Identifying Multiple Thermal Events in Polymetamorphic Rocks: Electron and Ion Microprobe Analysis of Complexly Zoned Titanite

9909410温奇在变质岩石中解释和测定多个热事件的能力将是理解造山事件和古构造环境的主要工具。 然而，矿物具有中等闭合温度的放射性同位素用于年龄测定通常会失去一些或所有积累的时间依赖性同位素产品，造成模糊的结果，而高闭合温度邀请遗传和多个过度生长。 本项目将探讨利用钛铁矿中的U-Pb对确定多变质事件的年代。 相对于该系统，钛铁矿具有高闭合温度，但与锆石和其他副矿物不同，钛铁矿由主要组分组成，因此它可以更容易地与特定变质事件或阶段中发生的特定变质反应联系起来。 这项研究将涉及新英格兰含钛岩石的岩石学特征，以确定生长的原因和年龄。 这些结果将被应用于了解的分布和强度的阿巴拉契亚造山运动和叠加的阿勒格尼造山运动。

9909410WintschThe ability to decipher and date multiple thermal events in metamorphic terranes would be a major tool in understanding orogenic events and paleotectonic settings. However minerals with moderate closure temperatures to radioactive isotopes useful for age determination commonly lose some or all of the accumulated time-dependant isotopic products, causing ambiguous results, whereas high closure temperatures invite inheritance and multiple overgrowths. This project will explore the utility of using the U-Pb pair in titanite to date polymetamorphic events. Titanite has a high closure temperature with respect to this system, but unlike zircon and other accessory minerals, is composed of major components and therefore it can be more easily linked to specific metamorphic reactions occurring in a particular metamorphic event or phase. The study will involve petrologic characterization of titanite-bearing rocks of New England to determine the causes and ages of growth. These results will be applied to understanding the distribution and intensity of the Acadian Orogeny and overprinting by the Alleghanian Orogeny.