General Information
Secondary Commodities: gold
Deposit Type(s): Vein Au-Quartz
Location(s): 61.838610 N, -139.484170 W
NTS Mapsheet(s): 115G14
Location Comments: 1.5 Kilometres
Hand Samples Available at YGS: No
Capsule
Work History
R. Berdahl staked the JSB (YB27789) and OHK (YB27799) claims in Aug/90. The OHK claims are located 3 km southwest of the JSB claims, on the opposite side of the Kluane River. Berdahl tied on MBB (YB36203) and JIB cl (YB27696) south of the JSB claims in Jul/91, and performed prospecting, linecutting and geochemical sampling. The MPS claims (YB27845) 12 km to the southeast were staked as part of the same project. The MPS property is documented as Minfile occurrence 115G 107.
In Aug/94 Berdahl restaked the prospect. The MBB cl 1-8 (YB47277) covered the prospect, the JSB cl 1-16 (YB47261) the northern boundary and the JIB cl 1-16 (YB47245 the southern boundary. The HAB cl 1-3 (YB47285) and the OHK cl 1-6 (YB47288) were staked by Berdahl on the opposite side of the Kluane River. In Sep/95 Berdahl carried out a VLF geophysical survey over the northern and southern ends of the main claim block.
Capsule Geology
The claims cover the thrust faulted contact between metamorphosed rocks of oceanic affinity (quartz-chlorite-sericite schist, greenschist and limestone of Devonian to Cretaceous age) and continental rocks of the Nisling Terrane (quartz-biotite schist, quartz-feldspar-biotite gneiss). These rocks are intruded by small granodiorite to diorite stocks of Triassic age, and an alaskite intrusion of Eocene age.
Gold is found in graphitic shear zones, quartz-carbonate veins and silicified shale. The shear zones are strongly sericitized and clay altered. The most significant mineralization discovered to date consists of pyrite and arsenopyrite in quartz-carbonate-mariposite veins and stockworks.
Galena and sphalerite have been found in quartz-carbonate vein float, but not in outcrop.
A specimen of vein material from a graphitic shear zone on Malachite Creek contained 6 830 ppb Au. A chip sample across the same zone returned 5 347 ppb Au across 1 m. Specimens of siliceous shale from the JSB claims contained up to 3 140 ppb Au. Most samples containing anomalous levels of gold also returned elevated values of silver, lead, zinc, cadmium and arsenic.
The VLF survey covered two areas characterized by brown mineralization (heavily oxidized rocks?). Five conductors were outlined on the northern grid while 1 conductor was outlined on the southern grid. All of the conductors trend northwest. The southern most conductor followed Malachite Creek and was interpreted to represent a strong fault cross cutting geologic strike. Two of the other conductors appear to outline known mineralization, but heavy overburden and scarcity of outcrop prevented their explanation.
References
BERDAHL, R. Mar/92. Assessment Report #093021 by R. Hulstein.
BERDAHL, R. Aug/95. Assessment Report #093385 by R. Berbahl .
R. Berdahl staked the JSB (YB27789) and OHK (YB27799) claims in Aug/90. The OHK claims are located 3 km southwest of the JSB claims, on the opposite side of the Kluane River. Berdahl tied on MBB (YB36203) and JIB cl (YB27696) south of the JSB claims in Jul/91, and performed prospecting, linecutting and geochemical sampling. The MPS claims (YB27845) 12 km to the southeast were staked as part of the same project. The MPS property is documented as Minfile occurrence 115G 107.
In Aug/94 Berdahl restaked the prospect. The MBB cl 1-8 (YB47277) covered the prospect, the JSB cl 1-16 (YB47261) the northern boundary and the JIB cl 1-16 (YB47245 the southern boundary. The HAB cl 1-3 (YB47285) and the OHK cl 1-6 (YB47288) were staked by Berdahl on the opposite side of the Kluane River. In Sep/95 Berdahl carried out a VLF geophysical survey over the northern and southern ends of the main claim block.
Capsule Geology
The claims cover the thrust faulted contact between metamorphosed rocks of oceanic affinity (quartz-chlorite-sericite schist, greenschist and limestone of Devonian to Cretaceous age) and continental rocks of the Nisling Terrane (quartz-biotite schist, quartz-feldspar-biotite gneiss). These rocks are intruded by small granodiorite to diorite stocks of Triassic age, and an alaskite intrusion of Eocene age.
Gold is found in graphitic shear zones, quartz-carbonate veins and silicified shale. The shear zones are strongly sericitized and clay altered. The most significant mineralization discovered to date consists of pyrite and arsenopyrite in quartz-carbonate-mariposite veins and stockworks.
Galena and sphalerite have been found in quartz-carbonate vein float, but not in outcrop.
A specimen of vein material from a graphitic shear zone on Malachite Creek contained 6 830 ppb Au. A chip sample across the same zone returned 5 347 ppb Au across 1 m. Specimens of siliceous shale from the JSB claims contained up to 3 140 ppb Au. Most samples containing anomalous levels of gold also returned elevated values of silver, lead, zinc, cadmium and arsenic.
The VLF survey covered two areas characterized by brown mineralization (heavily oxidized rocks?). Five conductors were outlined on the northern grid while 1 conductor was outlined on the southern grid. All of the conductors trend northwest. The southern most conductor followed Malachite Creek and was interpreted to represent a strong fault cross cutting geologic strike. Two of the other conductors appear to outline known mineralization, but heavy overburden and scarcity of outcrop prevented their explanation.
References
BERDAHL, R. Mar/92. Assessment Report #093021 by R. Hulstein.
BERDAHL, R. Aug/95. Assessment Report #093385 by R. Berbahl .
Location Map
Regional Geology - Terrane
Group: Intermontane
Affinity: W Laurentia
Name: Yukon-Tanana
Realm: peri-Laurentian
Regional Geology - Bedrock
Supergroup:
Group/Suite: Snowcap
Formation:
Member: meta-siliciclastic
Terrane: Yukon-Tanana
Period Max: Ediacaran
Age Max: 635 MA
Period Min: Devonian
Age Min: 375 MA
Rock Major: psammitic schist
Rock Minor: pelitic schist
Reference: Murphy (2014) - unpublished compilation
Geological Unit (1M): PDS
Geological Unit (250K): PDS1
Assessment Reports that overlap occurrence
| Report Number | Year | Title | Worktypes | Holes Drilled | Meters Drilled |
|---|---|---|---|---|---|
| 094576 | 2004 | Soils Survey for the Toshingermann Lake Project 115G13/14 | Soil - Geochemistry | ||
| 093385 | 1994 | Geophysical and Geochemical Report on the Tosh Property 115G13/14 | EM - Ground Geophysics, Line Cutting - Other | ||
| 093021 | 1990 | Summary Report on the Tosh Project | Rock - Geochemistry, Silt - Geochemistry, Soil - Geochemistry |
Related References
| Number | Title | Page(s) | Document Type |
|---|---|---|---|
| ARMC013083 | Map of Toshingermann Lakes area with geology notations - Aeromagnetic series map 4301G | Geoscience Map (Geological - Bedrock) |
| Citations |
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