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奥陶纪末的生物冰川灾变事件结束后,华南板块上扬子区进入志留纪初的海进期。黔东北志留纪初期香树园组(兰多维列统鲁丹阶上部-埃隆阶中部)是壳相动物群复苏时沉积的灰岩相地层,具有显著的生物-岩相分异。“白沙型”后生动物化石密集的礁滩沉积仅限于近岸正常浪基面附近的浅海区展布。同期石阡枫香铺沟村剖面远岸带“印江型”香树园组薄层灰岩中壳相动物大化石的生物多样性和丰度低,没有原地绑结岩型的生物礁和粗颗粒堆积的生屑滩,岩相和生物相特征显示各种细颗粒的生屑呈碎片堆积。尽管这里海水清澈度较高,但由于水深偏大且水动力偏低的环境指标抑制了“白沙型”造礁动物向广海区的空间拓展。这一实例凸显了黔东北陆表海区海水深度对香树园组底栖生态组合多样性的控制,导致志留纪最早复苏的生物礁古地理分布的局限性。
After the end of the Ordovician bio-glacier catastrophe, the upper Yangtze region of the South China Plateau entered the seaward phase of the Silurian. In the early Silurian of Qiandongqian, the Xishshuyuan Formation (the upper part of the Loudoun Order - the middle of the Elon Stage) of the Late Silurian is a limestone facies deposit during the recovery of the shell facies fauna, with significant bio-lithofacies differentiation. “White sand type ” metazoa fossil reef beach deposition is limited to the normal coastal surface near the shallow sea area distribution. In the same period, the biological diversity and abundance of the large-sized fossils of the shell-phase fauna in the “Yinjiang-type” and “Yinjiang-type” And the swarms of coarser sediments, lithofacies and biofacies show the accumulation of various fine particles of crumbs. Although the seawater here is relatively clear, due to the fact that the water depth is too large and the hydrodynamic force is low, the spatial expansion of the “white sand” reef-bearing animal to the Guanghai area is inhibited. This example highlights the control of the diversity of benthic ecosystems in the Xiangshuyuan Formation by seawater depth in the surface sea areas of the northeastern Guizhou Province, resulting in the limitation of the paleogeographic distribution of the reefs that led to the earliest rejuvenation of the Silurian.