Intrusive contact between the sedimentary, Eocene Claron Formation below and the quartz-monzonite Pine Valley Mountains laccolith above. The Pine Valley laccolith is the world's largest example of such a pluton. Around 21 million years ago, magma intruded within the Claron Formation at a depth of about 200 m, shallower than is typical for a laccolith, allowing the magma to spread far laterally and dome up higher than normal. #geology #geoscience #igneous #Utah #pluton #laccolith #naturalhistory