成都理工大学学报（自然科学版）2025，Vol.52Issue(3)：409-422,14.DOI:10.12474/cdlgzrkx.2025021601
扬子西南缘早新元古代沉积物源特征及其对Rodinia超大陆聚散转换的响应
Provenance characteristics of early Neoproterozoic sediments in the southwestern Yangtze Block and their response to the assembly-breakup transition of the Rodinia Supercontinent
摘要
Abstract
The Liubatang Formation,unconformably overlying the Kunyang Group and underlying the Chengjiang Formation in the southwestern Yangtze Block,preserves critical records of tectonic regime transition in the early Neoproterozoic.Systematic stratigraphic,sedimentological,and geochronological investigations are conducted on the Liubatang Formation in central Yunnan to constrain its depositional age,provenance characteristics,and tectonic implications.Zircon U-Pb dating of tuff layers from the base and top of the formation yield ages of 895±2 Ma and 856±3 Ma,respectively,refining its depositional time frame to 900～850 Ma.The lower conglomerates and sandy conglomerates of the Liubatang Formation were deposited in alluvial to fluvial fan environments,with gravels predominantly composed of slate and meta-sandstone.Detrital zircons from the upper clastic rocks exhibit significant abrasion features and age distributions,comparable to those of the underlying Kunyang Group(particularly the Meidang Formation),indicating sedimentary recycling of preexisting strata.Based on an integrated regional stratigraphic and tectonic dataset,it is suggested that the unconformity between the Liubatang Formation and the Kunyang Group represents a tectonic uplift and erosion surface(950～900 Ma),while the boundary with the overlying Chengjiang Formation corresponds to an extensional unconformity(850～810 Ma).These two unconformities respectively record the final amalgamation and incipient breakup of the Rodinia supercontinent,providing key constraints on the tectonic transition during the assembly and breakup cycle of this supercontinent.关键词
华南/柳坝塘组/碎屑锆石/物源分析/罗迪尼亚Key words
South China/Liubatang Formation/detrital zircon/provenance analysis/Rodinia supercontinent分类
天文与地球科学引用本文复制引用
庞维华,崔晓庄,任光明,陈风霖,孙志明,任飞..扬子西南缘早新元古代沉积物源特征及其对Rodinia超大陆聚散转换的响应[J].成都理工大学学报（自然科学版）,2025,52(3):409-422,14.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）
