The Evolution of Mantle Melting During Development of the Southernmost Basin and Range Province, Mexico

这是一个持续的项目，其中详细，综合 已经对年轻的地幔进行了研究， 圣刘易斯波托西的衍生玄武岩，包括Sr的测量 Nd同位素比值。 这些数据表明至少有三个地幔 源组件。 该奖项将使PI能够执行Pb 同位素分析相同的样品，并扩大外地为基础 调查，包括杜兰戈地区和老年人， 这两个地区都有富含巨晶的玄武岩。 他们还将尝试 推断捕虏体中Nd和Sr的总量收支。 应当 那么就有可能追溯地幔熔融的历史， 横跨最南端的盆岭省的500公里样带 在极端构造运动时期 K-Ar年龄测定 Ar-Ar方法将在加州大学伯克利分校完成。 探针研究 并对二辉橄榄岩中的单斜辉石进行浸出 在同位素分析之前。

This is a continuing project in which detailed, integrated studies have already been conducted of the younger, mantle- derived basanites of San Luis Potosi, including measurement of Sr and Nd isotope ratios. These data indicate at least three mantle source components. This award will enable the PIs to perform Pb isotopic analyses on the same samples, and to expand field based investigations to include the Durango area and the older, magacryst-rich basenites from both areas. They will also attempt to deduce total Nd and Sr budgets in the xenoliths. It should then be possible to trace the history of mantle melting for a 500-km transect across the southernmost Basin and Range Province throughout the period of extreme tectonism. Age dating by both K-Ar and Ar-Ar methods will be done at Cal-Berkeley. Probe studies and leaching of clinopyroxenes from lherzolites will be carried out prior to isotopic analysis.