Richterite-bearing peridotites and MARID-type inclusions in lavas from North Eastern Morocco: mineralogy and D/H isotopic studies

Wagner, Christiane; Deloule, Étienne; Mokhtari, Abdelkader

doi:10.1007/s004100050200

Cited by 33 publications

(14 citation statements)

References 34 publications

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“…There are substantial uncertainties on the NanoSIMS measurements (2r from 317 to 650‰) due to poor counting statistics when using relatively low probe currents, which are a result of low water abundances in the apatite, but these data are consistent with more precise measurements of apatite in the same sample (14321,1047 apt1) made with the ims-1280. Correction for spallogenic D decreases the dD value by up to 184‰, yet many lunar apatites with detectable water show dD values higher than in the Earth's mantle, À218 to +60‰ (Boettcher and O'Neil, 1980;Michael, 1988;Ahrens, 1989;Deloule et al, 1991;Bell and Rossman, 1992;Thompson, 1992;Graham et al, 1994;Jambon, 1994;Wagner et al, 1996;Xia et al, 2002;Hallis et al, 2015). The dD values of other apatites fall near or somewhat below the terrestrial range.…”

Section: Resultsmentioning

confidence: 94%

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Water in evolved lunar rocks: Evidence for multiple reservoirs

Robinson

Barnes

Nagashima³

et al. 2016

Geochimica et Cosmochimica Acta

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Section: Resultsmentioning

confidence: 94%

“…The range in dD value of Earth's present day upper mantle is estimated to be between À218 and +60‰ (Boettcher and O'Neil, 1980;Michael, 1988;Ahrens, 1989;Deloule et al, 1991;Bell and Rossman, 1992;Thompson, 1992;Graham et al, 1994;Jambon, 1994;Wagner et al, 1996;Xia et al, 2002;Hallis et al, 2015), shown by a line on Fig. 6.…”

Section: Earth-like Reservoirmentioning

confidence: 99%

Water in evolved lunar rocks: Evidence for multiple reservoirs

Robinson

Barnes

Nagashima³

et al. 2016

Geochimica et Cosmochimica Acta

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“…MARID rocks [18][19][20][21][22] and rocks produced by metasomatized lithospheric mantle magmas 8 with features similar to orangeites 1,4-7 have been identified in localities worldwide. It is therefore likely that the genetic relationship that we have established between mantle MARID assemblages and orangeite melts in South Africa can be extended to other continents.…”

Section: Discussionmentioning

confidence: 99%

“…MARID rocks have been transported from the lithospheric mantle to the Earth's surface by kimberlite, orangeite and lamprophyre magmas from various localities worldwide [18][19][20][21][22] . MARID rocks represent an extreme example of mantle metasomatism because of their exceptional enrichment in alkalis, LREE, HFSE (for example, Ti, Zr, Nb) and volatile species, primarily H 2 O (ref.…”

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confidence: 99%

Did diamond-bearing orangeites originate from MARID-veined peridotites in the lithospheric mantle?

et al. 2015

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Kimberlites and orangeites (previously named Group-II kimberlites) are small-volume igneous rocks occurring in diatremes, sills and dykes. They are the main hosts for diamonds and are of scientific importance because they contain fragments of entrained mantle and crustal rocks, thus providing key information about the subcontinental lithosphere. Orangeites are ultrapotassic, H 2 O and CO 2 -rich rocks hosting minerals such as phlogopite, olivine, calcite and apatite. The major, trace element and isotopic compositions of orangeites resemble those of intensely metasomatized mantle of the type represented by MARID (mica-amphibolerutile-ilmenite-diopside) xenoliths. Here we report new data for two MARID xenoliths from the Bultfontein kimberlite (Kimberley, South Africa) and we show that MARID-veined mantle has mineralogical (carbonate-apatite) and geochemical (Sr-Nd-Hf-O isotopes) characteristics compatible with orangeite melt generation from a MARID-rich source. This interpretation is supported by U-Pb zircon ages in MARID xenoliths from the Kimberley kimberlites, which confirm MARID rock formation before orangeite magmatism in the area.

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“…7, Deloule et al 1991a, Wagner et al 1996, Valley et al 1998, Stone et al 2003, though it is smaller than that for the Cenozoic Nushan amphibole (-94 to 46‰; Xia et al 2002). Seven of the thirteen points gave positive ␦D values, up to +54‰, much higher than the +8‰ value of the inclusion amphibole in ultramafi c sills of this area (Stone et al 2003) and the +8‰ value of megacryst amphibole from the Cima basanite (Boettcher & O'Neil 1980), though similar to the +46‰ value for Nushan amphibole (Xia et al 2002) (Fig.…”

Section: Resultsmentioning

confidence: 99%

Anomalously High d Values in an Archean Ferropicritic Melt: Implications for Magma Degassing

Stone¹,

Deloule

Beresford

et al. 2005

The Canadian Mineralogist

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In situ H isotope analysis of igneous amphibole from the Boston Creek ferropicrite, in the Abitibi Belt, Ontario, a 100-m-thick layered mafi c-ultramafi c unit, provides insights into the evolution of Archean mantle-derived hydrous melts in the crust. Ionmicroprobe analyses of the ultramafi c-rock-hosted interstitial igneous magnesiohastingsite indicate a wide range of ␦D values, from -47 to +54‰ and 2-3 wt% H 2 O at the 100-1000 m intragrain scale, but relatively uniform major-element and incompatible trace-element compositions. This wide range encompasses values signifi cantly higher than the ␦D values of -50‰ for whole-rock samples, <+10‰ for igneous amphiboles from ultramafi c sills, -80 to -30‰ values for hydrothermal-metamorphic fl uids in the area, and -90 to -60‰ values for mantle materials. The anomalously high ␦D values cannot be attributed entirely to H loss from amphibole during secondary processes. The contrast with the relatively uniform magnesiohastingsite composition and H 2 O and trace-element contents of the amphibole excludes the possibility that the ␦D values refl ect variable fl uid/mineral fractionation. The anomalously high ␦D values most plausibly record the composition of the ferropicritic melt from which the amphibole formed. Considering the widespread distribution and abundance of vesicles in the Boston Creek ferropicrite, these values can be explained by degassing of H relative to deuterium, perhaps by dissociation of H 2 O during emplacement at shallow levels in the crust. The resulting increase in oxidation state of the residual degassed melt led to Fe-Ti oxide crystallization, which reduced the FeO content of the melt and triggered the Cu-PGE-Ag sulfi de mineralization during formation of the magnetite gabbro host-rock.Keywords: Abitibi belt, Archean, igneous magnesiohastingsite, H isotope, magmatic degassing, ferropicrite, platinum-groupelement mineralization, Boston Creek, Ontario. SOMMAIREUne analyse isotopique in situ de l'amphibole ignée provenant de la ferropicrite de Boston Creek, ceinture de l'Abitibi, en Ontario, une unité mafi que-ultramafi que de 100 m d'épaisseur, fournit une nouvelle information à propos de l'évolution de magmas archéens enrichis en H 2 O, dérivés du manteau, et mis en place dans la croûte. Les analyses faites avec une microsonde ionique de la magnésiohastingsite interstitielle d'une roche ultramafi que indique un grand intervalle de valeurs de ␦D, allant de -47 à +54‰ et une teneur de 2-3% H 2 O (poids) à une échelle intragranulaire de 100 à 1000 m, mais une composition relativement uniforme en termes des éléments majeurs et des éléments traces incompatibles. Ce grand intervalle dépasse largement les valeurs de ␦D obtenues pour les roches globales, -50‰, les valeurs inférieures à +10‰ pour l'amphibole ignée des fi lonscouches ultramafi ques, les valeurs entre -80 et -30‰ pour les fl uides hydrothermaux-métamorphiques de la région, et les valeurs entre -90 et -60‰ pour les matériaux du manteau. Les valeurs de ␦D anomalement élevées ne sauraient...

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Richterite-bearing peridotites and MARID-type inclusions in lavas from North Eastern Morocco: mineralogy and D/H isotopic studies

Cited by 33 publications

References 34 publications

Water in evolved lunar rocks: Evidence for multiple reservoirs

Water in evolved lunar rocks: Evidence for multiple reservoirs

Did diamond-bearing orangeites originate from MARID-veined peridotites in the lithospheric mantle?

Anomalously High d Values in an Archean Ferropicritic Melt: Implications for Magma Degassing

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