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

这项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全球重要的地壳形成造山作用。该奖项支持一项全面的地球物理调查(即MCS、重力、磁学、南极半岛两个部分的声纳浮标和多波束测深)，以阐明南设得兰群岛-布兰斯菲尔德海槽区域作为安第斯造山过程的现代模拟所起的作用，并作为对较难到达且因此较差的地区进行构造勘察的具体步骤西南极边缘的已知部分，与别林豪森海和阿蒙森海接壤。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加深对以下过程的理解方面取得真正进展：安第斯型造山作用；大陆岩石圈在会聚大陆边缘背景下的伸展；海脊俯冲；大错动断裂带与会聚边缘的相互作用，包括俯冲杂岩的抬升。这项研究将为美国南极地球科学倡议提供动力，进行迄今为止任何国家都没有进行过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.