Bulletin of the Geological Society of Malaysia, Volume 11, Dec, 1979, pp. 253 – 265
School of Applied Geology, University of N.S.W., Kensington, N.S.W. Australia
Department of Geology, Robinson University College, Broken Hill, N.S.W. Australia
Abstract: The field setting, mineralogy and geochemistry of the cassiterite-bearing pegmatites and greisens of the Broken Hill area are described for the first time. The tin ore occurs in cassiterite-bearing pegmatites generally emplaced parallel to the bedding of the regional Precambrian, Carpentarian (1700 m.y.) phyllites and schists of the Willyama Complex. The cassiterite is not disseminated through the rocks but is usually found in irregular masses at the intersection of cross-fractures within the pegmatite bodies. Greisens are often associated with these cassiterite pegmatites. The pegmatites are considered to be part of a differentiated felsic sequence derived from a tin-bearing anatectic melt now represented by a foliated biotite granite. A tectonic model is presented that relates the tin deposits to a Proterozoic rifting event controlled by a fundamental regional NE trending dextral shear couple.