The Kerguelen Plateau (//, //) is an underwater volcanic large igneous province (LIP) and also a microcontinent and submerged continent in the southern Indian Ocean. It lies about 3,000 km to the southwest of Australia and is nearly three times the size of Japan. The plateau extends for more than 2,200 km in a northwest-southeast direction and lies in deep water.
The plateau was produced by the Kerguelen hotspot, starting with or following the breakup of Gondwana about 130 million years ago. There is a small portion of the plateau that breaks sea level, forming the Kerguelen Islands plus the Heard and McDonald Islands. Intermittent volcanism continues on the Heard and McDonald Islands.
Symmetrically located across the Indian Ocean ridge and due west of Australia is the Broken Ridge underwater volcanic plateau, which at one time was contiguous with the Kerguelen Plateau prior to rifting by the mid-ocean ridge.
The formation of the Kerguelen Plateau started with a series of large volcanic eruptions 110 million years ago. The presence of soil layers in the basalt with included charcoal and conglomerate fragments of gneiss indicate that much of the plateau was above sea level as what is termed a microcontinent for three periods between 100 million years ago and 20 million years ago. Large parts of the now submarine Southern (SKP) and Central Kerguelen Plateaus (CKP) were subaerial during the formation of the LIP. The SKP probably formed an island of 500,000 km2 (190,000 sq mi) with major peaks reaching 1–2 km (0.62–1.24 mi) above sea level.
It finally sank 20 million years ago and is now 1 to 2 km (0.6 to 1.2 mi) below sea level.
- Oxford English Dictionary
- UT Austin 1999
- "Leg 183 Summary: Kerguelen Plateau-Broken Ridge—A Large Igneous Province". Proceedings of the Ocean Drilling Program 183.
- Frey et al. 2003, Subsidence of the Kerguelen Plateau, pp. 16–17
- Mohr, Barbara A.R.; Veronika Wähnert, and David Lazarus "Mid-Cretaceous paleobotany and palynology of the central Kerguelen Plateau, southern Indian Ocean (ODP Leg 183, Site 1138)". In Frey, F.A., Coffin, M.F., Wallace, P.J., and Quilty, P.G. (Eds.), Proc. ODP, Sci. Results, 183 Sept 2002 
- "UT Austin scientist plays major role in study of underwater "micro-continent"". University of Texas at Austin. May 28, 1999. Retrieved October 2012.
- Frey, F. A.; Coffin, M. F.; Wallace, P. J,; Weis, D. (2003). Frey, F. A.; Coffin, M. F.; Wallace, P. J. et al., eds. "Leg 183 Summary: Kerguelen Plateau-Broken Ridge—A Large Igneous Province" (PDF). Proceedings of the Ocean Drilling Program 183: 1–48. Retrieved August 2015.
- Weis, D; Frey, F.A. (1997). "Kerguelen plateau—broken ridge: a major lip related to the Kerguelen plume" (PDF). Seventh Annual V. M. Goldschmidt Conference.