Episodic Accretion on the Mid-Atlantic Ridge: Interpretationand Sampling of Crustal Sections from the Kane Transform Fault

了解海洋地壳的组成和化学成分一直是海洋地球科学的长期目标。这些信息对地幔物质向地壳转移的过程提供了重要的限制，这些过程导致火成岩地壳的形成，并随后改变地壳的化学成分和控制海水的成分。然而，这样的理解需要一种对地壳岩石取样的方法，以及一种将单个地壳层与上、下地层联系起来的方法。虽然深地壳钻探是一种这样的技术，但深地壳孔是昂贵的，并且提供有限的地壳物质的面积采样。最近，人们对研究地壳断层暴露重新产生了兴趣，通过潜水/疏浚或一系列浅层钻孔对地壳岩石的地层序列进行取样。目前的合同将对北大西洋凯恩变换断层中暴露的地壳岩石进行侧扫声纳调查。该项目的目标是绘制地壳层的连续性图，对沿转换暴露的火成岩的地层演替进行取样，并检查沿主要陡崖暴露的断裂模式。这些数据将用于确定地壳增生的历史和随后的变形。此外，这些数据将为该地区后续的潜水研究提供所需的调查数据。该项目是华盛顿大学、杜克大学和巴黎大学的科学家之间的合作研究。

Understanding the composition and chemistry of the oceanic crust has been a long term goal of the marine geosciences. Such information provides important constraints on the processes that transfer mantle material to the crust, that lead to the formation of the igneous crust, and that subsequently modify the chemistry of the crust and control the composition of seawater. Such an understanding, however, requires a means to sample crustal rock and a way to relate individual crustal layers to over- and underlying strata. Although deep crustal drilling is one such technique, deep crustal holes are expensive and provide limited areal sampling of crustal material. Recently there has been renewed interest in studying faulted crustal exposures as a way to sample a stratigraphic succession of crustal rocks by submersible/dredging or by a series of shallow drill holes. The present award will undertake a side-scan sonar survey of exposed crustal rocks in the Kane Transform Fault in the north Atlantic. Objectives of the project are to map the continuity of crustal layers, to sample the stratigraphic succession of igneous rocks exposed along the transform, and to examine the faulting pattern exposed along major scarps. These data will be used to determine both the history of crustal accretion and subsequent deformation. Additionally, these data will provide the needed survey for subsequent submersible research in the area. The project is a cooperative study between scientists at the University of Washington, Duke University and the University of Paris.