鲁西新太古代末期构造演化--来自徂徕山二长花岗岩的U-Pb年龄和岩石化学证据  

Late Neoarchean tectonic evolution of western Shandong:Evidence from U-Pb chronology and petrogeochemistry of monzogranites in the Culai Mountain

作　　者：刘伟 靳立杰 阎海青 周永刚 张振飞 高继雷 王刚 王辉 李春稼 王子圣 LIU Wei;JIN Li-jie;YAN Hai-qing;ZHOU Yong-gang;ZHANG Zhen-fei;GAO Ji-lei;WANG Gang;WANG Hui;LI Chun-jia;WANG Zi-sheng(No.1 Institute of Geology and Mineral Resources of Shandong Province,J'nan 250014,China;Shandong Engineering Laboratory for High-Grade Fe Ores Exploration and Exploitation,J'nan 250014,China;Shandong Testing Center of China Metallurgical Geology Bureau,J'nan 250013,China)

机构地区：[1]山东省第一地质矿产勘查院,山东济南250014 [2]富铁矿勘查开发技术山东省工程研究中心,山东济南250014 [3]中国冶金地质总局山东局测试中心,山东济南250013

出　　处：《岩石矿物学杂志》2025年第2期243-258,共16页Acta Petrologica et Mineralogica

基　　金：山东省地质勘查项目(SDZS-2015-GTT01)。

摘　　要：鲁西地区是开展华北克拉通东部早前寒武纪地质演化的最佳地区之一,赋存有丰富的地球早期地壳演化和太古宙板块构造信息。本文对徂徕山地区的二长花岗岩进行了系统研究,进一步揭示了华北克拉通东部鲁西地区前寒武纪地壳演化历史。LA-ICP-MS锆石U-Pb同位素测年显示,二长花岗岩形成于约2.48 Ga,该年龄同时约束了徂徕山地区深熔作用的时限。岩石主量元素分析显示其高Si,富Na和K,低P,A/CNK=0.94~1.10,属于高钾钙碱性系列。微量元素方面,轻稀土元素富集,Eu异常不明显,富集Rb、Sr、Ba等大离子亲石元素,亏损Nb、Ta、P、Ti等高场强元素。综合分析认为徂徕山二长花岗岩来源于约2.7 Ga加厚下地壳(英云闪长质TTG岩石)的部分重熔,形成于新太古代末期陆块碰撞造山后的伸展环境,标志着新太古代晚期鲁西地区微陆块已拼贴完成,并与其他地区一起构成稳定的华北太古宙克拉通。Early Precambrian basement is well developed in western Shandong Province of the North China Craton.This paper shows a systematic study of the monzogranites from Culai Mountain,western Shandong,revealing the evolution history of Precambrian crust in the eastern part of North China Craton.LA-ICP-MS zircon U-Pb isotopic dating shows that the monzogranites from Culai Mountain were formed at about 2.48 Ga,which also restricts the time limit of metamorphism-anatexis in Culaishan area.The rocks have high Si,Na and K,low P,a A/CNK ratio of 0.94~1.10,and belong to the high-K calc-alkaline series.The monzogranites exhibit enriched light rare earth elements(LREEs)with noδEu anomalies,and are enriched in large ion lithophile elements(LILEs)(e.g.,Rb,Sr and Ba),and depleted in high field strength elements(HFSEs)(e.g.,Nb,Ta,P and Ti).Based on comprehensive analysis,it is believed that the monzogranite from Culai Mountain originated from partial remelting of the about 2.7 Ga thickened lower crust(tonalite TTG rocks).Formed in an extensional environment after collisional orogenesis,it marks that the completion of the collage of micro-land masses in western Shandong in the late Neoarchean,and together with other regions to formed a stable North China Archean Craton.

关 键 词：二长花岗岩 地球化学 新太古代晚期-古元古代早期 鲁西 华北克拉通 

分 类 号：P581.121[天文地球—岩石学] P597[天文地球—地质学]