新元古代九里桥组中的风暴活动记录及生物学响应

Storm Records and Their Biological Responses in Neoproterozoic Jiuliqiao Formation

安徽淮南地区新元古代九里桥组主要由砂质、泥质灰岩,叠层石灰岩和白云质灰岩组成.该组沉积物中保存了特征明显的海洋风暴活动记录.对该组风暴沉积序列的岩性和沉积构造的不同组合特征的研究表明,这一时期发生的风暴活动作用过程经历了平静期、强盛期、减弱期和消亡期四个阶段.在不同的作用阶段,风暴活动发生的频率与强度有所不同,对沉积物的改造和破坏作用也不同,与之相关的岩层中叠层石、微体浮游生物化石和宏体生物化石的分布和保存也各具特色,这些迹象表明长期的风暴活动作用对区域性的生物生存和发展具有显著的影响.

The Neoproterozoic Jiuliqiao Formation silty, stromatolitic and dolomitic limestones. in the Huainan region consists of sandy, Typical ocean-storm deposits are well preserved in this Formation. The study on lithology and the sedimentary structures of the storm deposits in the Formation indicate that the storm activity during this depositional period has four stages： quiet stage, strong stage, weakening stage and dying-out stage. In different active stages, the frequency and strength of the storms and the correlative reconstructive effects on the deposits are different; the preservation and distribution of stromatolites, micro-plankton fossils and macro-fossils in corresponding strata have different typical characteristics. Such evidences suggest that the regional ocean storm activity may have a remarkable influence on the organisms＇ developments in this area.