AnEXTENDED ABSTRACTis available for download._x000D_
A full-length paper was notprepared for this presentation._x000D_
Low-sulfidation epithermal gold mineralisation at Ridge Mountain occurs within the Oligocene to Miocene volcanic rocks comprising andesite, porphyritic dacite and diatreme breccia. A diatreme breccia complex with a NE-SW elongated orientation covers an area of 3.0_x000D_
1.7 km. Four main stages of mineralisation were identified, comprising: E-W- to NW-SE-trending quartz-chalcedony veins with disseminated pyrite, chalcopyrite and gold._x000D_
N-S- to NNE-SSW-trending breccia veins with quartz matrix and disseminated pyrite and accessory sphalerite, galena, chalcopyrite and gold._x000D_
NE-SW-trending quartz and calcite veins with disseminated pyrite and accessory sphalerite, galena, chalcopyrite and gold._x000D_
ESE-WNW- to ENE-WSW-trending quartz veins with disseminated pyrite. This stage is only mineralisation that is hosted by diatreme breccia and clearly postdates._x000D_
Quartz veins of the first, third and fourth stage are less than 2 m wide._x000D_
Only breccia veins of the second stage are up to 10 m wide. Gold is present in all stages as microscopic inclusions in quartz and sporadically in pyrite._x000D_
Macroscopic gold can be seen in the first and second mineralisation stages. Gold commonly occurs in association with sphalerite, galena and chalcopyrite in the second and third mineralisation stages.CITATION:Kucera, J, 2015. Diatreme breccia-hosted epithermal gold deposit at Ridge Mountain, eastern Mindanao, Philippines, in Proceedings PACRIM 2015 Congress, pp 587-592 (The Australasian Institute of Mining and Metallurgy: Melbourne).