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

0091676 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探险队（ANARE）在东南极洲查尔斯王子山脉的地质实地考察队。实地考察的目的是调查东南极冰盖过去的波动，这些波动记录在该地区Pagodroma组的冰川地层中。这些山脉位于兰伯特地堑两侧，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群进行了初步实地考察。野外和实验室工作已经确定了几个海洋生物原地地层单位和其他单位，其中含有冰川改造的海洋沉积物，距离目前的海岸线300公里。这些沉积物是在中新世和上新世-更新世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以及氨基酸外消旋化进行了年代测定。在这些时期的冰川退缩和开放的海洋沉积的古环境条件，确定从原位海洋微体化石数据。相反，地层中明显的侵蚀和冰接地特征代表了冰川前进的间隔。这笔奖金将促进主要研究员和澳大利亚同事在2000-2001年ANARE期间进行地质实地研究方面的合作，并将支持随后对回收的Pagodroma组材料进行初步实验室分析，以确定年龄和古环境关系。在该地区进行的先前实地勘察和对潜在新矿床的航空照片判读将指导即将到来的实地季节的初步实地活动。主要的研究领域在三个地区：Amery绿洲地区、Lanyon/Meredith地区，以及如果有后勤支持，沿Fisher地块东部低边缘的沿着。近年来关于南极晚第三纪冰期的讨论主要集中在天狼星群的时代和海洋硅藻在这些地层中的侵位方式上。Pagodroma组的同时代地层的初步结果支持解释的显着变化的体积的东南极冰盖在晚第三纪。在Pagodroma群的某些间隔中硅藻的丰度（高达3.5%的生物硅）和原地海洋泥质纹层的地层位置阻止了关于这些海洋微体化石风源的相反讨论。需要大量的地层学（实地）和古生物学内容（实验室）的基本文件，以便将不同的沉积物纳入时间和地层框架，并使查尔斯王子山脉和南极洲其他地区能够相互关联。如果对回收材料的初步检查确定了可供微体古生物学分析的生产性样品，将编写一份后续建议，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.