The lava released during volcanic eruptions cools to form igneous rocks. Depending on the location of cooling, these are classified as volcanic rocks (cooling at the surface) and plutonic rocks (cooling in the crust). The forms assumed by lava cooling within the crustal portions are called intrusive forms.

Dykes form when lava makes its way through cracks and fissures, solidifying almost perpendicular to the ground. These wall-like structures are commonly found in western Maharashtra and are considered feeders for the Deccan traps.

Batholiths are large bodies of magmatic material that cool at deeper depths, forming large domes. These granitic bodies cover large areas and appear on the surface only after denudational processes remove overlying materials. Lacoliths are large dome-shaped intrusive bodies with a level base, connected by a pipe-like conduit from below. They resemble surface volcanic domes but are found at deeper depths, such as the domal hills in the Karnataka plateau.

Other forms include Lapoliths and Phacoliths. A Lapolith is a saucer-shaped body, concave to the sky, formed when lava moves horizontally along a weak plane. A Phacolith is a wavy mass found at the base of synclines or top of anticlines in folded igneous country, connected to source magma chambers.