ALVIN Diving in the Intra-Transform Spreading Centers of theSiqueiros Transform

该计划将侧重于岩石学和地球化学 内变换扩展中心的特征 Siqueiros转换断层，确定结构 通过ALVIN字段映射沿变换域沿着历史， 从岩壁上回收的变形岩石的结构研究 每一个断层陡坎的位置， 影响了发展的进程， 西凯罗斯在过去的4 Ma里发生了变化。会有十八个 阿尔文潜水在transfrom和夜间节目的岩石 取芯和疏浚，将提供额外的样本， 沿着扩展轴和沿着走向的不同地点- 滑动断层SeaBeam将在夜间使用， 每个扩展轴的10 m等高线图。疑问待 解决的问题包括：哪些过程负责 启动内部转换扩展吗什么是进化论 当一个新的扩张中心 开始吗？什么是重大改造附属性质 地幔成分的不连续性规模如何 地幔化学不均匀性的证据吗是独特的岩浆类型 沿着转换断层产生的

This program will focus on a petrological and geochemical characterization of the intra-transform spreading centers in the Siqueiros transform fault, on determining the structural histroy along the transform domain through ALVIN field mapping, structural studies of deformed rocks recovered from the walls of each fault scarp, and on understanding the tectonci processess that have influenced the development of the Siqueiros tranform for the past 4 Ma. There will be eighteen ALVIN dives in the transfrom and a night-time program of rock coring and dredging that will provide additional samples from along the spreading axis and at various sites along the strike- slip faults. SeaBeam will be used at night to produce detailed 10 m contour maps of each spreading axis. Questions to be addressed include: What processes are responsible for initiating intra-transform spreading? What is the evolutionary sequence of lava types erupted when a new spreading center start? What is the nature of major transform-affiliated compositional discontinuities in the mantle? What is the scale of chemical heterogeneity in the mantle? Are unique magma types generated along transform faults?