华东地质2026，Vol.47Issue(1)：124-140,17.DOI:10.16788/j.hddz.32-1865/P.2025.11.002
扬子陆块西北缘新元古代早―中期地层与岩浆活动:进展、争议与认识
Early-Middle Neoproterozoic strata and magmatism in the northwestern margin of the Yangtze Block:advances,controversies and insights
摘要
Abstract
The Early-Middle Neoproterozoic is a critical period for the assembly and breakup of the Rodinia Supercontinent.The northwestern margin of the Yangtze Block,preserving abundant information on stratigraphic records and magmatic activities during the Early to Mid-Neoproterozoic,serves as an important window to probe the Precambrian tectonic evolution of the Yangtze Block and its links to the supercontinent's assembly and breakup.This study systematically summarizes the Early-Middle Neoproterozoic stratigraphic sequences and magmatic characteristics to clarify the stratigraphic ages,basin properties,and tectonic settings of magmatic rocks in different subregions of the northwest Yangtze.Results prove that the Bikou Group,Liujiaping Formation,Tiechuanshan Formation,and Xixiang Group in the northwest Yangtze Block are coeval with the maximum depo-sitional age of(825±5)Ma.They are characterized by continental volcanic rocks,pyroclastic rocks,and alluvial-pluvial purplish red polymictic conglomeratic sandstone,and formed in a continental rift basin.The Sanhuashi Group and Baimianxia Formation of the underlying Tongmuliang Group,Huodiya Group and Sanwan Formation exhibit significant lateral variations in rock associations and sedimentary sequences,which may reflect the dis-tinct evolutionary characteristics of different masses.Magmatic activities can be divided into four stages:985-905 Ma,898-887 Ma,884-830 Ma,and 825-750 Ma.These stages correspond to the tectonic settings of initial subduction of intra-oceanic arc,passive continental margin,evolution of arc-basin systems,and amalgamation of blocks,and intracontinental rifting and extension,respectively,responding to the entire assembly-breakup cycle of the Rodinia Supercontinent.关键词
扬子陆块西北缘/新元古代/沉积序列/岩浆活动/构造演化/Rodina超大陆Key words
northwestern margin of the Yangtze Block/Neoproterozoic/sedimentary sequence/magmatism/tectonic evolution/Rodinia Supercontinent分类
天文与地球科学引用本文复制引用
邓奇,汪正江..扬子陆块西北缘新元古代早―中期地层与岩浆活动:进展、争议与认识[J].华东地质,2026,47(1):124-140,17.基金项目
中国地质调查局"四川宝兴—大川地区1∶5万区域地质调查(编号:DD20240208303)"、国家自然科学基金地质联合基金"扬子西北缘早古生代海相盆地多幕次构造-沉积转换及其成烃成储响应(编号:U2344209)"、四川省自然科学基金"四川南江—旺苍地区火地垭群沉积-变质事件及成矿地质背景研究(编号:2023NSFSC0275)"项目联合资助. （编号:DD20240208303）
