What type of rock is associated with low-grade metamorphosis in the Transverse Ranges?

The correct association of low-grade metamorphism in the Transverse Ranges is Pelona Schist. This rock type is primarily composed of schistose textures characterized by fine to medium-grained minerals, as well as a significant presence of mica, which is typical in low-grade metamorphic settings.

The formation of Pelona Schist occurred under conditions of relatively low temperature and pressure, which aligns with the definition of low-grade metamorphism. Geologically, it is believed to have originated from protoliths that were primarily sedimentary rocks, such as shale or mudstone, subjected to enough heat and pressure to facilitate the growth of new minerals and align their orientations.

Furthermore, Pelona Schist is an integral part of the geological framework of the Transverse Ranges, contributing to our understanding of the region's tectonic history and metamorphic processes. The presence of other types of rocks, like slate and gneiss, in various contexts can imply different metamorphic conditions or histories, with schists being more directly indicative of the specific low-grade metamorphism seen in the area.