The Character and Spatial Distribution of Epsthermal Gold Mineralisation at the Ladofam Gold Deposit, Lihir Island, Papua New Guinea

摘要

The 40 Moz Ladolam gold deposit on Lihir Island, Papua New Guinea is the world's largest, low-sulfidation, epithermal gold deposit, in terms of contained gold. The deposit has average grades of 2.42 g/tAu (LGL Resources Reserves Update, 2008) and gold is hosted primarily in refractory pyrite. Lihir Island is part of the 150 km long, Tabar-Lihir-Tanga-Feni, alkalic, volcanic island chain located in the New Ireland basin. Five volcanic blocks comprise Lihir; Plio-Pliestocene Huniho, Kinami and Luise volcanic edifices are built on top of remnant Pleistocene Wurtol Wedge and Londolovit Block (Wallace et al, 1983). The Ladolam gold deposit is located in the central portion of the dissected Luise volcanic edifice and is composed of four main orebodies: 1. Minifie, 2. Lienetz, 3. Coastal, and 4. Kapit. An active geothermal system is overprinted on the ore deposit, localised along north-trending lineaments, and is expressed as hot mud pools and fumaroles.