Collaborative Research: 10Be and 9Be in Volcanic Arc Lavas: Investigation of Sediment Recycling

不同地区~250个火山岩中Be-10的最新测量结果 地质环境表明，年轻的近地表海洋 沉积物被俯冲并并入弧岩浆中， 千岛群岛、阿留申群岛、中美洲、秘鲁-智利和新不列颠 弧。 Be-10数据与地球物理和构造数据的综合 对收敛边缘的研究表明， 在俯冲板块的地堑中俯冲的，如Be-10 弧熔岩的浓度最高， 厚度近似等于下的垂直位移， 摔盆。 大学最近的改进 宾夕法尼亚加速器允许分析更小的样品 更准确地说，以及最近获得的国际合作伙伴。 卡内基的一台光谱仪允许测量Be-9。 这 项目是测量Be-10/Be-9比值和Sr、Nd、Pb同位素 矿物分离物、新火山弧熔岩和 现有样本集合的子集。 尽可能 结果将与其他地球化学研究相结合， 在地球物理研究的背景下进行评估， 沉积物俯冲和再循环的综合模型， 火山弧

Recent measurements of Be-10 in ~250 volcanic rocks from various geologic settings indicate that that young, near-surface oceanic sediments are subducted and incorporated in arc magmas in the Kurile, Aleutian, Central America, Peru-Chile and New Britain arcs. Integration of Be-10 data with geophysical and structural studies of convergent margins suggests that sedfiments may be subducted in grabens in the subducting plate, as Be-10 concentrations an arc lavas are highest where the pelagic sediment thickness approximately equals vertical displacement of the down- dropped basins. Recent improvements in the University of Pennsylvania accelerator permit smaller samples to be analyzed more precisely, and the recent acqusition of an I.C.P. spectrometer at Carnegie permits measurement of Be-9. This project is to measure Be-10/Be-9 ratios and Sr, Nd and Pb isotopic compositions for mineral seperates, new volcanic arc lavas, and a subset of the existing sample collection. Wherever possible results will be combined with other geochemical studies and evaluated in the context of geophysical studies in order to arrive at an integrated model of sediment subduction and recycling at volcanic arcs.