湘渝黔地区奥陶系红色岩溶地貌与沉积作用关系  

Relationship between sedimentation and red karst landform during the Ordovician in Hunan,Chongqing and Guizhou

作　　者：陈友智 姜伏伟 陈颖 杨贵来[4] 于宁 苏孝良 CHEN Youzhi;JIANG Fuwei;CHEN Ying;YANG Guilai;YU Ning;SU Xiaoliang(Southwest Geophysical Institute of BGP,CNPC,Chengdu,Sichuan 610213,China;School of Water Resources and Environmental Engineering,East China University of Technology,Nanchang,Jiangxi 330013,China;Development Division,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610017,China;Chengdu Geological Survey Center of China Geological Survey,Chengdu,Sichuan 610218,China;College of Resources and Environmental Engineering,Guizhou Institute of Technology,Guiyang,Guizhou 550003,China;Guizhou Provincial Department of Science and Technology,Guiyang,Guizhou 550002,China)

机构地区：[1]中国石油集团东方地球物理勘探有限责任公司西南物探研究院,四川成都610213 [2]东华理工大学水资源与环境工程学院,江西南昌330013 [3]中国石油集团西南油气田分公司开发事业部,四川成都610017 [4]中国地质调查局成都地质调查中心,四川成都610218 [5]贵州理工学院资源与环境工程学院,贵州贵阳550003 [6]贵州省科学技术厅,贵州贵阳550002

出　　处：《中国岩溶》2024年第3期694-703,共10页Carsologica Sinica

基　　金：中国地质调查局项目“全国地质遗迹立典调查与评价”(DD20190074);贵州省科技计划项目(黔科合JZ字[2015]2005)。

摘　　要：文章基于野外露头观测、薄片观察、牙形石研究以及X射线衍射分析,从沉积角度探讨了风化作用与湘渝黔地区奥陶系红色岩溶地貌之间的关系。结果表明:同生成岩阶段,大气氧含量的增加,浅海陆棚水底氧化,陆源碎屑中铁离子被氧化形成Fe_(2)O_(3)进入沉积地层,奠定了地貌颜色;受岩相古地理的影响,早中奥陶世大湾期中上扬子地块自西向东岩相存在分带性,岩溶地貌仅出现在以武汉-松滋-松桃-黄平为中心的浅海陆棚碳酸盐岩弧形相带上;沉积微相决定碳酸盐岩孔隙大小与结构影响风化作用,岩石之间差异风化造就地貌凹凸形;米兰科维奇旋回导致牯牛潭组泥质灰岩与生物碎屑泥晶灰岩相互叠置,环潮坪型米级旋回造就出岩溶地貌的韵律性;灰岩中不溶残余物黏土矿物种类及含量暗示其沉积物源与埋藏史的差异,并影响岩层水化膨胀律和抗风化能力。The Ordovician red karst is a newly discovered geological landscape in Hunan,Chongqing and Guizhou.Its appearances,distributions and rhythms are distinctive.With the development of red stone forest parks in the study area,red karst landforms have attracted great attention in recent years.Researchers have analyzed red karst landforms from their appearance characteristics,geomorphological types,surface corrosion,geological structures,climatic and neo-tectonic movement.However,there is still lack of research on the relationship between formation of red karst landforms and sedimentation.Integrating the field geological survey,observation of thin sections,odontolite analysis and X-ray diffraction analysis,this study tried to discuss the inner connection between weathering and red karst landforms in the view of sedimentation.During the syndiagenetic stage,the increase of oxygen content in the atmosphere caused the oxidation at the bottom of shallow continental shelf.During this process,Fe_(2)O_(3)that was formed by the oxidation of iron ions in terrigenous debris entered sedimentary strata,which contributed to red-colored landform.Controlled by the distribution of lithofacies in the early-to-mid Ordovician,karst landforms were only developed in the carbonate arc blet of the shallow continental shelf along the area of Wuhan-Songzi-Songtao-Huangping.Pore sizes and structures of carbonate rocks affected by sedimentary microfacies would influence weathering,and hence the differential weathering caused concave and convex terrains.The Milankovitch cycle resulted in the overlapping of argillaceous limestone and bioclastic micritic limestone in the Guniutan Formation,and the meter-scale cycle of circum-tidal flat caused the rhythms of karst landforms.Types and contents of clay minerals within the limestone indicate the differences in sediment sources and burial histories and also affects hydration expansion and weathering resistance of the formation.In summary,the sedimentation process that controls the rock formation and weat

关 键 词：红色岩溶地貌 沉积作用 沉积相 野外露头 沉积旋回 

分 类 号：P931.5[天文地球—自然地理学]