安徽灵璧地区新元古代臼齿构造（徽亮晶）碳酸盐沉积及意义

微亮晶碳酸盐岩是一种发育在前寒武纪尤其是元古代的特殊类型碳酸盐岩，它在结构上与基质有明显区别，是由均一、等轴、多边形的微亮晶方解石组成，个体为5～15μm。安徽灵璧地区微亮晶碳酸盐岩按其成因可分为原地和异地两类。原地微亮晶主要分布于泥晶灰岩、粉屑泥晶灰岩、泥灰岩或泥岩中；异地微亮晶主要发育在粉屑灰岩或砾屑灰岩中。微亮晶碳酸盐岩的岩石学特征指示其形成并发育于稳定克拉通浅海潮下及环潮坪环境，特别是中浅缓坡向上变浅旋回的底部，风暴浪基面是其发育的最大深度。微亮晶碳酸盐岩作为一种具有全球性意义的沉积碳酸盐岩类，具有特定的时限分布范围，这对于提高前寒武纪地层对比精度具有重要意义。

NEO-PROTEROZOIC MTS CARBONATITE DEPOSITION IN THE LINGBI AREA, ANHUI AND THE IMPLICATIONS

MTS carbonatite is a special kind of carbonatite that developed in Precambrian, especially in Proterozoic, for it is composed of uniform, coaxial and polygonal microsparry calcites of 5～15um in size and texturally apparently different from matrix. The MTS carbonatites in the Lingbi area, Anhui fall into two categories in origin： in-situ and alien. The in-situ MTS mainly occurs in micrite, fine micrite, marlite or mudstone, while alien MTS substantially develops in calcisihite or calcirudite. The petrological features of MTS carbonatite indicate that it formed and developed in subtidal and circum-tide flat environment in stable craton, especially at the bottom of the mediumshallow gentle slope cycle that became shallow upward, reaching storm wave base at most.As a sedimentary type of global significance, MTS carbonatite that distributes in a specific timeframe can improve the precision in Precambrian stratigraphic correlation.