Sierra Nevada Batholith

[1] The batholith is composed of many individual masses of rock called plutons, which formed deep underground during separate episodes of magma intrusion, millions of years before the Sierra itself first began to rise.

The batholith – the combined mass of subsurface plutons – became exposed as tectonic forces initiated the formation of the Basin and Range geologic province, including the Sierra Nevada.

The exposed portions of the batholith became the granite peaks of the High Sierra, including Mount Whitney, Half Dome and El Capitan.

The resultant molten rock rose through the Earth's crust over the span of 100 Ma, forming several plutons, or a chain of volcanoes if the magma reached the surface.

Fission tracks – destructive remnants of radioactive decay in Uranium-bearing minerals – were shorter than expected in samples taken from several Sierra Nevada plutons.