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	Mantle plume - Wikipedia, the free encyclopedia
		Mantle plumes are thought to be the cause of volcanic centers known as hotspots and probably also have caused flood basalts.
		In this theory, convection in the mantle slowly transports heat from the core to the Earth's surface.
		Computer modeling of the mantle plume theory shows that changes of temperature and chemical composition of rising plumes can lead to plumes of varying contours as opposed to the early conceptualization that plumes developed as a homogeneous mushroom shape (Farnetani and Samuel, 2005).
	en.wikipedia.org /wiki/Mantle_plume (1001 words)

	Beyond the Plume Myth
		Accommodating plumes relegates mantle convection to a weak, sluggish effect such that basal drag appears as a minor, resisting force, with plates having to move themselves by boundary forces and continents having to be rifted by plumes” (IX p.
		The source of mantle plumes is a thermal boundary layer deep in the mantle, perhaps the core-mantle boundary, although some have argued for a shallower source” (IV p.
		The “plume head, which is assumed to have a diameter of 1000 km, rises to form, beneath the lithosphere, an oblate circular disk, with a diameter of 2000-2500 km.
	www.newgeology.us /presentation23.html (6760 words)

	mantle - Hutchinson encyclopedia article about mantle
		The temperature of the mantle can be as high as 3,700°C/6,692°F. Heat generated in the core causes convection currents in the semi-liquid mantle; rock rises and then slowly sinks again as it cools, causing the movements of the tectonic plates.
		The mantle is composed primarily of magnesium, silicon, and oxygen in the form of silicate minerals.
		In the upper mantle, the silicon in silicate minerals, such as olivine, is surrounded by four oxygen atoms.
	encyclopedia.farlex.com /mantle (524 words)

	Mantle Plumes
		Mantle plumes, most geochemists believe, provide a sample of the deep mantle, though the exact depth from which plumes rise remains uncertain.
		Schilling [1991] used the distinctive isotope and trace element ratios in plumes as ``tracers of upper mantle dynamics, much as dyes are used to follow flow patterns.'' He investigated 13 plumes located sufficiently close to spreading centers that they influenced the composition of basalt erupted on those spreading centers.
		That is the conclusion Weis and Frey [1991] from a study of the basalts from the Ninetyeast Ridge, produced by the Kerguelen mantle plume.
	www.agu.org /revgeophys/white00/node5.html (1108 words)

	A fiery debate about volcanoes
		An additional volcanic mechanism, the mantle plume model, was proposed over 30 years ago and is almost as widely accepted as plate tectonics itself.
		A mantle plume is a source of extra-hot rock rising from deep in the planet -- probably from the base of the mantle itself, where it meets the iron-rich liquid core.
		Mantle plumes are thought to underlie "hotspots" far from plate boundaries, like those under the Hawaiian Islands or Yellowstone National Park.
	www.lbl.gov /Science-Articles/Archive/ESD-volcanic-debate.html (1109 words)

	Hot Spots and What Lies Beneath Them
		Mantle plumes are created by the temperature differential at the core/mantle boundary, he suggested, when a hotter region within the mantle rises as a result of decreased density.
		The alternative to the Mantle Plume Model lies not in refuting the existence of hot spots (which are pretty plain to see) but rather in the completeness of plate tectonic theory - that plumes are not necessary to explain the various processes in question.
		Plumes could be the cause of massive eruptions that have altered the environment on earth drastically, perhaps to the point of mass extinction.
	www.emporia.edu /earthsci/student/sedlacek2/mantle.htm (2353 words)

	Geological Society of America - GSA Today - v. 10, no. 12, December 2000 (Site not responding. Last check: 2007-10-22)
		A plume origin is argued for Iceland based on tomograms of the upper mantle (Wolfe et al., 1997) and imaged deflection of the temperature- sensitive 410 km and 660 km seismic discontinuities (Shen et al., 1998).
		Imaged seismic structures and calculated mantle buoyancy beneath the Yellowstone swell imply that the swell mantle is anomalously hot to depths of greater than or equal to 200 km, is not anomalously hot at 410 km, and is hot again at 660 km.
		The red mantle beneath the Snake River Plain in Figure 3 is 1%–2% partially molten, and the blue mantle beneath the adjoining swell is 5%–10% depleted of basaltic components.
	www.geosociety.org /pubs/gsatoday/gsat0012.htm (3889 words)

	The PLUME Eperiment
		xperiment studies the shape and the origin of the mantle plume beneath the Hawaiian hotspot that is responsible for spectacular volcanism on the surface.
		Plume basalts (a type of volcanic rock), or OIB (ocean island basalts), seem to be different from mid-ocean ridge basalts (MORB).
		The transition zone between 410 and 660km that separates the upper from the lower mantle tends to be thinner when a hot plume intersects it, where the 660 domes upward and the 410 is depressed.
	mahi.ucsd.edu /Gabi/plume.html (2359 words)

	Nonplume manuscript
		This plume model is especially related to the pattern of Early Mesozoic dikes around the initial rift, which May (1971) described as radial about the Blake Plateau, an area roughly east of Florida in the pre-drift configuration (Fig.
		Hotspot plume proposals for the origin of the seamounts shifted to the Cretaceous and later (Crough, 1980), although problems with the plume models are still apparent (McHone, 1996a).
		A mantle plume is not a likely mechanism for basaltic magmatism and rifting during the Early Jurassic opening of the central North Atlantic.
	www.auburn.edu /academic/science_math/res_area/geology/camp/Nonplumems.html (4890 words)

	Plume-Ridge Interaction Workshop Abstracts (Site not responding. Last check: 2007-10-22)
		Hotspots are the steady-state ("tail") phase of mantle plumes that, evidence indicates, rise from the lower mantle and begin with wide-spread, catastrophic volcanism resulting from decompression melting of the plume "head".
		Petrology and Geochemistry of the Galapagos: Portrait of a Pathological Mantle Plume.
		This deep mantle material was particularly enriched in Nb and Ta, along with radiogenic Sr and unradiogenic Nd, relative to the asthenosphere and mixed extensively with the upper mantle beneath the young central Atlantic Ocean, producing the oldest Atlantic MORB with mildly radiogenic Sr, unradiogenic Nd and positive Nb and Ta anomalies.
	ridge.oce.orst.edu /meetings/PRIworkshop/PRIabstracts.html (18848 words)

	CIW - News 991110
		For the Iceland plume, the answer is now in." The other authors of the paper are Yang Shen, the lead author (previously of Woods Hole and recently relocated to the University of Rhode Island), Cecily Wolfe (Woods Hole), and Ingi Bjarnason (University of Iceland's Science Institute).
		Their map of the upper mantle beneath the Iceland hotspot, based on seismic data gathered from an array of portable seismometers on the surface, showed that a cylinder of hot, upwelling material directly beneath Iceland occupies a slender zone about 300 km wide.
		Plumes, if Iceland is representative, are part of a distinct mantle flow system involving exchange between the lower and upper mantle.
	www.carnegieinstitution.org /news_980902.html (904 words)

	Vic Camp - intraplate (hotspot) volcanism
		These mantle plumes appear to be generated in the lower mantle and rise slowly through the mantle by convection.
		Many scientists believe that mantle plumes may be derived from near the core-mantle boundary, as demonstrated in this computer simulation from the Minnesota supercomputing lab.
		Mantle plumes appear to be largely unaffected by plate motions.
	www.geology.sdsu.edu /how_volcanoes_work/intraplvolc_page.html (693 words)

	Plumes - Louise Kellogg (Site not responding. Last check: 2007-10-22)
		According to this model, hotspots are the surface manifestation of mantle plumes.
		In terms of heat flow, plumes are relatively minor; Davis (1988) and Sleep (1990) used the topography and gravity anomalies associated with hot-spots to estimate that actively upwelling mantle plumes account for about 10% of the total heat loss of the Earth.
		A widely accepted picture is that in the Earth's mantle, a hot thermal plume originates as an instability at a thermal boundary layer, forming a large mushroom-shaped head as it grows.
	www-geology.ucdavis.edu /~kellogg/plume.html (463 words)

	Geological Society - News - Mantle plumes: an alternative to the alternative
		3) A deep-seated velocity anomaly in the mantle
		Criticisms of the plume model (such as the suggestion that the Hawaiian plume moves through the mantle, or that there is no evidence that the Hawaiian plume ever had a start-up head) do not seriously challenge the validity of the model.
		Few supporters of mantle plume theory push for every volcanic field to be plume-related, just as few supporters of the ophiolite model advocated that every pillow basalt represents an ancient ocean.
	www.geolsoc.org.uk /template.cfm?name=Saunders (1483 words)

	Geological Society - News - Wot, no plumes?
		The single, unifying theme in plume science is the unquestioning belief of most Earth scientists in their existence, indicated by the use of the term “the” plume when discussing one’s area of interest.
		The change in thinking from convection cell to mantle plume is substantial, and caution should be observed in the transfer of plate-baggage.
		I assert that because the predictions of the plume hypothesis are not borne out, it is unsafe to assume, a priori, that this model is correct.
	www.geolsoc.org.uk /template.cfm?name=NakedEmperor (5242 words)

	Hawaii
		Mantle plumes are thought to be relatively narrow columns of hot, plastically-flowing, solid mantle-rock rising from the base of the Earth's mantle (Plummer and McGeary, 1996).
		When the mantle plume reaches the base of the crust-mantle boundary, melting occurs that results in volcanism.
		We assume the mantle plume is stationary in the sense that we can use to define our frame of reference.
	cc.ysu.edu /~dafowler/hawaii.htm (407 words)

	Articles - Magma (Site not responding. Last check: 2007-10-22)
		Under the great confining pressures deep within the Earth´s mantle, as little as 5% partial melting may be sufficient to cause this melted rock to be squeezed from its source.
		Primary melts derived from the mantle are especially important, and are known as ´´primitive melts´´ or primitive magmas.
		By finding the primitive magma composition of a magma series it is possible to model the composition of the mantle from which a melt was formed, which is important because science has little direct evidence of the mantle.
	www.zdiamond.net /articles/Magma (1605 words)

	Hotspot (geology) - Wikipedia, the free encyclopedia
		Tuzo Wilson came up with the idea in 1963 that volcanic chains like the Hawaiian Islands result from the slow movement of a tectonic plate across a "fixed" hot spot deep beneath the surface of the planet.
		Hotspots were thought to be caused by a narrow stream of hot mantle convecting up from the mantle-core boundary called a mantle plume [1], the latest geological evidence is pointing to upper-mantle convection as a cause[2][3][4].
		This in turn has re-raised the antipodal pair impact hypothesis, the idea that pairs of opposite hot spots may result from the impact of a large meteor.
	en.wikipedia.org /wiki/Hotspot_(geology) (214 words)

	Seismic structure of the Iceland mantle plume (Site not responding. Last check: 2007-10-22)
		Understanding the geometry of upwelling mantle flow and the characteristics of melting beneath hotspots and mid-ocean ridges is of fundamental importance for topics ranging from the formative processes for the crust and lithosphere to the large-scale dynamics and chemical makeup of the mantle.
		We obtain the three-dimensional seismic velocity structure of the upper mantle using the relative travel times of body waves from teleseismic earthquakes recorded across the ICEMELT array.
		This high-resolution upper mantle image indicates that Iceland is underlain by a hot and narrow plume of upwelling mantle.
	www.mbari.org /seminars/1998/may13_wolfe.html (218 words)

	Fate of mantle plume material trapped within a lithospheric catchment with reference to Brazil
		Unless replenished, the trapped plume material cools by convection to the mantle adiabat by several tens of million years.
		In particular, currently hot material from the ∼130 Ma, Paraná starting plume head is unlikely to supply 85 Ma to recent volcanism on the mainland of Brazil and the Martin Vaz and Fernando hot spots.
		If the tomographic study in fact found a plume tail, the track crossed the Amazon rift at ∼85 Ma and (since then) lateral flow along thin regions of the lithosphere from the tail fed widespread feeble volcanism including the flow line hot spots of Martin Vaz and Fernando.
	www.agu.org /pubs/crossref/2003/2002GC000464.shtml (245 words)

	[No title] (Site not responding. Last check: 2007-10-22)
		Global mantle tomography generally yields images at a horizontal resolution larger than the expected dimensions of plume conduits, although recent work suggests that sufficiently strong anomalies in structure are beginning to be resolved.
		Most postulated mantle plumes lie beneath oceanic lithosphere, a situation that limits regional-scale seismic experiments designed to sharpen the resolution of mantle seismic images in these areas.
		While global mantle tomography has made great strides in the last few years, the resolution of global and large-scale regional models is still insufficient to discern confidently the details of features such as plumes with expected horizontal dimensions of a few hundred kilometers or less.
	www.ciw.edu /plume3/abstracts/Solomon.doc (943 words)

	Peter John Wyllie: Publications 1951-1994
		Wyllie, P. J., and Huang, W. Influence of mantle CO in the generation of carbonatites and kimberlites.
		Wyllie, P. Mantle fluid compositions buffered in peridotite-CO by carbonates, amphibole, and phlogopite.
		Granite melt convecting in an experimental micro-magma chamber at 1050¡C, 15 kb.
	www.gps.caltech.edu /~wyllie/pjwpub5189.html (4864 words)

	Mantle Plume Narrative @ Encyclopedia.LocalColorArt.com (Local Color Encyclopedia) (Site not responding. Last check: 2007-10-22)
		Mantle Plume Narrative @ Encyclopedia.LocalColorArt.com (Local Color Encyclopedia)
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	encyclopedia.localcolorart.com /encyclopedia/Mantle_plume (73 words)

	Fossil Mantle Plume Under South America
		"In a challenge to a major aspect of the theory of plate tectonics, NSF-supported scientists have discovered the presence of an ancient conduit deep in the Earth's mantle beneath Brazil.
		This result also implies that large-scale convection in the mantle may be responsible for the motion of the great continental plates, such as South America, where the driving force for plate motion has not been well understood."
		The computerless may read more in: VanDecar, John C., et al; "Seismic Evidence for a Fossil Mantle Plume beneath South America and Implications for Plate Driving Forces," Nature, 378:25, 1995.
	www.science-frontiers.com /sf103/sf103g09.htm (158 words)

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