Fluid Flow Around a Mid-Crustal Granite Pluton: Evidence from Fluid Inclusions

这项研究旨在记录南达科他州黑山1.7Ga Harney Peak花岗岩--一种独特的富含挥发性和稀有元素的同变质花岗岩--周围的热、流体循环和交代效应。原始数据库将由40个泥质岩样品组成，变质程度从黑云母到硅线石带不等。样品导线将被限制在一个单一的地层单位内，并将从花岗岩接触处延伸40公里。将在每个样品上确定主要、次要和微量元素化学和~(18)O，以及P-T路径的估计。选定的样品将提交使用40Ar/39Ar和U-Pb-Th(独居石)技术进行热计时，流体包裹体成分和捕获条件将使用显微测温和激光消融电感耦合等离子体质谱进行评估。

This study is to document the scale of thermal, fluid- circulation, and metasomatic effects around a distinctively volatile-and rare-element-rich synmetamorphic graite-the 1.7 Ga Harney Peak Granite in the Black Hills, South Dakota. The primary data base will consist of 40 samples of pelitic rocks ranging in metamorphic grade from the biotite through the sillimanite zone. The sample traverse will be confined to a single stratigraphic unit, and will extend 40 km from the granite contact. Major-,minor-, and trace-element chemistry and 18O will be determined on each sample, along with estimates of P-T paths. Selected samples will be submitted for thermochronometry using 40Ar/39Ar and U-Pb-Th (monazite) techniques, and fluid inclusion compositions and trapping conditions will be evaluated using microthermometry and laser-ablation ICP-MS.