Great Meteor Seamount

The Great Meteor Seamount, also called the Great Meteor Tablemount, is a guyot and the largest seamount in the North Atlantic with a volume of 24,000 km3 (5,800 cu mi). It is one of the Seewarte Seamounts, rooted on a large terrace located south of the Azores Plateau. The crust underlying Great Meteor has an age of 85 million years, deduced from the magnetic anomaly 34 (An34) at this location.[2]

Great Meteor Seamount
Great Meteor Seamount at the southern edge of the Atlantis-Meteor Seamount Complex
Summit depth270 m (890 ft)
Height4,500 m (14,800 ft)
Summit area50x28 km² (1465 km²)[1]
Location
LocationNorth Atlantic Ocean, 1,000 km (620 mi) south of the Azores
Coordinates29°57′10.6″N 28°35′31.3″W
Geology
TypeGuyot
Volcanic arc/chainSeewarte Seamounts
History
Discovery date1938
Discovered byMeteor

The shallow and flat summit of the Great Meteor Seamount, ranging between 150 and 300 m (490 and 980 ft) below sea level, suggests that it may have emerged sometime in the past 30 million years.[3] It is covered by a 150 to 600 m (490 to 1,970 ft) thick layer of limestone, pyroclastic rocks and bioclastic sandstones.[4] Dredged basalts from the top of the eastern and southeastern flanks of the seamount have been K–Ar dated 10.7 ± 0.5 and 16.3 ± 0.4 million years old, respectively.[5] The oldest sample has been 40Ar/39Ar dated at 17 ± 0.3 million years old.[6]

Two small seamounts exist just southwest of Great Meteor and are encircled by the −3800 m bathymetric line. These are the Closs Seamount, roughly oriented NNE-SSW, with its peak at 1,400 m (4,600 ft) depth and covering an area of approximately 390 km2 (150 sq mi), and the Little Meteor Seamount, located NNE of Closs, with over 960 km2 (370 sq mi) and a flat top 400 m (1,300 ft) below sea level.

The German research vessel Meteor discovered the tablemount between 1925 and 1927. It was given the name Great Meteor Bank, a designation still used in the official GEBCO gazetteer.

Formation

The New England hotspot formed the White Mountains 124 to 100 million years ago when the North American continent was directly overhead. As the continent drifted to the west, the hotspot gradually moved offshore. On a southeasterly course, the hotspot formed Bear Seamount, the oldest in the chain, about 100 to 103 million years ago. Over the course of millions of years, it continued creating the rest of the seamounts, eventually culminating in the Nashville Seamount about 83 million years ago. As the Atlantic Ocean continued to spread, the hotspot eventually traveled further east, forming the Great Meteor Seamount where it is found today.[7] Radiometric dating of basalt from the Great Meteor Seamount has given ages of about 11 and 16 million years old, with the bulk of the seamount possibly having formed about 22 million years ago.[8]

Ecology

The unique ecological condition of the Great Meteor Seamount is shown by the many endemic copepod and nematode species.[1]

References
  1. SPOTLIGHT 5 Great Meteor Seamount
  2. Verhoef, Jaap (1984). "A Geophysical Study of the Atlantis-Meteor Seamount Complex". Geologica Ultraiectina. 38: 1–153. hdl:1874/238521. ISSN 0072-1026.
  3. Gente, Pascal; Dyment, Jérôme; Maia, Marcia; Goslin, Jean (2003-10-01). "Interaction between the Mid-Atlantic Ridge and the Azores hot spot during the last 85 Myr: Emplacement and rifting of the hot spot-derived plateaus". Geochemistry, Geophysics, Geosystems. 4 (10): 8514. Bibcode:2003GGG.....4.8514G. doi:10.1029/2003gc000527. ISSN 1525-2027. S2CID 56297775.
  4. Ulrich, von Rad (1974-11-14). "Composition of bioclastic sands, carbonates and pyroclastic rocks of the Great Meteor and Josephine Seamounts, eastern North Atlantic". PANGAEA. doi:10.1594/pangaea.548422.
  5. Wendt, I.; Kreuzer, H.; Müller, P.; Rad, U. von; Raschka, H. (1976). "K-Ar age of basalts from Great Meteor and Josephine seamounts (eastern North Atlantic)". Deep Sea Research and Oceanographic Abstracts. 23 (9): 849–862. Bibcode:1976DSROA..23..849W. doi:10.1016/0011-7471(76)90852-4.
  6. Geldmacher, Jörg; Hoernle, Kaj; Klügel, Andreas; Bogaard, Paul v. d.; Wombacher, Frank; Berning, Björn (2006-09-01). "Origin and geochemical evolution of the Madeira-Tore Rise (eastern North Atlantic)". Journal of Geophysical Research: Solid Earth. 111 (B9): B09206. Bibcode:2006JGRB..111.9206G. doi:10.1029/2005jb003931. ISSN 2156-2202.
  7. "Geological Origin of the New England Seamount Chain". Office of Ocean Exploration and Research, National Oceanic and Atmospheric Administration. U.S. Department of Commerce. 2005. Retrieved 14 April 2014.Revised August 25, 2010 by the Ocean Explorer
  8. Hekinian, Roger; Stoffers, Peter; Cheminée, Jean-Louis (2012). Oceanic Hotspots: Intraplate Submarine Magmatism and Tectonism. Springer. p. 116. ISBN 978-3-642-62290-8.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.