The Pacific Margin of the Antarctic Pennisula: A Marine Geophysical Study of the Tectonic Evolution of Andean-Type Orogens

本研究的重点是在南极洲太平洋边缘复杂的构造历史中活跃的几个具有全球重要意义的地壳造山过程。该奖项支持全面的地球物理调查(即MCS，重力，磁力，以阐明南设得兰群岛-布兰斯菲尔德海槽地区作为安第斯造山过程的现代模拟物的作用，以及作为对南极西部边缘边界不易接近、因此鲜为人知的部分进行构造侦察的一个具体步骤别令斯豪森海和阿蒙森海通过将海洋数据与陆上地质观测和板块运动历史相结合，这项调查应该能够在增进对以下过程的理解方面取得真正的进展：安第斯型造山作用；收敛大陆边缘环境下的大陆岩石圈伸展；脊顶俯冲；以及带辐合边缘的大偏移断裂带的相互作用，包括俯冲杂岩的隆升。这项研究将为美国南极地球科学倡议提供动力，开展迄今为止由任何国家开展的最雄心勃勃的南极海洋地球物理研究。

This study focuses on several globally important, crustforming orogenic processes that have been active during the complex tectonic history of the Pacific margin of Antarctica. This award supports a comprehensive geophysical survey (i.e., MCS, gravity, magnetics, sonobuoys and multi- beam bathymetry) of two parts of the Antarctic Peninsula to illuminate the role of the South Shetland Islands-Bransfield Trough region as a modern analog of Andean orogenic processes and as a specific step toward tectonic reconnaissance of the less accessible and therefore more poorly known parts of the West Antarctic margin bordering the Bellingshausen and Amundsen seas. By integrating the marine data with onshore geologic observations and kinematic plate motion histories, this investigation should be able to make real progress towards increased understanding of the following processes: Andean-type orogenesis; continental lithosphere extension in a convergent continental margin setting; ridge crest subduction; and interaction of large- offset fracture zones with convergent margins, including the uplift of subduction complexes. The study will provide impetus for the U.S. Antarctic Geoscience Initiative by undertaking the most ambitious Antarctic marine geophysical study yet carried out by any nation.