Hafnium Isotopes and Crustal Chemical Processes

该项目是对(1)来自熔融时古老的地壳来源的一组广泛的花岗岩，以及(2)来自年轻来源的花岗岩的参考套件进行的Hf和(必要时)ND同位素研究。样本将来自PI自己的收藏，来自其他已发表的研究，以及拟议的来自美国西南部的1.4Ga花岗岩的新收藏。还计划研究Lu-Hf同位素系统在变形/蚀变岩石中的弹性。介绍了元古代糜棱岩化花岗岩的Lu-Hf、Sm-ND和Rb-Sr结果，并计划研究钾质交代作用、富HCl和富F蚀变环境中的变化。

This project is for a Hf and (where needed) Nd isotopic study of (1) a wide-ranging set of granites derived from crustal sources that were old at time of melting, and (2) a reference suite of granites derived from juvenile sources. Samples will be from the PIs'own collections, from other published studies and from a proposed new collection of 1.4 Ga granites from the S.W. USA. Also planned is a study of the resilience of the Lu-Hf isotopic system in deformed/altered rocks. Lu-Hf, Sm-Nd and Rb-Sr results for a mylonitized Proterozoic granite are described, and studies of changes that occur in potassic metasomatism, in HCl-rich and in F-rich alteration environments are planned.