The Kapit ore zone of the Ladolam low-sulfidation epithermal gold deposit: geology, alteration, and comparison with the Lienetz and Minifie ore zones

The 46 Moz Ladolam gold deposit, Papua New Guinea, has an average grade of 2.42 g/t and is the world's largest known low sulfidation epithermal gold deposit. The deposit is characterised by a telescoped porphyry-epithermal system <0.5 million years in age, hosted in the brecciated core of a volcanic edifice (Sillitoe, 1994; Carman, 2003, Blackwell, 2010). The Ladolam breccia complex that hosts gold mineralization includes brecciated mafic volcanics, alkalic intrusive and sedimentary rocks, together with hydrothermally cemented and matrix-rich breccias. In order to understand the location of the gold and the timing of the formation of gold hosted mostly in refractory pyrite LA-ICPMS analyses on pyrite from different stages and ore zones have been performed. The results demonstrate that several episodes of gold deposition occurred in each ore zone at Lihir, and that indivudal Au-rich growth bands in pyrite contain high concentrations of As, Te and/or TI.