Alvin Diving on the EPR 9-10 Degrees North: Hydrothermal, Volcanological, and Geochemical Studies in Support of ODP Bare Rock Drilling

从详细的水深、地球物理和岩石学数据集的整合中，出现了海底扩张中心过程的新观点。岩浆供应沿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“分割”方面起着根本作用。这种岩浆分割对新形成地壳的热渗透特征控制的热液过程具有重要意义。目前的项目将支持对克利珀顿变换断层以南的东太平洋隆起的热液过程进行详细检查。使用标准的地质和地球物理技术对这段脊进行了广泛的研究。该项目只收集了关于该山脊段喷口流体的化学和性质的数据。此外，未来的钻探计划将提供火山和热液过程的深度视角。这些额外的数据将提供脊峰扩展段的第一个完整的三维特征。在这项研究中，Alvin潜水期间要完成的其他工作包括：构造测绘、玄武岩取样和评估未来钻探的特定地点。

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.