Great Basin Gold, an international gold mining company, has provided updated estimates on its mineral resource and reserves in the Hollister Gold Project ("Hollister") in Nevada, on the Carlin Trend. The update as on June 30, 2012, reports yield of around 400,000 Au eqv oz, and resource depletion of more than 370,000 t.
The underground drilling over the previous one and a half years had concentrated on the delineating material in the basement meta-sediment hosted gold-silver low sulfidation epithermal veins and the Tertiary volcanic-hosted disseminated gold mineralization veins.
The mineral resource estimate for Hollister has been made based on a Tertiary-hosted mineralization wireframe and grade shell model and an in-situ epithermal vein wireframe model. The estimate reports 12,312 grade intersections which are due to 941 underground and 630 surface boreholes, and 5,547 ore control channel samples. Rigorous geological and vein modeling led to reductions in epithermal vein resource estimates. Silver grades have also declined due to the addition of the Tertiary volcanic hosted disseminated material.
Detailed surface mapping at Hollister has led to the identification of hydrothermal vent and eruptive centers, which indicate further deposition of Au-Ag mineralization. Targets located outside the Clementine-Gwenivere vein systems will be followed up soon. Initially, drilling is being planned for the Velvet - Butte areas and the Hatter target.
The cut-off grade of the mineral reserves has been estimated at 0.15 oz/t Au for the Tertiary mineralization and 0.25 oz/t Au for the epithermal veins. The break even grade for Tertiary mineralization is 0.25 oz/t Au and for epithermal veins it is 0.42 oz/t Au.
The results of the ongoing delineation drilling and trial mining activities have confirmed the prospectivity of the Hollister Gold Project.
Source: http://www.greatbasingold.com/