100,ChinaResearch Institute of Petroleum Exploration and Development,Shengli Oilfield,SINOPEC,Dongying,Shandong 257000,China

TriassicA-type graniteXingxingxiaCentral TianshanCentral Asian orogenic belt

《地质学报(英文版)》 2024 (002)

337-351 / 15

This project was supported by Shandong Provincial Natural Science Foundation(Grant No.ZR2021MD059)and Gansu Provincial Natural Science Foundation(Grant No.22JR5RA820).We express our sincere appreciation to the editors and two referees for their constructive comments.The kind assistance from Drs.Wang Wei and Shi Yuruo for the analysis in the SHRIMP Laboratory,as well as Zhang Youkui and Qi Wei for their help in fieldwork,is also gratefully acknowledged and thanked.

10.1111/1755-6724.15150

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