The rocks of the southern half of the Morven-Cabrach mass consist mainly of norites, with two northerly dipping layers of ore- and olivine-rich ferrogabbro. In the north there is a progression of rocks from hypersthene-gabbro through quartz-biotite-norite to xenolithic quartz-mica-diorite. All the rocks are relatively iron-rich, and no highly magnesian types are found. Mineral compositions are remarkably constant, and chemical variation is slight. The mass has been intruded in its present position and is a (relatively) narrow, steep-sided, dyke-like body.