成果归属作者：

罗照华

成果归属机构：

地球科学与资源学院

作者：

Wang, Jiawei ; Cai, Pengjie ; Yang, Jingsui ; Szilas, Kristoffer ; Lian, Dongyang ; Luo, Zhaohua ; Xiong, Fahui

单位：

CAGS, Inst Mineral Resources, MNR Key Lab Metallogeny & Mineral Assessment, Beijing 100037, Peoples R China;China Univ Geosci Beijing, Sch Earth Sci & Resources, 29 Xueyuan Rd, Beijing 100083, Peoples R China;Nanjing Univ, Sch Earth Sci & Engn, State Key Lab Mineral Deposits Res, Nanjing 210093, Peoples R China;Chinese Acad Geol Sci, Inst Geol, Ctr Adv Res Mantle CARMA, Minist Nat Resources, Key Lab Deep Earth Dynam, Beijing 100037, Peoples R China;Univ Copenhagen, Dept Geosci & Nat Resource Management, Oster Voldgade 10, DK-1350 Copenhagen, Denmark

关键词：

ISUA-GREENSTONE-BELT; OS ISOTOPE SYSTEMATICS; PLATINUM-GROUP ELEMENTS; ITSAQ GNEISS COMPLEX; RE-OS; CONTINENTAL-CRUST; PLATE-TECTONICS; PODIFORM CHROMITITES; SINGHBHUM CRATON; VOLCANIC-ROCKS

摘要：

The chromite deposits of the Seqi Ultramafic Complex are part of layered ultramafic bodies that occur within Mesoarchaean tonalitic orthogneiss in the 3.2-3.0 Ga Akia Terrane of the North Atlantic Craton, southern West Greenland. The calculated Al2O3-melt and TiO2-melt concentrations of the parental melt are within the range of 12.22-12.60 and 0.34-0.41 wt%, respectively. Seqi chromitites exhibit the patterns of PGE normalised with chondrite with positive Os, Ir and Ru anomalies and negative PPGE anomalies. These geochemical characteristics indicate that the Seqi chromitites formed as part of cumulates originated from a parental komatiitic magma that experienced crustal contamination. The ReOs isotope data present a minimum Re-depletion model age (TRD) of 3124-3014 Ma for the Seqi chromitite, which is the best estimate of the magmatic age of this ultramafic intrusion. Abundant zircon grains occur within the Seqi chromitites, yielding a UPb weighted mean age of 2985.43 +/- 4.26 Ma, which is identical to the peak of regional granulite-facies metamorphism of the Akia Terrane. This study presents the first dating of the formation age of the Seqi chromitite of >3124 Ma.

基金：

National Natural Science Foundation of China [92062215, 42302080, 42330306]; Fundamental Research Funds for the Central Universities [020614380175, 020614380186]; Outstanding Postdoctoral Program of Jiangsu Province [2022ZB12]; Special Funds Projects for Basic Scientific Research Business Expenses of Mineral Resources Research Institutes in Chinese Academy of Geological Sciences [KK2217]; Villum Foundation [18978]

语种：

英文

DOI：

10.1016/j.lithos.2024.107714

来源：

LITHOS,2024():.

出版日期：

2024-10

提交日期：

2024-08-09

引用参考：

Wang, Jiawei; Cai, Pengjie; Yang, Jingsui; Szilas, Kristoffer; Lian, Dongyang; Luo, Zhaohua; Xiong, Fahui. Age and petrogenesis of Archaean chromitite from the Seqi Ultramafic Complex, southern West Greenland[J]. LITHOS,2024():.