Analysis of Ultrastructure and Diagenesis of Micritic Carbonate Rocks
Wang Yinhua, Zhang Xiulian, Zhang Wanzhong, Pan Rongsheng (Department of Geology)
Studying fine-grained carbonate rocks by ultra-technique can inquire into its vari-ous origin, secondary change in diagenesis and type of pores and evaluate its reservior properties. Analysis by SEM proved that chemogenic carbonate rocks have the equigran-ular and inequigranular texture with various euhedral degree, and the inter-crystaline pores are abundant. The remains of fossil fragment, algae trace or distint sporangia, algae tube, algae ball can be seen under SEM system in biogenic carbonote rocks. Pores in this kind of rocks are mainly inter- particle and intra-particle. The micritic carbonate rocks of mechanical origin have mud-debris structure. Identification of clay minerals in fine-grained carbonote rocks is useful, in deterimning the sedimentary and diagenetic environment.By synthetical study on fine-grained carbonate rocks of various ages in southern and northern China, we can find out the primary and secondary types of pores and its developmental history which is of practical significance in calculate the potential reservoir beds.