Trace element variations generated by magmatic and post-crystallization processes in eucrite meteorites

Eucrite meteorites are early-formed (>4.5 Ga) basaltic rocks that likely to derive from the asteroid 4 Vesta, or a similarly differentiated planetesimal. To understand trace element and moderately volatile (MVE) behavior more fully within between eucrites, laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) study is reported for plagioclase pyroxene, as well fusion crust vitrophyric materials ten eucrites. These eucrites span cumulate eucrite (Northwest Africa [NWA] 1923) samples corresponding Main Group (Queen Alexandra Range 97053, Pecora Escarpment 91245, Cumulus Hills 04049, Bates Nunatak 00300, Lewis Cliff 85305, Graves Nunataks 98098) Stannern (Allan 81001, NWA 1000) compositions, in addition Elephant Moraine 90020. Along with range of refractory elements, focus was given abundances five MVE (K, Zn, Rb, Cs, Pb) interrogate abundance distributions mineral phases. Modal recombination analyses reveals important role accessory phases (zircon, apatite) some incompatible (ITE) distributions, but not which, were analyzed, mostly sited (Cs, K) pyroxene (Zn, Pb), equilibrium parental melt composition The new data reveal possible relationship total ITE enrichment texture, most enriched examined (NWA 1000, ALHA 81001) having acicular textures and, case 81001 young degassing age (∼3.7 Ga). Collectively results suggest may be related anatexis eucritic by thermal metamorphism, heat source possibly coming impacts. Impact processes do have pronounced effect on MVE, where plagioclase, crust, whole rock compositions all significantly depleted Zn/Fe, Rb/Ba K/U similar lunar rocks. Assessment however, suggests Vesta has heterogeneous distribution elements slightly less volatile-depleted than Moon. Phase dependence (e.g., Cl apatite, Zn primarily into spinel early formed phases, including pyroxene) influence comparison diagrams stable isotopes shown. In δ37Cl versus δ66Zn, metamorphism impact lead decrease value δ66Zn raising possibility late-stage had profound planetesimal crusts.