Collaborative Research: Permian and Triassic Icehouse to Greenhouse Paleoenvironments and Paleobotany in the Shackleton Glacier Area, Antarctica

该合作项目的重点是收集南极沙克尔顿冰川（SHK）地区岩石中的植物化石、木材、沉积物和化学信息。这些信息将用于重建南极洲二叠纪和三叠纪（约2.95 - 2.05亿年前）的植物生命和环境。这个时间间隔对于研究南极洲是很重要的，因为南极洲在二叠纪经历了一次大规模的冰川作用，随后是冰川消退和植物和动物生命的恢复，只是在二叠纪末遭受了地球历史上最大的灭绝。在大灭绝事件之后，南极洲的气候持续变暖，在古南极附近有森林生长。这些古老的环境为研究气候变化对植物生命的影响提供了天然实验室。该项目的成果将推动该领域在全球变冷和变暖期间不断变化的沉积模式，以及冰川作用后和全球变暖期间的植物进化。该项目将研究SHK地区冈瓦纳冰川作用的程度，冰川退缩后生物的入侵和随后的繁荣，以及晚二叠世灭绝事件后植物生命的最终恢复。只有在南极洲，在这种气候和生物转变中才会发生完整的极地到近极地的演替。SHK地区是一个重要的地区，因为它是世界上为数不多的二叠纪-三叠纪界线（PTB）暴露在陆地岩石中的地区之一。该项目的野外和实验室工作围绕三个假设组织，这些假设解决了地球历史中的基本问题，包括从二叠纪到晚古生代冰期期间植物群的范围和多样性的变化，PTB可能的穿时性，以及早三叠纪期间化石保存不良给人一种错误的印象，即南极洲在这段时间没有植物。 这些假设将通过将各种类型的古植物学方法与详细的沉积学、地层学和地球化学相结合来进行检验。 将从数量和质量两方面收集压缩植物群和石化木材（受地层学限制），以获得生物多样性和丰度数据，并作为古生态分析的数据来源。将进行标准的沉积学和地层学分析，以及古土壤分析，包括矿物学和主要及微量元素地球化学分析。还将收集U-Pb锆石地质年代学，以更好地限制地质和生物事件通过时间。该项目的成果将纳入教育和外联活动，这些活动旨在让妇女和代表人数不足的群体参与南极地球科学和古生物学的活动，包括在堪萨斯和威斯康星州举办讲习班，以及在实地考察期间与科学课程建立联系。

The focus of this collaborative project is to collect fossil plants, wood, and sedimentary and chemical information from rocks in the Shackleton Glacier (SHK) area of Antarctica. This information will be used to reconstruct plant life and environments during the Permian and Triassic (~295-205 million years ago) in Antarctica. This time interval is important to study as Antarctica experienced a large glaciation in the Permian followed by deglaciation and recovery of plant and animal life, only to be subjected to the largest extinction in Earth history at the end of the Permian. After the extinction events, the climate in Antarctica continued to warm extensively and there were forests growing close to the paleo-South Pole. These ancient environments provide a natural laboratory in which to study the effects of climate change on plant life. The results of this project will advance the field in the areas of changing sedimentary patterns during global cooling and warming, as well as plant evolution during times following glaciation and during global warmth. This project will study the extent of the Gondwana glaciation in the SHK area, the invasion and subsequent flourishing of life following glacial retreat, and the eventual recovery of plant life after Late Permian extinction events. Only in Antarctica does a complete polar-to-near-polar succession occur across this climatic and biologic transition. The SHK area is an important one as it is one of the few regions in the world where the Permian-Triassic boundary (PTB) is exposed within terrestrial rocks. The field and lab work for this project is organized around three hypotheses that address fundamental issues in Earth history, including changes in the extent and diversity of flora during the Permian build up to the Late Paleozoic Ice Age, the possible diachronous nature of the PTB, and that poor fossil preservation during the Early Triassic has given a false impression that Antarctica was devoid of plants during this time. The hypotheses will be tested by integrating various types of paleobotanical approaches with detailed sedimentology, stratigraphy, and geochemistry. Compression floras and petrified wood will be collected (constrained by stratigraphy) both quantitatively and qualitatively in order to obtain biodiversity and abundance data, and as a data source for paleoecological analysis. Standard sedimentologic and stratigraphic analyses will be performed, as well as paleosol analyses, including mineralogic and major- and trace-element geochemistry. Collections will also be made for U-Pb zircon geochronology to better constrain geologic and biotic events through time. Results of the project will be incorporated into educational and outreach activities that are designed to include women and under-represented groups in the excitement of Antarctic earth sciences and paleontology, including workshops in Kansas and Wisconsin, as well as links to science classes during fieldwork.