Petrologic and Isotopic Investigations of Chemically Reactive Fluid Flow During Metamorphism

9805346 FerryProposed研究将解决有关变质作用过程中化学过程的基本问题：（1）反应变质流体流通道化的规模、几何形状和构造控制是什么？(2)有多少质量通过扩散和分散被输送到流动通道中或从流动通道中输送出来？(3)主要元素通过流动进行质量迁移的数量和规模是多少？(4)如何确定变质流体流动的年代？这些问题将通过对加州、意大利和苏格兰3个接触变质区的碳酸盐岩进行新的野外研究，以及对来自新英格兰的3个岩石样品组进行实验室研究来解决。流体流动的通道将根据矿物反应产物的分布在现场绘制，并与结构特征相关联。 利用输运理论定量解释反应过程和氧同位素数据，评价传质几何和机理。 硅迁移的数量和规模将通过岩石的化学分析来评估。 流动事件的年龄将通过定义独居石和褐帘石形成的变质条件和用质谱法测量矿物的Pb-Th-U年龄来确定。

9805346FerryProposed research will address fundamental questions about chemical process during metamorphism: (1) What is the scale, geometry, and structural control on the channelization of reactive metamorphic fluid flow? (2) How much mass is transported into or out of the flow channels by diffusion and dispersion? (3) What is the amount and scale of major element mass transport by flow? (4) How can episodes of metamorphic fluid flow be dated? The questions will be addressed by new field studies of carbonate rocks in 3 contact metamorphic terrains in California, Italy, and Scotland as well as by laboratory study of 3 rock sample suites from New England at hand. Channels for fluid flow will be mapped in the field from the distribution of mineral reaction products and correlated with structural features. The geometry amd mechanisms of mass transfer will be evaluated by quantitatively interpreting reaction progress and O-isotope data with transport theory. The amount and scale of Si-transport will be assessed from chemical analyses of rocks. The age of flow events will be determined by defining the metamorphic conditions at which monazite and allanite form and measurement of the minerals' Pb-Th-U ages by mass spectrometry.