淮南地区新元古代刘老碑组叠层石消失原因初探

安徽淮南地区新元古代刘老碑组主要由页岩和中薄层泥质、粉砂质灰岩组成。在该组上部中薄层砂质灰岩中产有该地区新元古代最古老的叠层石Baicalia和?Linella。大量的臼齿碳酸盐脉体穿插在该组叠层石的基本层中的现象较为独特,该组上部发育的滑塌构造和臼齿碳酸盐岩脉体的特征表明该沉积时期发生过强烈的地震活动;此外,在叠层石礁体周围还有大量的风暴沉积产出。这些现象表明,该组叠层石发育于风暴活动和地震活动交织的环境之中,地震活动是导致该组叠层石消失的主要原因。

Extinct mechanism of the Neoproterozoic stromatolites from the Liulaobei Formation in the Huainan region,Anhui

The Neoproterozoic Liulaobei Formation in the Huainan region, Anhui Province mainly consisits of shale and sandy and silty limestone. The stromatolites Baicalia and ?Linella, which crop out from the upper limestone strata, are the oldest Neoproterozoic stromatolites in this area. It is peculiar that many molar-tooth carbonate(MTC) veins interpenetrated into the basic layer of the stromatolites. The slump structures and the characters of the MTC veins indicate that intense earthquake events had happened during this deposit period. The phenomena that storm deposits and earthquake deposits crop out with stromatolites indicate that the stromatolites were formed in the environment that storm and earthquake events happened alternately, and the disastrous earthquake events made the stromatolites disappear from the Liulaobei Formation.