沉积学报2025，Vol.43Issue(2)：453-466,14.DOI:10.14027/j.issn.1000-0550.2023.038
黔南萨克马尔期珊瑚礁特征及其环境背景
Basic Characteristics and Palaeoenvironmental Background of a Sakmarian Coral Reef in Southern Guizhou
摘要
Abstract
[Objective]During the Early Permian,shallow water carbonate platforms were widely developed in Zi-yun area,southern Guizhou,which is a significant region for studying the characteristics of bioconstructions and the implications to palaeoenvironment.[Methods]The methods of paleontology and sedimentary petrology were systemati-cally used to study the Gaozhai coral reef in Zongdi town,Ziyun county,Guizhou province.The Gaozahi coral reef was meticulously measured in the field.The lithology,sedimentary structures,bed thickness and components were documented in detail.[Results]Based on field observations,the Gaozhai coral reef is exposed with a thickness of ap-proximately 3.0 m and a lateral exposure of nearly 23.6 m.A total of 10 species in 8 genera fusulinids were recog-nized:Eoparafusulina parashengi,E.pararegularis,Mccloudia contracta,Pseudofusulina cf.wulungensis,Rugosofusu-lina paragregariformis,Triticites daaoziensis,Zellia ex.gr.crassialveola,Sphaeroschwagerina borealis,S.sp.indet.,Boultonia wills.The fusulinids collected from the reef indicate an Early-Middle Sakmarian age.The Gaozhai coral reef is primarily composed of the in suit colonial rugose coral Fomichevella.A small quantity of solitary rugose coral Bothrophyllum,Timiania and colonial rugose coral Kepingophyllum are also recognized.The coral framework is pre-dominantly built by the branching colonial rugose coral Fomichevella preserved in situ.The great majority of corals are well-preserved,and the fragments are rare.The growth mechanism of Fomichevella is mostly attached to each oth-er with asexual budding structure in branching forms and mostly occupies as much space as possible.The associated biotic compositions of the coral reef,including foraminifera,fusulinids,brachiopods,bryozoans,crinoids,ooids and calcareous algae,are abundant and spatially diverse.The differences in the composition of coral reef-dwellers re-flect the temporal and spatial changes in the biotic constitutions of the coral reef.Four microfacies types have been identified,including bioclastic grainstone,bioclastic packstone,coral framestone and bioclastic wackestone.In the substrate of the Gaozhai coral reef,the microfacies types are predominantly characterized by bioclastic grainstone and bioclastic packstone,including the bioclasts of foraminifers,brachiopods,bryozoans and calcareous algae.In the core of the coral reef,the microfacies types are dominated by the coral framestone.Bioclastic wackestone is common in the interior of this coral reef,filling the spaces between coral skeletons.Bioclastic packstone is predominant in the cap of the coral reef.[Conclusions]Fasciculate corals have the highest growth rates among rugose corals,which can occupy ecologic niches much quicker than other forms and become relatively dominant at times.The dominance of the fasciculate colonial coral Fomichevella is more adaptable to the environment and could build a strong coral framework in the development of the reef.According to the growth of the reef-builder(corals)and microfacies analyses,relative sea-level changes are interpreted to control the development of the Gaozhai coral reef,which provides compelling evi-dence for the response of the reef evolution to the Late Palaeozoic glaciation at low latitudes.The development of the Gaozhai coral reef in South China was strongly coupled to the relative global deglaciation episode and associated sea-level rise during the Sakmarian.关键词
珊瑚礁/萨克马尔期/生物组成/微相/黔南Key words
coral reef/Sakmarian/biotic composition/microfacies/southern Guizhou分类
地质学引用本文复制引用
王立芙,巩恩普,杨臻元,王俊杰,张永利,关长庆..黔南萨克马尔期珊瑚礁特征及其环境背景[J].沉积学报,2025,43(2):453-466,14.基金项目
国家自然科学基金项目(41972002,42272008)[National Natural Science Foundation of China,No.41972002,42272008] （41972002,42272008）
