Eastern California's Sierra Nevada mountain range consists of granite. This is the lightweight material that builds up continents. Here, large complexes of non-erupting magma were stuck in the Earth’s crust. Such batholiths cool down extremely slow. Basically they are composed of feldspar, quartz and mica. Due to tectonic forces, this former batholith raised to elevations up to 4500 m. Granite typically erodes by spheroidal weathering leaving huge marbles.
Canon 20D, EF-L 24-105mm, f/22, 1/4sec, ISO 100, polarization filter, tripod