Vein textures at the Hill Reef Zone, the Poboya prospect, Central Sulawesi, Indonesia

Abstract

Three vein zones hosting gold mineralization have been outlined at the Poboya prospect, named as the River Reef Zone, the Hill Reef 1 Zone, and the Hill Reef 2 Zone. The vein zones were observed within metamorphic rocks leading to an issue regarding classification of the deposit type and exploration of the gold deposit. This paper aims to explain the deposit type of the Hill Reef 1 and Hill Reef 2 Zones according to the characteristics of their vein textures. Macroscopic observation on the considerable number of veins collected from the Hill Reef 1 and Hill Reef 2 Zones show that the vein textures consist of massive chalcedony, massive quartz, massive carbonate, banded chalcedony, colloform, crustiform, cockade, and lattice textures. These textures represent primary growth and replacement textural groups, which are similar to the vein textures observed at the River Reef Zone. Accordingly, the gold mineralization at the Hill Reef 1 and Hill Reef 2 Zones can be classified as a low-sulfidation epithermal deposit. Besides, the predominance of massive and lattice textures in the surface indicate that the veins analyzed in this study are from Chalcedonic Superzone and gold mineralization at the Hill Reef 1 and Hill Reef 2 Zones are well preserved.