Having now received a key drill permit in early October, this next phase of drilling will test large-scale porphyry and high-grade skarn targets with step-outs and deeper holes guided by decades of geologic mapping, geochemical sampling, geophysical surveying, and 3D structural modelling.
Targeting the porphyry system at depth
The highest-priority holes will probe beneath previously intersected copper-gold skarn zones, testing induced-polarisation (IP) chargeability highs and coincident magnetic boundaries interpreted to represent the top of a concealed porphyry copper-gold centre.
“As our geologic team has continued to generate, compile, and model data, the source of Madison’s high-grade skarns and veins is becoming much clearer,” commented Managing Director of Exploration, Eric Saderholm. “This is truly an exciting time for American Pacific given that, less than two years ago when we started evaluating new and historic datasets, concepts like these targets were not yet defined or well understood. At that time, we understood Madison to be a high-grade copper-gold porphyry expression, the origins of which we could only speculate. Today, we have a much more precise understanding of the source of those high-grade zones and Phase II drilling will focus on these newly identified targets as we work to demonstrate Madison’s full potential.”
Expanding high-grade skarn mineralisation
Step-out holes along the Silver Star structural corridor will aim to expand known zones of high-grade copper-gold skarn mineralisation. Historical intercepts included 30.18 m of 24.50 grams per tonne (“g/t”) gold and 0.39% copper and 10.97 m of 41.65 g/t gold and 0.38% copper from underground drilling. The upcoming program will test down-dip and along-strike extensions where skarn alteration remains open, particularly at lithologic contacts between the Madison Group limestone and the Rader Creek intrusions.
Untested structural targets
In addition to known zones, several new areas are now within the Company’s targeted plan, including structurally hosted style targets defined by strong alteration, veins, and copper-oxide staining at surface along structural pathways. Shallow holes will evaluate these features as potential feeder conduits linking upper-level skarn and vein mineralisation to deeper intrusive sources.
District-scale potential
American Pacific’s geologic team has outlined multiple magnetic and geochemical anomalies across the district. One newly mapped mafic intrusion returned assays up to 38.5 g/t Au and 33 g/t Ag from grab sampling. These anomalies will be tested with shallow reconnaissance holes to evaluate the scale and continuity of the mineralised system across the property. About the Madison Copper-Gold Project The Madison Project was host to small-scale production that concluded in 2012, with 2.7 million pounds of copper produced at grades ranging from 20-35% copper. Subsequent drilling at Madison in 2017 included 30.18 m of 24.50 g/t gold and 0.39% copper and 10.97 m of 41.65 g/t gold and 0.38% copper (UG17-05 and UG17-06, respectively). Additional production at the nearby Broadway/Hudson Mines is reported to total ~147 000 ounces gold at 9.9 g/t and recent drilling has provided substantial evidence to demonstrate a structural and stratigraphic link connected the past-producing, which are located along the same northwest-trending corridor of altered quartz monzonite and associated skarn that is now understood to be a part of the same mineralising system.