海拉尔盆地贝尔凹陷南屯组火山碎屑岩成岩作用的讨论

Discussion of diageneses of volcaniclastic rocks of Nantun Formation in Beier sags,Hailar Basin

利用偏光显微镜、扫描电镜、染色法以及X-衍射分析等方法,查明南屯组火山碎屑岩成岩作用模式。研究表明火山碎屑岩成岩作用方式包括:机械压实作用、胶结作用与自生作用、交代作用和溶蚀溶解作用。成岩共生序列为:黏土矿物包壳-泥晶碳酸盐矿物、自生蒙皂石、自生伊利石-长石溶解-自生石英-自生高岭石-绿泥石、白云石-铁方解石-铁白云石。成岩阶段划分为早成岩阶段B期和中成岩阶段A期,并且以中成岩阶段A期为主。

Using polarization microscope, scanning electron microscope, staining method and X-ray diffraction, the authors studied diagenetic pattern of volcaniclastic rocks of Nantun Formation. The reseach shows that the major diagenesises of volcaniclastic rocks include mechanical compaction,cementation and dissolution,authigenesis, replacement and erosion-dissolution. The sequence of diagenesises is clay bulb-micritecarbonate-authigenicsmectites, authigenicinites-feldspardisslution-authigenicquartz-authigenickaolinite-chlorite, dolomite-ferrocalcite-ferrodolomite.According the reflectivity of Ro, the colour index of spore and ancient tempreture, the highest pyrogenation tempreture and the combination of clay mineral, the diagenetic phases is divided into the B issue of early diagenetic phase and the A issue middle diagnetic phase, the latter is more important.