Geochemical Evolution of the Galapagos Hotspot

来自加拉帕戈斯群岛的初步数据证明了氦对理解地幔过程的重要性。虽然高的3He/4He比率本身很重要，但这个项目的重点是了解当地的变化，并将它们与羽流中的过程联系起来。这项工作的一个特别重要的方面是，宇宙射线产生的氦可以用来确定年龄，从而提供年龄控制。这将是一种综合方法，将结合实地工作、主要和微量元素测量、He、Sr、Nd和Pb的同位素，以及表面暴露测年提供的年表。这项工作将与Dennis Geist（爱达荷大学）合作进行，他在加拉帕戈斯群岛有长期的实地工作记录。提出的研究目标是：1。利用地表暴露定年法评估加拉帕戈斯群岛热点和个别火山中心的时间演化。通过获取地球化学数据，结合年代学，对群岛内整体梯度的各种模型进行严格测试，应该是可能的。2. 记录群岛内氦同位素的变化。

9418889 Kurz Preliminary data from the Galapagos demonstrate the importance of helium to understanding mantle processes. Although the high 3He/4He ratios alone are important, the focus of this project is to understand the local variations, and relate them to processes within the plume. A particularly important aspect of the proposed work is that cosmic ray produced 3He can be used to determine ages, thus providing age control. This will be an integrated approach that will combine field work, major and trace element measurements, and the isotopes of He, Sr, Nd and Pb, with chronology provided by surface exposure dating. This work will be carried out in collaboration with Dennis Geist (University of Idaho) who has a long record of field work in the Galapagos. The goals of the proposed research are to: 1. Evaluate the temporal evolution of Galapagos hotspot, and individual volcanic centers using surface exposure dating. By obtaining the geochemical data in conjunction with chronology to rigorously test the various models for the overall gradients within the archipelago it should be possible. 2. Document the helium isotopic variability within the archipelago.