Laser Ablation ICPMS Analysis of Pyrite and U-Pb Zircon Dating of Host Rocks From the Tersang Gold Deposit, Malaysia

Abstract

The Central gold belt of peninsular Malaysia comprises a number of gold deposits located in the east of the N-S striking Bentong-Raub Suture Zone. The Tersang gold deposit is a mesothermal, orogenic gold deposit, which is hosted in sandstone, shale, rhyolite and breccia. The deposit has an inferred and indicated resource of 120,000 ounces of gold in the JORC category. Detrital zircon grains from the host sandstones returned a maximum depositional age ranging from Early Carboniferous to Early Permian (333.5 ± 2.5 Ma-261.5 ± 4.9 Ma) and those of the rhyolite indicated a crystallization age of 218.8 ± 1.7 Ma. Pyrite trace element mapping has revealed four pyrite phases. Laser Ablation ICPMS analyses on pyrite has shown that pyrite phase 1 has the lowest Au concentration (mean 0.4 ppm) and is interpreted to have preceded the main Au mineralisation stage. Pyrite phases 2 and 3 are the main Au mineralisation stage with Au mean range from 1.5 to 4.5 ppm and contributed most of the invisible gold to the ore-forming system. Pyrite phase 4 has low gold concentrations (mean 0.5 ppm) and post-dated the main Au mineralisation stage recorded in pyrite phases 2 and 3. The trace element chemistry of pyrite indicates that Au mineralisation recorded in pyrite is likely a product of four stages ore forming system centred on the rhyolite corridor. In terms of gold exploration, gold has a positive correlation with As, Ag, Cu, Se, Sb, Pb and Tl in pyrite. These metals can be used as pathfinders to detect proximity to ore for orogenic gold deposit type in the central gold belt of Peninsular Malaysia.

Keywords

• LA-ICP-MS
• Trace element
• Pyrite
• Tersang gold deposit
• Bentong-Raub Suture Zone
• Malaysia