SGER Proposal:Pagodroma Group Stratigraphy and Paleontology: Participation in ANARE 2000-2001

SGER 提案：Pagodroma 群地层学和古生物学：参加 ANARE 2000-2001

• 批准号: 0091676
• 负责人: David Harwood
• 金额: $ 3万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0091676&HistoricalAwards=false
• 关键词: SGER; Proposal; Pagodroma; Group; Stratigraphy

0091676 HarwoodThis award, provided by the Office of Polar Programs, allows a US investigator to join a geological field team of the Australian National Antarctic Research Expedition (ANARE) in the Prince Charles Mountains of East Antarctica. The purpose of the fieldwork is to investigate past fluctuations of the East Antarctic Ice Sheet that are recorded in glacial strata of the Pagodroma Group in the region. The mountains flank the sides of the Lambert Graben, through which the largest catchment area of the East Antarctic Ice Sheet drains into Prydz Bay. Preliminary fieldwork on the Pagodroma Group has been conducted by the Russian Antarctic Expeditions and the ANARE. Field and laboratory work has identified several marine fossiliferous in situ stratigraphic units and other units that contain glacially reworked marine sediments 300 km inland from the current coastline. These sediments were deposited during ice sheet and ice shelf retreat, during the Miocene and Pliocene-Pleistocene, and were dated through diatom and foraminiferal biostratigraphy and amino acid racemization. Paleoenvironmental conditions during these times of glacial retreat and open marine deposition are determined from in situ marine microfossil data. In contrast, erosional and ice grounding features evident in the strata represent intervals of glacial advance. This award will facilitate collaboration between the principal investigator and Australian colleagues on geological field research during ANARE 2000-2001 and will support subsequent preliminary laboratory analysis on recovered Pagodroma Group materials in order to establish age and paleoenvironmental relationships. Prior field reconnaissance in the area and air photo interpretation of potential new deposits will direct the initial field activities during the coming field season. Chief areas of study are in three regions: the Amery Oasis area, the Lanyon/Meredith area and, if logistical support is available, along the eastern low margin of Fisher Massif. Recent discussions about the Neogene history of Antarctic glaciation center on the age of the Sirius Group and mode of emplacement of marine diatoms in these strata. Preliminary results from coeval strata of the Pagodroma Group support interpretations of significant variation in volume of the East Antarctic Ice Sheet during the Late Neogene. The abundance of diatoms in some intervals of the Pagodroma Group (up to3.5% biogenic silica) and the stratigraphic position of in situ marine diatomaceous laminites prevents contrary discussions about wind-derivation of these marine microfossils. Significant basic documentation of stratigraphy (in the field) and paleontological content (in the laboratory) is required to place the disparate deposits into a temporal and stratigraphic framework and enable correlation within the Prince Charles Mountains and into other areas of Antarctica. If preliminary examination of the recovered materials identifies productive samples for micropaleontological analysis, a follow-up proposal will be prepared to support further study of these materials.

0091676 哈伍德 该奖项由极地计划办公室提供，允许美国调查员加入澳大利亚国家南极研究考察队 (ANARE) 在东南极洲查尔斯王子山的地质实地考察队。实地考察的目的是调查该地区帕戈德罗马群冰川地层中记录的东南极冰盖过去的波动。山脉位于兰伯特地堑两侧，东南极冰原最大的集水区通过兰伯特地堑流入普里兹湾。俄罗斯南极考察队和 ANARE 已对 Pagodroma 群进行了初步实地考察。现场和实验室工作已确定了几个海洋含化石原位地层单元和其他包含距离当前海岸线 300 公里内陆冰川改造海洋沉积物的单元。这些沉积物是在中新世和上新世-更新世期间冰盖和冰架退缩期间沉积的，并通过硅藻和有孔虫生物地层学和氨基酸外消旋来测定年代。冰川退缩和开放海洋沉积时期的古环境条件是根据原位海洋微化石数据确定的。相比之下，地层中明显的侵蚀和冰接地特征代表了冰川前进的间隔。该奖项将促进首席研究员和澳大利亚同事在 ANARE 2000-2001 期间地质实地研究方面的合作，并将支持随后对回收的 Pagodroma 群材料进行初步实验室分析，以确定年龄和古环境关系。先前对该地区的实地勘察和对潜在新矿床的航空照片解释将指导即将到来的实地季节的初步实地活动。主要研究区域位于三个地区：Amery Oasis 地区、Lanyon/Meredith 地区，如果有后勤支持，还可以沿着 Fisher Massif 东部低地边缘进行研究。最近关于南极新近纪冰川作用历史的讨论集中在天狼星群的年龄和海洋硅藻在这些地层中的侵位模式。来自 Pagodroma 群同期地层的初步结果支持了对新近纪晚期东南极冰盖体积显着变化的解释。 Pagodroma 群的某些层段中硅藻的丰度（高达 3.5% 生物硅）和原位海洋硅藻层压岩的地层位置阻止了关于这些海洋微化石的风衍生的相反讨论。需要对地层学（现场）和古生物学内容（实验室）进行重要的基础记录，才能将不同的沉积物放入时间和地层框架中，并实现查尔斯王子山脉和南极洲其他地区的相关性。如果对回收材料的初步检查确定了用于微古生物学分析的有效样本，则将制定后续提案以支持对这些材料的进一步研究。