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

摘要该奖项支持拉森盆地第四纪冰川海洋沉积物的合作研究。 这些沉积矿床是唯一适合于现代环境背景和最近的古气候演变的研究东北南极半岛大陆架，一个地区被认为表现出明显的气候变化的敏感性。这些沉积物中的微体化石及其稳定同位素组成提供了有关不同海洋条件、冰体范围和沉积物分散的信息。需要回答的问题包括：1）在该地区各种中小型冰块的近端和远端，动物群和同位素对冰川作用的反应是什么？ 2)以沉积物和地震数据表示的冰位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)在何种程度上是一个环境模式的高度可变的间冰期现代货架适用于描述和理解晚第四纪环境代表不同的气候制度？使用表层和取芯沉积物进行的初步研究结果表明，有孔虫组合组成和稳定同位素比值记录了高度可变的现代和晚第四纪环境条件。 然而，重建南极半岛晚第四纪环境史需要大量的岩心资料。研究方法包括有孔虫和孢粉分析、有孔虫碳氧同位素比值和碳-14测量。 拟议的一年期项目的主要研究目标如下：1）为西摩岛近海浅水深度钻探的南极边缘项目提供第一项研究。 （2）首次建立南极大陆架准三元稳定同位素年代地层学; 3）记录和解释第四纪气候波动，包括建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，并反映了当地和区域冰堆积、物理和化学海洋学以及沉积物源区的变化。 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.