In the Marziqallal sill clinopyroxenes occur in all the units but
the uppermost unit. The composition varies from diopside (mg#:
100xMg/Mg + Fetotal = 70) in the lower set of the sill to Fe-augite
(mg# = 50) in the ilmenite-rich upper set (Table 2, Fig. 3A). TiO2
(Fig. 4A) and Cr2O3 contents decrease along with the mg# towards
the upper set of the sill.