Testing the stratigraphic and paleoenvironmental resolution of sediment drifts off West Antarctica for IODP drilling

测试 IODP 钻探西南极洲沉积物漂移的地层和古环境分辨率

• 批准号: NE/I006214/1
• 负责人: David Hodell
• 金额: $ 6.44万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI006214%2F1
• 关键词: Testing; stratigraphic; paleoenvironmental; resolution; sediment

There is intense scientific and public interest in the potential response of the Antarctic Peninsula and West Antarctica ice sheets to global warming. Recent observations suggest that this region is undergoing rapid changes including warming, ice-shelf disintegration, ice-sheet thinning and retreat. These recent changes need to be considered in a longer geological context by studying marine sediments proximal to the West Antarctic and Antarctic Peninsula Ice-Sheets. Toward this end, we have submitted and IODP proposal, currently awaiting scheduling, to drill a serie of sites on sediment drifts located in the Bellinghausen Sea (Pacific Ocean). Imprecise chronological control, due in large part to lack of foraminiferal carbonate for isotopic analysis, has stymied paleoceanographic interpretations of sediment cores from the Southern ocean. In preparation for the anticipated IODP expedition, we propose a 'proof-of-concept' study to apply the main paleoceanographic and stratigraphic methods to be employed in the study of the long sequences to be recovered by IODP. We will study piston core PC466 taken at one of the proposed IODP Sites (Pen-1), It was recovered at a water depth of 2400m on a sediment drift on the continental rise in the Bellinghausen Sea (64S, 69W ) by the British Antarctic Survey on RRS James Clark Ross. This short sedimentary record of 10.5 meters spans the last glacial period (~70,000 years) with high sedimentation rates and exhibiting distinct millennial-scale variability in both elemental composition (XRF) and magnetic susceptibility. Our goals for core PC-466 are three-fold. 1) Develop an accurate age model that can be used for stratigraphic correlation to other marine sediment cores and polar ice cores in both hemispheres. 2) Study the advance and retreat of ice sheets using ice-rafted detritus. 3) Reconstruct surface water conditions (temperature, salinity, carbonate-ion concentration, and sea ice). If we are successful in demonstrating that it is possible to apply traditional stratigraphic and paleoceanographic tools to the last glacial period of core PC-466, (a time period that paleoclimatologists and paleoceanographers know best), then we can be reasonably confident that such approaches will work for thousands of meters of record envisaged by proposal-732 and covering the last several million years.

南极半岛和南极洲西部冰盖对全球变暖的潜在反应引起了科学界和公众的强烈兴趣。最近的观测表明，该地区正在经历快速变化，包括变暖、冰架解体、冰盖变薄和退缩。通过研究南极西部和南极半岛冰盖附近的海洋沉积物，需要在更长的地质背景下考虑这些最近的变化。为此，我们提交了一份IODP提案，目前正在等待调度，以在位于别林豪森海（太平洋）的沉积物漂流上钻探一系列地点。由于缺乏用于同位素分析的有孔虫碳酸盐，不精确的年代控制阻碍了对南大洋沉积物岩心的古海洋学解释。为了准备预期的IODP考察，我们提出了一项“概念验证”研究，将主要的古海洋学和地层学方法应用于IODP将恢复的长序列研究中。我们将研究在提议的IODP站点之一（Pen-1）采集的活塞芯PC466，它是由英国南极考察队詹姆斯·克拉克·罗斯号（RRS James Clark Ross）在Bellinghausen海（64S, 69W）大陆隆起沉积物漂移处水深2400m处回收的。这个10.5米的短沉积记录跨越了末次冰期（~7万年），具有高沉积速率，在元素组成（XRF）和磁化率方面表现出明显的千年尺度变化。我们对核心PC-466的目标有三个方面。1)建立一个精确的年龄模型，可以用于与两个半球其他海洋沉积物岩心和极地冰芯的地层对比。2)利用漂流碎屑研究冰盖的前进和后退。3)重建地表水条件（温度、盐度、碳酸盐离子浓度和海冰）。如果我们成功地证明将传统的地层学和古海洋学工具应用于PC-466岩芯的末次冰期（古气候学家和古海洋学家最了解的一个时期）是可能的，那么我们就可以有理由相信，这些方法将适用于提案732所设想的数千米的记录，覆盖过去的几百万年。

项目成果

Palaeoenvironmental records from the West Antarctic Peninsula drift sediments over the last 75 ka

过去 75 ka 西南极半岛漂移沉积物的古环境记录

• DOI: 10.1144/sp381.12
• 发表时间: 2013
• 期刊: Geological Society, London, Special Publications
• 作者: Vautravers M