Toronto-based Borneo Gold (BNO-V) has intersected two styles of gold occurrence during an initial phase of drilling on the Bunut epithermal project in West Kalimantan, Indonesia.
Gold mineralization occurred along descrete fractures, sometimes with free gold, as was typified by intersections over narrow widths such as 23.6 grams gold per tonne over 1.5 metres, 4.83 grams over 1.5 metres and 4.58 grams over 1.5 metres.
In addition, sub-economic disseminated gold mineralization was encountered over significant widths, including 88 metres grading 0.21 gram, 46.5 metres of 0.22 gram, 33 metres of 0.36 gram, and 16.5 metres of 2.17 grams.
The intrusive-related processes necessary to form a gold deposit were found to occur in the area of the Monsan dome. However, Bunut reports that the hydrothermal system there did not have sufficient intensity to evolve into an economic gold deposit.
The junior believes the Bunut property continues to have significant untested potential. The limited gold values encountered in the initial drilling program do not explain the significant gold mineralization in the Bunut intrusive complex that has not been identified through exploration on the property to date. This source is likely to be one or more of the other untested intrusions on the property which may have developed a hydrothermal system with the intensity necessary to form an economic gold deposit.
The property is dominated by a series of volcanic and sub-volcanic domes. The Monsan dome complex has the focus of exploration efforts to date.
The dominant alteration in the Monsan dome is sercite-clay. Sericite replacement of biotite, hornblende and partial replacement of feldspar phenocrysts characterize this alteration style. Pyrite is found in pseudomorphing biotite or hornblende, while disseminated and vein pyrite is limited.
The source of the significant concentrations of gold in alluvial and in soils has been a determining factor in exploring the property. The surface soil geochemical sampling seems to reflect the limited gold distribution encountered in drill-testing of the Monsan dome. Soil pan concentrate sampling is believed to reflect the distribution and concentration of gold in soils transported from a source other than the Monsan dome complex, which appears to have been too weakly mineralized to be responsible for the significant gold concentrations encountered. It has been concluded, therefore, that there is a source of significant gold mineralization in the Bunut intrusive complex that has yet to be located.
Drill-testing of the Monsan dome complex has established the geologic charter of this intrusive system, a multi-phase extrusive and intrusive dome complex of Sintang age. Hydrothermal alteration contains alteration styles consistent with magmatic fluid sources. These observations indicate that at least one intrusive phase segregated a gold-bearing magmatic fluid that is capable of producing economic gold concentrations. Borneo Gold believes that other dome complexes in the contract area may be more productive.
Radiometric surveys have defined the limits of the dome complexes, and soil geochemistry has proved effective in identifying broad gold concentrations in soil, while depressing the effects of reconcentration of transported gold.
Borneo Gold, which has more than $2 million in cash, is seeking a joint-venture partner for its Bunut project.
Be the first to comment on "Borneo Gold completes drill phase in Indonesia"