湖北京山地区寒武—奥陶系碳酸盐岩成岩作用及孔隙演化

THE CARBONATES DIAGENESIS AND POROSITY EVOLU-TION OF CAMBRIAN-ORDOVICIAN IN JINGSHAN REGION, HUBEI PROVINCE

本文通过对京山地区寒武—奥陶系碳酸盐岩成岩作用和孔隙演化的研究,认为本区寒武—奥陶系普遍经历了海底、大气淡水、埋藏及表生成岩环境,其间发生的成岩作用主要有胶结作用、白云岩化、压实-压溶、溶蚀和破裂作用。在这些成岩作用的改造下,岩石孔隙度从大于20％下降到1.5～5％,其中在中新生代孔隙相对较发育。

The carbonates diagenesis and porosity evolution of Cambrian-Ordovician in Jingshan region have been studied in this paper. The study has shown that Cam-brian-Ordovician carbonates have undergone epibenthile, atmos pheric-freshwater, burial and epigenetic diagenetic environments. The diageneses are mainly cementa-tion, dolomitation, compaction-chemical compaction, solution and fracture. The porosity of carbonates decreases from more than 20% to 1.5% by the diagenetic effects.