地质论评2025，Vol.71Issue(4)：1119-1142,24.DOI:10.16509/j.georeview.2024.12.065
3.1 Ga左右全球岩浆事件和地壳演化
～3.1 Ga Global magmatic events and crustal evolution
摘要
Abstract
Objectives:During the Archean,approximately 90％of the global craton's crust may have formed,particularly during the 3.5～3.1 Ga,2.8～2.7 Ga,and 2.6～2.5 Ga.More rocks are preserved from the 2.8～2.7 Ga and late 2.6～2.5 Ga periods.While the mechanisms of crustal accretion and remodeling are frequently investigated,research is limited by the scarcity of samples,resulting in relatively weak studies on magmatic events and crustal formation prior to 3.0 Ga.Furthermore,the understanding of earlier Preambrian magmatic events and crustal accretion remains controversial. Methods:Building upon previous research,this study summarizes and compares zircon ages,rock types,whole-rock geochemistry,and zircon Lu-Hf-O isotope signatures of global Mesoproterozoic rocks,primarily from the 3.2～3.0 Ga period,in order to concluding the global magmatic events and crustal evolution patterns around 3.1 Ga. Results:Rocks from the 3.2～3.0 Ga period are found across all continents,with a predominant concentration in the Northern Hemisphere,while the Southern Hemisphere exhibits a relatively smaller number in present.The peak zircon ages of these rocks are concentrated around 3.05 Ga and 3.15 Ga.The main lithologies include stromatolitic and peraluminous aeolian granite.The primary lithologies of the rocks consist of angstromatolite and aeolian granite with peraluminous characteristics.Different regions exhibit distinct rock assemblages,and the εHf(t)values of zircons from these regions demonstrate significant variations,reflecting differences in the origin and evolutionary history of the rocks.Most zircons have δ18O values in equilibrium with mantle melt;however,some zircons exhibit higher δ18O values,reaching+8.93％o,suggesting that the rock source areas underwent low-temperature alteration or mixing with crustal materials.The rocks display a right-tilted pattern characterized by an enrichment of light rare earth elements and a deficit of heavy rare earth elements,with pronounced europium anomalies.Overall,elements such as Th,U,K,and Pb are relatively enriched,whereas elements like Nb,Ta,P,Sm,and Ti are comparatively deficient. Conclusions:The～3.1 Ga rocks likely formed through partial melting of a basaltic source region that experienced low-temperature alteration.This source region originated from partial melting of a mildly deficient mantle around～3.3 Ga.A global event of magmatism and crustal growth occurred during the early Mesoarchean(primarily between 3.2 and 3.0 Ga),with peaks at approximately 3.05 Ga and 3.15 Ga.Furthermore,tectonic regimes akin to modern plate motions began to emerge in certain areas during the Mesoarchean.关键词
中太古代/地壳增生/岩浆事件/TTG岩石Key words
Mesoarchean/crustal accretion/magmatic event/TTG rocks引用本文复制引用
边天一,孟凡超,杨飞..3.1 Ga左右全球岩浆事件和地壳演化[J].地质论评,2025,71(4):1119-1142,24.基金项目
本文为国家自然科学基金资助项目(编号:42272225)、崂山实验室科技创新项目(编号:LSKJ202203401)、山东省自然科学基金面上项目(编号:ZR2021MD083)和中央高校基本科研业务费专项(编号:23CX09004A)的成果. This study was supported by the Natural Science Foundation of China(No.42272225),Science and Technology Innovation Foundation by Laoshan Laboratory(No.LSKJ202203401),Natural Science Foundation of Shandong Province(No.ZR2021MD083)and Fundamental Research Funds for the Central Universities of Ministry of Education of China(No.23CX09004A) （编号:42272225）
