早三叠世生物复苏期的特殊沉积——"错时相"沉积

经历了对二叠纪末大灭绝及相关地质灾变事件的多年热点研究后，近年来科学家们将注意力转移到灭绝后的事件效应上，即生态系和沉积体系状况。但紧随二叠纪末灭绝事件之后的早三叠世生态系以分异度极低的广适性分子和机会分子为主，这就突显沉积记录的重要，也使得下三叠统地层中的特殊沉积及相关构造——“错时相”沉积，如扁平砾石砾岩、蠕虫状灰岩、潮下皱纹构造、微生物岩、海底碳酸盐胶结岩扇、薄层灰岩和条带灰岩等，成为研究灭绝—残存—复苏领域的学科前沿。作为地质历史环境一次大跃变后的直接产物，“错时相”沉积紧接生物大灭绝后出现，并随中生代海洋生态系的重建而退出正常浅海环境，这种耦合关系表明沉积体系、生态系、生物灭绝与复苏、异常环境之间存在必然的联系。对于化石保存单调稀少的下三叠统地层，“错时相”沉积的研究，为探索二叠纪末生物灭绝与复苏提供了宝贵的材料和全新的视角。

The Distinctive Sediments in the Early Triassic Recovery Time:"Anachronistic Facies"

After long term hotspot study about the end Permian mass extinction and relative catastrophic events, scientists recently focused on the aftermaths of mass extinction, such as ecosystems and sedimentary systems. The Early Triassic ecosystems immediately following the end Permian mass extinction were dominated by cosmopolitan members and opportunists, therefore, the importance of sediment records are obviously emerged, and "anachronistic facies" are becoming research foreland, such as flat pebble conglomerates, vermicular limestone, subtidal wrinkle structures, microbialite, carbonate seafloor fans, thin bedded limestone and zebra limestone mudstone. As the aftermaths of geologic transition, the appearance of "anachronistic facies" sediment immediately following the mass extinction and the elimination from normal shallow marine setting in the early Middle Triassic with the final establishment of the Mesozoic ecosystems in the Late Anisian. The dramatic synchronization between the changes of sedimentary systems and the radiation of the Mesozoic biotas further demonstrates that there were the inevitable interrelations among the sedimentary systems, ecosystems, mass extinction and recovery and specific environment. The study of the "anachronistic facies" sediment in an absence of fossils record Lower Triassic strata provide valuable materials and new angle of view to seek the end Permian mass extinction and recovery.