Returns from copper and gold won from the Moonta-Wallaroo district supported the South Australian economy from 1860-1920. During those 60 years some 355,000 t of copper and 2 t of gold were extracted from the twin mining fields of Wallaroo and Moonta: it is to this mineralisation that the towns of Kadina and Moonta owe their existence. Only in 1994 did the Moonta Mining Company entity withdraw from the area, following the extraction of latterly discovered orebodies from its Poona Mine and Wheal Hughes, an operation which produced ~18,000 t Cu from 450,000 t of ore running 1.0 g/t Au (AMALG Resources, 1993). Mineralisation and alteration throughout the district is so widespread that, in spite of intensive, albeit unsuccessful exploration, it is difficult to believe that other hidden, viable commercial deposits are absent. Many major explorers (Aquitaine, BHP, CRAE, MIMEX, Poseidon, St Joe Minerals, Uranerz) have spent money in the area, with WMC and NBH holding the ground for 30 years. The main difficulty for explorers has stemmed from the area being marginal to the 'Adelaide Rift'. Onlapping shelf sediments of Adelaidean, Lower Cambrian, Permian, Tertiary and Recent age form thin, irregular remnants covering basement; the difficulties in accessing the basement are further increased by the masking effects due to deep weathering which occurred during the Tertiary, and by the current saline groundwater regime. Patrick Ryan, a shepherd, and James Boor are given the credit of discovering the Moonta Field in 1861 by recognising copper minerals in spoil from a wombat burrow. 'Wombats 2, geologists nil' is an historic comment pencilled in the margin of a MESA Open File Envelope; it indicates the status of exploration for the period 1920-1985! Fortunately the discovery of Poona Mine and Wheal Hughes by WMC in 1985 evened the score a bit; anyway, the wombats have had a longer time to look!