Leeuwkraal

This occurrence consists of two inliers within Karoo grits one of which is approximately circular with a diameter of about 1.5 km; the other, lying a kilometre to the southeast, is about 400x150 m. The larger body is a phonolite with 2-3 mm alkali feldspar phenocrysts and sparser phenocrysts of diopside zoned to aegirine rims, and in some facies nepheline. Sodalite, a sodic amphibole, generally with cores of biotite, titanite, apatite and titanomagnetite are also present. The smaller body consists of foyaite, most of which contains phenocrysts of alkali feldspar up to 1.5 cm, 3-5 mm nephelines and small aegirines, some with diopsidic cores, in a groundmass of the same minerals together with analcime, titanite and an opaque phase. Analyses of phonolite and foyaite are given by Shand (1922) who considered the former to be extrusive and the latter intrusive facies of the same igneous event.