slgwv's photos with the keyword: pegmatite

Black Canyon of the Gunnison National Park, Colorado. The cliff here is roughly 2000 ft high (~610 m). The "paint" streaks are pegmatite dikes, traditionally interpreted as intruded into the dark host metamorphic rock from an outside reservoir, but which may instead have largely formed in place by partial melting ("anatexis.") Looking west and downstream from the south rim of the canyon.