Liquidus phase relationships have been determined for a high-MgO basalt (STV301: MgO 12.5 wt%, Ni 250 ppm, Cr 728 ppm) from Black Point, St Vincent (Lesser Antilles arc). Piston-cylinder experiments were conducted between 7.5 and 20 kbar under both hydrous and oxidizing conditions. AuPd capsules were used as containers. Compositions of supraliquidus glasses and mass-balance calculations show th...

Ultra-calcic ankaramitic magmas or melt inclusions are ubiquitous in arc, ocean-island and mid-ocean ridge settings. They are primitive in character (XMg 4 0 65) and have high CaO contents (414 wt %) and CaO/Al2O3 (41 1). Experiments on an ankaramite from Epi, Vanuatu arc, demonstrate that its liquidus surface has only clinopyroxene at pressures of 15 and 20 kbar, with XCO2 in the volatile comp...

Early Cretaceous alkaline picrites and high-magnesium basalts from the North China craton provide evidence for recycling of continental lithosphere by density foundering. Both the picrites and basalts contain xenocrystic olivines with high Fo92-93 and low CaO (<0.10%), consistent with the lavas’ derivation from, or interaction with Archean mantle lithosphere. Most importantly, both the picritic...

The title of Larsen & Pedersen (2009) speaks to the tug that picrites have on the petrological conscience, extant at least since O’Hara (1968), but perhaps even before (Drever & Johnston, 1957), namely that all picrites represent great heat and high temperature. This idea today is rather entrenched. However, Clague et al. (1995) proposed that most picritic basalt from Kilauea volcano and offsho...

Introduction: Knowledge of the density, compressibility and other physical properties of magmas at high pressure are required in order to understand the differentiation of the lunar interior. We present here the first experiments to determine the effect of dissolved volatiles on the physical properties of ultramafic mantle melts as represented by the lunar picritic glasses. Lunar picritic glass...

The eruption of the orange glass magma to form the deposits sampled at the Apollo 17 site is considered to have been a gas-rich, fire-fountain eruption. The deposit consists entirely of small 1-2 mm spherical beads of the orange glass created during fragmentation of the magma. The data on the gas phase components in the pre-eruption A17 orange glass magma are constrained by C-O-S system phase e...

Abstract Some geochemical models for basaltic and more primitive rocks suggest that their parental magmas have assimilated tens of weight percent crustal silicate wall rock. But what are the thermodynamic limits assimilation in magmas? We pursue this question quantitatively using a freely available tool phase equilibria modeling open magmatic systems—the Magma Chamber Simulator (https://mcs.geo...

Introduction: The composition and origin of the lunar volatiles has been the subject of considerable interest and one of the most important unsolved questions regarding the formation of the Moon. The general consensus has been that the Moon formed and evolved through a single or series of catastrophic heating events [1] in which most of the highly volatile elements were either stripped or evapo...

anomolously low A1203, low Ti02 and are enriched in chromium and nick~A We present petrographic and chemical c ata on the Kamloops Lake picritic tmalts as we1 I as the stratigraphic setting for thwe ultramafic lavas. Age constraints derive From field relationships, Mineral chemistry indicates th 31 these ultramafic rocks represent mantle-deri.ed material which has undergone: minimal differentia...