地质与勘探2025，Vol.61Issue(4)：698-714,17.DOI:10.12134/j.dzykt.2025.04.003
祁零盆地中二叠统孤峰组地层序列特征及其构造-沉积演化规律
Stratigraphic Sequence Characteristics and Tectonic-Sedimentary Evolution Patterns of the Middle Permian Gufeng Formation in Qiling Basin
摘要
Abstract
The Qiling Basin in the southwestern part of Hunan Province is an important Permian manganese ore metallogenic belt in China,with huge resource potential.However,the lack of understanding of its sedimentary environment characteristics and evolutionary patterns has restricted further breakthroughs in mineral exploration.This study aims to systematically reveal the sedimentary system characteristics of the Gufeng Formation,the manganese ore enrichment patterns,and their constraints by the sedimentary paleogeographic evolution,providing scientific support for regional mineral exploration and target area selection.The study primarily focused on the core samples from three boreholes(Shuibutou,Xinzhaili,and Maozhu)in the Qiling Basin.A combination of sedimentology and petrology analysis methods,along with detailed stratigraphic correlation of manganese-bearing rock series,was used for the systematic study of the Gufeng Formation.The results indicate that:(1)The Gufeng Formation as a whole develops a carbonate platform-slope-foreland basin sedimentary system.The open platform subfacies is characterized by bioclastic limestone and trough cross-bedding.The platform edge slope subfacies is dominated by nodular limestone and mudstone interbedding,with spongiolites and siliceous radiolarians.The foreland basin subfacies is marked by black organic-rich mudstone interbedded with rhodochrosite.(2)The Gufeng Formation can be divided into two members from bottom to top,with the manganese-rich interval developed in the upper member,where the manganese ore grade ranges from 8%to 22%.Manganese ores mainly occur in the black shale or manganese-bearing limestone in the platform and slope environments.The platform area is dominated by granule rhodochrosite,while the slope area is characterized by idiomorphic rhodochrosite.(3)The vertical sedimentary evolution sequence clearly shows that the Gufeng Formation underwent a complete cycle from platform → slope → platform → platform/foreland basin → platform,recording two significant sea-level fluctuations.(4)The temporal and spatial distribution of manganese-bearing rock series in the Gufeng Formation is controlled by regional differential subsidence and global sea-level fluctuations.This study systematically clarifies the sedimentary environmental characteristics,evolutionary patterns,and their relationship with manganese ore enrichment,providing key sedimentological basis for target area selection in regional mineral exploration.关键词
菱锰矿/地层序列/沉积演化/孤峰组/中二叠统/祁零盆地/湘西南Key words
rhodochrosite/stratigraphic sequence/sedimentary evolution/Gufeng Formation/Middle Permian/Qiling Basin/southwestern Hunan分类
天文与地球科学引用本文复制引用
黄乐清,张懿,曾志方,周英爱,廖志伟,徐军伟,柳智,石少华,邹光均..祁零盆地中二叠统孤峰组地层序列特征及其构造-沉积演化规律[J].地质与勘探,2025,61(4):698-714,17.基金项目
湖南省地质院重大科研项目"湖南祁零盆地及邻区二叠系沉积型锰矿成因机制研究与找矿预测"(编号:HNGSTP202402)、湖南省自然科学基金项目"湘西南地区中二叠世晚期沉积环境剧变与锰矿聚集机理研究"(编号:2025JJ80005)和湖南省永州市零陵区水埠头矿区锰矿详查项目(湖南省商业性地质勘查项目)联合资助. （编号:HNGSTP202402）
