ALVIN Diving on the East Pacific Rise, 9-10 Degrees North: Hydrothermal, Volcanological, and Geochemical Studies in Support of ODP Bare Rock Drilling

海底扩张中心过程的一个新的观点正在出现从详细的测深，地球物理和岩石学数据集的整合。岩浆供应沿着脊轴的变化似乎在控制扩张中心的形态、构造、地震和地球化学“分段”方面起着根本性的作用。这种岩浆分段对热液作用具有深刻的意义，而热液作用受新形成地壳的热特性和渗透性的控制。本项目将支持对克利珀顿转换断层以南东太平洋海隆沿着的热液过程进行详细研究。这一段海脊已利用标准地质和地球物理技术进行了广泛研究。该海脊段仅缺少关于该项目将收集的喷口流体的化学性质和性质的数据。此外，还计划在今后进行钻探，以便对火山和热液过程进行深入观察。这些额外的数据将提供第一个完整的三维表征的山脊波峰扩展部分。在这项研究中，阿尔文潜水期间要完成的其他工作包括：构造测绘、玄武岩取样和对未来钻探的具体地点进行评估。

A new view of sea-floor spreading center processes is emerging from integration of detailed bathymetric, geophysical, and petrological data sets. Variations in the supply of magma along the ridge axis appears to play a fundamental role in controlling morphologic, tectonic, seismic and geochemical "segmentation" of spreading centers. Such magmatic segmentation has profound implications for hydrothermal processes which are controlled by the thermal and permeability characteristics of the newly formed crust. The present project will support a detailed examination of hydrothermal processes along the East Pacific Rise south of the Clipperton Transform Fault. This section of ridge has been extensively studied using standard geologic and geophysical techniques. Only data on the chemistry and nature of vent fluids to be gathered by this project is lacking for this ridge segment. Additionally, future drilling is planned which will provide a depth perspective on volcanic and hydrothermal processes. These additional data will provide the first complete three dimensional characterization of a ridge crest spreading segment. Additional work to be accomplished during Alvin dives in this study includes: structural mapping, basalt sampling, and evaluation of specific sites for future drilling.