巴布亚新几内亚利希尔岛拉多拉姆(Ladolam)金矿矿床地质特征及找矿标志

巴布亚新几内亚利希尔岛拉多拉姆金矿处于太平洋板块与印澳板块的板块边界部位,为西南太平洋地区最大的碱性侵入岩有关的低硫型浅成低温热液型金矿。矿床赋存在Luise火山内,成矿与更新世碱性二长闪长岩侵入体有关,该岩体形成于俯冲带环境下被流体交代的上地幔的部分熔融。矿床的矿化可分为三个阶段,在岩体侵入后形成斑岩铜矿化,并在之后逐渐过渡为浅成低温热液型金矿化。该类矿床在成矿过程和矿体的分布明显受到区域性构造、蚀变带和成矿有关角砾岩等成矿结构面的控制,在找矿标志上具有特定的物化探和地质特征,具有较好的找矿远景。

Geological features and exploration indicators of the Ladolam gold deposit in the Lihir Island, Papua New Guinea

The Ladolam gold deposit in Lihir island, Papua New Guinea is located at the boundary between the Pacific and Indo-Australian plates. It is the biggest alkaline-related low-sulfadation epithermal gold mine in the Southwest Pacific area. This deposit is hosted by Luise caldera, and associated with Pleistocene alkaline monzodiorite which was formed by partial melting of the upper mantle in the subduction zone metasomatosed by fluids. Its mineralization can be divided into three stages, which are porphyry mineralization after ignoeous rock intruded, then gradually transiting into the epithermal deposit, and finally becoming an epithermal hydrothermal deposit. The mineralization and distribution of ore bodies are controlled by regional faults, breccia and alteration zones, and show distinct geological, geochemical and geophysical indicators. This type of mineralization possesses has a great potential for exploration in the Southwest Pacific area.