摘要
宏观与微观结合并以地球化学分析为主要手段,研究认为:鄂尔多斯盆地南部奥陶系马家沟组存在准同生白云岩化、渗透回流及混合水白云岩化、埋藏白云岩化和热液白云岩化4种白云岩化成因。准同生白云岩主要发育于马一、三、五段,由常规蒸发泵白云岩化形成;渗透回流及混合水白云岩由富镁盐水下渗白云岩化以及富镁盐水混同大气淡水对先成碳酸盐岩进行白云岩化共同作用形成;埋藏白云岩为大气降水溶蚀古陆老硅铝质岩石形成的盐水下渗和海(湖)水沿溶蚀孔洞下渗这两种白云岩化叠加形成的;热液白云岩为热液在粗晶粒白云岩孔隙或构造裂缝中溶蚀碳酸盐岩,过饱和后晶出。
There developed four kinds of dolomitization in genesis in Majiagou Formation of southern Ordos basin：penecontemporaneous dolomitization,circumfluence and mixing water dolomitization,burial dolomitization and hydrothermal dolomitization,based on the study of macro-analysis,micro-analysis and geochemical characteristics.Penecontemporaneous dolostone developed in 1st,3rd and 5th members of Majiagou Formation,and its genesis is evaporative pumping dolomitization.Circumfluence and mixing water dolostone is produced by two kinds of effects： one is salt water rich in magnesium,another is the mixture of salt water rich in magnesium and fresh water,which finally cause metasomatism of limestone,and produce circumfluence and mixing water dolostone.Burial dolostone results from metasomatism of limestone by salt water rich in silicon and aluminum and seawater or salt lake water along the pore space.Hydrothermal fluid dolostone is mostly produced by hydrothermal fluid which is supersaturated in pore space of coarse-crystaline dolostone and structural fracture in Yanshan era.
出处
《现代地质》
CAS
CSCD
北大核心
2011年第5期925-930,共6页
Geoscience
基金
国家重大专项项目(2008ZX05004)
