Garnet and/or Spinel Bearing Pyroxenites in Alkaki Basalts Near Azrou (Middle Atlas, Morocco): Mantle Derived Alumina-Rich Xenoliths Related to the “ariegite-Grospydite” Trend.

摘要: Abstract The Bou Ibalrhatene-Maar (Volcanic district of Azrou, Middle Atlas, Morocco) ejected a family recrystallized pyroxenites closely related to ultramafic tectonites. They consist garnet and/or spinel westerites and clinopyroxenites. Igneous primary mineralogy involves enstatite-rich orthopyroxene clinopyroxene probably spinel. Metamorphic textures developed at ca 1000° C 12-14 kb with, in some instances, secondary crystallization as exsolutions from or rims around Petrological features lead consider these rocks mantle xenoliths rather than cognate inclusions host basalt. Their high-alumina well low-iron contents would make them close the “ariegite-grospydite” trend “griquaite” family.