成都理工大学学报（自然科学版）2025，Vol.52Issue(3)：423-439,17.DOI:10.12474/cdlgzrkx.2025022801
扬子西南缘新元古代早期构造热事件——来自撮科杂岩榍石U-Pb年代学的新证据
Early Neoproterozoic tectonothermal events in the southwestern Yangtze Block,south China:New evidence from titanite U-Pb geochronology of the Cuoke Complex
摘要
Abstract
The spatiotemporal framework of early Neoproterozoic tectonothermal events in central Yunnan(Dianzhong area)holds critical significance for reconstructing the tectonic evolution and metallogenic processes in the southwestern Yangtze Block during the assembly of the Rodinia supercontinent.This study conducts LA-ICP-MS U-Pb geochronology and in situ trace element analysis of zircon and titanite in a gneissic granite sample from the Cuoke Complex.The results show that the zircons exhibit typical oscillatory zoning and high Th/U ratios(0.56～1.46),indicating a magmatic origin.Their weighted mean 207Pb/206Pb age of 2 334±18 Ma(MSWD=0.44)constrains the formation time of the gneissic granite.The titanite U-Pb ages can be divided into two groups,with 207Pb-corrected weighted mean 206Pb/238U ages of 987±7 Ma(MSWD=0.50)and 932±8 Ma(MSWD=1.05),respectively.Their low Th/U ratios,enrichment in heavy rare earth elements and weak Eu anomalies,suggest a metamorphic origin,indicating that the Cuoke Complex underwent at least two episodes of metamorphism during the early Neoproterozoic.Integrated with regional geological data,this study further confirms that the southwestern margin of the Yangtze Block witnessed extensive early Paleoproterozoic magmatic activity and underwent multiple episodes of regional metamorphism during the assembly of both the Columbia and Rodinia supercontinents,while demonstrating a pronounced spatiotemporal coupling among early Neoproterozoic magmatism,metamorphism,and mineralization events in this region.关键词
榍石U-Pb年龄/构造热事件/撮科杂岩/新元古代/扬子陆块Key words
titanite U-Pb age/tectonothermal events/Cuoke Complex/Neoproterozoic/Yangtze Block分类
天文与地球科学引用本文复制引用
郑鹏威,崔晓庄,王鹏,任光明,陈风霖,庞维华,孙志明..扬子西南缘新元古代早期构造热事件——来自撮科杂岩榍石U-Pb年代学的新证据[J].成都理工大学学报（自然科学版）,2025,52(3):423-439,17.基金项目
中国地质调查局项目(DD20240033) （DD20240033）
国家自然科学基金项目(41872120). （41872120）
