Collaborative Research: Evaluation of Cumulus Petrofabrics Using Magnetic Fabrics

[902761] [au:]积云岩石的结构保存了硅酸盐液体分馏结晶过程的唯一直接证据。这些火成岩织物的量化和了解它们的起源是至关重要的，因为产生织物的机械过程具有化学和纹理后果。由于组构的定量岩石学研究是耗时的，我们建议使用蒙大拿静水杂岩的积累物来开发一种方法，将磁性组构（对磁性矿物和硅酸盐矿物的方向都很敏感）与超镁基性和基性积累物中的硅酸盐组构联系起来。这些磁性方法具有提供直接的3D织物信息的优点，具有检测小程度（~0.5%）各向异性的精度，并且足够快速地从大量样品中收集织物数据。我们的初步结果表明，这些磁技术提供了岩浆片理的准确信息，并且在某些情况下，恢复了单独从岩石学分析中不明显的线理。如果火成岩结构能够以收集地球化学数据的系统方式进行分析和量化，那么对累积物的研究将从推测机械过程的重要性发展到记录它们的重要性

9902761MeurerThe fabrics of cumulus rocks preserve the only direct evidence of the mechanical processes involved in fractional crystallization of silicate liquids. Quantification of these igneous fabrics and understanding their origin is critical since the mechanical processes that give rise to the fabrics have chemical as well as textural consequences. Because quantitative petrographic studies of fabrics are time consuming, we propose to use cumulates from the Stillwater complex, Montana to develop an approach for relating magnetic fabrics (that are sensitive to both the orientation of magnetic minerals as well as the silicate minerals) to silicate fabrics in ultramafic and mafic cumulates. These magnetic methods have the advantage of providing direct 3D fabric information, having precision to detect small degrees (~0.5%) anisotropy, and being rapid enough to collect fabric data from a large number of samples. Our initial results suggest that these magnetic techniques provide accurate information on magmatic foliations and, in some cases, recover lineations that are not evident from petrographic analysis alone. If igneous fabrics can be analyzed and quantified in the systematic manner that geochemical data are collected, then studies of cumulates will progress past the point of speculating as to the importance of mechanical processes to documenting their importance