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

这个项目是一项为期3年的研究，研究最近（过去100年左右）的火山喷发年代学和大洋中脊的熔岩地球化学，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。洋中脊系统发生的过程的时间变异性是理解这些全球重要火山结构动力学及其如何影响陆地环境的关键组成部分。火山喷发年表将通过分析熔岩中自然产生的放射性元素和应用锕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，但项目的一部分涉及开发新的岩石测年工具，以进一步深入到过去。工作计划由三个方面组成，将半同时进行：[1]“readi”到非常年轻（喷发后0至1.5年）的岩石，在我们现有的设施中使用210Po-210Pb技术进行喷发验证。[2]研究210Pb- 226Ra作为1-100年时间尺度的计时器，并将其应用于最近洋中脊喷发区域的熔岩。[3]通过长寿命的锕系同位素的测量和数据建模，研究了与最近的洋中脊喷发相关的次脊地幔中磁条件的变化。

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.