PETROLOGICAL FEATURES OF A NEW UREILITE (NWA6235) FROM FEZZOU, MOROCCO

Abstract

A ureilite-like meteorite (NWA 6235), about 6cm x 5cm x 5cm and 216g, with a dark brown to black fusion crust, was collected at Fezzou, Morocco (30°55.68'N, 4°51.50'W). This study of petrographical analyses of NWA 6235 is based on microscopy, areal compositional mapping and mineral chemistry by EPMA (X-ray microanalyzer) and cathodoluminescence (CL). In addition, carbonaceous matter was analyzed using pyrolysis gas chromatography (py-GC) and mass spectrometry (py-GC/MS), and Raman icrospectorometric analysis. C-N-S elemental analysis and stable carbon and oxygen isotope analyses of powdered samples were also performed. NWA 6235 consists mainly of olivine and pigeonite with minor amounts of enstatite, augite, graphite, diamond, metallic iron, iron oxide, limonite and Fe-Cr-Ni sulfide as a mesostasis. The meteorite shows ureilite texture with triple junctions between olivine grains.