General Information
Secondary Commodities: tungsten, gold, silver, lead, zinc
Aliases: Flat Ridge, Rau Trend, Rackla Gold Belt
Deposit Type(s): Manto Polymetallic Ag-Pb-Zn
Location(s): 64.2054 N, -134.366040 W
NTS Mapsheet(s): 106D01
Location Comments: Coordinates supplied by ATAC 2019
Hand Samples Available at YGS: Yes
Last Reviewed: May 4, 2016
Capsule
Last Updated: May 4, 2016Work History
Staked within Blue Lite cl 1-128 (YA40742) in August, 1979 by the Prism Joint Venture 1979 (Asamera Oil Corporation Ltd., Chieftain Development Company Ltd., Prism Resources Ltd., Dome Petroleum Ltd. and E & B Explorations Ltd.) during a regional exploration program. The claim block covered the Blue Lite occurrence (MINFILE occurrence 106D 084) located approximately 5 km to the northeast.
The joint venture carried out a regional silt sampling and prospecting program over the entire claim block during the 1979 season. Results from this program led to the discovery of a mineralized skarn in an area the joint venture group informally named Flat Ridge (now Flat Top). The area surrounding the occurrence was trenched, grid soil sampled and regionally mapped later in the summer. In 1980, the group carried out detailed mapping around the occurrence.
Re-staked within Rau cl 1-64 (YC50268) in July, 2006 by ATAC Resources Ltd. In 2007 and 2008 the company flew helicopter-borne magnetic and VTEM surveys over the claim block as part of a larger program carried out over the entire Rau exploration property. ATAC Resources added Rau cl 65-96 (YC57529) in October 2007, R cl 1-1295 (YC68334) in July 2008 and S cl 1-1250 in 2009.
In April 2008, ATAC Resources optioned Rau cl 1-32 (YC50268) and cl 87-94 (YC57551) (referred to as the Wau option) to Yankee Hat Minerals Ltd. in return for shares in Yankee Hat and certain work commitments. The option agreement allowed Yankee Hat to explore the area for tungsten mineralization in the vicinity of the occurrence. Between June and July 2008 Yankee Hat Minerals prospected and collared 3 diamond drill holes (437.38 m) on the claims with only one of these drill holes testing the Flat Top occurrence. In February 2009 the company dropped its option without any interests being earned.
ATAC Resources carried out prospecting at the Flat Top occurrence in 2009.
Regional & Property Geology
ATAC Resources carried out the 2008 exploration program on behalf of Yankee Hat Minerals. At that time, the Rau claims surrounding this occurrence had seen very little modern detailed mapping. Based on geological mapping and correlation studies carried out in later programs the occurrence is located along the contact between Mackenzie Platform dominantly shallow water carbonate and clastic sediments and regionally metamorphosed basinal sediments deposited in the Selwyn Basin. Both packages were deposited on the western margin of North America. The contact is believed to be marked by a thrust fault that thrusts older Mackenzie Platform Bouvette Formation (Cambrian to Devonian) rocks onto younger Selwyn Basin Earn Group (Devonian to Mississippian) rocks. In the south end of the claim block a high angle normal fault(?) places Selwyn Basin rocks against Mackenzie Platform rocks.
ATAC Resources (AR 096936) has mapped 3 main units in the area comprising the Rau Trend:
1. Cambrian to Ordovician massive, grey dolostone,
2. Ordovician and/or Silurian bedded, grey and buff silty limestone and massive white limestone, and
3. Silurian to Devonian thick, bedded dolostone and limestone.
The company has assigned all three units to the Cambrian to Devonian Bouvette Formation. Colpron’s 2013 geological map generally supports this interpretation; however it uses slightly different age dates and doesn’t include the oldest rocks (Cambrian to Ordovician dolostones) within the Bouvette formation.
In the southwest corner of the claim group thin volcanic horizons assigned to the Marmot Formation (Cambrian to Silurian) are interbedded with the Bouvette Formation rocks. The horizons range from a few metres to about 20 m thick and are locally magnetic. Although volumetrically insignificant it appears these horizons have played an important role in localizing mineralization in the underlying carbonates by acting as an impermeable cap. The Rackla Pluton, a granitic intrusion assigned a (U-Pb zircon) age of 62.9 ± 0.5 Ma intrudes Bouvette Formation rocks in the east central portion of the claim block. Numerous dyke and sills associated with the pluton intrude the Bouvette Formation in the northwest portion of the claim block.
Mineralization & Results
The Flat Top showing lies along a north trending ridge (originally named Flat Ridge by the Prism joint venture), that outcrops along the contact between Bouvette Formation and Earn Group strata. Prism Resource discovered scheelite and tungsten mineralization on the ridge in 1979. Soil sampling carried out in 2008 outlined coincident, moderately to strongly anomalous gold, copper and tungsten values in an area measuring approximately 600 m long and up to 300 m wide. Prospecting carried out in 2009 traced skarn mineralization around the nose of the ridge for approximately 400 m. Geological mapping carried out by ATAC Resources noted four types of skarn mineralization occurring across a stratigraphic thickness of about 40 m. The four types of skarn (AR 096936) noted are:
1. Felted to radiating masses of acicular tremolite/actinolite or wollastonite/actinolite in a localized band up to several metres wide above the limestone/shale contact,
2. Masses of tremolite ± calcite in cm sized veinlets within unaltered carbonate,
3. Fe-rich skarn with aggregates of radiating, acicular tremolite/actinolite masses replacing carbonate,
4. Most Fe-rich skarn with masses of light green actinolite, local tourmaline, biotite, grey quartz and massive limonite upward from the contact.
Prism Resources (1980) reported rock samples assaying up to 8.38% tungsten oxide (WO30), although typical samples from the area returned average grades of less than 0.04% tungsten oxide. Two skarn samples collected in 2008 from talus lying overtop the mineralized zone, close to the collar of the drill hole returned 166 ppb gold, 176 ppm tungsten and 289 ppb gold and 92 ppm tungsten. ATAC Resources tested the mineralized zone with a single drill hole in 2008 but the hole was collared too far downhill and only intersected shale belonging to the Earn Group (AR 096936).
ATAC Resource collared a second hole to test a linear magnetic high that trends through an area of mineralized actinolite-diopside +/- garnet skarn float located in the southwest end of the claim block. The hole intersected 182.54 m of limestone that is cut by several narrow pegmatite and granitic dykes and sills. The best result came from actinolite skarn bands which returned peak values of 781 ppm and 445 ppm tungsten over 1.08 m and 1.0 m respectively.
The last drill hole collared by ATAC Resources tested a magnetic anomaly in an area where a skarn band is exposed near a creek on the west-central side of the claim block. Rock samples collected during a prospecting program carried out in 2006 returned values up to 4 010 ppm tungsten. The hole intersected limestone interbedded with chlorite skarn bands, which are less that 0.5 m thick except for one that is 8.13 m thick. Core samples of skarn typically returned 36.5 to 610 ppm tungsten, with a peak value of 1,220 ppm W over 9 cm.
Staked within Blue Lite cl 1-128 (YA40742) in August, 1979 by the Prism Joint Venture 1979 (Asamera Oil Corporation Ltd., Chieftain Development Company Ltd., Prism Resources Ltd., Dome Petroleum Ltd. and E & B Explorations Ltd.) during a regional exploration program. The claim block covered the Blue Lite occurrence (MINFILE occurrence 106D 084) located approximately 5 km to the northeast.
The joint venture carried out a regional silt sampling and prospecting program over the entire claim block during the 1979 season. Results from this program led to the discovery of a mineralized skarn in an area the joint venture group informally named Flat Ridge (now Flat Top). The area surrounding the occurrence was trenched, grid soil sampled and regionally mapped later in the summer. In 1980, the group carried out detailed mapping around the occurrence.
Re-staked within Rau cl 1-64 (YC50268) in July, 2006 by ATAC Resources Ltd. In 2007 and 2008 the company flew helicopter-borne magnetic and VTEM surveys over the claim block as part of a larger program carried out over the entire Rau exploration property. ATAC Resources added Rau cl 65-96 (YC57529) in October 2007, R cl 1-1295 (YC68334) in July 2008 and S cl 1-1250 in 2009.
In April 2008, ATAC Resources optioned Rau cl 1-32 (YC50268) and cl 87-94 (YC57551) (referred to as the Wau option) to Yankee Hat Minerals Ltd. in return for shares in Yankee Hat and certain work commitments. The option agreement allowed Yankee Hat to explore the area for tungsten mineralization in the vicinity of the occurrence. Between June and July 2008 Yankee Hat Minerals prospected and collared 3 diamond drill holes (437.38 m) on the claims with only one of these drill holes testing the Flat Top occurrence. In February 2009 the company dropped its option without any interests being earned.
ATAC Resources carried out prospecting at the Flat Top occurrence in 2009.
Regional & Property Geology
ATAC Resources carried out the 2008 exploration program on behalf of Yankee Hat Minerals. At that time, the Rau claims surrounding this occurrence had seen very little modern detailed mapping. Based on geological mapping and correlation studies carried out in later programs the occurrence is located along the contact between Mackenzie Platform dominantly shallow water carbonate and clastic sediments and regionally metamorphosed basinal sediments deposited in the Selwyn Basin. Both packages were deposited on the western margin of North America. The contact is believed to be marked by a thrust fault that thrusts older Mackenzie Platform Bouvette Formation (Cambrian to Devonian) rocks onto younger Selwyn Basin Earn Group (Devonian to Mississippian) rocks. In the south end of the claim block a high angle normal fault(?) places Selwyn Basin rocks against Mackenzie Platform rocks.
ATAC Resources (AR 096936) has mapped 3 main units in the area comprising the Rau Trend:
1. Cambrian to Ordovician massive, grey dolostone,
2. Ordovician and/or Silurian bedded, grey and buff silty limestone and massive white limestone, and
3. Silurian to Devonian thick, bedded dolostone and limestone.
The company has assigned all three units to the Cambrian to Devonian Bouvette Formation. Colpron’s 2013 geological map generally supports this interpretation; however it uses slightly different age dates and doesn’t include the oldest rocks (Cambrian to Ordovician dolostones) within the Bouvette formation.
In the southwest corner of the claim group thin volcanic horizons assigned to the Marmot Formation (Cambrian to Silurian) are interbedded with the Bouvette Formation rocks. The horizons range from a few metres to about 20 m thick and are locally magnetic. Although volumetrically insignificant it appears these horizons have played an important role in localizing mineralization in the underlying carbonates by acting as an impermeable cap. The Rackla Pluton, a granitic intrusion assigned a (U-Pb zircon) age of 62.9 ± 0.5 Ma intrudes Bouvette Formation rocks in the east central portion of the claim block. Numerous dyke and sills associated with the pluton intrude the Bouvette Formation in the northwest portion of the claim block.
Mineralization & Results
The Flat Top showing lies along a north trending ridge (originally named Flat Ridge by the Prism joint venture), that outcrops along the contact between Bouvette Formation and Earn Group strata. Prism Resource discovered scheelite and tungsten mineralization on the ridge in 1979. Soil sampling carried out in 2008 outlined coincident, moderately to strongly anomalous gold, copper and tungsten values in an area measuring approximately 600 m long and up to 300 m wide. Prospecting carried out in 2009 traced skarn mineralization around the nose of the ridge for approximately 400 m. Geological mapping carried out by ATAC Resources noted four types of skarn mineralization occurring across a stratigraphic thickness of about 40 m. The four types of skarn (AR 096936) noted are:
1. Felted to radiating masses of acicular tremolite/actinolite or wollastonite/actinolite in a localized band up to several metres wide above the limestone/shale contact,
2. Masses of tremolite ± calcite in cm sized veinlets within unaltered carbonate,
3. Fe-rich skarn with aggregates of radiating, acicular tremolite/actinolite masses replacing carbonate,
4. Most Fe-rich skarn with masses of light green actinolite, local tourmaline, biotite, grey quartz and massive limonite upward from the contact.
Prism Resources (1980) reported rock samples assaying up to 8.38% tungsten oxide (WO30), although typical samples from the area returned average grades of less than 0.04% tungsten oxide. Two skarn samples collected in 2008 from talus lying overtop the mineralized zone, close to the collar of the drill hole returned 166 ppb gold, 176 ppm tungsten and 289 ppb gold and 92 ppm tungsten. ATAC Resources tested the mineralized zone with a single drill hole in 2008 but the hole was collared too far downhill and only intersected shale belonging to the Earn Group (AR 096936).
ATAC Resource collared a second hole to test a linear magnetic high that trends through an area of mineralized actinolite-diopside +/- garnet skarn float located in the southwest end of the claim block. The hole intersected 182.54 m of limestone that is cut by several narrow pegmatite and granitic dykes and sills. The best result came from actinolite skarn bands which returned peak values of 781 ppm and 445 ppm tungsten over 1.08 m and 1.0 m respectively.
The last drill hole collared by ATAC Resources tested a magnetic anomaly in an area where a skarn band is exposed near a creek on the west-central side of the claim block. Rock samples collected during a prospecting program carried out in 2006 returned values up to 4 010 ppm tungsten. The hole intersected limestone interbedded with chlorite skarn bands, which are less that 0.5 m thick except for one that is 8.13 m thick. Core samples of skarn typically returned 36.5 to 610 ppm tungsten, with a peak value of 1,220 ppm W over 9 cm.
Location Map
Last Updated: Oct 2, 2020
Work History
| Year | Work Type | Comment |
|---|---|---|
| 2009 | Other: Prospecting | |
| 2008 | Airborne Geophysics: Magnetic | |
| 2008 | Airborne Geophysics: VTEM | |
| 2008 | Drilling: Diamond | Three holes (437.38 m). Only one hole tested occurrence area but it was collared too far downhill and only intersected shale belonging to Devonian to Mississippian Earn Group. |
| 2008 | Geochemistry: Rock | |
| 2008 | Other: Prospecting | Carried out over Wau option. |
| 2007 | Airborne Geophysics: VTEM | Geophysical program flown over entire Rau property. Magnetics also collected. |
| 1980 | Drilling: Diamond | Number of holes drilled: 1 Amount of work done: 151 METRES |
| 1980 | Geochemistry: Silt | |
| 1979 | Drilling: Diamond | Number of holes drilled: 1 Amount of work done: 140 METRES |
| 1979 | Geochemistry: Soil | |
| 1979 | Geology: Bedrock Mapping | |
| 1979 | Trenching: Hand |
Regional Geology - Terrane
Group: Ancestral North America
Affinity: W Laurentia
Name: North America - basinal strata
Realm: Laurentia
Regional Geology - Bedrock
Supergroup:
Group/Suite:
Formation: Bouvette
Member:
Terrane: Laurentia
Period Max: Cambrian
Age Max: 500 MA
Period Min: Devonian
Age Min: 392 MA
Rock Major: dolostone
Rock Minor: shale/limestone/conglo
Reference: Green & Roddick (1972) - GSC Map 1282A
Geological Unit (1M): CDB
Geological Unit (250K): CDB1
Assessment Reports that overlap occurrence
| Report Number | Year | Title | Worktypes | Holes Drilled | Meters Drilled |
|---|---|---|---|---|---|
| 096939 | 2015 | Technical Report and Preliminary Economic Assessment for the Tiger Deposit, Rackla Gold Project | VTEM - Airborne Geophysics, ZTEM - Airborne Geophysics, Mill/Concentrator Construction - Development, Surface, Tailings Pond - Development, Surface, Diamond - Drilling, Rock - Geochemistry, Soil - Geochemistry, Gravity Survey - Ground Geophysics, IP - Ground Geophysics, Resistivity - Ground Geophysics, Metallurgical Tests - Lab Work/Physical Studies, Data Compilation - Pre-existing Data, Data Compilation - Pre-existing Data, Environmental Assessment/Impact - Studies, Preliminary Economic Assessment - Studies, Resource Estimate - Studies | 150 | 26846.60 |
| 096732 | 2014 | Assessment Report Describing Metallurgical Test Pits, Metallurgical Auger Drilling, Geotechnical Auger Drilling, Geotechnical Study, Environmental Baseline Studies, Heritage Evaluation, and Water Quality and Climate Monitoring Surveys | Auger - Drilling, Water - Geochemistry, Metallurgical Tests - Lab Work/Physical Studies, Environmental Assessment/Impact - Studies, Geotechnical - Studies, Heritage/Archeological - Studies | 9 | 96.77 |
| 096607 | 2012 | Assessment Report Describing Metallurgical Testing, Wildlife Monitoring, Heritage Evaluation, and Water Quality and Climate Monitoring Surveys | Water - Geochemistry, Metallurgical Tests - Lab Work/Physical Studies, Environmental Assessment/Impact - Studies, Heritage/Archeological - Studies | ||
| 096597 | 2012 | Assessment Report Describing Geochemical Sampling, Auger Sampling, Geological Mapping, Diamond Drilling, and Geophysical Surveys | Air Strip - Development, Surface, Auger - Drilling, Diamond - Drilling, Rock - Geochemistry, Silt - Geochemistry, Soil - Geochemistry, Bedrock Mapping - Geology, EM - Ground Geophysics, Gravity Survey - Ground Geophysics, Magnetics - Ground Geophysics, Prospecting - Other, Hand - Trenching | 172 | 37340.37 |
| 095938 | 2011 | Assessment Report Describing Geochemical Sampling, Geological Mapping and Remote Sensing Surveys at the Rackla Gold Property | Rock - Geochemistry, Silt - Geochemistry, Soil - Geochemistry, Bedrock Mapping - Geology, LIDAR - Remote Sensing, Heritage/Archeological - Studies | ||
| 095721 | 2010 | Assessment Report Describing Geophysics, Soil Geochemistry and Diamond Drilling at the Rau Property | Electromagnetic - Airborne Geophysics, Electromagnetic - Airborne Geophysics, Magnetic - Airborne Geophysics, Magnetic - Airborne Geophysics, Diamond - Drilling, Diamond - Drilling, Drill Core - Geochemistry, Soil - Geochemistry, Soil - Geochemistry, Downhole Survey - Ground Geophysics, Gravity Survey - Ground Geophysics, IP - Ground Geophysics | 170 | 36900.84 |
| 095684 | 2009 | Geological Mapping, Prospecting, Soil Geochemistry and Diamond Drilling at the Rau Property | Interpretation - Airphotography, Diamond - Drilling, Drill Core - Geochemistry, Rock - Geochemistry, Soil - Geochemistry, Water - Geochemistry, Regional Surficial Mapping - Geology, IP - Ground Geophysics, Metallurgical Tests - Lab Work/Physical Studies, Petrographic - Lab Work/Physical Studies, Data Compilation - Pre-existing Data, Process/Interpret - Pre-existing Data, Biophysical Mapping - Studies, Environmental Assessment/Impact - Studies, Geotechnical - Studies, Heritage/Archeological - Studies | 58 | 9578.30 |
| 095622 | 2008 | Prospecting and Diamond Drilling at the Wau Property | Diamond - Drilling, Drill Core - Geochemistry | 3 | 437.38 |
| 095131 | 2008 | Geological Mapping, Prospecting, Soil Geochemistry, Diamond Drilling, and Geophysical Surveys at the Rau Property | Magnetic - Airborne Geophysics, VTEM - Airborne Geophysics, Diamond - Drilling, Silt - Geochemistry, Soil - Geochemistry, Bedrock Mapping - Geology, Prospecting - Other | 18 | 3423.21 |
| 095130 | 2007 | Geological Mapping, Prospecting, Soil Geochemistry, and Geophysical Surveys at the Rau Property | Magnetic - Airborne Geophysics, VTEM - Airborne Geophysics, Soil - Geochemistry, Bedrock Mapping - Geology, Prospecting - Other | ||
| 093987 | 1998 | Digital Topography, Landsat, and Colour Air Photo Survey over the Clark Claims] | Orthophoto - Airphotography, Rock - Geochemistry, Landsat - Remote Sensing | ||
| 090684 | 1980 | Blue Lite Assessment Report | Diamond - Drilling, Drill Core - Geochemistry, Rock - Geochemistry, Soil - Geochemistry, Bedrock Mapping - Geology | 1 | 139 |
Related References
| Number | Title | Page(s) | Document Type |
|---|---|---|---|
| 1990-1 | Geology of the Mt. Westman Map Area (106D/1) | Open File (Geological - Bedrock) | |
| 2003-9(D) | Yukon Digital Geology (version 2) | Open File (Geological - Bedrock) | |
| 2003Heon | Yukon Regional Geochemical Database - Stream sediment analyses | Database | |
| 1990-3 | Geology of 106D/8 & 7 (East Half) Map Areas | Open File (Geological - Bedrock) | |
| YEG2008_OV | Yukon Exploration and Geology Overview 2008 | 34, 37. | Annual Report |
| YEG1979_80 | Yukon Geology and Exploration 1979-80 | Annual Report | |
| 2013-13 | Geological map of the Rackla belt, east-central Yukon (NTS 106C/1-4, 106D/1) | Open File (Geological - Bedrock) | |
| YEG2013_OV | Yukon Exploration and Geology Overview 2013 | Annual Report |
| Citations |
|---|
| ATAC RESOURCES LTD, News Release, 10 APR/2008, 10 Jun/2008. |
| ATAC RESOURCES LTD. Website: www.atacresources.com. |
| HORNBROOK, ET AL., 1990. National Geochemical Reconnaissance Stream Sediment and Water Geochemical Data, East Central Yukon (106D; parts of 106C, 106E and 106F), Geological Survey of Canada Open File 2175. |
| YANKEE HAT MINERALS AND ATAC RESOURCES LTD, Dec/2008. Assessment Report #095622 by M. Dumala. |
| YANKEE HAT MINERALS LTD, Jul/2009. Audited Annual Financial Statements. For the years ended July 31, 2009 and 2008 (available on SEDAR). |
| YANKEE HAT MINERALS LTD, News Release. 10 Apr/2008. |
