Patterns in post-extinction recovery in the aftermath of the Permian-Triassic biotic crisis

二叠纪-三叠纪生物危机后的灭绝后恢复模式

基本信息

批准号：
RGPIN-2015-05635
负责人：
Zonneveld, JohnPaul
金额：
$ 1.97万
依托单位：
University of Alberta
依托单位国家：
加拿大
项目类别：
Discovery Grants Program - Individual
财政年份：
2018
资助国家：
加拿大
起止时间：
2018-01-01 至 2019-12-31
项目状态：
已结题

来源：
https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=669972
关键词：
Patterns post extinction recovery aftermath

项目摘要

The Triassic is a key interval in western North America, hosting 2 x 108 m3 oil and 1.15 x 1012 m3 gas representing a critical component of Alberta's and British Columbia's economies, but also recording the recovery interval after the most severe mass extinction event in earth's history. The purpose of this research program is to establish the nature of biotic recovery after this extinction event while concurrently providing a lithostratigraphic and biostratigraphic framework for the energy industry in western Canada.***The recovery period after this extinction lasted for millions of years. The biological diversity of Earth's oceans did not reach pre-extinction levels until the late Jurassic, an interval of ~90 million years. Biogeochemical analyses and palaeontological proxies have shown that dissolved oxygen levels and ocean chemistry fluctuated wildly during the Lower Triassic. It is commonly presumed that environmental stability, and concomitantly biotic recovery, occurred by the Middle Triassic. Mesozoic shallow marine faunas differ significantly in taxonomic composition from Paleozoic faunas, however the transition was neither abrupt nor simple. Palaeozoic-type faunas (dominated by crinoids, brachiopods, etc.) experienced several resurgences in the early Mesozoic before eventually being replaced by `modern' faunas (bivalves, gastropods, decapods, etc.).******Previous studies on recovery patterns have focused primarily on Lower Triassic successions, on narrow temporal intervals in restricted geographical settings and commonly on selected portions of the faunas. This limits comparison between successions and faunas, hampering analyses on marine faunal recolonization and rediversification in the extinction's aftermath. ******Detailed regional analyses that incorporate all elements of an ecosystem (including trace fossils, invertebrate fossils and vertebrate fossils), linked to assessments of environmental health (seawater oxygenation and chemistry) are required to establish the nature of post-extinction faunal and environmental recovery. This project addresses these shortcomings by integrating paleontological, ichnological, sedimentological and geochemical datasets to provide a comprehensive picture of Triassic shallow marine ecosystems on the northwestern margin of the Pangaea. The study extends from the lowermost Triassic to the end of the Carnian, an interval previously demonstrated to record an interval of prolonged environmental crisis (the Induan-Olenekian) with marine conditions gradually recovering to pre-extinction norms (the Anisian-Ladinian) and an interval of rapid re-diversification and environmental stabilization (the Ladinian-Carnian). This project seeks to establish the timing of environmental stabilization in the Triassic of western Canada and clarify the patterns of shallow marine faunal colonization and stabilization.**

三叠纪是北美西部的一个关键层段，蕴藏着 2 x 108 立方米石油和 1.15 x 1012 立方米天然气，是阿尔伯塔省和不列颠哥伦比亚省经济的重要组成部分，同时也记录了地球历史上最严重的大规模灭绝事件后的恢复区间。该研究计划的目的是确定这次灭绝事件后生物恢复的性质，同时为加拿大西部的能源工业提供岩石地层学和生物地层学框架。***这次灭绝事件后的恢复期持续了数百万年。直到侏罗纪晚期，地球海洋的生物多样性才达到灭绝前的水平，大约有9000万年的时间间隔。生物地球化学分析和古生物学代理表明，溶解氧水平和海洋化学在下三叠世期间剧烈波动。人们普遍认为，环境稳定以及随之而来的生物恢复发生在三叠纪中期。中生代浅海动物群在分类组成上与古生代动物群有显着差异，但这种转变既不突然也不简单。古生代动物群（以海百合、腕足动物等为主）在中生代早期经历了几次复兴，最终被“现代”动物群（双壳类、腹足类、十足类等）所取代。******之前的研究恢复模式主要集中于下三叠世的演替、有限地理环境中的狭窄时间间隔以及通常集中于动物群的选定部分。这限制了演替和动物群之间的比较，阻碍了对灭绝后海洋动物群的重新殖民和重新多样化的分析。 ******需要进行详细的区域分析，纳入生态系统的所有要素（包括痕迹化石、无脊椎动物化石和脊椎动物化石），并与环境健康评估（海水氧合和化学）相关联，以确定灭绝后的性质动物和环境恢复。该项目通过整合古生物学、技术学、沉积学和地球化学数据集来解决这些缺点，以提供盘古大陆西北边缘三叠纪浅海生态系统的全面图景。这项研究从三叠纪最低层一直延伸到卡尼期末期，此前已证明这一时期记录了一段长期环境危机时期（印度-奥伦尼克期），海洋条件逐渐恢复到灭绝前的正常水平（安尼期-拉丁期），快速再多样化和环境稳定期（拉丁期-卡尼期）。该项目旨在确定加拿大西部三叠纪环境稳定的时间，并阐明浅海动物群定居和稳定的模式。 **