Erebus hotspot

Last updated
satellite image MountErebusNASA.jpg
satellite image

The Erebus hotspot is a volcanic hotspot responsible for the high volcanic activity on Ross Island in the western Ross Sea of Antarctica. Its current eruptive zone, Mount Erebus, has erupted continuously since its discovery in 1841. Magmas of the Erebus hotspot are similar to those erupted from hotspots at the active East African Rift in eastern Africa. Mount Bird at the northernmost end of Ross Island and Mount Terror at its eastern end are large basaltic shield volcanoes that have been potassium-argon dated 3.8–4.8 and 0.8–1.8 million years old. [1]

About

There is currently disagreement over the cause of volcanic activity on Ross Island. The traditional view is that the area is underlain by a mantle plume which has given rise to volcanism and, in conjunction with a second plume thought to be under Marie Byrd Land on the mainland to the east, a system of rifts known as the West Antarctic Rift System. Support for a plume origin includes petrological, geochemical, and isotopic evidence for a deep-mantle source, [2] [3] high heat flow in the area, [4] high volcanic output, [5] domal uplift, [6] [7] and seismic anomalies in the upper mantle consistent with a plume approximately 250 to 300 km (160 to 190 mi) in diameter extending 200 km (120 mi) below the surface where it changes into a narrow column that extends at least a further 400 km (250 mi) [8] [9] and according to some studies as deep as 1,000 km (620 mi). [10] [11] The area lacks the time-progressive volcanism typically associated with mantle plumes. This has been explained by the Antarctic Plate being stationary since the late Cretaceous.

Other observations appear to be inconsistent with the plume model. Uplift in the region lacks the circular symmetry typically associated with mantle plumes. Rifting occurred mainly in the late Cretaceous, whereas uplift occurred mainly in the middle Eocene, so uplift followed extension rather than preceding it as would be expected with a mantle plume. The volume of magmatism, when the long duration of volcanic activity is taken into account, appears lower than would be expected to result from a mantle plume. Seismic imaging does not show the circular symmetry expected for a mantle plume but indicates rather a linear, tectonic feature extending from Tasmania to the Ross Sea. [12] [13] [14]

Owing to these issues, some scientists have questioned the plume model and propose instead a shallow, tectonic mechanism. In this view, lithospheric extension and rifting during the late Cretaceous stretched the lithosphere, giving rise to partial melts. Though insufficient to break the surface, fertile, low-liquidus material was distributed throughout the lithospheric mantle. During the middle Eocene, tectonic changes in the Southern Ocean gave rise to further lithospheric deformation, causing strike-slip faulting which enabled decompression melting and extrusion of the fertile material emplaced during the late Cretaceous. [12] [13] [14]

Related Research Articles

<span class="mw-page-title-main">Mantle plume</span> Upwelling of abnormally hot rock within Earths mantle

A mantle plume is a proposed mechanism of convection within the Earth's mantle, hypothesized to explain anomalous volcanism. Because the plume head partially melts on reaching shallow depths, a plume is often invoked as the cause of volcanic hotspots, such as Hawaii or Iceland, and large igneous provinces such as the Deccan and Siberian Traps. Some such volcanic regions lie far from tectonic plate boundaries, while others represent unusually large-volume volcanism near plate boundaries.

<span class="mw-page-title-main">Marie Byrd Land</span> Unclaimed West Antarctic region

Marie Byrd Land (MBL) is an unclaimed region of Antarctica. With an area of 1,610,000 km2 (620,000 sq mi), it is the largest unclaimed territory on Earth. It was named after the wife of American naval officer Richard E. Byrd, who explored the region in the early 20th century.

<span class="mw-page-title-main">Large igneous province</span> Huge regional accumulation of igneous rocks

A large igneous province (LIP) is an extremely large accumulation of igneous rocks, including intrusive and extrusive, arising when magma travels through the crust towards the surface. The formation of LIPs is variously attributed to mantle plumes or to processes associated with divergent plate tectonics. The formation of some of the LIPs in the past 500 million years coincide in time with mass extinctions and rapid climatic changes, which has led to numerous hypotheses about causal relationships. LIPs are fundamentally different from any other currently active volcanoes or volcanic systems.

<span class="mw-page-title-main">Iceland hotspot</span> Hotspot partly responsible for volcanic activity forming the Iceland Plateau and island

The Iceland hotspot is a hotspot which is partly responsible for the high volcanic activity which has formed the Iceland Plateau and the island of Iceland. It contributes to understanding the geological deformation of Iceland.

<span class="mw-page-title-main">East African Rift</span> Active continental rift zone in East Africa

The East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa. The EAR began developing around the onset of the Miocene, 22–25 million years ago. It was formerly considered to be part of a larger Great Rift Valley that extended north to Asia Minor.

<span class="mw-page-title-main">West Antarctic Rift System</span> Series of rift valleys between East and West Antarctica

The West Antarctic Rift System is a series of rift valleys between East and West Antarctica. It encompasses the Ross Embayment, the Ross Sea, the area under the Ross Ice Shelf and a part of Marie Byrd Land in West Antarctica, reaching to the base of the Antarctic Peninsula. It has an estimated length of 3,000 km (1,900 mi) and a width of approximately 700 km (430 mi). Its evolution is due to lithospheric thinning of an area of Antarctica that resulted in the demarcation of East and West Antarctica. The scale and evolution of the rift system has been compared to that of the Basin and Range Province of the Western United States.

<span class="mw-page-title-main">East Australia hotspot</span>

The East Australia hotspot is a volcanic province in southeast Australia which includes the Peak Range in central Queensland, the Main Range on the Queensland-New South Wales border, Tweed Volcano in New South Wales, and the Newer Volcanics Province (NVP) in Victoria and South Australia. A number of the volcanoes in the province have erupted since Aboriginal settlement. The most recent eruptions were about 5,600 years ago, and memories of them survive in Aboriginal folklore. These eruptions formed the volcanoes Mount Schank and Mount Gambier in the NVP. There have been no eruptions on the Australian mainland since European settlement.

<span class="mw-page-title-main">Kerguelen hotspot</span> Hotspot under the Indian Ocean

The Kerguelen hotspot is a volcanic hotspot at the Kerguelen Plateau in the Southern Indian Ocean. The Kerguelen hotspot has produced basaltic lava for about 130 million years and has also produced the Kerguelen Islands, Naturaliste Plateau, Heard Island, the McDonald Islands, the Comei large igneous province in south Tibet, and the Rajmahal Traps. One of the associated features, the Ninety East Ridge, is distinguished by its over 5,000 km (3,100 mi) length, being the longest linear tectonic feature on Earth. The total volume of magma erupted in 130 million years with associated features has been estimated to be about 25,000,000 km3 (6,000,000 cu mi). However, as well as large igneous provinces and seamounts the hotspot has interacted with other seafloor spreading features, so this volume figure has some uncertainty.

The Anahim hotspot is a hypothesized hotspot in the Central Interior of British Columbia, Canada. It has been proposed as the candidate source for volcanism in the Anahim Volcanic Belt, a 300 kilometres long chain of volcanoes and other magmatic features that have undergone erosion. This chain extends from the community of Bella Bella in the west to near the small city of Quesnel in the east. While most volcanoes are created by geological activity at tectonic plate boundaries, the Anahim hotspot is located hundreds of kilometres away from the nearest plate boundary.

<span class="mw-page-title-main">New England hotspot</span> Volcanic hotspot in the North Atlantic Ocean

The New England hotspot, also referred to as the Great Meteor hotspot and sometimes the Monteregian hotspot, is a volcanic hotspot in the North Atlantic Ocean. It created the Monteregian Hills intrusions in Montreal and Montérégie, the White Mountains intrusions in New Hampshire, the New England and Corner Rise seamounts off the coast of North America, and the Seewarte Seamounts east of the Mid-Atlantic Ridge on the African Plate, the latter of which include its most recent eruptive center, the Great Meteor Seamount. The New England, Great Meteor, or Monteregian hotspot track has been used to estimate the movement of the North American Plate away from the African Plate from the early Cretaceous period to the present using the fixed hotspot reference frame.

<span class="mw-page-title-main">Eifel hotspot</span> Volcanic hotspot in Western Germany

The Eifel hotspot is a volcanic hotspot in Western Germany. It is one of many recent volcanic formations in and around the Eifel mountain range and includes the volcanic field known as Volcanic Eifel. Although the last eruption occurred around 10,000 years ago, the presence of escaping volcanic gases in the region indicates that it is still weakly active.

<span class="mw-page-title-main">Darfur Dome</span>

Darfur Dome or Darfur Volcanic Province is an area of about 100x400 km in Western Sudan. As well as its best-known and central feature, Deriba Crater, it encompasses the surrounding Marra Mountains and Tagabo Hills, both formed around 16–10 Ma, and the Meidob Hills, formed around 6.8 Ma.

<span class="mw-page-title-main">Geology of Cape Verde</span>

Cape Verde is a volcanic archipelago situated above an oceanic rise that puts the base of the islands 2 kilometers (1.2 mi) above the rest of the seafloor. Cape Verde has been identified as a hotspot and the majority of geoscientists have argued that the archipelago is underlain by a mantle plume and that this plume is responsible for the volcanic activity and associated geothermal anomalies.

<span class="mw-page-title-main">Opening of the North Atlantic Ocean</span> Breakup of Pangea

The opening of the North Atlantic Ocean is a geological event that has occurred over millions of years, during which the supercontinent Pangea broke up. As modern-day Europe and North America separated during the final breakup of Pangea in the early Cenozoic Era, they formed the North Atlantic Ocean. Geologists believe the breakup occurred either due to primary processes of the Iceland plume or secondary processes of lithospheric extension from plate tectonics.

<span class="mw-page-title-main">Tectonic evolution of the Transantarctic Mountains</span>

The tectonic evolution of the Transantarctic Mountains appears to have begun when Antarctica broke away from Australia during the late Cretaceous and is ongoing, creating along the way some of the longest mountain ranges formed by rift flank uplift and associated continental rifting. The Transantarctic Mountains (TAM) separate East and West Antarctica. The rift system that formed them is caused by a reactivation of crust along the East Antarctic Craton. This rifting or seafloor spreading causes plate movement that results in a nearby convergent boundary which then forms the mountain range. The exact processes responsible for making the Transantarctic Mountains are still debated today. This results in a large variety of proposed theories that attempt to decipher the tectonic history of these mountains.

<span class="mw-page-title-main">Adare Basin</span>

The Adare Basin is a geologic structural basin located north-east of Cape Adare of Antarctica, for which its named, and north of the western Ross Sea. The Adare Basin is an extensional rift basin located along a seafloor spreading center that forms the failed arm of the Tertiary spreading ridge separating East and West Antarctica, known as the West Antarctic Rift System and similar in structure to the East Africa Rift System. Centrally located in the Adare Basin is the Adare Trough. The extension of this rift system is recorded in a series of magnetic anomalies which run along the seafloor at the extinct, north–south trending, Adare spreading axis. The Adare spreading system continues unbroken into the Northern Basin underlying the adjacent Ross Sea continental shelf.

<span class="mw-page-title-main">Noronha hotspot</span>

Noronha hotspot is a hypothesized hotspot in the Atlantic Ocean. It has been proposed as the candidate source for volcanism in the Fernando de Noronha archipelago of Brazil, as well as of other volcanoes also in Brazil and even the Bahamas and the Central Atlantic Magmatic Province.

The McMurdo Volcanic Group is a large group of Cenozoic volcanic rocks in the western Ross Sea and central Transantarctic Mountains areas of Antarctica. It is one of the largest provinces of alkaline volcanism in the world, having formed as a result of continental rifting along the West Antarctic Rift System. The McMurdo Volcanic Group is part of the Western Ross Supergroup, a stratigraphic unit that also includes the Meander Intrusive Group.

<span class="mw-page-title-main">Plate theory (volcanism)</span> Model of volcanic activities on Earth

The plate theory is a model of volcanism that attributes all volcanic activity on Earth, even that which appears superficially to be anomalous, to the operation of plate tectonics. According to the plate theory, the principal cause of volcanism is extension of the lithosphere. Extension of the lithosphere is a function of the lithospheric stress field. The global distribution of volcanic activity at a given time reflects the contemporaneous lithospheric stress field, and changes in the spatial and temporal distribution of volcanoes reflect changes in the stress field. The main factors governing the evolution of the stress field are:

  1. Changes in the configuration of plate boundaries.
  2. Vertical motions.
  3. Thermal contraction.

Intraplate volcanism is volcanism that takes place away from the margins of tectonic plates. Most volcanic activity takes place on plate margins, and there is broad consensus among geologists that this activity is explained well by the theory of plate tectonics. However, the origins of volcanic activity within plates remains controversial.

References

  1. ↑ Morgan, W.J.; Phipps Morgan, J. (2007) "Plate velocities in hotspot reference frame: electronic supplement".
  2. ↑ Hole, M.J.; LeMasurier, W.E. (1994). "Tectonic controls on the geochemical composition of Cenozoic, mafic alkaline volcanic rocks from West Antarctica". Contributions to Mineralogy and Petrology. 117 (2): 187–202. Bibcode:1994CoMP..117..187H. doi:10.1007/BF00286842. S2CID   129078098.
  3. ↑ Sims, K.W.W.; Blichert-Toft, J.; Kyle, P.R.; Pichat, S.; Gauthier, P-J.; Blusztajn, J.; Kelly, P.; Ballf, L.; Layne, G. (2008). "A Sr, Nd, Hf, and Pb isotope perspective on the genesis and long-term evolution of alkaline magmas from Erebus volcano, Antarctica". Journal of Volcanology and Geothermal Research. 177 (3): 606–618. Bibcode:2008JVGR..177..606S. doi:10.1016/j.jvolgeores.2007.08.006.
  4. ↑ Storey, B.; Leat, P.T.; Weaver, S.D.; Pankhurst, R.J.; Bradshaw, J.D.; Kelley, S. (1999). "Mantle plumes and Antarctica-New Zealand rifting: Evidence from mid-Cretaceous mafic dykes". Journal of the Geological Society, London. 156 (4): 659–671. Bibcode:1999JGSoc.156..659S. doi:10.1144/gsjgs.156.4.0659. S2CID   129513402.
  5. ↑ Esser, R.P.; Kyle, P.R.; McIntosh, W.C. (2004). "40Ar/39Ar dating of the eruptive history of Mount Erebus, Antarctica: volcano evolution". Bulletin of Volcanology. 66 (8): 671–686. Bibcode:2004BVol...66..671E. doi:10.1007/s00445-004-0354-x. S2CID   129118037.
  6. ↑ Kyle, P.R.; Moore, J.A.; Thirlwall, M.F. (1992). "Petrologic evolution of anorthoclase phonolite lavas at Mount Erebus, Ross Island, Antarctica". Journal of Petrology. 33 (4): 849–875. doi:10.1093/petrology/33.4.849.
  7. ↑ LeMasurier, W.E.; Landis, C.A. (1996). "Mantle-plume activity recorded by low-relief erosion surfaces in West Antarctica and New Zealand". GSA Bulletin. 108 (11): 1450–1466. Bibcode:1996GSAB..108.1450L. doi:10.1130/0016-7606(1996)108<1450:MPARBL>2.3.CO;2.
  8. ↑ Zhao, D (2007). "Seismic images under 60 hotspots: Search for mantle plumes". Gondwana Research. 12 (4): 335–355. Bibcode:2007GondR..12..335Z. doi:10.1016/j.gr.2007.03.001.
  9. ↑ Gupta, S.; Zhao, D; Raia, S.S. (2009). "Seismic imaging of the upper mantle under the Erebus hotspot in Antarctica". Gondwana Research. 16 (1): 109–118. Bibcode:2009GondR..16..109G. doi:10.1016/j.gr.2009.01.004.
  10. ↑ Sieminski, A.; Debayle, E.; Lévêque, J-J. (2003). "Seismic evidence for deep low-velocity anomalies in the transition zone beneath West Antarctica". Earth and Planetary Science Letters. 216 (4): 645–661. Bibcode:2003E&PSL.216..645S. doi:10.1016/S0012-821X(03)00518-1.
  11. ↑ Montelli, R.; Nolet, G.; Dahlen, F.A.; Masters, G. (2006). "A catalogue of deep mantle plumes: New results from finite-frequency tomography". Geochemistry, Geophysics, Geosystems. 7 (11): n/a. Bibcode:2006GGG.....711007M. doi: 10.1029/2006GC001248 .
  12. 1 2 Rocchi, S.; Armienti, P.; D’Orazio, M.; Tonarini, S.; Wijbrans, J.R.; Di Vincenzo, G. (2002). "Cenozoic magmatism in the western Ross Embayment: Role of mantle plume versus plate dynamics in the development of the West Antarctic Rift System". Journal of Geophysical Research. 107 (B9): ECV 5-1-ECV 5-22. Bibcode:2002JGRB..107.2195R. doi: 10.1029/2001JB000515 .
  13. 1 2 Rochi, S.; Storti, F.; Di Vincenzo, G.; Rossetti, F. (2003). "Intraplate strike-slip tectonics as an alternative to mantle plume activity for the Cenozoic rift magmatism in the Ross Sea region, Antarctica". In Storti, F; Holdsworth, R.E.; Salvini, F. (eds.). Intraplate strike-slip deformation belts: Geological Society, London, Special Publications, 210. Vol. 210. Geological Society of London. pp. 145–158. doi:10.1144/GSL.SP.2003.210.01.09. S2CID   134316807.{{cite book}}: |journal= ignored (help)
  14. 1 2 Rocchi, S.; Armienti, P.; Di Vincenzo, G. (2005). "No plume, no rift magmatism in the West Antarctic Rift". In Foulger, G.R.; Natland, J.H.; Presnall, D.C.; Anderson, D.L. (eds.). Plates, plumes and paradigms: Geological Society of America Special Paper 388. Geological Society of America. pp. 435–447. doi:10.1130/0-8137-2388-4.435. ISBN   9780813723884.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.