巢县五通组碎屑岩的成岩作用研究

DIAGENESES OF CLASTIC ROCKS OF THE WUTONG FORMATION

巢县五通组碎屑岩的主要成岩作用，包括胶结作用、次生加大、压实─压溶和溶解作用。胶结物主要为硅质以及少量的粘土矿物，此外还有自生矿物：高岭石、石英、水云母和黄铁矿。压实作用和石英的次生加大使碎屑岩的原生孔隙度极大的降低，溶解作用是次生孔隙形成的主要因素。五通组岩石的主要孔隙类型是次生孔隙，其次是微孔隙。孔隙度是低的。

The main diageneses of clastic rocks of the Wutong Formation in Chao county include cementa-tion, compaction─pressure solution and dissolution. Cements are mainly siliceous materials and a few clayminerals, as well as some authigenic minerals such as kaolinite,quartz, hydromica and pyrite. The compactionand secondary enlargement of quartz lead to the great decrease of primary porosity of clastic rocks, and disso-lution is contributed to the formation of secondary pore space. With low porosity, the Wutong Formation de-velops secondary porosity mainly and microporosity secondarily.