ROW: Petrologic Studies of Migrating Ridge-Mantle Heterogeneity Interactions at the Heckle Seamounts, N.E. Pacific

这项研究将检验一些海山形成于 由于在小的、低的温度范围内的优先的、离轴熔化， 地幔内部的熔融温度不均匀性 扩张中心下方的上升流， 绝对参照系 该假设预测， 系统的变化将显示沿着链， 反映了时间变化的相互作用之间的 海山和海脊轴源。 数据将在 在一个为期14天的实地项目中， 海克尔海山和邻近的深海丘陵。 实验室 分析样品中的主要微量稀土元素 浓度和Sr、Nd和Pb同位素比值。 Ar-Ar年龄 选定样本的年代测定将有助于确定 海山熔岩的成分变化。 %%% 下方熔体偏析区的几何形状和尺寸 扩散中心是一个基本的科学问题。 直接 观察是困难的，但推论可以通过 研究附近形成的小海山之间的相互作用 扩展中心和相邻的脊轴。 研究 本项目正在开展一项这样的互动活动。

This study will test the hypothesis that some seamounts form as a result of preferential, off-axis melting within small, low melting temperature heterogeneities embedded within the mantle upwelling beneath spreading centers that migrate in the absolute reference frame. The hypothesis predicts that a systematic variation will be exhibited along the chain which reflects the temporally varying interaction between the seamount and ridge axis sources. The data will be obtained on rock samples dredged during a fourteen day field program on the Heckle seamount and adjacent abyssal hills. Laboratory analysis of the samples for major, trace, rare earth element concentrations and Sr, Nd and Pb isotope ratios. Ar-Ar age dating of selected samples will help constrain the chronology of compositional variations in seamount lavas. %%% Geometry and dimensions of the melt segregation zone beneath spreading centers is a fundamental scientific problem. Direct observation is difficult, but inferences can be made by examining interactions between small seamounts forming near spreading centers and the adjacent ridge axis. The study of one such interaction is being carried out in this project.