涪陵地区茅三段热液白云岩展布影响因素分析

针对热液白云岩展布非均质性强的问题,开展基底断裂与茅三段沉积演化关系研究,分析断裂样式与白云岩分布关系,建立沉积演化模式,预测白云岩的分布。研究结果表明:茅三段可划分为5个小层,1~3小层为白云岩发育主要时期,4~5小层为台地均一化时期,不发育白云岩;15-1、15-2和16号基底断裂控制了早期“台-洼”相间的沉积地貌,断裂附近的地貌高部位为生屑滩发育有利部位,为白云岩的发育提供物质基础;15-1、15-2号基底断裂样式为花状,周边生屑滩白云石化程度高,为白云岩发育最有利区;16号基底断裂为直立状,附近白云石化发育程度较低,为白云岩发育较有利区。研究成果可为热液白云岩领域的进一步勘探提供指导依据。

Analysis of Influencing Factors on Distribution of Hydrothermal Dolomite of Member 3 of Maokou Formation in Fuling Area

In view of the strong heterogeneity of hydrothermal dolomite distribution, the relationship between basement rift and sedimentary evolution of the Member 3 of Maokou Formation was studied, the relationship between rift mode and dolomite distribution was analyzed, and the sedimentary evolution model was established to predict the distribution of dolomite. According to the study, the Member 3 of Maokou Formation was divided into 5 layers, 1 to 3 layers were the main period of dolomite development, 4 and 5 layers were the platform homogenization period, and no dolomite was not developed;15-1, 15-2 and 16 basement rifts controlled the sedimentary landform of the early "platform-sag" facies, the high geomorphic layer near the rift was favorable for the development of bioclastic beaches, which provided the material basis for the development of dolomite; 15-1 and 15-2 basement rift were flower-shaped, and the surrounding bioclastic beaches were highly dolomitized, which was the most favorable area for the development of dolomite; the 16 basement rift was upright, with low dolomitization in surrounding area, which was relatively favorable for the development of dolomite. The study results can provide a guiding basis for further exploration of hydrothermal dolomite.