Kerguelen Plateau
The Kerguelen Plateau (/ˈkɜrɡələn/, /kərˈɡeɪlən/)[1] is an underwater volcanic large igneous province (LIP)[2] 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.
Geographical extent
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.
To the north of Broken Ridge lies the linear Ninety East Ridge which continues almost due north into the Bay of Bengal and is considered to be a hotspot track.
Kerguelen microcontinent
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.[3] The so-called Kerguelen microcontinent may have been covered by dense conifer forest in the mid-Cretaceous.[4] It finally sank 20 million years ago and is now 1 to 2 km (0.6 to 1.2 mi) below sea level.
See also
References
- ↑ Oxford English Dictionary
- ↑ "UT Austin scientist plays major role in study of underwater "micro-continent"". University of Texas at Austin. May 28, 1999. Retrieved October 2012.
- ↑ "Leg 183 Summary: Kerguelen Plateau-Broken Ridge—A Large Igneous Province". Proceedings of the Ocean Drilling Program 183.
- ↑ 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
External links
- Weis, D; Frey, F.A. "Kerguelen plateau—broken ridge: a major lip related to the Kerguelen plume" (PDF). Seventh Annual V. M. Goldschmidt Conference.
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