The Marie Byrd Land Margin: Early Seafloor Spreading History

该奖项支持对南极洲玛丽伯德陆缘早期海底扩张历史的调查。这项工作将仔细绘制磁力线、重力异常、地形，并在可能的情况下，通过地震确定基底的深度。该研究将结合重力、测深和地震信息确定的构造线与磁异常，构建新的玛丽伯德陆缘海底扩张史。对这些新数据集的分析和由此产生的海底扩张历史将用于解决以下问题：(1)太平洋-南极脊的早期开放是否涉及一个额外的板块，即别林斯高森板块，或者脊是否经历了非常不对称的、非正交的扩张？(2)对太平洋南极脊的开放历史有了更精确的认识，这对南极洲西部的构造块体之间的相对运动和玛丽·伯德陆缘的结构和演化有什么意义？(3)通过细化早第三纪太平洋-南极海底扩张史，全球板块环流解是否能够得到增强？

This award supports an investigation of the early seafloor spreading history of the Marie Byrd Land Margin, Antarctica. This effort will carefully map the magnetic lineations, the gravity anomalies, the topography and, where possible, the seismically determined depth to basement. The study will integrate the tectonic lineations determined from the gravity, bathymetry and seismic information with the magnetic anomalies to construct a new seafloor spreading history of the Marie Byrd Land Margin. The analysis of these new data sets and the resultant seafloor spreading history will be used to address the following questions: (1) Did the early opening of the Pacific-Antarctic Ridge involve an additional plate, the Bellingshausen Plate, or did the ridge undergo very asymmetric, non-orthogonal spreading? (2) With a better refined opening history for the Pacific Antarctic Ridge, what are the implications for relative motions between the tectonic blocks which compromise West Antarctica and for the structure and evolution of the Marie Byrd Land Margin? (3) Can the global plate circuit solution be enhanced by refining the early Tertiary history of Pacific-Antarctic seafloor spreading?