New Gold Discovery in the White Gold District
The Mariposa property is located approximately 120 km south of Dawson City. The western boundary of the lies approximately 12 kilometres northeast of Kaminak Gold's Coffee Gold project and 15 kilometres southeast of Kinross Gold's White Gold project. Since 2009, the Company has expanded the original Mariposa property area by more than 500%, to now comprise approximately 1450 quartz claims covering an area of 280 square kilometers.
The property lies within the Dawson Range Mineral Belt, a 125 kilometre long, northwest trending corridor of mineral deposits and prospects, that extends from the Mt. Nansen area in the southeast, into the White Gold area in the northwest.
Exploration targets on the property lie within a 30 kilometre length of prospective geology that bears similarities to that of both the White Gold and Coffee gold discoveries. The targets identified to date lie within a 15 kilometre long brittle deformation zone referred to as the Mariposa Fault. This structure remains largely unexplored; however, in prolific gold mining camps, such corridors have potential to host significant gold deposits. The Mariposa Fault and its related subsidiary structures are interpreted to cut the drainages of Scroggie and Mariposa Creeks, where placer mining of alluvial gold has been conducted for over 100 years. Our exploration activities are focused on finding bedrock sources to these productive placer gold deposits, and in 2011, significant gold mineralization was intersected in the first hole drilled on the property.
Since 2009, Pacific Ridge has been exploring the vast property holdings with soil geochemical and geophysical surveys, backhoe trenching, prospecting and diamond drilling. This work has been designed to identify new targets, and also to refine existing targets before diamond drilling. To date, the company has collected 13,000 soil and silt samples; excavated and sampled 7 trenches; conducted an airborne magnetic survey over 25% of the property; conducted detailed ground magnetic and electromagnetic surveys over 190 line kilometers, and completed 6000 metres of drilling in 41 holes. The compiled results for over 7500 soil samples collected on the property this year, are pending.
Highlights of our work to date include:
- Significant gold in bedrock drilled at Skookum Main, with intercepts of up to 2.44 over 39 metres.
- 14 of 18 holes drilled at Skookum Main intersected gold mineralization within steeply dipping, brittle structures. Gold intercepts lie within an open-ended corridor of strong gold-in-soil results that is closely coincident with magnetic lows defining geological structures within the Mariposa Fault.
- Five gold-in-soil and multi-element soil anomalies identified on the Mariposa Grid, within the property scale, Mariposa Fault Zone. Results from an additional 7500 soil samples collected this season, are pending
- Expanding footprint of 3500 m long x 600 m wide Skookum Jim Trend, based on geochemical anomalism (soil, silt, rock) and prospective structures interpreted from geophysical surveys. Prospecting located anomalous rock samples in the Skookum Main area, of up to 8.1 g/t gold near the trenches and to 2.3 g/t gold downslope, to the north, where soil sampling had not been completed . Anomalous silt samples draining this north slope also returned highly anomalous results of up to 323 ppb gold. Soil results are pending.
- Trenches in the Skookum Main area (eastern part of Skookum Jim Trend) expose widespread fractured, oxidized rock with local quartz breccias and veinlets. Results from composite rock samples returned up to 1.25 g/t gold over 30 metres. Results of infill soils are pending, as well as from a 2011 trench excavated to the northeast.
- Expansion of property holdings by staking, to cover prospective interpreted structural trends and possible sources to geochemical anomalism in government stream sediment samples.
Work to date has mostly focused on the 10 km long x 5 km wide Mariposa Grid, which covers the original property area, and 10% of the current holdings. The combined results of geological mapping and both airborne and ground geophysical surveys indicate the area is underlain by older, metamorphic rock types that have been affected by multiple episodes of faulting. This brittle deformation is recognized as breaks and offsets of linear magnetic trends that map different rock types, and provides ground preparation that is favourable for migration of gold-bearing fluids and deposition of gold. The observed patterns of a series of EW trending structures, together with subsidiary NE and NS trending structures, define a property scale corridor which is collectively referred to as the Mariposa Fault.
The 2010 soil sampling program was focused on the Mariposa Grid, where magnetic signatures indicate converging arrays of NE, NS and EW trending structures are present. Five gold and multi-element soil anomalies were identified from grid sampling, with peak gold results to 1570 ppb. The largest anomaly is the open-ended 3500 metres long x 600 metres wide Skookum Jim trend, which is centred on a northeastern trending plateau dissected by converging NE, NW and NS trending topographic breaks and creeks.
Follow-up prospecting in 2010 and 2011 along Skookum Jim soil trend also located anomalous gold in rock samples (float) of up to 8.1 g/t in the eastern area (Skookum Main), 19.9 g/t in the western area (Skookum West), and 2.3 g/t in the north. These results, together with highly anomalous gold up to 323 ppb obtained from silt samples of creeks draining the frozen (permafrost) north slope of the plateau, suggest that footprint of the Skookum Jim Trend may be much larger than the original soil anomaly. To test this possibility, soil sampling in 2011 extended the Mariposa grid, to cover areas north and east of the Skookum Jim Trend. Results from this work are pending.
In 2010, five north-trending trenches were excavated within the Skookum Main area to test the strong soil anomalism. Broad areas of strongly fractured, oxidized rock with local quartz +/- K feldspar veinlets and breccias were exposed. The best results from composite rock samples were obtained from Trench SJ-2, where an interval returned 1.25 g/t gold over 30 metres, within a broader interval of 0.67 g/t gold over 105 metres. Selected rock samples within Trench SJ-2 returned up to 3.54 g/t gold, and up to 521 ppm molybdenum.
In 2011, the first diamond drilling program on the Mariposa property tested five areas with encouraging soil and trenching results that are closely coincident with interpreted geological structures. The program tested five areas on the Mariposa Grid: Skookum Main, Skookum West, Maisy May, Gertie and Hackly Gold. The occurrence of significant gold in bedrock was confirmed in and successfully intersected gold in bedrock in several drillholes in the Skookum Main area.