At Windfall, gold occurs within a 1.7 km north-south trend where approximately 110,000 oz was mined and processed from the Windfall, and adjacent Paroni and Rustler open pits from the mid-1970’s to early 1980’s. The operation was among the industry’s first stand-alone, open pit heap leach operations in Nevada.
Windfall-trend Drill-indicated Gold Zone
The gold mineralized zone at Windfall occurs along the north-south structural trend which typically separates steeply-dipping Hamburg Dolomite Formation to the west, from moderate east-dipping Dunderberg Shale Formation to the east. Gold appears to be dominantly associated with brecciated dolomite adjacent to and between northeasterly and northwesterly trending cross-faults. Gold grade-thickness anomalies from historic drill hole intercept assays suggest similar structural control on higher-grade gold mineralization. The structures appear to focus gold mineralization within intensely bleached and “sanded”, variably brecciated (collapse-style, and/or structural breccias) Hamburg Dolomite Formation. Limited silicification (e.g. as jasperoid) is evident in the rocks which likely relates to the reported historic excellent leachability of gold in the Windfall mine.
Distribution of Gold in Rocks of the Windfall Pit Area
Timberline recently collected 40 rock chip samples within and immediately south of the Windfall pit; assays are summarized below. Highlights include 10 samples with greater than 1 g/t (0.029 opt) gold and 6 greater than 3 g/t (0.088 opt), up to a maximum of 13.1 g/t (0.382 opt). In total, 17 samples assayed greater than 0.250 g/t (0.007 opt), documenting the extensive zone of gold mineralization.
Windfall Trend Rock Chip Sampling Results
Thirty-one BHWF-series reverse circulation holes and one core hole have been drilled in the Windfall target area since approximately 2008 resulting in several intercepts documenting the presence of unmined mineralization in the trend.
Gold Assays and Grade-thickness for 2008-2015 Windfall Trend Drilling
The historic Paroni-Windfall-Rustler pit area is owned by Timberline as patented claims which provides excellent flexibility in exploration planning. Exploration plans have been developed for the Windfall trend including a CSAMT geophysical survey, along with follow-up drilling.