How did granite form in the Sierra Nevada?

The granite that characterizes much of the Sierra Nevada range formed deep beneath the Earth's surface through the cooling and solidification of magma. This process occurred during the Nevadan orogeny, a major mountain-building event that began approximately 156 million years ago.123

As the North American plate moved westward, oceanic crust was thrust beneath the continent at a subduction zone, generating large volumes of magma. This magma intruded into the crust and cooled slowly, allowing for the growth of large, visible mineral crystals characteristic of granite. These massive bodies of intrusive igneous rock, known as batholiths, eventually formed the core of the mountain range.312

These deep-seated rocks were later exposed at the surface through long periods of denudation and tectonic forces that pushed the crust upward. The Sierra Nevada itself was further shaped as an upfaulted, tilted block, with significant uplift occurring over the past several million years.14