The Idaho Springs Batholith
Pegmatitic intrusion through a slab of grey gneiss on the right. The cooling was slow enough to allow the formation of large crystals, closer to granite. Gneiss exposure displaying wide banding on the left.
Pegmatitic intrusion through a slab of grey gneiss on the right. The cooling was slow enough to allow the formation of large crystals, closer to granite. Gneiss exposure displaying wide banding on the left.