Neogene Paleoenvironmental changes in the McMurdo Sound region: High resolution chemical and sedimentological analysis of Miocene (~17 Ma) to Pleistocene sediments from ANDRILL Site SMS

麦克默多海峡地区新近纪古环境变化：来自 ANDRILL Site SMS 的中新世（~17 Ma）到更新世沉积物的高分辨率化学和沉积学分析

• 批准号: 46608598
• 负责人: Professor Dr. Hilmar von Eynatten
• 金额: --
• 依托单位: Abteilung Sedimentologie und Umweltgeologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/46608598?language=en
• 关键词: Neogene; Paleoenvironmental; changes; McMurdo; Sound

In late 2007, a 1138 m thick sediment core was drilled from a sea-ice platform at ANDRILL (ANtarctic geological DRILLing) site SMS (Southern McMurdo Sound, Ross Sea, Antarctica). The core covers Early Miocene (~20 Ma) to Pleistocene strata deposited on the western flank of the Victoria Land Basin (VLB), a structural half-graben that forms part of the West Antarctic Rift system. On this core we propose to combine high-resolution on-ice measurement of chemical element concentrations using XRF core-scanner with off-ice highprecision chemical and sedimentological analysis on bulk samples (XRF, XRD, ICP-MS, biogenic components) and individual lithoclasts (LA-ICP-MS, electron microprobe, microscopy). The resulting multiple dataset will provide detailed information on sediment composition and, thus, contribute to several scientific objectives of ANDRILL such as (i) the history of the Ross ice shelf (RIS) expansion and retreat since ~20 m.y., the (ii) varying control of the West (WAIS) and East Antarctic ice sheets (EASI) on RIS dynamics, (iii) seaice presence/absence in the McMurdo region, and the history of Neogene sediment provenance and accumulation rates in the VLB. Our major goal is to improve the understanding of the Miocene paleoenvironmental evolution of Antarctica with special emphasis on high-resolution analysis of the Mid-Miocene climatic optimum (~18-15 Ma), and the subsequent onset of major cooling along with the key question on the stability of coldpolar climate conditions during the last 14 m.y.

2007年底，在ANDRILL（南极地质钻探）站点SMS（南极洲罗斯海南麦克默多湾）的海冰平台上钻取了1138米厚的沉积物岩心。岩心覆盖早中新世（~20 Ma）至更新世地层，沉积于维多利亚陆盆地（VLB）西侧，该盆地是构成南极西部裂谷系一部分的构造半地堑。在该岩心上，我们建议将XRF岩心扫描仪的高分辨率冰上化学元素浓度测量与冰外高精度化学和沉积学分析相结合，对大块样品（XRF， XRD, ICP-MS，生物成分）和单个岩屑（LA-ICP-MS，电子探针，显微镜）进行分析。由此产生的多个数据集将提供沉积物组成的详细信息，从而有助于ANDRILL的几个科学目标，如(i)罗斯冰架（RIS）自20m以来的扩张和退缩历史，（ii）南极西部（WAIS）和南极东部冰架（EASI）对RIS动力学的不同控制，（iii）麦克默多地区的海冰存在/缺失，以及VLB新近纪沉积物来源和积累速率的历史。我们的主要目标是提高对南极洲中新世古环境演化的认识，特别强调对中中新世气候最佳（~18-15 Ma）的高分辨率分析，以及随后的大冷却的开始，以及最后14 m.y冷极气候条件稳定性的关键问题。