Batholith
A batholith is a large mass of igneous rock that forms when magma cools and solidifies deep beneath the Earth's surface. These formations can cover an area of over 100 square kilometers and are typically composed of granite or similar rocks. Batholiths are often exposed at the surface due to erosion over millions of years.
Batholiths are significant in geology because they provide insights into the processes of volcanism and the formation of the Earth's crust. They can also influence the surrounding landscape, leading to the creation of features like mountains and valleys. Examples of famous batholiths include the Sierra Nevada Batholith in California.