潜江凹陷潜江组盐间泥质白云岩形成模式分析  

The Forming Pattern of Intersalt Argillaceous Dolomite in Qianjiang Formation of Qianjiang Depression

作　　者：漆智先[1] 舒向伟[1] 桑利[1] 张永生[2] 

机构地区：[1]中石化江汉油田分公司勘探开发研究院,湖北武汉430074 [2]中国地质科学院矿产资源研究所,北京100037

出　　处：《长江大学学报（自科版）（上旬）》2012年第7期19-23,4-5,共5页JOURNAL OF YANGTZE UNIVERSITY (NATURAL SCIENCE EDITION) SCI ＆ ENG

摘　　要：从潜江凹陷潜江组沉积环境分析入手,通过盐间层中自云岩岩石学特征描述,结合盐间泥质白云岩地球化学特征,论述了盐间白云岩成因。研究表明潜江凹陷潜江组盐间层中白云岩有原生白云岩、准同生白云岩和次生成岩白云岩。其中原生白云岩具有粒度细、镁钙比值低、有序度低、碳酸钙分子含量高的特点,是一种特殊类型的白云岩;准同生白云岩是在盐湖近岸湖坪带经过洪水搬运改造后,继而被高浓度分层盐湖水体"筏运"、漂移至较深水区沉积而成;次生成岩白云岩属于后生交代白云化作用的产物,以白云石交代钙芒硝为主。Based on the results of sedimentary environment analysis of Qianjiang Formation and petrological character description of intersait dolomite in the formation within Qianjiang Depression,the intersalt argillaceous dolomite origin is expounded in this paper,combined with geochemical characteristics of the dolomite.The research results show that the intersalt argillaceous dolomite in Qianjiang Formation within Qianjiang Depression is composed of primary,penecontemporaneous and secondary dolomites,of which primary dolomite is characterized by fine grain size,low ratio of magnesium to calcium,low degree of order and high molar content of calcium carbonate,It is a particular type of dolomite which was developed firstly.The penecontemporaneous dolomite is the sediments which were rafted by the stratified salt lake water body with high salt concentration and drifted to deep waters after transported and reworked by flood water in nearshore lake flat belt of salt lake.The secondary dolomite belongs to the product of epigenic-metasomatic dolomitization,dominated by metasomatic replacement of glauberite by dolomite.

关 键 词：潜江凹陷 潜江组 白云岩 成因 沉积环境 

分 类 号：P618.13[天文地球—矿床学]