Neoproterozoic Glaciation in Antarctica?

智力价值：极地计划办公室指派PI担任横贯北极山脉中部野外营地的首席科学家，这为PI提供了重新考察尼姆罗德冰川顶部一个独特的地质位置的机会。在1985-86年的野外季节，棉花高原上的PI发现了一个被解释为冰川成因的英云闪长岩。测年结果表明，该英云母时代为新元古代。据认为，这是南极新元古代冰川作用的第一个证据。在1985-86年的野外季节，PI还在棉花高原发现了与含二辉橄榄岩的沉积层序互层的火山流纹岩。在这项建议中，PI建议对流纹岩进行锆石U-Pb分析，以提供该直流纹岩的年龄，并允许将该矿床与全球新元古代冰川分区进行对比。此外，还将对角闪岩附近的岩石进行详细的研究，以确定更多与冰川相似的地点，从而了解南极洲？S在地球历史上这一重要时期所起的作用。广泛影响：一名目前正在攻读横贯北极山脉收集的岩石的硕士论文的学生将参与野外工作和后续的实验室工作。拟议的实地工作将为论文工作提供更广泛的背景。由于野外工作将在CTAM营地进行，学生将有机会与广泛的其他地质学家互动。从科学上讲，新元古代冰川是目前国际上非常感兴趣的研究主题，能否证明和准确测定南极新元古代冰川的年龄将对科学产生重大影响。

Intellectual Merit: The assignment of the PI to the role of Chief Scientist at the Central Transantarctic Mountains field camp by the Office of Polar Programs has presented the PI with the opportunity to re-examine a unique geological locality at the head of Nimrod Glacier. During the 1985-86 field season, a diamictite interpreted to be of glacial origin was discovered by the PI on the Cotton Plateau. Relative dates indicated that the diamictite is of Neoproterozoic age. It is believed that this is the first evidence of Neoproterozoic glaciation in Antarctica. During the 1985-86 field season, the PI also discovered a volcanic rhyolite at Cotton Plateau interbedded with the sedimentary sequence containing the diamictite. In this proposal, the PI proposes to sample the rhyolite for U-Pb analyses on zircons to provide an age for the diamictite and allow for correlation of this deposit with the global Neoproterozoic glacial subdivisions. Detailed examination of rocks in the vicinity of the diamictite will also be undertaken to identify additional localities with a glacial affinity, thus our understanding of Antarctica?s role during this important interval of Earth history.Broader impacts: A student currently working on a M.S. thesis on rocks collected in the Transantarctic Mountains will be involved in the fieldwork and follow up lab work. The proposed field work will give a broader context for the thesis work. Because the field work will be conducted from the CTAM camp, the student will have the opportunity to interact with a broad range of other geologists. Scientifically, the Neoproterozoic glaciation is currently a research theme of great international interest and the ability to demonstrate and accurately date Neoproterozoic glaciation in Antarctica will have significant scientific impact.