江汉盐湖盆地盐间白云岩特征及成因分析

Characteristics and genesis of the inter-salt dolostones in the Jianghan Basin

1. Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, Hubei, China;
2. Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, Sichuan, China;
3. Research Institute of Petroleum Exploration and Development, Jianghan Oil Field Company, SINOPEC, Qianjiang 433124, Hubei, China

摘要: 江汉盐湖盆地潜江凹陷古近系潜江组广泛沉积了一套盐间非砂岩,本文详细研究了该套盐间非砂岩中白云岩的分布、类型、矿物学特征及地球化学特征,探讨了盐间白云岩的成因。研究表明,该套白云岩主要为泥晶白云岩。发育程度与盐岩量成正比。盐间白云岩的矿物组分复杂,白云石有序度低,微量元素以富Fe、Na、高Fe/Mn比值为特征。盐间白云岩主要为盐湖湖盆沉积环境的产物,水体盐度高,总体为碱性环境,Mg/Ca比值低,主要为原生-准同生阶段沉积的产物。
- 江汉盆地 /
- 盐湖 /
- 白云岩 /
- 成因
Abstract: A succession of inter-salt non-sandstones occurs on a wide range of scales in the Palaeogene Qianjiang Formation in the Qianjiang depression,Jianghan salt lake basin.The present paper deals,in detail,with the distribution,type,mineralogy,geochemistry and genesis of the dolostones in the inter-salt non-sandstones from the basin.The inter-salt dolostones dominated by micritic dolostones are characterized by complex mineral compositions,lower ordering degree,rich Fe and Na and high Fe/Mn ratios,and thus interpreted as the products deposited in the sedimentary environment of salt lake basin during the primary-penecontemporaneous stages.
- Jianghan Basin /
- salt lake /
- dolostone /
- genesis