雾迷山旋回层：米级旋回的一个特例

摘要

As the result of“punctuated aggradational cycle”mechanism of sedimentary processes,the integrated define of“meter-scale cycle”indicates that cyclostratigraphy has entered the main stream of stratigraphic prac-tice,since the formation of meter-scale cycle can be interpreted as the product of the Milankovitch cycles.As a typical example of peritidal carbonate meter-scale cycle,the “Wumishan cyclothem”is famous for its approxi-mately symmetrical lithofacies succession,which can replace the “Lofer cyclothem”,and can characterize the cyclic carbonate sedimentation.Ultimately,the “Wumishan cyclothem”becomes an important mark of strati-graphic texture for the very thick stromatolite carbonate succession of the Precambrian.Therefore,the “Wumi-shan cyclothem”not only is a typical example of carbonate meter-scale cycle,but also implies very clear Milan-kovitch cycle properties,and it further illustrates that meter-scale cycle can replace parasequence,because parasequence is an incomplete concept within the concept system on sequence stratigraphy.%作为地层堆积作用的“间断-加积旋回”机制的产物，“米级旋回”的完整定义代表了旋回地层学进入地层学实践的主流，因为米级旋回的形成可以运用米兰柯维奇旋回得到合理的解释。作为特殊的环潮坪型碳酸盐米级旋回---“雾迷山旋回层”，因其罕见的近似对称的相序组构可以替代“洛菲尔旋回层（Lofer cyclothem）”，成为旋回性碳酸盐沉积作用的表征，从而进一步成为前寒武纪巨厚叠层石碳酸盐序列中地层结构的标志。因此，“雾迷山旋回层”不但作为碳酸盐米级旋回的特别实例，而且蕴含着较为明显的米兰柯维奇旋回属性，同时进一步说明了米级旋回可以成为层序地层学概念体系中欠完整性的“副层序”的替代物。