东昆仑南带中元古代晚期—新元古代早期叠层石组合的发现

东昆仑南带加嗡门地区碳酸盐岩地层中发现的中元古代晚期-新元古代早期叠层石组合以大型锥叠层石及其相关的分子Conophyton garganicus vat．inkeni，C．cf．ressoti Menchikov，Jacutophyton f．和Conicodomenia f．等最丰富，并与Baicalia共生，故可视之为Conophyton--Baicalia组合。该叠层石组合可以与天山和华北等地蓟县系中部-青白口系中部叠层石组合对比，尤其酷似于天山地区蓟县系的爱尔基干组合和华北蓟县系的闪坡岭叠层石组合，而显著有别于华南地块。它还可以与南乌拉尔、西伯利亚、北美、北非和阿拉斯加半岛等地区的中里菲界上部-上里菲界下部层位中的叠层石组合对比。加嗡门叠层石组合的时限为距今1 300～850Ma，大致为蓟县纪中期一青白口纪中期或中里菲晚期一晚里菲早期。东昆仑南带存在前寒武纪微地块，当时此微地块的古地理和古环境与天山、华北、西伯利亚和阿拉斯加半岛等地区的前寒武纪地块相似，均位于低纬度区，其上均广泛发育适宜叠层石繁育的温暖陆表海，它们可能共同处于罗迪尼亚超大陆的低纬度大陆边缘部位，与华南地块的不同。这对本区和东昆仑地层和大地构造研究，以及对罗迪尼亚超大陆重建提供了新的古生物约束。

Possible impact event in the Late Cambrian

The repeated investigation of the Batyrbay section has been done by the authors.Today we see increasing of interest to revising of volumes and boundaries of Stages and Series in the Cambrian and Ordovician,as well as to the events of this time.In this work the description of iron spherules and particles,found in the deep-water limestone layer of the conodont Cordylodus primitivus Zone in the middle Upper Cambrian of the Batyrbay section,Malyi Karatau of South Kazakhstan,and formed during the time of global sea-level changes known as a world-wide Lange Ranch Eustatic event,have been done.From our point of view,finds of iron spherules and particles may evidence about new unknown yet Event of cosmic origin,i.e.falling of a meteorite on Earth in the middle Late Cambrian.