An Integrated Seismic and Petrologic Investigation of the Effects of Plume-Ridge Interaction on Crustal Accretion: The Galapagos Spreading Center Between 91 deg. W and 98 deg. W

该项目是一个综合性的野外和实验室项目，涉及沿加拉帕戈斯扩张中心西经91度至98度长800公里的地震学、岩石学和理论建模研究。该项目的目标是：(1)通过测量沿隆起的地壳厚度和从玄武岩化学推断的熔融程度，确定如何在地壳厚度和熔融密度的变化之间分配对加拉帕戈斯膨胀的补偿；(2)确定是否存在控制从轴向高压向裂谷过渡的门槛因素；(3)确定脊玄武岩的岩浆分异程度如何与是否存在熔融透镜有关；以及(4)确定为什么热点附近的部分熔融程度似乎较低。

This project is a comprehensive field and laboratory program that involves coordinated seismic, petrologic and theoretical modeling studies along an 800-km-long section of the Galapagos spreading center between 91 and 98 degrees west. The objectives of the project are to: (1) determine how the compensation of the Galapagos swell is partitioned between variations in crustal thickness and mangle density by measuring crustal thickness along the swell and the degree of melting inferred from the chemistry of basalts, (2) determine if there is a threshold factor that controls the transition from an axial high to a rift valley, (3) determine how the extent of magmatic differentiation of ridge basalts relates to the presence or absence of a melt lens, and (4) determine why the degree of partial melting appears to be lower near the hotspot.