Mineral Hill

Nepheline syenite was mapped at Mineral Hill by Darton (1905) and some petrographic details were given by Smith (in Darton, 1905, p. 4). Welch (1974), in a preliminary report, describes the intrusion as a ring dyke complex, the outermost ring being of nepheline syenite, an intermediate ring of jacupirangite and the core of feldspathic breccia which has been intruded by dioritic rocks. Dykes are widespread and include lamprophyres and pseudoleucite porphyries.