The Origin and Evolution of Mantle Plumes

9418398白色这是一个分析程序，将产生一个关于许多关键地幔热柱的全面数据集。这一套将包括放射性同位素比率(锶、钕和铅)、痕量元素(Rb、Cs、Sr、Ba、稀土、Y、Zr、Nb、Hf、Ta、U、Th、Pb、所有第一过渡金属，可能还有Li、Be、As、Mo、Tl、SnSb和W)、氧和硼的稳定同位素比率以及常量元素。这项工作将把重点放在已经对一些元素和同位素进行分析的样本上；因此，这更多的是努力使现有数据集复杂化，而不是产生新的数据集。分析工作将通过从文献中收集现有数据，筛选其质量，并创建一个关于大洋岛和岛弧火山的广泛的地球化学数据库来加以赞扬。根据所得到的数据集，将试图回答以下问题：(1)三类主要地幔热柱的微量元素和稳定同位素特征是什么？(2)不同来源在地幔热柱储集层的地球化学演化中的相对贡献是什么？(3)岩石圈再循环发生的时间尺度是什么？(4)上述物质在热柱中所占的比例是多少？(5)所有热柱中是否存在共同的成分？

9418398 White This is an analytical program that will produce a comprehensive data set on a number of key mantle plumes. This set will include radiogenic isotope ratios (Sr, Nd, and Pb), trace elements (Rb, Cs, Sr, Ba, rare earths, Y, Zr, Nb, Hf, Ta, U, Th, Pb, all the first transition metals, and possibly Li, Be, As, Mo, Tl, Sn, Sb, and W), stable isotope ratios of oxygen and boron, and major elements. The effort will focus on samples that have already been analyzed for a number of elements and isotopes; it is thus more an effort at complexing existing data sets rather than producing new ones. The analytical effort will be complimented by harvesting existing data from the literature, filtering it for quality, and creation of a n extensive geochemical database on oceanic island and island arc volcanics. From the resulting data set, an attempt will be made to answer the following questions: (1) What are the trace element and stable isotope characteristics of the 3 principal mantle plume classes? (2) What is the relative contribution of various sources in the geochemical evolution of mantle plume reservoirs? (3) What are the time scales upon which lithospheric recycling occurs? (4) In what proportions are the above materials present in plumes? (5) Can the existence of a common component in all plumes be verified?