辽南新元古代营城子组臼齿灰岩的沉积环境

臼齿(Molar—Toom)灰岩是发育于中新元古代碳酸盐台地的一种特殊灰岩类型。辽东半岛南部大连地区震旦系营城子组中部臼齿灰岩十分发育，野外观测、室内薄片以及比较沉积学研究表明，臼齿灰岩的出现与环境密切相关。通过米级旋回研究发现，该岩相段以发育浅水碳酸盐岩米级旋回层序为主，臼齿构造主要产出在微旋回中下部的中薄层泥晶灰岩和粉屑灰岩中，形成环境为潮下浅水环境。

Depositional environments of molar-tooth limestones of the Neoproterozoic Yingchengzi Formation in southern Liaoning

Molar-tooth(MT )limestone is a special type of limestone developed in the Meso-and Neo-proterozoic carbonate platform.MT limestone is very well developed in the middle part of the Sinian Yingchengzi Formation in the Dalian area in the southern Liaodong Peninsula.Based on the field observa-tions and thin section examination,as well as the comparative sedimentologic study,the appearance of MT limestone is closely related to the diagenetic environment ,and its location is related to the sea-flood-ing events.According to the study of the meter-scale cycle,in this rock facies segment ,mainly meter-scale cyclothems of shallow-water carbonates rocks are developed,and MT structure dominantly occurs in the moderately thick-to thin-bedded micrite and calcisiltite in the middle and lower parts of this micro-cycle,which indicates a subtidal shallow-water environment.