Collaborative Research: Integrated Structural and Geochemical Investigation of Alternate Origins for 'Crack-Seal' Veins

尖锐带状纤维脉是变形岩石中的常见特征，通常被解释为裂缝-密封机制的作用，在这种机制中，由于局部压降，裂缝事件之后立即发生水泥沉淀事件。然而，最近的质量平衡研究结果对这是否是一种有效机制提出了质疑。该项目将从一个新的视角模型来研究带状矿脉的形成问题，该模型包括两个简化过程——生长晶体施加的压力和地球化学自组织，即在矿脉-寄主壁上几乎恒定的流体组成导致沉淀物种的振荡。我们将利用地球化学/显微温度测量数据和纹理信息对矿脉组进行一系列测试，以了解形成这些矿脉的化学和机械过程。研究结果将有助于提高对脉体形成的认识，从而有助于了解脉体形成的构造环境。

0107079 Wiltschko0107064 SharpBanded fibrous veins are common features in deformed rocks, and are classically interpreted to indicate operation of a crack-seal mechanism in which a crack event is immediately followed by a cement-precipitation event due to local pressure drop. However, recent results of mass-balance considerations have cast doubt on this being a valad mechanism. This project will examine the question of the formation of banded veins from a new perspective model that includes two simplifying processes - pressure exerted by growing crystals and geochemical self-organization whereby a nearly constant fluid composition at the vein-host walls leads to oscillations in precipitated species. A series of tests will be applied to veins sets using both geochemical/microthermometric data and textural information to understand chemical and mechanical processes responsible for these types of veins. Results will help improve understanding of vein formation and therefore their use in understanding the tectonic setting in which they formed.