The Burra (Burra) Mine, situated 150 km north of Adelaide within the Adelaide Geosyncline, produced 2.7 million tonnes of copper ore in two major mining phases - 1845-1877 and 1970-1981. The first phase was initially progressed by underground high-grade tributing, with open cutting commencing later, in the 1870s, to reduce costs. This mining phase realised around 700 000 t averaging 7% Cu. The second phase, carried out by Samin Ltd, was done entirely by open cutting a resource estimated at the time as ~3.5 million tonnes grading 1.52% Cu. The actual final amount of ore mined during 1970-1981 was 1.89 million tonnes grading 1.71% Cu. The pre-mining grade was close to 3% Cu. Field mapping undertaken in 1980-1981 by Mines and Energy geologists J.F. Drexel and W.S. McCallum, followed by petrological studies of approximately 150 rock samples carried out during 1983-1984, and a reinterpretation of the thin- and polished sections during the current appraisal of the Burra Mine, have concluded that the orebody was developed by secondary remobilisation of presumably primary chalcopyrite mineralisation, emplacement of the latter being associated with syn-depositional and post-depositional magmatic and hydrothermal activity occurring during sedimentation of the host Skillogalee Dolomite of Neoproterozoic age. Secondary copper sulphides, mostly chalcocite, developed from the primary sulphides in an epigenetic environment. Primary and secondary sulphides are now scarce in the open cut, but chalcocite, bornite, covellite and chalcopyrite were formerly present at the bottom of the mine pit. Supergene enrichment formed the main copper minerals that have been mined - malachite, azurite, chrysocolla and cuprite, with lesser native copper and libethenite. These developed as fracture fills and veins in a relatively open-space environment. Gem-quality botryoidal malachite extracted during the 1845-1877 mining period made the mine become world renowned. Jigsaw and crackle breccias, often copper mineralised, occur in country rock up to 200 m from the magmatic foci, and related mineralisation extends slightly beyond the open cut limits. The Skillogalee Dolomite in the Burra area consists of a lower portion comprising dominantly pale-coloured dolomite and an upper portion of dark blue-grey dolomite. Within the lower unit, a distinctive assemblage of siltstone, limestone and dolomite that is atypical of the remainder of the Skillogalee Dolomite has been traced southward from Burra towards Robertstown during regional mapping performed by W.V. Preiss, and this stratigraphic assemblage is labelled 'Nms9' on the Burra 1:50 000 geological map. The name "Kooringa Member" has been reserved for this unit, and will be formalised in a future publication. The geology mapped within the Burra mine open cut is divided in two by the Kingston Shear. On its western side, a diapiric body intruding the Skillogalee Dolomite occupies the entire length of the mine pit, and may extend up to 500 m to the west. On the eastern side, the greater part of the mine pit is occupied by an overall east-dipping succession of the Kooringa Member, with pale-coloured dolomites of the Skillogalee Dolomite above and below. Petrographic examinations made by A. Kemp and M. Farrand indicate that the Kooringa Member contains probable volcaniclastic or air-fall tuff components, developed during a period of syn-depositional magmatic activity which culminated in intrusion of a felsic porphyry which has been dated during this current project at 797±5 Ma by PIRSA geochronologist A. Reid. This date has led to significant reinterpretation of the timing of primary mineralisation. Recognition that the porphyry and associated mineralisation at Burra are of similar age to the host Skillogalee Dolomite now promotes large tracts of the Adelaide Geosyncline as being prospective for finding possible occurrences of similar mineralisation. The Burra orebody was previously thought to be much younger than the dolomite, and indeed probably post-Delamerian, a concept which influenced previous exploration programmes. Rather than having future exploration approaches being confined to a fault-emplacement model for copper mineralisation, the Kooringa Member, which at Burra is ~150 m thick, should now be regarded as the metallogenic focus as it represents a period of possibly widespread volcanism in an otherwise carbonate-dominated sedimentary environment. Coarsely crystalline dolomitic marble and brecciated dolomitic marble carrying variable amounts of copper sulphides and pyrite were formerly exposed at the very bottom of the open cut and in small pods lying along the Kingston Shear. Of several possible origins considered for this sulphide mineralisation, an origin involving recrystallisation and mineralisation by hydrothermal fluids of the lower portion of the Skillogalee Dolomite is considered the most likely. Diapiric material, which is generally unmineralised, is juxtaposed adjacent to the mineralisation at Burra by the Kingston Shear, and it too may have been tapped from lower in the Adelaidean sequence, using the Kingston Shear as its conduit to higher levels in the sedimentary pile.