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

[00:91676]哈伍德这份由极地项目办公室提供的奖励，允许一名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脉的地质实地小组。实地考察的目的是调查该地区Pagodroma群冰川地层中记录的南极东部冰盖过去的波动情况。这些山脉位于兰伯特地堑的两侧，东南极冰盖最大的集水区通过这里流入普里兹湾。俄罗斯南极考察队和ANARE对Pagodroma群进行了初步的实地工作。实地和实验室工作已经确定了几个海洋化石原位地层单元和其他单元，这些单元包含从目前海岸线向内陆300公里处冰川重新加工的海洋沉积物。这些沉积物沉积于中新世和上新世-更新世冰盖和冰架退缩时期，并通过硅藻和有孔虫生物地层学和氨基酸消旋作用进行了年代测定。这些时期的古环境条件是根据原位海洋微化石资料确定的。相反，地层中明显的侵蚀和冰接地特征代表了冰川推进的间隔。该奖项将促进首席研究员和澳大利亚同事在ANARE 2000-2001期间的地质实地研究合作，并将支持随后对回收的Pagodroma组材料进行初步实验室分析，以建立年龄和古环境关系。在该地区的事先实地侦察和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。主要研究区域在三个地区：Amery绿洲地区，Lanyon/Meredith地区，如果有后勤支持，沿着Fisher地块的东部低边缘。最近关于南极新近纪冰期史的讨论主要集中在天狼星群的年龄和这些地层中海洋硅藻的侵位方式。Pagodroma群同年代地层的初步结果支持了晚新近纪南极东部冰盖体积显著变化的解释。Pagodroma群中硅藻的丰度（高达3.5%的生物成因硅）和原位海洋硅藻质层状岩的地层位置阻止了对这些海洋微化石的风源性的相反讨论。为了将不同的沉积物置于一个时间和地层框架中，并在查尔斯王子山脉和南极洲其他地区进行对比，需要有重要的地层学（野外）和古生物学内容（实验室）的基本文件。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生产样品，将准备后续提案以支持对这些材料的进一步研究。

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.