Olivier Alard

Macquarie University

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Suzanne Y. O′Reilly

ARC Centre of Excellence for Core to Crust Fluid Systems

William L. Griffin

Macquarie University

Norman J. Pearson

Macquarie University

Jean‐Louis Bodinier

Géosciences Montpellier

M. Gounelle

Laboratoire de Minéralogie & Cosmochimie du Muséum

Jean-Pierre Lorand

Institut de minéralogie, de physique des matériaux et de cosmochimie

Jean‐Marie Dautria

Géosciences Montpellier

Marguerite Godard

Centre National de la Recherche Scientifique

Yoann Gréau

Macquarie University

Kevin W. Burton

Durham University

Cooperative Institutions

Centre National de la Recherche Scientifique

Macquarie University

ARC Centre of Excellence for Core to Crust Fluid Systems

Université de Montpellier

Géosciences Montpellier

Australian Research Council

The Open University

Institut de Recherche pour le Développement

Max Planck Institute for Chemistry

Sorbonne Université

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Trace element geochemistry of ordinary chondrite chondrules: The type I/type II chondrule dichotomy

Geochimica et Cosmochimica Acta (2015)

Emmanuel Jacquet Olivier Alard M. Gounelle

Chondrule

Ordinary chondrite

Trace element

Carbonaceous chondrite

TRACE (psycholinguistics)

10.1016/j.gca.2015.02.005

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Citations (37)

Ba Isotope Study on Arc Lavas and Mantle Peridotites with the Application of 1013 ohm Resistor

Goldschmidt Abstracts (2020)

Fei Wu Bruce F. Schaefer Olivier Alard Simon Turner

10.46427/gold2020.2890

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Citations (0)

A new Tektite Strewnfield in Atacama, Chile

HAL (Le Centre pour la Communication Scientifique Directe) (2014)

Bertrand Devouard P. Rochette J. Gattacceca Jean‐Alix Barrat F. Moustard

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Citations (2)

Chondrule trace element geochemistry at the mineral scale

Meteoritics and Planetary Science (2012)

Emmanuel Jacquet Olivier Alard M. Gounelle

We report trace element analyses from mineral phases in chondrules from carbonaceous chondrites (Vigarano, Renazzo and Acfer 187), carried out by laser ablation inductively coupled plasma mass spectrometry. Results are similar in all three meteorites. Mesostasis has Rare Earth Element (REE) concentrations of 10-20 x CI. Low-Ca pyroxene has light REE (LREE) concentrations near 0.1 x CI and heavy REE (HREE) near 1 x CI respectively. Olivine has HREE concentrations at 0.1-1 x CI and LREE around 10-2 x CI. The coarsest olivine crystals tend to have the most fractionated REE patterns, indicative of equilibrium partitioning. Low-Ca pyroxene in the most pyroxene-rich chondrules tends to have the lowest REE concentrations. Type I chondrules seem to have undergone a significant degree of batch crystallization (as opposed to fractional crystallization), which requires cooling rates slower than 1-100 K/h. This would fill the gap between igneous CAIs and type II chondrules. The anticorrelation between REE abundances and pyroxene mode may be understood as due to dilution by addition of silica to the chondrule melt, as in the gas-melt interaction scenario of Libourel et al. (2006). The rapid cooling rate (of the order of 1000 K/h) which seems recorded by low-Ca pyroxene, contrasted with the more diverse record of olivine, may point to a nonlinear cooling history or suggest that formation of pyroxene-rich chondrule margins was an event distinct from the crystallization of the interior.

Pyroxene

Chondrule

Trace element

Parent body

Fractional crystallization (geology)

10.1111/maps.12005

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Citations (43)

Nature and Evolution of the Lithospheric Mantle beneath the Hoggar Swell (Algeria): aR ecord from Mantle Xenoliths

Fatna Kourim Jean‐Louis Bodinier Olivier Alard Abderrahmane Bendaoud Alain Vauchez

Xenolith

Swell

Hotspot (geology)

Source

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Citations (0)

Platinum-group element micronuggets and refertilization process in Lherz orogenic peridotite (northeastern Pyrenees, France)

Earth and Planetary Science Letters (2009)

Jean‐Pierre Lorand Olivier Alard Ambre Luguet

Peridotite

Platinum group

Metasomatism

Massif

Refractory (planetary science)

10.1016/j.epsl.2009.11.017

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Citations (142)

Determination of intratest variability of trace elements in foraminifera by laser ablation inductively coupled plasma‐mass spectrometry

Geochemistry Geophysics Geosystems (2003)

Ed C. Hathorne Olivier Alard Rachael H. James Nick Rogers

We have developed a technique to determine the variability of trace elements (including Li, B, Na, Mg, Mn, Cu, Zn, Sr and Ba) within foraminifera tests using laser ablation inductively coupled plasma mass spectrometry (LA‐ICP‐MS). This technique has a high spatial resolution (width 40–80 μm, depth >0.5 μm), is reproducible (<8% external reproducibility) and has low detection limits (generally <0.05 μg g −1 ). We demonstrate that normalization of data to a calcite standard usually gives results that are more consistent with solution ICP‐MS data than normalization to NIST 612. Rastering into the wall of the final chamber of Globigerinoides sacculifer shows that the outermost ∼1.5 μm of the test is enriched in trace elements, including Mn, relative to the interior, indicating the presence of a contaminant surface phase. Pustule calcite close to the aperture of Globorotalia tumida has different Sr/Ca and Ba/Ca compared to other parts of the test. Sr/Ca and Ba/Ca partition coefficients suggest that the pustule calcite is diagenetic and/or formed in a more open system. Multiple analyses of Orbulina universa tests recovered from a latitudinal transect in the North Atlantic give a relationship between Mg/Ca and sea surface temperature similar to that reported elsewhere in the literature. These initial data demonstrate the validity of this technique, and show that it is potentially an extremely powerful microanalytical tool for palaeoceanographic and palaeontological studies.

Laser Ablation

Microanalysis

10.1029/2003gc000539

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Citations (125)

Laser ablation ICP-MS study of IIIAB irons and pallasites: constraints on the behaviour of highly siderophile elements during and after planetesimal core formation

Chemical Geology (2004)

E. Mullane Olivier Alard M. Gounelle S. S. Russell

Kamacite

Fractional crystallization (geology)

Platinum group

Iron meteorite

Parent body

10.1016/j.chemgeo.2004.04.024

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Citations (27)

Evidence for interaction of Proterozzoic (2 Ga) sub-continental mantle, with an enriched mantle plume from Re-Os isotope systematics in French Massif Central peridotite xenoliths

David D Lambert Olivier Alard Sylvie Costa Louise R Frick Jean‐Louis Bodinier

Recent studies of mantle xenoliths and orogenic peridotite bodies have emphasized the consistent agreement between Re-Os melt-depletion (TRo) model ages for the mantle and ages of overlying and/or surrounding crust. Moreover, Re-Os isotopic investigations of sub-continental lithospheric mantle underlying non-cratonic areas suggest that these mantle segments have remained stable for long periods of time (>1 Ga). However, several important questions remain to be answered. Does the lithospheric mantle remain coupled to the overlying continental crust through major and multiple orogenic events? Is there any age stratigraphy preserved within the continental mantle root? We have carried out petrographic, trace element and Re-Os isotopic studies of six shallow mantle peridotite xenoliths sampled by alkali basalts from localities scattered throughout the French Massif Central (FMC). The FMC is an appropriate lithospheric segment for assessing the behaviour of Re-Os isotopic systematics during major orogenic and magmatic events. The non-cratonic crust of the FMC has undergone at least two main orogenies (Cadomian and Variscan) during the past 700 Ma. More recently, the FMC lithosphere has been affected by a mantle plume which induced extensive Quaternary alkali volcanism. The six samples were subdivided into two groups. The first group consists of olivine-rich harzburgites displaying a poikiloblastic microtexture. They have high equilibrium temperatures, ranging from 1150~ to 1250~ and very refractory geochemical characteristics with low A1203 and Lu contents (0.1-1.8 wt.% and 9 -20 ppb, respectively). The geochemistry of constituent silicate minerals (e.g. olivine with low mg#) as well as whole rock trace element patterns suggest that these poikiloblastic olivine-rich peridotites have experienced ' lbasaltic' melt infiltration at high melt/rock ratio. Their high equilibration temperatures may be consistent with a deep lithospheric mantle source. The second group of samples does not display a poikiloblastic microtexture, but have a porphyroclastic to protogranular microtexture. They are clinopyroxene-poor lherzolites ( 4 6 % cpx) or lherzolites (11% cpx). Equilibrium temperatures within this group range from 950-1100~ A1203 contents vary from 1.3-3.5 wt.%, and Lu contents range from 10-57 ppb. Trace element diagrams show that the cpx-poor lherzolites are L R E E enriched, whereas the lherzolites display 'depleted MORB mantle' trace element patterns. However, samples from both groups display large positive U/ Th anomalies in both whole rocks and separated clinopyroxenes. These xenoliths display a large range in Os concentrations (1.74-3.60 ppb) that is inversely correlated with indices of mantle fertility, and exhibit a large range in Os isotopic compositions (lS7Os/lS8Os = 0.1122--0.1349; 7os = --13 to +4) that is inversely correlated with Re/Os (Fig. 1). Refractory harzburgite xenoliths have the lowest Os i s o t o p i c c o m p o s i t i o n s (187Os/188Os =

Peridotite

Xenolith

Massif

Mantle plume

Source

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Citations (1)

Laser-ablation microprobe (LAM)-ICPMS unravels the highly siderophile element geochemistry of the oceanic mantle

Earth and Planetary Science Letters (2001)

Ambre Luguet Olivier Alard Jean-Pierre Lorand Norman J. Pearson C.G. Ryan

Platinum group

Microprobe