Hilary Downes

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Ureilites are ultramafic achondrites that exhibit heterogeneity in mg# and oxygen isotope ratios between different meteorites. Polymict ureilites represent near-surface material of the ureilite parent asteroid(s). Electron microprobe analyses of >500 olivine and pyroxene clasts in several polymict ureilites reveal a statistically identical range of(More)
Bulk rock geochemistry and majorand trace-element compositions of clinopyroxene have been determined for three suites of peridotitic mantle xenoliths from the North Atlantic Craton (NAC) in northern Scotland, to establish the magmatic and metasomatic history of subcontinental lithospheric mantle (SCLM) below this region. Spinel lherzolites from the(More)
The chromosome set of the lesser kudu, Tragelaphus imberbis, consists of 38 elements in both sexes. In contrast to most other members of the bovid subfamily Tragelaphinae, both the X and the Y chromosomes are compound, having fused with identical autosomes from ancestors presumed to have higher chromosome numbers. From a comparison of the unusual sex(More)
Introduction: Ureilites are a group of carbonbearing ultramafic achondrites. The majority of samples are monomict with major and trace element compositions consistent with a restitic origin after extensive loss of basaltic melts and significant loss of their metallic component during anatexis. Monomict ureilites are thought to represent largely intact(More)
s of 33rd International Geological Congress, 6–14 August 2008, Oslo. Coltorti, M., Bonadiman, C., O’Reilly, S. Y., Griffin, W. L. & Pearson, N. J. 2010. Buoyant ancient continental mantle embedded in oceanic lithospheric (Sal Island, Cape Verde Archipelago). Lithos, doi: 10.1016/j.lithos.2009.11.005. Davies, G. R., Nixon, P. H., Pearson, D. G. & Obata, M.(More)
Anhydrous mantle peridotite xenoliths from a single volcanic vent in the French Massif Central are compositionally varied, ranging from relatively fertile lherzolites to refractory harzburgites. Fertile lherzolites closely resemble previous estimates of undepleted mantle compositions but the average of the Ray Pic xenoliths is much less enriched in LILE and(More)
Lower crustal xenoliths from the Udachnaya and Komsomolskaya kimberlite pipes in Siberia are mainly meta-igneous mafic garnet granulites, with subordinate feldspar-rich garnet granulites. Pressure and temperature estimates are interpreted as the conditions in the lower crust at the time of the last granulite-facies metamorphic event (800^8908C) followed by(More)