AbstractsEarth & Environmental Science

The geology of some pegmatites near Gumeracha South Australia.

by R. A. Eggleton




Institution: University of Adelaide
Department:
Year: 1959
Keywords: Adelaide Geosyncline, Mt Lofty Ranges fold belt, South Australia; Honours; Geology; Adelaide Supergroup; pegmatites; mineralogy; petrology
Record ID: 1033330
Full text PDF: http://hdl.handle.net/2440/84999


Abstract

Detailed mineralogical and petrological descriptions of the pegmatites are given, and a more generalised petrological description of the Adelaide System rocks enclosing the pegmatites. The tabular pegmatites are classified into three groups based on textural and mineralogical differences. Group 1 has a finely crystalline margin containing quartz, albite and tourmaline, and a coarsely crystalline core consisting of quartz, microcline and muscovite. Pegmatites of group 2 have a coarsely crystalline margin containing quartz, microcline, albite, muscovite, tourmaline and beryl, and a coarse core of quartz, microcline and muscovite. Group 3 pegmatites have no zoning and consist of quartz, feldspars and muscovite of variable crystal size. The irregular pegmatites show properties of all 3 groups. It is concluded that the pegmatites formed by intrusion of fluids rather than by differentiation or replacement. A Geological map of the area is included.