ALVIN Diving on the East Pacific Rise, 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，出现了关于海底扩展中心过程的新观点。岩浆沿山脊轴线的供应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”方面发挥了基本作用。这种岩浆分段对新形成的地壳的热和渗透性特征所控制的热液作用具有深远的意义。本项目将支持对克利珀顿转换断层以南的东太平洋隆起沿线的热液过程进行详细研究。使用标准的地质和地球物理技术对这段山脊进行了广泛的研究。对于这个海脊段，只有这个项目要收集的喷口流体的化学和性质的数据是缺乏的。此外，未来的钻探计划将提供火山和热液过程的深度透视。这些附加数据将提供第一个完整的脊峰展开段的三维特征。在这项研究中，阿尔文潜水期间要完成的其他工作包括：构造制图、玄武岩取样和为未来钻探而对特定地点进行评估。

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.