Northwest Africa 1500: Plagioclase-bearing monomict ureilite or ungrouped achondrite?

Al-Mg SYSTEMATICS OF THE UNGROUPED ACHONDRITE NORTHWEST AFRICA 11119: TIMING OF EXTRATERRESTRIAL SILICA-RICH MAGMATISM

Nwa 1586: Macrosmelting in a Monomict Ureilite

Introduction: NWA 1586 is a provisional new ureilite obtained by a meteorite dealer in Morocco in the spring of 2001. In thin section, NWA1586 displays the typical monomict ureilite texture with abundant triple junctions, curved intergranular boundaries and coarse grain sizes (1-2 mm average grain size with one or two grains up to 5 mm in length, Figure 1). Modal silicate mineralogy is 75% oliv...

Oxygen Isotopes in Ungrouped Achondrite Nwa 1500 and Comparison to Brachinites

Introduction: North West Africa (NWA) 1500 is an olivine-rich achondrite that is currently classified as ungrouped, based on petrography and oxygen isotope ratios [1-2]. Although some petrographic characteristics of NWA 1500 suggest a relationship to the augitebearing ureilites, it shows a distinct thermal history (equilibration to much lower T) that rules out derivation from the ureilite paren...

U-Pb AGE OF THE UNGROUPED ACHONDRITE NWA 8486

Asteroidal Differentiation Processes Deduced from Ultramafic Achondrite Ureilite Meteorites

Hilary Downes, David W Mittlefehldt, Pierre Hudon, Christopher S. Romanek and Ian Franchi Lunar and Planetary Institute, Houston, Texas, USA ([email protected]); School of Earth Sciences, Birkbeck, University of London, London, UK; NASA/Johnson Space Centre, Houston, Texas, USA; Dept. of Earth and Planetary Sciences, McGill University, Montreal, Quebec, Canada; 5 Savannah River Ecology Labora...