General Information
Primary Commodities: zinc, lead
Secondary Commodities: silver
Deposit Type(s): Vein Polymetallic Ag-Pb-Zn+/-Au
Location(s): 62.903820 N, -132.199420 W
NTS Mapsheet(s): 105K16
Location Comments: Location taken from Overland Resources location map.
Hand Samples Available at YGS: No
Capsule
Work History
The Hess Syndicate (Atlas Explorations Ltd, Quebec Cartier Mining Company and Phillips Brothers (Canada) Ltd), carried out reconnaissance scale geological mapping and rock, silt and soil sampling during the summer of 1967. Based on early geochemical results the syndicate, staked Lad cl 3-12, 19-38 and 45-62 (Y14076), approximately 2.6 km to the north and northwest.
In the summer of 1968 the syndicate carried out geological mapping, rock and soil sampling, hand trenching and a ground magnetic and electromagnetic survey. In August and Sep/68 the syndicate expanded the claim block southward by staking Lad cl 65-102 (Y31259). The enlarged claim block included the Darcy occurrence (this occurrence) and other mineralized occurrences located eastward along the same mineralized trend. In 1969, the syndicate carried out road construction, bulldozer trenching, geological mapping, geochemical sampling and geophysical (airborne and ground) surveys. Most of this information was never filed for assessment credit.
The Atlas interest in the syndicate was transferred in 1974 to Cima Resources Ltd, which in 1977 drilled two diamond drill holes (14.8 m) on the Lad occurrence (Minfile Occurrence 105K 029), located approximately 3 km to the north.
Restaked within Andrew cl 3-10 (YB65798), in Jun/96 by R. Berdahl, who also staked Andrew cl 1-2 (YB65796), 2 km to the northwest to cover the Hugo Creek area (part of Lad Occurrence). In 1996, Berdahl prospected and collected grab samples from various mineralized showing previously discovered by the syndicate and now located on the Andrew claims.
In Jul/99, Berdahl carried out hand and blast trenching and geochemical sampling on the Andrew showing (Minfile Occurrence 105K 089 - previously called the “J” showing by the syndicate) located approximately 600 m to the northwest. No work was carried out on this occurrence.
Noranda Incorporated optioned the Andrew claims in Aug/2000 and immediately staked AMB cl 1-68, 70 and 72-104 (YC02355) forming a contiguous claim block that included the Andrew claims and other historic showing located further to the north. During the winter of 2000/01, Noranda carried out airborne magnetic and EM geophysical surveys over the area, including the Andrew/AMB claim block and Berdahl's previously staked Scott claims located to the southwest.
In Jul/2001 the company staked AMB cl 105-112 (YC02776) on the southwest corner of the claim group. From July to Oct/2001 the company carried out geological mapping, prospecting, ground magnetic and gravity geophysical surveys, rock and soil geochemical sampling and drilled 15 diamond drill holes (2 717.7 m). One drill hole (AN0108 – 146.3 m) was collared near this occurrence. The remaining holes tested the Andrew occurrence and other targets located within the property.
Between Sep/2001 and Feb/2002, Noranda staked AMB cl 115-162 (YC09953, includes fractional claims) on the northeast side of the claim block to protect internal fractions within the group and to extend the claim block to the southeast. During August and Sep/2002 the company soil sampled along a trend line starting northwest of the Andrew occurrence and running southeast through the Darcy showing and the future Darin occurrence (Minfile Occurrence 105K 033). Noranda collared one hole (AN02-21 – 147.2 m) southwest of the 2001 drill hole to test soil anomaly C. The company also drilled 8 diamond drill holes (1 838.3 m) to test the Andrew mineralized zone and the immediate surrounding area for similar mineralization. Noranda subsequently terminated its option agreement on the property and returned the claims to Berdahl.
On February 1, 2007 Overland Resources Ltd announced it had secured a twelve month exclusive option to acquire a 90% interest in the Andrew property from Berdahl for US$50,000.00. Overland Resources immediately renamed the property the Andrew Base Metal project and undertook due diligence including reviewing all previous exploration data and calculating a JORC (Australian –Joint Ore Reserve Committee) compliant resource calculation for the Andrew showing. On March 15, 2007 the company announced an inaugural JORC-compliant resource estimate for the (newly defined – (formerly zone)), Andrew (Zinc) deposit. The resource calculation was based on the results of 23 diamond drill holes (4,556 m) previously drilled on the deposit by Noranda Inc during 2001 and 2002.
In Jul/2007 Overland Resources staked Bridge cl 1-8 (YC56739), cl 11-16 (YC56747) and cl 19-32 (YC5677753) to the southwest linking the main property to the pre-existing Scott claims. The company also staked Ozzie cl 1-16 (YC56665) and cl 17-32 (YC56703) south and southwest of the Andrew deposit.
On July 15, 2007 following the completion of 5 diamond drill holes, Overland Resources announced that it had elected to exercise its option early to acquire a 90% interest in the Andrew Base Metal project from Berdahl in return for cash and 5 million shares. In Nov/2007 Overland Resources released initial metallurgic test work conducted on representative samples submitted from the Andrew Zinc deposit. In February/2008 the company was issued a Winter Road Permit allowing it to mobilize heavy equipment and other supplies to the project area.
In Apr/2008 Overland Resources announced an updated JORC compliant resource for the Andrew Zinc deposit. The resource estimate was based on the 24 drillholes completed by Noranda Inc and the 10 drill holes completed by the company in 2007.
Overland Resources commenced their 2008 exploration program in mid-April. The company completed 133 diamond drillholes on the property. Seventeen diamond drill holes (2,820 m) tested the Darcy zone. The remaining holes tested the Andrew deposit and other targets located within the property.
In May/2009 Overland Resources released an updated JORC compliant mineral resource estimate for the Andrew deposit and an initial JORC compliant resource for the newly defined Darcy (Zinc) deposit. The new resource estimate incorporated drill data collected from the 2008 drill program.
Overland Resources did not carry out any field work in 2009, instead the company worked towards releasing an preliminary independent economic evaluation of the entire Yukon Base Metal project and conducting metallurgical experiments on the project’s ore. The economic evaluation report and preliminary metallurgical results was released in Jun/2009.
In 2010 Overburden Resources collared 17 diamond drill holes (2,020.3 m) on the Darcy (Zinc) deposit. The company also drilled hydrogeological holes on the Andrew Zinc) deposit and drill tested the Darin zone (Minfile Occurrence 105K 033) located 1.4 km to the southeast. Other exploration work included 22 test pits dug over the Andrew Zinc deposit to establish soil mechanics and permafrost conditions for an ongoing feasibility study and a soil sample survey carried out northeast of the Andrew (Zinc) deposit which later evolved into the Andrew Northeast zone.
In Feb/2011 Overland Resources released a JORC compliant resource estimate for the newly defined Darin (Zinc) deposit and updated resource estimates for the Darcy and Andrew (Zinc) deposits. As part of this exercise the company released an updated JORC compliant resource estimate for the entire Yukon Base Metal Project.
During the 2011 exploration season Overland Resources drilled 74 diamond drill holes (10,437 m) on the property. Twenty-nine holes were collared to test for extensions of mineralization at the Andrew and Darcy (Zinc) deposits. Eleven holes tested the Andrew Northeast zone (prospect). The remaining thirty-one holes collected geotechnical and hydrogeological data. The company continued working on the technical, economic and environmental components of mine permitting.
In Mar/2012 Overland Resources released updated JORC compliant resource calculations for the Andrew and Darcy (zinc) deposits and the entire Yukon Base Metal project. In Jun/2012 the company released an updated study into the economics of developing a mining operation at the Yukon Base Metal project. Despite robust grades the economic study indicated a sustained long term improvement in both zinc and lead prices would be required to provide a suitable return to the company. Thus the company elected to suspend all further mine permitting work for the entire Yukon Base Metal project.
All mining claims necessary for the project are in good standing until at least 2026.
Capsule Geology
The property area is located approximately 15 km east of Mt Selous, in east-central Yukon. The closest settlements Faro and Ross River, Yukon are located 100 km to the southwest and 115 km south of the property, respectively. A winter trail connects the property to the North Canol Road at Dragon Lake located approximately 60 km to the south. Normal access to the property is by helicopter or short take-off and landing fixed wing aircraft via a 400 m unsealed airstrip located approximately 4 km northwest of the Andrew occurrence.
The property is located in the western portion of the Selwyn Basin; a continental margin rift-fill and cover sedimentary sequence lying off the coast of ancestral North America. The oldest stratigraphic units on the property are the Yusezyu and Narchilla formations of the Neoproterozoic to Lower Cambrian Hyland Group. They are overlain by Ordovician to Silurian Road River Group rocks which are in turn overlain by Devonian to Mississippian Earn Group rocks. The Hyland Group comprises an upper thrust sheet that overlies the Road River and Earn Group rocks. The entire sequence has been intruded by Cretaceous granite, quartz monzonite and granodiorite intrusions assigned to the Selwyn Plutonic Suite.
Initial exploration work carried out by Atlas Explorations in 1968 identified 14 separate vein showings on the property. The Darcy zone was initially discovered in 1969 and explored with a series of trenches (A, O, P, Q and V). Actual assays from this work are missing but the company decided that despite high grade results obtained from some other areas of the property none of the mineralization appeared significant enough to warrant additional work. *It appears much of the data for this period is missing.
Berdahl staked the Andrew claims south of the bulk of Atlas Explorations effort and concentrated his efforts along a 4 km long northwesterly trending structure which ran southeast of the Andrew showing northwesterly to the Hugo Creek area (Minfile Occurrence 105K 029). Berdahl resampled showings A, O, P, Q and V which are located about 800 m southeast of showing J (original trench on Andrew deposit). Showing A is described as oxide material containing sphalerite in quartzite and a minor galena vein in phyllite. A grab sample of the oxide material returned 3.88% zinc. Showings O, V, P and Q consist of narrow galena veins averaging 10 to 20 cm in width cutting quartzites, black sales and black limestone. A grab sample from showing O returned 81% lead and 57 g/t silver. Showing P was the only showing of the four, to return significant zinc values. A grab sample of coarse grained galena in slumped black shales with sphalerite and black limestone returned an assay of 3.93% lead, 3.2% zinc and 51.5 g/t silver.
In 2001 Noranda examined the previously discovered showings in the course of their property wide mapping and prospecting program and identified several new occurrences or clusters of occurrences. Ground magnetic and gravity surveys were carried out over selected targets identified during the earlier airborne survey to distinguish sulfide-bearing sources from non-sulfide bearing sources and limited soil geochemical sampling was carried out over targets near the northern boundary of the property, in areas not covered by previous work.
Diamond drillhole AN01-08 collared by Noranda in 2001 tested the wide spread zinc and lead mineralization discovered in and around the 5 showings trenched by Atlas Explorations. The hole intersected black shale, quartzite, siltstone and limestone throughout its length. Minor sphalerite stringers were intersected in two narrow zones. No significant assays were returned.
The 2002 soil sampling program was designed to test for extensions of the Andrew mineralized zone to the southeast. Sampling outlined 5 lead, zinc and silver anomalies over a distance of 2 km southeast of the Andrew zone. Two anomalies; B and C lie over the future Darcy deposit. Anomaly C was tested by Noranda’s 2001 drill hole while anomaly B was tested with one hole (AN02-21). The hole intersected mineralization in two separate intervals. The first interval intersected sphalerite associated with quartz and calcite veins in brecciated limestone and quartzite adjacent to a fault zone. It returned assays of 7.54% zinc, 0.01% lead and 0.6 g/t silver from a downhole depth of 39.95 to 45.5 m. The second interval intersected small high grade veins of galena and sphalerite from a downhole depth of 70.5 to 76.0 m which returned 2.04% zinc, 2.51% lead and 5.0 g/t silver.
On February 1, 2007, Overland Resources Ltd obtained an option to acquire a 90% interest in the Andrew property from Berdahl. The company immediately renamed the property the Andrew Base Metal project. On March 15, 2007 the company released a JORC (Australian –Joint Ore Reserve Committee) compliant resource calculation for the new designated Andrew (Zinc) deposit Minfile Occurrence 105K 089). The resource calculation was based on 24 diamond drillholes completed by Noranda Exploration between 2001 and 2002.
Overland Resources carried out a lengthy due diligence program in the early part of 2007 before starting their field exploration program. The 2007 diamond drill project was focused on expanding and upgrading the existing resources at the Andrew deposit. Following completion of the first 5 drillholes the company announced that it had elected to exercise its option to acquire 90% of the Andrew Base Metal project from Berdahl. No significant work was carried out on the Darcy zone.
In Nov/2007 Overland Resources announced that initial metallurgical test work conducted by an independent metallurgical laboratory on Andrew (zinc) deposit drill core, achieved metal recovery rates of up to 96.3% for zinc and 98.4 % for lead using a conventional grind and floatation circuit. The resulting metal concentrate was of saleable grade. In Apr/2008 Overland Resources released an updated JORC compliant resource for the Andrew (zinc) deposit incorporating the results from the 2007 drill program.
Soil sampling completed by Overland Resources in 2007 and 2008 and merged with historical data collected by Atlas Explorations, Berdahl and Noranda Explorations outlined a 2,500 m long, zinc in soil anomaly that extends to the southeast of the Andrew (zinc) deposit through the Darcy showing and continuing southward. The 2008 drilling program carried out on the Darcy zone was designed to test the extensive northwest-southeast trending zinc soil anomaly and mineralization encountered in Noranda Inc.’s 2001 drill hole which intersected 7.5% zinc over 5.5 m. Hole DY08-002, the second hole collared in 2008, intersected two mineralized intervals including 13.6% zinc over 28.29 m and 11.9% zinc over 43.89 m. A further 15 holes were subsequently drilled and significant results were obtained.
In May/2009 Overland Resources released an updated JORC compliant resource for the Andrew (zinc) deposit and an inaugural resource for the newly defined Darcy (zinc) deposit.The deposit is located approximately 600 m southeast of the Andrew deposit and is characterized by resistivity low, anomalous zinc in soils and outcrop of mineralized quartz stockworks in host sediments. The deposit appears to be composed of several sub-parallel tabular zones, striking roughly west by northwest with right stepping jog and pinch and swell geometry. A main zone hosts the bulk of mineralization with several smaller and discontinuous hanging wall and footwall zones and splay structures potentially associated with the steps and flexures in the main zone. Geology consists of Neoproterozoic to Paleozoic sediments dominantly massive to poorly bedded quartz-rich sandstones interbedded with vari-textured maroon/grey and black mudstone, limestone, chert and breccia. Mineralization consists of blebby to massive sphalerite and galena associated with brecciation and quartz and carbonate veining and breccia infill. Based on a 2% zinc cutoff the initial resource estimate reported an Inferred resource of 1.75 million tonnes grading 6.7% zinc and 0.0% lead.
In Jun/2009 the company released the results of an independent economic evaluation of developing a mining operation at the Andrew and Darcy (zinc) deposits. The plan calls for the Andrew (zinc) deposit to be mined by open pit and underground methods with additional feed produced by an open pit mine at the Darcy (zinc) deposit. Initial mine life would be 6 years with an annual production of 700,000 tonnes per year producing separate zinc and lead concentrates. Annual production is estimated at 493,000 tonnes of zinc and 135,000 tonnes of lead concentrates. Preliminary metallurgical work conducted on diamond drill core from the Andrew (zinc) deposit estimated possible recovery rates of 98.5% for lead and 96.0% for zinc. Given the preliminary nature of the evaluation report the company spent the rest of the year and the early part of 2010 examining various scenarios to reduce the project’s costs and begin work on a bankable feasibility study and submission for mine permitting.
In Nov/2009 Overland Resources released the results of Heavy Liquid Separation (HLS) test work conducted by an independent Canadian laboratory. HLS is used in the laboratory to simulate the process of Dense Media Separation. Tests completed on various crush sizes showed that over 90% of the sample was rejected as waste while over 80% of the zinc metal was recovered. In all cases this resulted in an upgrade of the zinc grade of at least eight times that of the initial sample head grade of 2.4% zinc. The Dense Media Separation beneficiated material could be readily processed further through the plant currently proposed for the Andrew Base Metal project. In Dec/2009 the company announced that they would fund a definitive feasibility study into the development of the project.
The 2010 diamond drill program was focused on defining and evaluating the Darcy (zinc) deposit and the Darin zone. Drilling at the Darcy (zinc) deposit increased the known strike length to over 400 m, doubling the previously known strike extent.
In Feb/2011 Overburden Resources released an updated JORC compliant resource for the Darcy (Zinc) deposit and an inaugural for the newly defined Darin (Zinc) deposit incorporating drilling results from 2010. The updated JORC compliant resource calculation shows that the Darcy (Zinc) deposit hosts Indicated resources of 884,000 tonnes grading 5.3% zinc and 0.1% lead and Inferred resources of 2,601,000 tonnes grading 5.3% zinc and 0.0% lead.
The 2011 diamond drill program targeted vertical and lateral extensions of the high grade Andrew and Darcy (Zinc) deposits where mineralization at both deposits remained open in all directions following the 2010 drill program. Drilling on the Darcy (Zinc) deposit confirmed that mineralization continues below 150 m depth, verifying that open pit development at the deposit can extend deeper than the current design. Step-out drilling to the west of the deposit failed to intersect significant mineralization, suggesting that the western end of the Darcy (zinc) deposit has been truncated and displaced by a fault.
In Mar/2012 Overland Resources released an updated JORC compliant resource for the Andrew and Darcy (zinc) deposits. Given that no new diamond drilling was carried out on the Darin (zinc) deposit its JORC compliant resource remained unchanged. Incorporating a 2% zinc cut-off, the entire Yukon Base Metal project (Andre, Darcy and Darin (zinc) deposits) hosts a total JORC compliant mineral resource estimate of 13.7 million tonnes grading 5.3% zinc and 0.9% lead or 13.7 million tonnes at 6.2% zinc equivalent. At the Darcy (zinc) deposit the updated indicated and inferred JORC code compliant resource for the deposit increased 60% to 5,555,000 million tonnes grading 4.7% zinc and 0.0% lead. See reserve/resource section for each deposit for breakdown of various resource classifications.
In Jun/2012 Overland Resources released an updated mining study for the Yukon Base Metal Project which included the Andrew, Darcy and Darin (zinc) deposits. The plan called for separate open pits at the Andrew and Darcy deposits. The plan also updated many of the monetary details of the mining plan. The main conclusion of the plan was that a sustained long term improvement in both zinc and lead metal prices will be required to provide a suitable return to the company. Thus the company decided to suspend all further exploration and mine permitting work on the project and “mothball” the project until economic conditions improved.
The Hess Syndicate (Atlas Explorations Ltd, Quebec Cartier Mining Company and Phillips Brothers (Canada) Ltd), carried out reconnaissance scale geological mapping and rock, silt and soil sampling during the summer of 1967. Based on early geochemical results the syndicate, staked Lad cl 3-12, 19-38 and 45-62 (Y14076), approximately 2.6 km to the north and northwest.
In the summer of 1968 the syndicate carried out geological mapping, rock and soil sampling, hand trenching and a ground magnetic and electromagnetic survey. In August and Sep/68 the syndicate expanded the claim block southward by staking Lad cl 65-102 (Y31259). The enlarged claim block included the Darcy occurrence (this occurrence) and other mineralized occurrences located eastward along the same mineralized trend. In 1969, the syndicate carried out road construction, bulldozer trenching, geological mapping, geochemical sampling and geophysical (airborne and ground) surveys. Most of this information was never filed for assessment credit.
The Atlas interest in the syndicate was transferred in 1974 to Cima Resources Ltd, which in 1977 drilled two diamond drill holes (14.8 m) on the Lad occurrence (Minfile Occurrence 105K 029), located approximately 3 km to the north.
Restaked within Andrew cl 3-10 (YB65798), in Jun/96 by R. Berdahl, who also staked Andrew cl 1-2 (YB65796), 2 km to the northwest to cover the Hugo Creek area (part of Lad Occurrence). In 1996, Berdahl prospected and collected grab samples from various mineralized showing previously discovered by the syndicate and now located on the Andrew claims.
In Jul/99, Berdahl carried out hand and blast trenching and geochemical sampling on the Andrew showing (Minfile Occurrence 105K 089 - previously called the “J” showing by the syndicate) located approximately 600 m to the northwest. No work was carried out on this occurrence.
Noranda Incorporated optioned the Andrew claims in Aug/2000 and immediately staked AMB cl 1-68, 70 and 72-104 (YC02355) forming a contiguous claim block that included the Andrew claims and other historic showing located further to the north. During the winter of 2000/01, Noranda carried out airborne magnetic and EM geophysical surveys over the area, including the Andrew/AMB claim block and Berdahl's previously staked Scott claims located to the southwest.
In Jul/2001 the company staked AMB cl 105-112 (YC02776) on the southwest corner of the claim group. From July to Oct/2001 the company carried out geological mapping, prospecting, ground magnetic and gravity geophysical surveys, rock and soil geochemical sampling and drilled 15 diamond drill holes (2 717.7 m). One drill hole (AN0108 – 146.3 m) was collared near this occurrence. The remaining holes tested the Andrew occurrence and other targets located within the property.
Between Sep/2001 and Feb/2002, Noranda staked AMB cl 115-162 (YC09953, includes fractional claims) on the northeast side of the claim block to protect internal fractions within the group and to extend the claim block to the southeast. During August and Sep/2002 the company soil sampled along a trend line starting northwest of the Andrew occurrence and running southeast through the Darcy showing and the future Darin occurrence (Minfile Occurrence 105K 033). Noranda collared one hole (AN02-21 – 147.2 m) southwest of the 2001 drill hole to test soil anomaly C. The company also drilled 8 diamond drill holes (1 838.3 m) to test the Andrew mineralized zone and the immediate surrounding area for similar mineralization. Noranda subsequently terminated its option agreement on the property and returned the claims to Berdahl.
On February 1, 2007 Overland Resources Ltd announced it had secured a twelve month exclusive option to acquire a 90% interest in the Andrew property from Berdahl for US$50,000.00. Overland Resources immediately renamed the property the Andrew Base Metal project and undertook due diligence including reviewing all previous exploration data and calculating a JORC (Australian –Joint Ore Reserve Committee) compliant resource calculation for the Andrew showing. On March 15, 2007 the company announced an inaugural JORC-compliant resource estimate for the (newly defined – (formerly zone)), Andrew (Zinc) deposit. The resource calculation was based on the results of 23 diamond drill holes (4,556 m) previously drilled on the deposit by Noranda Inc during 2001 and 2002.
In Jul/2007 Overland Resources staked Bridge cl 1-8 (YC56739), cl 11-16 (YC56747) and cl 19-32 (YC5677753) to the southwest linking the main property to the pre-existing Scott claims. The company also staked Ozzie cl 1-16 (YC56665) and cl 17-32 (YC56703) south and southwest of the Andrew deposit.
On July 15, 2007 following the completion of 5 diamond drill holes, Overland Resources announced that it had elected to exercise its option early to acquire a 90% interest in the Andrew Base Metal project from Berdahl in return for cash and 5 million shares. In Nov/2007 Overland Resources released initial metallurgic test work conducted on representative samples submitted from the Andrew Zinc deposit. In February/2008 the company was issued a Winter Road Permit allowing it to mobilize heavy equipment and other supplies to the project area.
In Apr/2008 Overland Resources announced an updated JORC compliant resource for the Andrew Zinc deposit. The resource estimate was based on the 24 drillholes completed by Noranda Inc and the 10 drill holes completed by the company in 2007.
Overland Resources commenced their 2008 exploration program in mid-April. The company completed 133 diamond drillholes on the property. Seventeen diamond drill holes (2,820 m) tested the Darcy zone. The remaining holes tested the Andrew deposit and other targets located within the property.
In May/2009 Overland Resources released an updated JORC compliant mineral resource estimate for the Andrew deposit and an initial JORC compliant resource for the newly defined Darcy (Zinc) deposit. The new resource estimate incorporated drill data collected from the 2008 drill program.
Overland Resources did not carry out any field work in 2009, instead the company worked towards releasing an preliminary independent economic evaluation of the entire Yukon Base Metal project and conducting metallurgical experiments on the project’s ore. The economic evaluation report and preliminary metallurgical results was released in Jun/2009.
In 2010 Overburden Resources collared 17 diamond drill holes (2,020.3 m) on the Darcy (Zinc) deposit. The company also drilled hydrogeological holes on the Andrew Zinc) deposit and drill tested the Darin zone (Minfile Occurrence 105K 033) located 1.4 km to the southeast. Other exploration work included 22 test pits dug over the Andrew Zinc deposit to establish soil mechanics and permafrost conditions for an ongoing feasibility study and a soil sample survey carried out northeast of the Andrew (Zinc) deposit which later evolved into the Andrew Northeast zone.
In Feb/2011 Overland Resources released a JORC compliant resource estimate for the newly defined Darin (Zinc) deposit and updated resource estimates for the Darcy and Andrew (Zinc) deposits. As part of this exercise the company released an updated JORC compliant resource estimate for the entire Yukon Base Metal Project.
During the 2011 exploration season Overland Resources drilled 74 diamond drill holes (10,437 m) on the property. Twenty-nine holes were collared to test for extensions of mineralization at the Andrew and Darcy (Zinc) deposits. Eleven holes tested the Andrew Northeast zone (prospect). The remaining thirty-one holes collected geotechnical and hydrogeological data. The company continued working on the technical, economic and environmental components of mine permitting.
In Mar/2012 Overland Resources released updated JORC compliant resource calculations for the Andrew and Darcy (zinc) deposits and the entire Yukon Base Metal project. In Jun/2012 the company released an updated study into the economics of developing a mining operation at the Yukon Base Metal project. Despite robust grades the economic study indicated a sustained long term improvement in both zinc and lead prices would be required to provide a suitable return to the company. Thus the company elected to suspend all further mine permitting work for the entire Yukon Base Metal project.
All mining claims necessary for the project are in good standing until at least 2026.
Capsule Geology
The property area is located approximately 15 km east of Mt Selous, in east-central Yukon. The closest settlements Faro and Ross River, Yukon are located 100 km to the southwest and 115 km south of the property, respectively. A winter trail connects the property to the North Canol Road at Dragon Lake located approximately 60 km to the south. Normal access to the property is by helicopter or short take-off and landing fixed wing aircraft via a 400 m unsealed airstrip located approximately 4 km northwest of the Andrew occurrence.
The property is located in the western portion of the Selwyn Basin; a continental margin rift-fill and cover sedimentary sequence lying off the coast of ancestral North America. The oldest stratigraphic units on the property are the Yusezyu and Narchilla formations of the Neoproterozoic to Lower Cambrian Hyland Group. They are overlain by Ordovician to Silurian Road River Group rocks which are in turn overlain by Devonian to Mississippian Earn Group rocks. The Hyland Group comprises an upper thrust sheet that overlies the Road River and Earn Group rocks. The entire sequence has been intruded by Cretaceous granite, quartz monzonite and granodiorite intrusions assigned to the Selwyn Plutonic Suite.
Initial exploration work carried out by Atlas Explorations in 1968 identified 14 separate vein showings on the property. The Darcy zone was initially discovered in 1969 and explored with a series of trenches (A, O, P, Q and V). Actual assays from this work are missing but the company decided that despite high grade results obtained from some other areas of the property none of the mineralization appeared significant enough to warrant additional work. *It appears much of the data for this period is missing.
Berdahl staked the Andrew claims south of the bulk of Atlas Explorations effort and concentrated his efforts along a 4 km long northwesterly trending structure which ran southeast of the Andrew showing northwesterly to the Hugo Creek area (Minfile Occurrence 105K 029). Berdahl resampled showings A, O, P, Q and V which are located about 800 m southeast of showing J (original trench on Andrew deposit). Showing A is described as oxide material containing sphalerite in quartzite and a minor galena vein in phyllite. A grab sample of the oxide material returned 3.88% zinc. Showings O, V, P and Q consist of narrow galena veins averaging 10 to 20 cm in width cutting quartzites, black sales and black limestone. A grab sample from showing O returned 81% lead and 57 g/t silver. Showing P was the only showing of the four, to return significant zinc values. A grab sample of coarse grained galena in slumped black shales with sphalerite and black limestone returned an assay of 3.93% lead, 3.2% zinc and 51.5 g/t silver.
In 2001 Noranda examined the previously discovered showings in the course of their property wide mapping and prospecting program and identified several new occurrences or clusters of occurrences. Ground magnetic and gravity surveys were carried out over selected targets identified during the earlier airborne survey to distinguish sulfide-bearing sources from non-sulfide bearing sources and limited soil geochemical sampling was carried out over targets near the northern boundary of the property, in areas not covered by previous work.
Diamond drillhole AN01-08 collared by Noranda in 2001 tested the wide spread zinc and lead mineralization discovered in and around the 5 showings trenched by Atlas Explorations. The hole intersected black shale, quartzite, siltstone and limestone throughout its length. Minor sphalerite stringers were intersected in two narrow zones. No significant assays were returned.
The 2002 soil sampling program was designed to test for extensions of the Andrew mineralized zone to the southeast. Sampling outlined 5 lead, zinc and silver anomalies over a distance of 2 km southeast of the Andrew zone. Two anomalies; B and C lie over the future Darcy deposit. Anomaly C was tested by Noranda’s 2001 drill hole while anomaly B was tested with one hole (AN02-21). The hole intersected mineralization in two separate intervals. The first interval intersected sphalerite associated with quartz and calcite veins in brecciated limestone and quartzite adjacent to a fault zone. It returned assays of 7.54% zinc, 0.01% lead and 0.6 g/t silver from a downhole depth of 39.95 to 45.5 m. The second interval intersected small high grade veins of galena and sphalerite from a downhole depth of 70.5 to 76.0 m which returned 2.04% zinc, 2.51% lead and 5.0 g/t silver.
On February 1, 2007, Overland Resources Ltd obtained an option to acquire a 90% interest in the Andrew property from Berdahl. The company immediately renamed the property the Andrew Base Metal project. On March 15, 2007 the company released a JORC (Australian –Joint Ore Reserve Committee) compliant resource calculation for the new designated Andrew (Zinc) deposit Minfile Occurrence 105K 089). The resource calculation was based on 24 diamond drillholes completed by Noranda Exploration between 2001 and 2002.
Overland Resources carried out a lengthy due diligence program in the early part of 2007 before starting their field exploration program. The 2007 diamond drill project was focused on expanding and upgrading the existing resources at the Andrew deposit. Following completion of the first 5 drillholes the company announced that it had elected to exercise its option to acquire 90% of the Andrew Base Metal project from Berdahl. No significant work was carried out on the Darcy zone.
In Nov/2007 Overland Resources announced that initial metallurgical test work conducted by an independent metallurgical laboratory on Andrew (zinc) deposit drill core, achieved metal recovery rates of up to 96.3% for zinc and 98.4 % for lead using a conventional grind and floatation circuit. The resulting metal concentrate was of saleable grade. In Apr/2008 Overland Resources released an updated JORC compliant resource for the Andrew (zinc) deposit incorporating the results from the 2007 drill program.
Soil sampling completed by Overland Resources in 2007 and 2008 and merged with historical data collected by Atlas Explorations, Berdahl and Noranda Explorations outlined a 2,500 m long, zinc in soil anomaly that extends to the southeast of the Andrew (zinc) deposit through the Darcy showing and continuing southward. The 2008 drilling program carried out on the Darcy zone was designed to test the extensive northwest-southeast trending zinc soil anomaly and mineralization encountered in Noranda Inc.’s 2001 drill hole which intersected 7.5% zinc over 5.5 m. Hole DY08-002, the second hole collared in 2008, intersected two mineralized intervals including 13.6% zinc over 28.29 m and 11.9% zinc over 43.89 m. A further 15 holes were subsequently drilled and significant results were obtained.
In May/2009 Overland Resources released an updated JORC compliant resource for the Andrew (zinc) deposit and an inaugural resource for the newly defined Darcy (zinc) deposit.The deposit is located approximately 600 m southeast of the Andrew deposit and is characterized by resistivity low, anomalous zinc in soils and outcrop of mineralized quartz stockworks in host sediments. The deposit appears to be composed of several sub-parallel tabular zones, striking roughly west by northwest with right stepping jog and pinch and swell geometry. A main zone hosts the bulk of mineralization with several smaller and discontinuous hanging wall and footwall zones and splay structures potentially associated with the steps and flexures in the main zone. Geology consists of Neoproterozoic to Paleozoic sediments dominantly massive to poorly bedded quartz-rich sandstones interbedded with vari-textured maroon/grey and black mudstone, limestone, chert and breccia. Mineralization consists of blebby to massive sphalerite and galena associated with brecciation and quartz and carbonate veining and breccia infill. Based on a 2% zinc cutoff the initial resource estimate reported an Inferred resource of 1.75 million tonnes grading 6.7% zinc and 0.0% lead.
In Jun/2009 the company released the results of an independent economic evaluation of developing a mining operation at the Andrew and Darcy (zinc) deposits. The plan calls for the Andrew (zinc) deposit to be mined by open pit and underground methods with additional feed produced by an open pit mine at the Darcy (zinc) deposit. Initial mine life would be 6 years with an annual production of 700,000 tonnes per year producing separate zinc and lead concentrates. Annual production is estimated at 493,000 tonnes of zinc and 135,000 tonnes of lead concentrates. Preliminary metallurgical work conducted on diamond drill core from the Andrew (zinc) deposit estimated possible recovery rates of 98.5% for lead and 96.0% for zinc. Given the preliminary nature of the evaluation report the company spent the rest of the year and the early part of 2010 examining various scenarios to reduce the project’s costs and begin work on a bankable feasibility study and submission for mine permitting.
In Nov/2009 Overland Resources released the results of Heavy Liquid Separation (HLS) test work conducted by an independent Canadian laboratory. HLS is used in the laboratory to simulate the process of Dense Media Separation. Tests completed on various crush sizes showed that over 90% of the sample was rejected as waste while over 80% of the zinc metal was recovered. In all cases this resulted in an upgrade of the zinc grade of at least eight times that of the initial sample head grade of 2.4% zinc. The Dense Media Separation beneficiated material could be readily processed further through the plant currently proposed for the Andrew Base Metal project. In Dec/2009 the company announced that they would fund a definitive feasibility study into the development of the project.
The 2010 diamond drill program was focused on defining and evaluating the Darcy (zinc) deposit and the Darin zone. Drilling at the Darcy (zinc) deposit increased the known strike length to over 400 m, doubling the previously known strike extent.
In Feb/2011 Overburden Resources released an updated JORC compliant resource for the Darcy (Zinc) deposit and an inaugural for the newly defined Darin (Zinc) deposit incorporating drilling results from 2010. The updated JORC compliant resource calculation shows that the Darcy (Zinc) deposit hosts Indicated resources of 884,000 tonnes grading 5.3% zinc and 0.1% lead and Inferred resources of 2,601,000 tonnes grading 5.3% zinc and 0.0% lead.
The 2011 diamond drill program targeted vertical and lateral extensions of the high grade Andrew and Darcy (Zinc) deposits where mineralization at both deposits remained open in all directions following the 2010 drill program. Drilling on the Darcy (Zinc) deposit confirmed that mineralization continues below 150 m depth, verifying that open pit development at the deposit can extend deeper than the current design. Step-out drilling to the west of the deposit failed to intersect significant mineralization, suggesting that the western end of the Darcy (zinc) deposit has been truncated and displaced by a fault.
In Mar/2012 Overland Resources released an updated JORC compliant resource for the Andrew and Darcy (zinc) deposits. Given that no new diamond drilling was carried out on the Darin (zinc) deposit its JORC compliant resource remained unchanged. Incorporating a 2% zinc cut-off, the entire Yukon Base Metal project (Andre, Darcy and Darin (zinc) deposits) hosts a total JORC compliant mineral resource estimate of 13.7 million tonnes grading 5.3% zinc and 0.9% lead or 13.7 million tonnes at 6.2% zinc equivalent. At the Darcy (zinc) deposit the updated indicated and inferred JORC code compliant resource for the deposit increased 60% to 5,555,000 million tonnes grading 4.7% zinc and 0.0% lead. See reserve/resource section for each deposit for breakdown of various resource classifications.
In Jun/2012 Overland Resources released an updated mining study for the Yukon Base Metal Project which included the Andrew, Darcy and Darin (zinc) deposits. The plan called for separate open pits at the Andrew and Darcy deposits. The plan also updated many of the monetary details of the mining plan. The main conclusion of the plan was that a sustained long term improvement in both zinc and lead metal prices will be required to provide a suitable return to the company. Thus the company decided to suspend all further exploration and mine permitting work on the project and “mothball” the project until economic conditions improved.
Location Map
Last Updated: Aug 6, 2018
Work History
| Year | Work Type | Comment |
|---|---|---|
| 2012 | Studies: Preliminary Economic Assessment | Updated economic assessment report released, concluded that company needed higher commodity prices to move forward towards production. Company mothballed entire project. |
| 2012 | Studies: Resource Estimate | Updated JORC (Australian) compliant resource estimate released for Darcy deposit and entire Yukon Base Metal project (whole property). |
| 2011 | Drilling: Diamond | 29 holes tested Andrew and darcy deposits. |
| 2011 | Studies: Resource Estimate | Updated JORC (Australian) compliant mineral resource calculated for Darcy deposit. |
| 2010 | Drilling: Diamond | 17 holes (2,020.3 m) tested Darcy deposit. |
| 2010 | Geochemistry: Soil | |
| 2009 | Studies: Preliminary Economic Assessment | Conducted for entire property including Darcy deposit. |
| 2009 | Studies: Resource Estimate | Initial JORC (Australian) compliant resource estimate calculated for newly defined Darcy deposit. |
| 2008 | Drilling: Diamond | 17 holes (2,820 m) tested the Darcy zone. |
| 2007 | Geochemistry: Rock | Old trenches resampled. |
| 2007 | Geochemistry: Soil | Regional program. |
| 2007 | Geology: Regional Bedrock Mapping | |
| 2002 | Drilling: Diamond | 1 hole (147.2 m) |
| 2002 | Geochemistry: Soil | |
| 2001 | Airborne Geophysics: Electromagnetic | Also magnetics. Flown over entire property during winter of 2000 - 2001. |
| 2001 | Drilling: Diamond | 15 holes (2,717.7 m) |
| 2001 | Geochemistry: Rock | Also soil sampling. |
| 2001 | Geology: Detailed Bedrock Mapping | Property wide. |
| 1996 | Geochemistry: Rock | resampled trenches in and around Darcy showing. |
| 1969 | Airborne Geophysics: Electromagnetic | Also magnetics. Collected over entire property. Darcy showing wasn't explored until 1969. |
| 1969 | Geochemistry: Rock | Grab samples collected. Darcy showing wasn't explored until 1969. |
| 1969 | Geology: Detailed Bedrock Mapping | Darcy showing wasn't explored until 1969. |
| 1969 | Trenching: Mechanical | Darcy showing wasn't explored until 1969. |
Regional Geology - Terrane
Group: Ancestral North America
Affinity: W Laurentia
Name: North America - basinal strata
Realm: Laurentia
Regional Geology - Bedrock
Supergroup: Windermere
Group/Suite: Hyland
Formation: Yusezyu
Member:
Terrane: Laurentia
Period Max: Ediacaran
Age Max: 635 MA
Period Min: Ediacaran
Age Min: 542 MA
Rock Major: phyllite/shale/sandstone/grit/conglomerate/limestone
Rock Minor: marble
Reference: Gordey (1996) - GSC Map 19-1987, sheet 1
Geological Unit (1M): PCH
Geological Unit (250K): PCH6
Assessment Reports that overlap occurrence
| Report Number | Year | Title | Worktypes | Holes Drilled | Meters Drilled |
|---|---|---|---|---|---|
| 096194 | 2011 | 2011 Assessment Report Geological and Geochemical Surveying on the Selous Claims | Diamond - Drilling, Rock - Geochemistry, Soil - Geochemistry, Bedrock Mapping - Geology | 68 | 1414.04 |
| 095705 | 2010 | Geological, Geochemical and Drilling Assessment Report for Quartz Mining Claims Grouping HM02805 | Diamond - Drilling, Drill Core - Geochemistry, Rock - Geochemistry, Soil - Geochemistry, Detailed Bedrock Mapping - Geology, Metallurgical Tests - Lab Work/Physical Studies, Prospecting - Other, Environmental Assessment/Impact - Studies, Geotechnical - Studies | 3712.10 | |
| 095648 | 2008 | Geological, Geochemical and Diamond Drilling Assessment Report on the Yukon Base Metal Project | Diamond - Drilling, Drill Core - Geochemistry, Rock - Geochemistry, Silt - Geochemistry, Soil - Geochemistry, Bedrock Mapping - Geology, Prospecting - Other, Backhoe - Trenching | 135 | 23424.70 |
| 094363 | 2002 | Report of Assessment Work Conducted on the Andrew Property, Mayo Mining District Yukon Territory | Diamond - Drilling, Soil - Geochemistry | 8 | 1838.30 |
| 094274 | 2001 | Exploration Report on the Andrew Property, Mayo Mining District | Diamond - Drilling, Soil - Geochemistry, Bedrock Mapping - Geology, Gravity Survey - Ground Geophysics, Magnetics - Ground Geophysics, Prospecting - Other | 15 | 2717.66 |
| 095285 | 1999 | Andrew Claim Group Trenching Report | Rock - Geochemistry, Soil - Geochemistry, Handblast - Trenching | ||
| 093881 | 1996 | Andrew Claim Group Prospecting and Geochemical Report | Bedrock Mapping - Geology, Prospecting - Other | ||
| 019011 | 1968 | Airborne Geophysical Survey Report (Magnetic, Electromagnetic) | Electromagnetic - Airborne Geophysics, Magnetic - Airborne Geophysics | ||
| 019013 | 1968 | Geochemical Report Lad Mineral Claim Group | Soil - Geochemistry, Line Cutting - Other | ||
| 018941 | 1968 | Hess Project Report 1968 Laforce Lake - Mount Selous Area | Rock - Geochemistry, Silt - Geochemistry, Soil - Geochemistry, Regional Bedrock Mapping - Geology, Prospecting - Other | ||
| 019809 | 1968 | Hess Area Project Proposed Property Follow-Up 1968 Field Season | Research/Summarize - Pre-existing Data | ||
| 018947 | 1967 | Hess River Project Report | Rock - Geochemistry, Soil - Geochemistry, Detailed Bedrock Mapping - Geology | ||
| 019032 | 1967 | Hess River Project Report | Data Compilation - Pre-existing Data |
Related References
| Number | Title | Page(s) | Document Type |
|---|---|---|---|
| YEG1987 | Yukon Exploration 1987 | 181. | Annual Report |
| YEG1999_OV | Yukon Mining & Exploration Overview 1999 | 25. | Annual Report |
| YEG2001_OV | Yukon Mining & Exploration Overview 2001 | 12, 25. | Annual Report |
| YEG2002_OV | Yukon Mining, Development & Exploration Overview 2002 | 20, 24, 26. | Annual Report |
| YEG2007_OV | Yukon Exploration and Geology Overview 2007 | 22, 37, 40. | Annual Report |
| YEG2008_OV | Yukon Exploration and Geology Overview 2008 | 18, 32, 36. | Annual Report |
| YEG2009_OV | Yukon Exploration and Geology Overview 2009 | 53. | Annual Report |
| YEG2010_OV | Yukon Exploration and Geology Overview 2010 | 53, 63, 64. | Annual Report |
| YEG2011_OV | Yukon Exploration and Geology Overview 2011 | 41-42, 70, 72. | Annual Report |
| 2003-9(D) | Yukon Digital Geology (version 2) | Open File (Geological - Bedrock) | |
| ARMC016724 | Geology map - 105K/2 - Swim Lakes | Geoscience Map (Geological - Bedrock) |
| Citations |
|---|
| BERDAHL, R.S., Dec/99. YEIP Report #99-050 by R.S. Berdahl. |
| Findlay, R.B., 1969. Mineralogical study and trend surface analysis of the Lad Group. Unpublished B.A.Sc. thesis, University of British Columbia. |
| Gordey, S.P., 2008. Geology, Selwyn Basin (105J and 105K), Yukon; Geological Survey of Canada, Open File 5438, 2 maps at 1:250,000 scale and 1 sheet cross-sections at 1:100,000 scale. |
