Collaborative Research: Quaternary Paleoenvironmental Evolution of the Larsen Basin, Offshore Seymour Island, Eastern Antarctic Peninsula

该奖项支持对拉森盆地第四纪冰川海洋沉积的合作研究。这些沉积沉积物非常适合研究南极半岛东北部大陆架的现代环境背景和现代古气候演化，该地区被认为对气候变化表现出明显的敏感性。来自这些沉积物的微体化石及其稳定的同位素组成提供了关于不同海洋条件、冰块范围和沉积物扩散的信息。有待回答的问题包括：1)冰川作用对该地区各种中小冰块的近端和远端的动物群和同位素响应是什么？2)沉积物和地震数据所表达的冰川位置的物理证据与其动物群和同位素特征之间的关系是什么？3)高度可变的间冰期现代陆架的环境模型在多大程度上适用于描述和理解代表不同气候制度的晚第四纪环境？利用表层和岩心沉积物进行的初步研究结果表明，有孔虫组合组成和稳定的同位素比率记录了高度多变的现代和晚第四纪环境条件。然而，要恢复南极半岛晚第四纪的环境历史，需要大量的岩心数据。研究中采用的方法是有孔虫和孢粉分析、有孔虫碳和氧同位素比率以及碳-14测量。拟议的为期一年的项目的主要研究目标如下：1)为南极边缘项目在西摩岛近海浅水深度钻探提供第一项研究。拟议的工作将有助于为第四纪沉积提供一个可靠的环境框架，用于解释新生代记录；(2)建立南极大陆架沉积物的第一个第四纪稳定同位素年代地层学；(3)记录和解释第四纪气候波动，包括拟议的全新世变暖事件，因为它们保存在沉积物、生物群和稳定同位素记录中，并反映当地和区域冰积累、物理和化学海洋学以及沉积物来源区的变化。这项研究是对国际全球变化研究的重要贡献。

Abstract This award supports a collaborative study of Quaternary glacial marine deposits of the Larsen Basin. These sedimentary deposits are uniquely suited for study of the Modern environmental setting and recent paleoclimatic evolution of the northeastern Antarctic Peninsula continental shelf, an area thought to exhibit pronounced sensitivity to climatic changes. Microfossils from these deposits and their stable isotope compositions provide information on varying oceanographic conditions, ice mass extent, and sediment dispersal. Questions to be answered include: 1) What are the faunal and isotopic responses to glaciation, both proximal and distal to the variety of small and medium ice masses in the area? 2) What is the relationship between physical evidence of ice position, as expressed in sediments and seismic data, and the faunal and isotopic signatures thereof? 3) To what extent is an environmental model of the highly variable interglacial Modern shelf applicable to describing and understanding late Quaternary environments representative of different climatic regimes? Preliminary results of a pilot study using surface and cored sediments indicate that foraminiferal assemblage composition and stable isotope ratios record highly variable Modern and late Quaternary environmental conditions. However, data are needed from a larger number of cores to reconstruct the Antarctic Peninsula late Quaternary environmental history. Methods to be employed in this research are foraminiferal and palynological analyses, foraminiferal carbon and oxygen isotope ratios, and carbon-14 measurements. The primary research objectives of the proposed one-year project are as follows: 1) Provide the first study for the Antarctic Margin Project for drilling in shallow water depths offshore of Seymour Island. The proposed work would serve to provide a sound environmental framework of the Quaternary deposits from which to interpret the Cenozoic record; 2) Establish the first Qua ternary stable isotope chronostratigraphy for Antarctic continental shelf sediments; 3) Document and interpret Quaternary climatic fluctuations, including proposed Holocene warming episodes, as they are preserved in the sediments, biota, and stable isotopic records, and reflect variations in local and regional ice buildup, physical and chemical oceanography, and sediment source areas. This research represents an important contribution to international global change studies.