Recent Ridge Eruptive Activity Dating and Investigations - 2: Lava Geochronology and Mantle Melting (The "RREADI-2" Project)

该项目对大洋中脊最近(过去100年左右)的喷发年代学和熔岩地球化学进行了为期3年的研究，以更好地了解世界上一些最活跃的海底火山的火山、水文和生物过程。大洋中脊系统发生的过程在时间上的变异性是了解这些全球重要火山构造的动力学及其如何影响陆地环境的关键组成部分。喷发年代学将通过对熔岩中自然产生的放射性元素的分析和应用鳗系不平衡技术来确定。这项工作的一部分将使用现有的技术，但该项目的一部分涉及开发新的岩石测年工具，以进一步扩大我们在过去的研究范围。工作计划由三个方面组成，将半同时进行：[1]在我们现有的设施中使用210Po-210Pb技术对非常年轻(自喷发以来0至1.5年)的岩石进行“RREADI”研究，以供喷发核查。[2)研究210Pb-226Ra用作1-100年时间尺度的计时器，并将其应用于最近大洋中脊喷发地区的熔岩。[3)通过对较长寿命的鳗系同位素的测量和数据模拟，研究与最近大洋中脊喷发有关的亚脊地幔中的岩浆成因条件的变异性。

This project is a 3-year study of very recent (last 100 yrs or so) eruption chronology and lava geochemistry at mid-ocean ridges to better understand volcanic, hydrologic and biological processes at some of the world's most-active submarine volcanoes. The temporal variability of processes occurring at the mid-ocean ridge system is a key component for understanding the dynamics of these globally important volcanic structures and how they affect terrestrial environments. Eruption chronology will be determined from analyses of naturally-occurring radioactive elements in the lavas and by applying actinide-series disequilibrium techniques. Part of this work will use established techniques but part of the project involves development of new rock dating tools to further our reach back in time. The work plan is composed of three aspects to be conducted semi-concurrently:[1] be "RREADI" to date very young (0 to 1.5 yrs since eruption) rocks for eruption verification in our existing facility using the 210Po-210Pb technique.[2] investigate 210Pb- 226Ra for use as a chronometer over the 1-100 yr time scale and apply it to lavas from areas of recent mid-ocean ridge eruptions.[3] investigate variability in magmagenetic conditions in the sub-ridge mantle associated with the most-recent mid-ocean ridge eruptions by measurements and data modeling of longer-lived actinide series isotopes.