Composition and evolution of submarine volcanic rocks from the central and western Canary Islands

Abratis, Michael; Schmincke, Hans‐Ulrich; Hansteen, Thor H.

doi:10.1007/s00531-002-0286-7

Cited by 49 publications

(20 citation statements)

References 79 publications

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“…Major elements were determined on fused beads by XRF using an automated Philips PW1480 spectrometer at IFM-GEOMAR, Germany. International reference materials BHVO-1, JA-2, JB-2, JB-3 and JR-1 were analysed for calibration, and standards analyses are given in Abratis et al (2002) Pyroxene, feldspar and feldspathoid compositions were measured by a Cameca SX50 electron microprobe at Uppsala University. Pyroxenes and feldspars were measured with standard operation conditions of 20 kV accelerating voltage and 15nA beam current.…”

Section: Methodsmentioning

confidence: 99%

“…The isotope heterogeneity of the southern islands reflects the availability of an EM1-like component in addition to the young-HIMU or FOZO-like component found throughout the archipelago (Gerlach et al 1988: Doucelance et al 2003Martins et al 2009;Barker et al 2010). The nature and origin of the EM1-like component are controversial with some authors proposing a component of recycled ocean crust and others arguing for a subcontinental lithospheric mantle source (Hoernle et al 1991;Kokfelt et al 1998;Doucelance et al 2003;Escrig et al 2005;Abratis et al 2002;Geldmacher et al 2008;Martins et al 2009;Barker et al 2010). Little or no evidence for crustal assimilation has been recorded in studies of mafic lavas from Cape Verde, probably a consequence of the limited potential for interaction with sediments or crust in the oceanic setting.…”

Section: Geological Settingmentioning

confidence: 96%

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Magmatic evolution of the Cadamosto Seamount, Cape Verde: beyond the spatial extent of EM1

Barker

Troll

Ellam

et al. 2011

Contrib Mineral Petrol

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The Cadamosto Seamount is an unusual volcanic centre from Cape Verde, characterised by dominantly evolved volcanics, in contrast to the typically mafic volcanic centres at Cape Verde that exhibit only minor volumes of evolved volcanics. The magmatic evolution of Cadamosto Seamount is investigated to quantify the role of magma-crust interaction and thus provide a perspective on evolved end-member volcanism of Cape Verde. The preservation of mantle source signatures by Nd-Pb isotopes despite extensive magmatic differentiation provides new insights into the spatial distribution of mantle heterogeneity in the Cape Verde archipelago. Magmatic differentiation from nephelinite to phonolite involves fractional crystallisation of clinopyroxene, titanite, apatite, biotite and feldspathoids, with extensive feldspathoid accumulation being recorded in some evolved samples. Clinopyroxene crystallisation pressures of 0.38-0.17 GPa for the nephelinites constrain this extensive fractional crystallisation to the oceanic lithosphere, where no crustal assimilants or rafts of subcontinental lithospheric mantle are available. In turn, magma-crust interaction has influenced the Sr, O and S isotopes of the groundmass and late crystallising feldspathoids, which formed at shallow crustal depths reflecting the availability of oceanic sediments and anhydrite precipitated in the ocean crust. The Nd-Pb isotopes have not been affected by these processes of magmacrust interaction and hence preserve the mantle source signature. The Cadamosto Seamount samples have high 206 Pb/ 204 Pb ([19.5), high eNd (?6 to ?7) and negative D8/ 4Pb, showing affinity with the northern Cape Verde islands as opposed to the adjacent southern islands. Hence, the Cadamosto Seamount in the west is located spatially beyond the EM1-like component found further east. This heterogeneity is not encountered in the oceanic lithosphere beneath the Cadamosto Seamount despite greater extents of fractional crystallisation at oceanic lithospheric depths than the islands of Fogo and Santiago. Our data provide new evidence for the complex geometry of the chemically zoned Cape Verde mantle source.

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Section: Methodsmentioning

confidence: 99%

Section: Geological Settingmentioning

confidence: 96%

Magmatic evolution of the Cadamosto Seamount, Cape Verde: beyond the spatial extent of EM1

Barker

Troll

Ellam

et al. 2011

Contrib Mineral Petrol

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“…A large number of isotopic studies have been carried out on the Canary Islands and related seamounts to assess the mantle components involved in forming the Canarian magmas (Sun, 1980;Cousens et al, 1990;Marcantonio et al, 1995;Thirlwall, 1997;Thirlwall et al, 1997;Hoernle, 1998;Widom et al, 1999;Simonsen et al, 2000;Geldmacher et al, 2001Geldmacher et al, , 2005Abratis et al, 2002;Lundstrom et al, 2003;Gurenko et al, 2006). These studies have identified three types of mantle components in the Canarian source, which can be broadly classified as HIMU-type (or LVC; Hoernle et al, 1995), DMM (MORB-source) and EM type components (e.g.…”

Section: Source Components Involved In the Canary Shield Magmatismmentioning

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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“…Samples were analysed on fused beads using a Philips PW1480 spectrometer and an Rh tube. Calibration was performed using international geological reference samples 50 . CO 2 and H 2 O contents were measured by IR photometry using a Rosemount CSA 5003 at GEOMAR.…”

Section: Methodsmentioning

confidence: 99%

Bimodal magmatism produced by progressively inhibited crustal assimilation

et al. 2014

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The origin of bimodal (mafic-felsic) rock suites is a fundamental question in volcanology. Here we use major and trace elements, high-resolution Sr, Nd and Pb isotope analyses, experimental petrology and thermodynamic modelling to investigate bimodal magmatism at the iconic Carlingford Igneous Centre, Ireland. We show that early microgranites are the result of extensive assimilation of trace element-enriched partial melts of local metasiltstones into mafic parent magmas. Melting experiments reveal the crust is very fusible, but thermodynamic modelling indicates repeated heating events rapidly lower its melt-production capacity. Granite generation ceased once enriched partial melts could no longer form and subsequent magmatism incorporated less fertile restite compositions only, producing mafic intrusions and a pronounced compositional gap. Considering the frequency of bimodal magma suites in the North Atlantic Igneous Province, and the ubiquity of suitable crustal compositions, we propose 'progressively inhibited crustal assimilation' (PICA) as a major cause of bimodality in continental volcanism.

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Composition and evolution of submarine volcanic rocks from the central and western Canary Islands

Cited by 49 publications

References 79 publications

Magmatic evolution of the Cadamosto Seamount, Cape Verde: beyond the spatial extent of EM1

Magmatic evolution of the Cadamosto Seamount, Cape Verde: beyond the spatial extent of EM1

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

Bimodal magmatism produced by progressively inhibited crustal assimilation

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