Gruesome California Crime Stories That May Play A Part In âTrue Detectiveâ Season 2. Nic Pizzolatto isnât letting us into his warped, deviant mind when it comes to salient plot points surrounding the second season of the highly-acclaimed HBO anthology series, True Detective, but he has dropped a few hints.
Rhyolite: Fine-Grained Felsic Rock Most rhyolites are light gray to pinkish in color, but red or even black rhyolites are not rare. Most rhyolites are porphyritic and are identified by the quartz phenocrysts and white to salmon K-feldspar phenocrysts. The groundmass is aphanitic or even glassy.
The difference between the two rock types is their grain size. Basalts are extrusive igneous rocks that cool quickly and have fine-grained crystals. Gabbros are intrusive igneous rocks that cool slowly and have coarse-grained crystals. Divergent boundary: In the oceanic crust, basalt forms near the surface at a divergent boundary, but gabbro forms at depth from slow crystallization.