Kap Dalton

Lying above the Tertiary basalts near Kap Dalton is a small area of Eocene-Oligocene fossiliferous sediments, principally sandstones, at the base of which is a conglomerate, less than 2 m thick containing rounded pebbles. Samples collected by Wager (1935, p. 19) were between 5 and 12 cm in diameter and proved to be alkaline igneous rocks including malignite, of about one third nepheline, rather less orthoclase and abundant analcime; tinguaite, with altered (?)nosean as well as nepheline and aegirine phenocrysts; monchiquite; leucite nephelinite with abundant microphenocrysts of pyroxene, nepheline, leucite and some perovskite and nepheline leucitite in which altered leucite occupies about 75% of the groundmass. Wager considered that the pebbles were derived from source regions further north.