A series of widely spaced, scattered dykes, up to a metre thick, are aligned northeast-southwest and cut variable Precambrian gneisses. Rock types represented include nepheline-phyric tinguaite, porphyritic shonkinite and monchiquite.
MELCHER, G.C. and MELCHER, B.A. 1972. Novas ocorrencias de rochas alcalinas no Estado de Sao Paulo. Anais Congresso Brasileiro de Geologia, 26(1): 216-7.
ULBRICH, H.H.G.J. and GOMES, C.B. 1981. Alkaline rocks from continental Brazil. Earth Science Reviews, 17: 135-54