Pb-Sr-He isotope and trace element geochemistry of the Cape Verde Archipelago

Doucelance, Régis; Escrig, Stéphane; Moreira, Manuel; Gariépy, Clément; Kurz, Mark D.

doi:10.1016/s0016-7037(03)00161-3

Cited by 111 publications

(122 citation statements)

References 72 publications

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“…Therefore, in most models for the origin of the EM-type components, they are ultimately related to/derived from the continental lithosphere, whether this be in the form of crustal splinters beneath the islands/seamounts or recycled subcontinental lithospheric mantle incorporated in the upper mantle beneath the volcanic structures closest to the continents, i.e. within lithospheric mantle, uppermost asthenosphere directly beneath the lithosphere and/or deeper portions of the upper mantle, where it can be entrained by rising plumes (e.g., Gerlach et al, 1988;Hoernle et al, , 1995Hoernle et al, , 2002Widom et al, 1999;Geldmacher and Hoernle, 2000;Lundstrom et al, 2003;Doucelance et al, 2003;Escrig et al, 2005;Geldmacher et al, 2005). Recently, Geldmacher et al (2008) have confirmed a shallow origin for at least some of the EM-type components in the northern Atlantic and provide evidence for the origin of EM-type mantle through recycling of subcontinental lithosphere globally.…”

Section: Introductionmentioning

confidence: 99%

Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume: A mixed-up mantle

Gurenko

Sobolev

Hoernle

et al. 2009

Earth and Planetary Science Letters

114

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Components:abstract -280 words; 1,834 characters with spaces; main text -6,330 words; 41,109 characters with spaces; 5 figures, 2 tables; list of references includes 60 citations. * Corresponding author and present address:Andrey Gurenko, Woods Hole Oceanographic Institution, Clark 114, MS#23, Woods Hole, MA 02543, USA; Phone: +1 508 289-2405, Fax: +1 508-457-2175; E-mail: agurenko@whoi.edu 2 Abstract − The Earth's mantle is chemically and isotopically heterogeneous, and a component of recycled oceanic crust is generally suspected in the convecting mantle Mantle plumes from ancient oceanic crust. Earth Planet. Sci. Lett. 57,[421][422][423][424][425][426][427][428][429][430][431][432][433][434][435][436]. Indeed, the HIMU component (high μ = 238 U/ 204 Pb), one of four isotopically distinct end-members in the Earth's mantle, is generally attributed to relatively old (≥1-2 Ga) recycled oceanic crust in the form of eclogite/pyroxenite, e.g. [Zindler and Hart, 1986. Chemical geodynamics. Ann. Rev. Earth Planet.Sci. 14, 493-571]. Although the presence of the recycled component is generally supported by element and isotopic data, little is known about its physical state at mantle depths. Here we show that the concentrations of Ni, Mn and Ca in olivine from the Canarian shield stage lavas, which can be used to asses the physical nature of the source material (peridotite versus olivine-free pyroxenite) [Sobolev et al., 2007. The amount of recycled crust in sources of mantle-derived melts. Science 316, 412-417], correlate strongly with bulk rock Sr, Nd and Pb isotopic ratios. The most important result following from our data is that the enriched, HIMU-type (having higher 206 Pb/ 204 Pb than generally found in the other mantle endmembers) signature of the Canarian hotspot magmas was not caused by a pyroxenite/eclogite constituent of the plume but appears to have been primarily hosted by peridotite. This implies that the old (older than ~1 Ga) ocean crust, which has more evolved radiogenic isotope compositions, was stirred into/reacted with the mantle so that there is not significant eclogite left, whereas younger recycled oceanic crust with depleted MORB isotopic signature (<1 Ga) can be preserved as eclogite, which when melted can generate reaction pyroxenite.

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Section: Introductionmentioning

confidence: 99%

Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume: A mixed-up mantle

Gurenko

Sobolev

Hoernle

et al. 2009

Earth and Planetary Science Letters

114

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“…The C1 chondrite-normalisation patterns (Taylor and McLennan, [17]) of the basalts in Western Senegal and in the Cape Verde Islands (Doucelance et al, [14]) all reveal similar fractionations (Figure 4). (18); Sal: SL3 (3), SL6 (6) and SL7 (7)] (Doucelance et al [14]).…”

Section: Geochemistry Of Rare Earths Elements (Ree)mentioning

confidence: 95%

“…These different features reveal two groups in the Tertiary lavas of Western Senegal: the group of the Cape Verde Peninsula Tertiary basalts (40% -52% in silicia with an average of 44.23%) and the group of the Thiès Plateau Tertiary basalts (43% -49% in silicia with an average of 45.6%). The basalts of the Cape Verde Islands (Doucelance et al, [14]) are more undersaturated with silica than those of Western Senegal (Figure 2). Islands.…”

Section: Geochemistry Of Major Elementsmentioning

confidence: 99%

“…Contrastingly, the Quaternary basalts of Western Senegal have higher concentrations of silica than the Tertiary basalts of Western Senegal or the basalts of the Cape Verde Islands. In the Cape Verde Islands, Doucelance et al [14] have shown that the average content of magnesium in the Southern islands (Fogo and Santiago) is 7.97% and the average magnesium content in the northern islands (Sao Vicente, Sao Nicolau and Sal) reaches 13.14%. This shows that the Tertiary basalts (10.42%) and Quaternary basalts (8.35%) of Western Senegal have average contents of magnesium between those of the South Islands and North Islands.…”

Section: Geochemistry Of Major Elementsmentioning

confidence: 99%

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Comparative Geochemical Study of the Tertiary and Quaternary Lavas of Western Senegal and the Cape Verde Islands: Geodynamic Implications

Yatte¹,

Diallo²,

Sagna³

2015

IJG

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The western area of Senegal was the site of a basic volcanism in the Tertiary and Quaternary. That volcanism had caused the formation of alkaline olivine basalts, basanites and nephelinites from microlitic and porphyritic texture to dolerite texture. The geochemistry of major elements shows that the Quaternary basalts are more aluminous and more siliceous, but they contain less magnesium, less iron and less calcium than the Tertiary basalts. Two types of basalt occur here, based on the characteristics of the major elements in the Tertiary lavas: the highly undersaturated basalts of the Cape Verde Peninsula and the slightly undersaturated basalts of the Thiès Plateau. The characteristics of the trace elements reveal shallow interactions due to the contamination and/or assimilation, and to the fractional crystallization, but not due to the heterogeneity of the source. The strong enrichment in light rare earth elements (LREE) and the slight enrichment in heavy rare earth elements (HREE), the anomalies which are negative in K and Pb and positive in Nb, Ta and Eu of the Tertiary and Quaternary basalts of Western Senegal and similar anomalies of the same elements (Pb not analyzed) described in the Cape Verde islands, allow us to establish links between the petrogenetic mechanisms that had caused the formation of the basalts of this Islands and Western Senegal. Moreover, the volcanic activity in Western Senegal (of continental lntraplate type) and that of the Cape Verde Islands (oceanic intraplate type) are probably related to the hot spot located on the vertical of the Cape Verde.

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“…Data acquisition in static multi-collection consisted of 50 x 4 seconds scans; the raw data were processed off-line, cycle by cycle to correct for on-peak-zero, abundance sensitivity effects , mass fractionation, and blank contribution. Tail corrections were based on the method proposed by Dechamps et al (2003) for uranium (see also Doucelance et al, 2003). A power law was used for mass fractionation corrections.…”

Section: Pb Isotope Measurementsmentioning

confidence: 99%

Géochimie isotopique Re-Os et Pb-Pb :

Poirier¹

2005

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Pb-Sr-He isotope and trace element geochemistry of the Cape Verde Archipelago

Cited by 111 publications

References 72 publications

Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume: A mixed-up mantle

Enriched, HIMU-type peridotite and depleted recycled pyroxenite in the Canary plume: A mixed-up mantle

Comparative Geochemical Study of the Tertiary and Quaternary Lavas of Western Senegal and the Cape Verde Islands: Geodynamic Implications

Géochimie isotopique Re-Os et Pb-Pb :

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