The host rocks are a part of the lower part of the Devonian Raneces Formation limestone.  The Carlés calcic skarn forms a rind around a granodioritic intrusive.  Intercalated pyroxene- and garnet-bearing rocks comprise the skarn; irregular layers of retrograde magnetite-amphibole host the higher grades of gold and copper.  Known mineralization is higher grade and more continuous along the northern and eastern parts of the intrusive.  Principal minerals are chalcopyrite, bornite, pyrhhotite, arsenopyrite, and electrum.  The mineralized layers are subvertical and are from 2 metres to 15 metres wide.
 
From 2000 through 2005, 305,000 tonnes of 4.5 g/t gold and 0.77% copper were mined by open-pit methods.  From 2003 through 2006, 444,000 tonnes of 5.1 g/t gold and 0.82% copper were mined by underground methods.