松辽盆地北部下白垩统下部含浊沸石砂岩的成岩作用

DIAGENESIS OF LAUMONTITE-BEARING SANDSTONES IN LOWER PART OF LOWER CRETACEOUS,NORTH SONGLIAO BASIN

松辽盆地北部深层下白垩统的砂岩为成分成熟度很低的岩屑长石砂岩及长石岩屑砂岩。主要成岩作用有:自生粘土边、石英长石次生加大、斜长石的钠长石化、自生浊沸石,以及次生长石和浊沸石溶蚀等。斜长石的钠长石化作用是浊沸石析出的主要机制,而粘土矿物的转化则为浊沸石的沉淀提供了钠和硅的来源。

Deep buried sandstones of Lower Cretaceous in North Songliao Basin are composi-tionally immature lithic arkose and feldspathic litharenite. The main diagenesis of thesandstones includes: authigenetic clay rim, quartz and feldspar overgrowth, albitization,authigenetic laumontite and the dissolution of feldspar and laumontite. The albitization ofanorthosite is the primary mechanism for generating laumontite, whereas the transforma-tion of clay minerals provides sodium and silicon for the precipitation of laumontite.