Mineral Deposits and Tectonics Through Time
Papua New Guinea and the Solomon Islands are located in one of the most prospective regions for intrusion-related mineral deposits (e.g. porphyry, epithermal, skarn). The region of Papua New Guinea and Solomon Islands hosts an abundance of porphyry, epithermal and skarn mineral deposits, such as Ok Tedi, Frieda River, Porgera, Wafi-Golpu, Ladolam (Lihir) and Panguna (Bougainville).
The general relationship between porphyry-epithermal mineralization and subduction zones across the globe implies that there are broad, plate-scale tectono-magmatic controls on where and when these deposits form in the crust. In particular, changes in the subduction regime are commonly considered as crucial parameters triggering mineralizing events, associated with, for example, terrane collisions, subduction of slab structure (e.g., aseismic ridge), or changes in the slab angle during subduction. As mineral exploration progresses to target deposits beneath cover, new approaches require an understanding of the geological settings linked to deposit emplacement. This is applicable on all scales, but we draw particular attention to the need for an appreciation of regional tectonics and the inherent tectonic complexities that arise through time, which may be favorable for deposit emplacement. However, current geological and ore deposit datasets for this area are inadequate to inform meaningful conclusions.
This research tests the hypothesis that subduction-related ore deposits have formed under special circumstances, for example, related to terrane collision, ridge subduction or slab tearing. This is tested through a combination of information from detailed tectonic reconstructions of subduction processes and arc magmatism through time, and the distribution of mineral deposits, the styles of mineralization, and the timing of mineralization.