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Occurrence Details


Occurrence Number
115I 140
Occurrence Name
Cyprus South
Occurrence Type
Hard-rock
Status
Showing


General Information

Secondary Commodities: copper, molybdenum
Deposit Type(s): Porphyry Cu-Mo-Au
Location(s): 62.088510 N, -137.159150 W
NTS Mapsheet(s): 115I03
Location Comments: Location provided by Rockhaven Resources 2019
Hand Samples Available at YGS: No

Capsule

Work History

The porphyry occurrence was first recognized in late 1969 by several exploration groups while most of it lay within the large claim block surrounding the Mt Nansen vein property. During 1970, the Swiss interests controlling Mt Nansen Mines Ltd. explored the porphyry potential with stream sediment and soil geochemical sampling and airborne magnetometer, EM and K40 surveying. The portion of the claims beyond the mill site and developed vein systems were optioned from 1971-1975 by Area Exploration Company, a Cyprus Exploration Corporation Ltd. subsidiary.

Mt Nansen Mines Ltd. transferred its interest to BYG Natural Resources Inc. in 1984. Chevron Canada Resources Ltd. optioned the BYG property in June 1985 and re-staked the west side of the occurrence as TBR cl 1-8 (YA86690) in May 1985 and EEK cl 1-18 (YA87210) to the east in June 1985. BYG encountered financial difficulties at the end of 1996 and suspended most exploration activities. In February 1999, BYG announced plans to temporarily shut down the Mount Nansen Mine. In March 1999, BYG was placed in receivership and the Nansen mine became a Type II Minesite. In 2004, the court appointed receiver PricewaterhouseCoopers to manage the mines’ assets. In 2007, the receiver sold 199 periphery claims to #101073531 Saskatchewan Corp., which included the Cyprus South, Flex, Webber and part of the Huestis zones.

In 2009, 101073531 Saskatchewan Corp. flew a regional airborne and magnetic survey that included the Cyprus South occurrence.

Guinness Exploration Inc. optioned the claims in 2010 and performed limited mapping and sampling in the Cyprus area which revealed historical trenching and bagged rotary drilling cuttings anecdotally attributed to BYG. No recorded history of this work was found. Guinness Exploration also performed trenching in the vicinity of the Cyprus South occurrence.

In 2011, Ansell Capital Corp. optioned the claims from Guinness Exploration and performed trenching and soils at the Cyprus South occurrence.

Regional & Property Geology

The occurrence is located in the Dawson Range within Yukon-Tanana Terrane (YTT). The rocks of the YTT in this region consist of Early Mississipian metamorphic rocks separated into meta-sedimentary and meta-igneous suites (Stroshein, 1998). The meta-sedimentary suite consists of micaceous quartz-feldspar gneiss, schist and quartzite of the Nasina Assemblage. The meta-igneous package is comprised of biotite-hornblende feldspar gneiss and coarse-grained granodiorite orthogneiss with lesser amphibolite.

Four rock types dominate the geology surrounding the occurrence and are comprised of:
1. Paleozoic metamorphic Yukon-Tanana gneiss, quartzite, and amphibolite to the south;
2. Triassic to Jurassic metamorphosed alkali-feldspar-rich plutonic suites;
3. Mid-Cretaceous Mount Nansen Suite andesite, felsic lapilli tuffs, basaltic to latite volcanic rocks; and quartz feldspar porphyry, dacite, latite, and quartz monzonite porphyritic hypabyssal rocks; and
4. Mid-Cretaceous Whitehorse granodiorite.
 
The Cyprus South is part of a porphyry copper-molybdenum complex (MINFILE occurrence 115I 066) found in the northeast section of the property, with argillic and propylitic alteration haloes covering the remainder. The porphyry complex occurs at the intersection between a major northwest structure and an east-west fault. Copper and molybdenum ± gold and silver occur in a porphyry stock and phyllic-altered granodiorite. Surface leaching and oxidation is variable, but can reach considerable depths. A steeply dipping, northwest-striking epithermal vein system which formed peripheral to the porphyry migrated inward during cooling and collapsed, creating a complex system of overlapping mineralization including: porphyry Cu-Mo-Au-Ag; northwest striking mesothermal quartz-pyrite-gold veins; and northwest striking epithermal quartz-Au-Ag-Pb-Zn-Cu veins.

Mineralization & Results

The Cyprus South occurrence is within a phyllic-altered northwest-trending porphyry dyke in the peripheral zone of the porphyry. Mineralization consists of pyrite in quartz stockworks up to 60 m wide (Hart, 1997).

Trenching near the Cyprus South occurrence by Guinness Exploration in 2010 encountered pyrite, as well as chalcopyrite, malachite, and arsenopyrite with phyllic and minor propylitic alteration.

Trenching in 2011 by Ansell Capital Corp. returned up to 0.129 g/t Au and 25.3 g/t Ag over 1.0 m in GRW-TR10-03 in a strongly altered clay zone. The trench contained variably clay altered, fine-grained granodiorite crosscut by a quartz-feldspar porphyry dyke and andesite with disseminated and fracture-controlled pyrite from 52.0 to 74.0 m. Trench GRW-TR11-06 contained more pyrite mineralization in interfingering medium-grained granodiotite and quartz-feldspar porphyry and returned 0.22 g/t Au and 0.90 g/t Ag over 2.7 m.

Location Map

Last Updated: Mar 12, 2024

Work History

Year Work Type Comment
2023 Geochemistry: Rock
2023 Geochemistry: Soil
2023 Ground Geophysics: Magnetics
2011 Geochemistry: Soil
2011 Trenching: Mechanical
2010 Geochemistry: Rock
2010 Geology: Bedrock Mapping
2010 Trenching: Mechanical
2009 Airborne Geophysics: Magnetic And EM.
1985 Geochemistry: Soil

Regional Geology - Terrane

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Related References

Number Title Page(s) Document Type
YEG1998_20 A summary report on the geology of the Brown-McDade gold-silver deposit, Mount Nansen mine area, Yukon Annual Report Paper
YEG1997_14 Geology and mineral deposits of the Mount Nansen camp, Yukon Annual Report Paper
Citations

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