A Target for High-Resolution Quaternary and Older Environmental Change Records: Site Survey for Drilling Mackay Sea Valley, Western Ross Sea

高分辨率第四纪和更古老的环境变化记录的目标：西罗斯海麦凯海谷钻探现场调查

• 批准号: 0003607
• 负责人: Ross Powell
• 金额: $ 4.42万
• 依托单位: Northern Illinois University
• 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: 2000-12-15 至 2002-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0003607&HistoricalAwards=false
• 关键词: Target; Resolution; Quaternary; Older; Environmental

0003607 PowellThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a geophysical site survey of the MacKay Sea Valley that is needed to evaluate the potential of this area to yield important sedimentary records of paleoenvironmental records of ice sheet fluctuations during Quaternary time (approximately the last 1.6 million years of Earth's history). Quaternary geological successions have been a recent focus for providing high-resolution records of past environmental changes on which to base future predictions, and to assist in deciphering natural variability from human-induced changes. This study is aimed at extending the data base of high-resolution marine geological records of environmental change that have been established recently in Antarctica, and to address Quaternary and perhaps older environmental changes.The current phase of the work, to achieve the goals outlined above, is specifically aimed at collecting information in a detailed site survey to be used for precisely locating the best drill sites, and also to provide data to use in an engineering evaluation of drilling and coring systems to meet sampling requirements. The location proposed for this study is Mackay Sea Valley (MSV), which is believed to have been formed by erosion associated with early Cenozoic expansion of Mackay Glacier, a major outlet glacier of the East Antarctic Ice Sheet. MSV extends through Granite Harbor and out to the western Ross Sea. Since being eroded, the valley has experienced sediment accumulation, at least in the Quaternary and possibly through earlier times during late Cenozoic.Coring sites in the MSV are excellent targets because: (1) their great water depth and near shore location, as well as the polar climate, appears to have led to the trough being a site of preservation for the highest resolution record of Quaternary marine environmental change known in the Ross Sea sector; (2) the sedimentation regime is one of the most intensely studied coastal settings in Antarctica; (3) there is a preliminary geophysical site survey, and (4) based on previous piston core work, the sediments appear to have the potential for good chronological control. Ultimately, the main goals of the coring study are to: (1) apply multi-proxy techniques to extract a high resolution (decadal(?) to century scale) of the Quaternary in the McMurdo Sound area; (2) establish marine-terrestrial correlations with geological and ice core records both locally and from elsewhere in Antarctica (e.g., Dry Valleys and Antarctic Peninsula Quaternary geological records; Taylor and Siple Dome ice core records); (3) test Antarctic variability with records from the Northern Hemisphere for cross-hemispheric comparisons; (4) determine the age of MSV unconformity that may well reflect glacial cutting within the MSV by Mackay Glacier during past Quaternary expansion(s) and provide constraints on Neogene erosion rates; and (5) characterize older Quaternary and/or Neogene(?) sediment below the unconformity that potentially could also provide information on Pliocene history of the area. However, before a proposal to achieve these overarching goals can be properly developed, high quality site survey information is required. This work will provide the site data needed for a full assessment of the potential for acquiring high-resolution records of environmental change in the MSV.

0003607 POWELLTHIS奖由《极地计划办公室的南极地质与地球物理学计划》提供，为Mackay Sea Valley的地球物理现场调查提供了资金，这些调查是在评估该地区的潜力，以产生对冰期冰期波动的古环境记录的重要沉积物的潜力（大约在冰期时间范围内的1.6百万年级1.6百万年度历史）。第四纪地质继承是最近的重点，用于提供过去的环境变化的高分辨率记录，以基于未来的预测，并协助从人类引起的变化中解释自然变异性。这项研究的目的是扩大最近在南极洲建立的高分辨率海洋地质记录的数据库，并解决了第四纪和较旧的环境变化的问题。工作的当前阶段，用于实现上述目标的当前阶段，以实现上述目标，专门用于在详细的网站上进行详细的信息，以便在详细的网站上进行统治，以便在典范中使用驱动器，以确定最佳练习站点，并将其用于培训，并将其用于最佳练习站点。满足采样要求。这项研究提出的位置是Mackay Sea Valley（MSV），据信这是由与早期的Cenozoic膨胀Mackay Glacier相关的侵蚀形成的，Mackay Glacier是东南极冰盖的主要出口冰川。 MSV穿过花岗岩港口，直到西罗斯海。自从被侵蚀以来，山谷已经经历了沉积物的积累，至少在第四纪，可能是在周末期间的早期时间。 （2）沉积物是南极洲研究最深入的沿海环境之一； （3）有一个初步的地球物理部位调查，（4）基于先前的活塞核心工作，沉积物似乎具有良好的时间顺序控制的潜力。最终，训练研究的主要目标是：（1）在麦克穆尔多声音区域中采用多核技术来提取第四纪的高分辨率（年代阶段（？）级）； （2）与当地和南极的其他地方建立了与地质和冰核记录建立海洋事物的相关性（例如，干山谷和南极半岛季季地质记录；泰勒和Siple Dome Ice Core Records）； （3）与北半球的记录测试南极变异性，以进行跨膜比较； （4）确定MSV不整合的年龄可能反映了过去第四纪膨胀过程中Mackay冰川在MSV内切割的冰川切割的年龄，并对新金元侵蚀率有限制； （5）特征是较旧的第四纪和/或新近纪（？）沉积物以下低于不整合的沉积物，这可能还可以提供有关该地区上新世历史的信息。但是，在实现这些总体目标的提议可以正确地制定之前，需要高质量的现场调查信息。这项工作将提供对获得MSV环境变化高分辨率记录的潜力进行全面评估所需的站点数据。