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

0091676哈伍德该奖项由极地计划办公室提供，允许一名美国调查人员加入澳大利亚国家南极研究考察队(ANARE)在东南极查尔斯王子山脉的地质野外考察队。实地调查的目的是调查记录在该地区帕格德罗马群冰川地层中的东南极冰盖过去的波动。这些山脉位于兰伯特地堡的两侧，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阿纳雷人对帕格德罗马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化石原地地层单位和其他单位，这些单位含有距目前海岸线内陆300公里处冰川改造过的海洋沉积物。这些沉积物沉积于中新世和上新世-更新世的冰盖和冰架消退时期，并通过硅藻和有孔虫生物地层学和氨基酸外消旋作用确定了年代。冰川退缩和开阔的海洋沉积时期的古环境条件是由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层固定特征代表了冰川推进的间隔。这项奖励将促进首席调查员和澳大利亚同事在Anare 2000-2001年间的地质实地研究方面的合作，并将支持随后对发现的Pagodroma Group材料进行初步实验室分析，以确定年龄和古环境关系。事先在该地区进行实地勘察，并对潜在的新矿藏进行航空照片判读，将指导即将到来的野外季节的初步实地活动。主要研究地区在三个地区：阿莫里绿洲地区、兰尼翁/梅雷迪斯地区，以及费舍尔地块东部低边缘沿线(如果有后勤支持)。最近关于南极冰川史的讨论主要集中在天狼星群的年龄和海洋硅藻在这些地层中的侵位方式。来自Pagodroma群同时代地层的初步结果支持对新近纪晚期南极东部冰盖体积显著变化的解释。Pagodroma群(高达3.5%的生物硅质)中某些区间的硅藻丰富，以及原位海洋硅藻质纹层的地层位置，阻止了对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)和古生物内容(实验室)的基本文件，才能将不同的沉积物置于时间和地层框架内，并能够在查尔斯王子山脉内和南极洲其他地区进行对比。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性样本，将编写后续建议，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.