Tourmaline as a Petrogenetic Indicator Mineral in Metamorphic Rocks

建议对电气石进行系统的研究，以扩大这种矿物在各种变质岩中作为成岩指示剂的用途。将对缅因州西北部的样品进行实地研究，那里的PI已经确定了变质条件。具体目标包括：(1)评价电气石边缘与块体岩石、矿物组合和T之间的组成关系；(2)变质历史与电气石分带模式之间的关系；(3)利用碎屑电气石的成分指示沉积来源；(4)自生电气石的成分与成岩流体的关系。这些研究还将有助于更好地了解电气石的晶体化学、B的地球化学循环和变质过程。

Systematic studies of tourmaline are proposed to extend the utility of this mineral as a petrogenetic indicator in a wide range of metamorphic rocks. Field-related studies will be conducted on samples from NW Maine where the PIs have already characterized conditions of metamorphism. Specific goals include: (1) assessment of compositional relations between tourmaline rims and bulk rocks, mineral assemblage, and T, (2) relations between metamorphic history and tourmaline zoning patterns, (3) utilization of compositions of detrital tourmalines to indicate sedimentary provenance, and (4) relations of compositions of authigenic tourmalines and diagenetic fluids. These studies will also lead to a better understanding of the crystal chemistry of tourmalines, geochemical cycles of B, and metamorphic processes.