This page requires extensive rework before it is factually correct.
The geology of the Cocos (Keeling) Islands may be a part of the Galapagos hot spot.
The island is the mountaintop of non-seismic, undersea Cocos Ridge.
Alkali basalt and trachyte are the only forms of bedrock on the island and fractional crystallization of olivine and clinopyroxene played a key role in the formation of the rocks.
[1] Sediments on the island include sand and gravel from the Holocene and cemented conglomerates made of coral fragments.