The KERGUELEN PLATEAU ( /ˈkɜːrɡələn/ , /kərˈɡeɪlən/ ) is
an oceanic plateau and a large igneous province (LIP) in the southern
Indian Ocean . It is also a microcontinent and submerged continent .
It is about 3,000 km (1,900 mi) to the southwest of
Australia and is
nearly three times the size of
Japan . The plateau extends for more
than 2,200 km (1,400 mi) 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. A small
portion of the plateau breaks sea level , forming the Kerguelen
Islands (a French territory) plus the Heard and McDonald Islands (an
Australian territory). Intermittent volcanism continues on the Heard
and McDonald Islands.
* 1 Geographical extent
* 2 Geological history
* 2.1 India–
* 2.2 India–
* 2.3 Cenozoic volcanism
* 4 Biodiversity
* 5 See also
* 6 References
* 6.1 Notes
* 6.2 Sources
* 7 External links
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
Bay of Bengal and is considered to
be a hotspot track.
One of the largest LIPs in the world, the Kerguelen
Plateau covers an
area of 1,250,000 km2 (480,000 sq mi) and rises 2,000 m (6,600 ft)
above the surrounding oceanic basins.
Located on the
Antarctic Plate , the Kerguelen
Plateau is separated
Australia by the
Southeast Indian Ridge (SEIR) and from
Southwest Indian Ridge (SWIR). These two ridge meet at the
Rodriguez Triple Junction . It is separated from
Princess Elizabeth Trough and the
Cooperation Sea . The eastern margin
north of the William Ridge is steep and formed during the breakup
between the Kerguelen
Plateau and the Broken Ridge. The southern part
of the margin is separated from the Australian–Antarctic Basin by
the deep Labuan Basin .
Plateau is surrounded by the Crozet Basin,
Antarctica Basin, Labuan Basin, and Enderby Basin.
From the initial opening of the
Indian Ocean until present, the
Kerguelen hotspot has produced several now widely dispersed large
scale structures. The Southern Kerguelen
Plateau (SKP) formed
119–110 Ma; the Elan Bank 108–107 Ma; the Central Kerguelen
Plateau (CKP) 101–100 Ma; the
Broken Ridge (connected to CKP before
the Eocene breakup) formed 95–94 Ma; the Skiff Bank (east of
Kerguelen archipelago) 69–68 Ma; Northern Kerguelen
Ninety East Ridge formed 82–38 Ma north to south; the
Bunbury Basalt (western Australia) formed 132–123 Ma; the Rajmahal
Traps in northeast India 118–117 Ma; and finally lamprophyres in
Antarctica 115–114 Ma.
The oldest volcanism that can be attributed to the Kerguelen plume
are the Bunbury Basalt in southwestern
Australia (132–123 Ma) and
Rajmahal Traps in eastern India (118 Ma). The formation of the
oldest portion of the Kerguelen LIP and these continental basalts are
linked to the opening of the eastern Indian Ocean. The Bunbury Basalt
is not of flood basalt dimension which suggest that the mantle
underlying the newly formed
Kerguelen hotspot was neither
significantly hot, wet, or voluminous. In contrast, the magmatism that
produced the Australia–India breakup 136–158 Ma created the
Plateau , but no known hotspot has been linked to this event.
The output from the
Kerguelen hotspot peaked 120–95 Ma, 12–70 Ma
after the India–
Antarctica breakup. No ridges or hotspot tracks such
as Walvis –Rio Grande , Chagos–Laccadive , Greenland–Scotland
have been found in the Princess Elizabeth Trough between SKP and
Antarctica or along India's conjugate eastern continental margin. The
relation between the
Kerguelen hotspot and these continental breakup
and volcanic margins is instead similar to that between the Réunion
hotspot and the
Deccan Traps and the breakup between western India and
The peak output of the
Kerguelen hotspot coincides with one or
several microcontinent formations, such as the Elan Bank. Since the
Indian Ocean began to open about 130 Ma, the
Kerguelen hotspot has
moved 3–10° southward and, consequently, the spreading ridge
between India and
Antarctica has jumped northward one or several
times. Parts of the Kerguelen Plateau, the Elan Bank and the SKP, were
originally attached to India and are composed of continental
lithosphere. One or several ridge jumps transformed the Elan Bank into
a microcontinent and dispersed continental fragments in the SKP, and
these structures were eventually left behind as India moved northward.
The ridge jump that made the Elan Bank a microcontinent occurred
after 124 Ma. The development of the Southern Kerguelen
118–119 Ma contributed to the oceanic anoxic event 1 .
Around 83.5 Ma sea floor spreading between India and
asymmetric in the Kerguelen
Plateau region with two-thirds of the sea
floor created being added to the Antarctic Plate. A ridge jump
eventually resulted in parts of the Kerguelen
transferred from the Indian to the Antarctic Plate.
Kerguelen hotspot produced the 5,000 km (3,100 mi) long Ninety
East Ridge 82–38 Ma, and geochemical evidence suggests that this
occurred at or near a spreading ridge. The lack of a conjugate
structure on the Antarctic Plate, however, makes it unlikely that the
hotspot was located at a spreading ridge during this long period. As
Antarctic Plate then moved over the
Kerguelen hotspot the NKP
formed over relatively old oceanic crust. Flood basalts in the
Kerguelen archipelago formed 30–24 Ma and less voluminous and more
recent volcanism occurred until 1 Ma. During the last 21 Ma volcanic
structures have formed on the CKP, including Heard Island, and both
Heard and McDonald Islands have had recent eruptions.
65 Ma, the CKP–
Broken Ridge LIP was located near the Kerguelen
plume and the plate boundaries of the Indian Ocean. The LIP was the
product of 25 Ma of relatively high magmatic activity followed by a 40
Ma period of lower activity.
Schlich et al. 1971 described tilted basement blocks near the
Kerguelen archipelago and was the first to identify the Kerguelen
Plateau as of continental origin, in contrast to other LIPs.
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 1,000–2,000 m (3,300–6,600 ft) above sea level.
The Kerguelen microcontinent may have been covered by dense conifer
forest in the mid-
It finally sank 20 million years ago and is now 1,000–2,000 m
(3,300–6,600 ft) below sea level.
During the austral summer there is a high density of migratory whales
such as sperm and baleen whales , such as minke , and humpback , along
the southern end of the Kerguelen
Plateau and the northern part of the
adjacent Princess Elizabeth Trough. These whales choose this location
for foraging because the Southern Front of the Antarctic Circumpolar
Current is steered off by the plateau — resulting in a poleward
extent for the Southern Front only found near the Kerguelen Plateau.
This brings shoaled, nutrient-rich Upper Circumpolar Deep Water to the
surface which brings macronutrients to the surface. Ice is
additionally advected north along the eastern side of the plateau.
* Life timeline
List of Antarctic and subantarctic islands
List of Antarctic and subantarctic islands
* Nature timeline
* ^ Oxford English Dictionary
* ^ UT Austin 1999
* ^ A B C Bénard et al. 2010 , Introduction, pp. 1–2
* ^ Bénard et al. 2010 , Geological and plate boundary setting, p.
* ^ Frey et al. 2003 , Geochronology, p. 4
* ^ Ingle et al. 2004 , Introduction, p. 84
* ^ A B C D E Frey et al. 2003 , The Kerguelen Hotspot and Indian
Ocean Plate Reconstructions, pp. 5–7
* ^ Wallace et al. 2002 , 1105–1106
* ^ Müller, Gaina & Clark 2000 , C34 Late
83.5 Ma, p. 9
* ^ Whittaker, Williams & Müller 2013 , Abstract
* ^ Schlich et al. 1971 , p. 2062: Toutes ces caractéristiques,
épaisse série sédimentaire plus ou moins structurée avec
l'ensemble inférieur lié à une tectonique de socle, importance des
accidents tectonique limitant le bassin sédimentaire, sont en faveur
d'une origine contintentale du plateau de Kerguelen-Heard.
* ^ "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.
* ^ Mohr, Wähnert -webkit-column-width: 30em; column-width:
* Bénard, F.; Callot, J. P.; Vially, R.; Schmitz, J.; Roest, W.;
Patriat, M.; Loubrieu, B.; The ExtraPlac Team (2010). "The Kerguelen
plateau: Records from a long-living/composite microcontinent" (PDF).
Marine and Petroleum Geology . 27 (3): 633–649. doi
:10.1016/j.marpetgeo.2009.08.011 . Retrieved September 6, 2015.
* "UT Austin scientist plays major role in study of underwater
"micro-continent"". University of Texas at Austin. May 28, 1999.
Archived from the original on September 18, 2007. Retrieved October
* 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 30, 2015.
* Ingle, S.; Scoates, J. S.; Weis, D.; Brügmann, G.; Kent, R. W.
(2004). "Origin of
Cretaceous continental tholeiites in southwestern
Australia and eastern India: insights from Hf and Os isotopes" (PDF).
Chemical Geology. 209: 83–106. doi :10.1016/j.chemgeo.2004.04.023 .
Retrieved September 6, 2015.
* Mohr, B. A. R.; Wähnert, V.; Lazarus, D. (2002). Frey, F. A.;
Coffin, M. F.; Wallace, P. J.; et al., eds. "Mid-Cretaceous
paleobotany and palynology of the central Kerguelen Plateau, southern
Indian Ocean (ODP Leg 183, Site 1138)". Proc. ODP, Sci. Results. 183.
doi :10.2973/odp.proc.sr.183.008.2002 . Retrieved September 5, 2015.
* Müller, R. D.; Gaina, C.; Clark, S. (2000). "Seafloor spreading
around Australia" (PDF). Billion-year earth history of
neighbours in Gondwanaland. North Ryde, N.S.W.: Gemoc Press. pp.
18–28. ISBN 1876315040 . Retrieved October 17, 2015.
* Schlich, R.; Delteil, J. R.; Moulin, J.; Patriat, P.; Guillaume,
R. (1971). "Mise en évidence d’une sédimentation de marge
continentale sur le plateau de Kerguelen-Heard". Comptes Rendus
Hebdomadaires des Séances de l’Académie des Sciences, Série D:
Sciences Naturelles (in French). 272 (16): 2060–2063. Retrieved
September 6, 2015.
* Tynan, C. T. (1997). "Cetacean distributions and oceanographic
features near the Kerguelen Plateau". Geophysical Research Letters. 24
(22): 2793–2796. doi :10.1029/97GL02860 . Retrieved October 3, 2015.
* Wallace, P. J.; Frey, F. A.; Weis, D.; Coffin, M. F. (2002).
"Origin and Evolution of the Kerguelen Plateau,
Broken Ridge and
Kerguelen Archipelago: Editorial". Journal of Petrology. 43 (7):
1105–1108. doi :10.1093/petrology/43.7.1105 .
* Whittaker, J. M.; Williams, S. E.; Müller, R. D. (2013). "Revised
tectonic evolution of the Eastern Indian Ocean". Geochemistry,
Geophysics, Geosystems. 14 (6): 1891–1909. doi :10.1002/ggge.20120 .
Retrieved September 7, 2015.
* Weis, D; Frey, F.A. (1997). "Kerguelen plateau—broken ridge: a
major lip related to the Kerguelen plume" (PDF). Seventh