The Mineral Ridge project is located ~6 km northwest of the town of Silver Peak and 56 km southwest of Tonopah in Esmeralda County, Nevada. The property consists of 616 mining claims totalling 5,010 hectares (12,380 acres).
Scorpio Gold holds a 70% interest in Mineral Ridge project with joint venture partner Waterton Global Value L.P. (30%). The Company is currently entitled to receive 80% of cash flow generated in accordance with project agreements and is the operator of the project.
Prior to Scorpio Gold's acquisition in March 2010, Mineral Ridge historically produced ~575,000 ounces of gold, including ~170,000 ounces from open pit and ~405,000 ounces from underground mining operations. Upon acquiring its interest, the Company commenced major site rehabilitation to bring the project to a fully operational status.
Mineral Ridge is a conventional open pit heap leaching operation. Gold and silver bearing solution from the leach pad is collected in the pregnant pond and processed through carbon columns in the ADR plant for recovery of the precious metals from leachate on carbon. Loaded carbon is shipped to Metals Research in Kimberley, Idaho for processing into doré. The doré bars are then delivered to Johnson Matthey's refinery in Salt Lake City for further refining of the precious metals into separate 99.9% pure gold and silver bars.
Crushing of gold-bearing material mined by previous owners was completed in February 2011 with some 280,000 tons placed on the leach pad. The heap leaching process was initiated in late February and the first shipment of loaded precious metals carbon left site in April 2011. The Company made its first precious metals sale in June 2011.
Pre-production mining commenced in the Drinkwater pit on May 31, 2011, and the Company achieved commercial production status effective January 1, 2012.
In September 2013, the Mineral Ridge Mine Operation received a safety award by the Nevada Mining Association for its performance in the 2012 calendar year. Seven Nevada-based mining operations were nominated for safety awards in the small surface mining category, with Mineral Ridge placing second in safety ratings behind Newmont Mining's Lone Tree operation. Scorpio Gold is honoured to be recognized amongst some of the major producers in Nevada for its commitment to worker safety at Mineral Ridge. The Company congratulates its employees at the Mineral Ridge Operation, its Elko operations office personnel, and everyone who participated in the Company's first year of commercial production and put safety first.
2014 Production Guidance
The Company's forecast for its third year of commercial production at Mineral Ridge is 40,000-45,000 ounces gold. The operation has consistently exceeded tonnage and grades indicated by the 2012 Life of Mine Plan Study completed by AMEC. These factors contributed to a strong operating performance in H1 2013, enabling the Company to increase its 2013 production forecast and decrease its cash cost estimate midway through the year. As in early 2013, the Company has taken a conservative approach to estimating total cash cost for 2014 at US$800-$850 per ounce of gold sold, and may revise this estimate at a future date if warranted by quarterly operating results.
Production in 2014 is scheduled from the Drinkwater and Mary/LC pits. Scorpio Gold recently received approval from the Nevada Bureau of Land Management for its Amended Plan of Operations, allowing the Company to proceed with the planned expansion of the current Mary pit to incorporate the Mary LC zone. The new Mary/LC pit will have dimensions far exceeding the current operating Drinkwater pit. Completion of a new mineral reserve estimate and Life of Mine plan, which will incorporate the Drinkwater, Mary and Mary LC mineralization, is expected in Q2 2014.
2014 Mineral Ridge Operations Forecast:
- Production: 40,000 to 45,000 ounces gold
- Total Cash Cost: US$800 to US$850 per ounce of gold sold
Key estimated parameters forming the basis for the 2014 forecast are:
- Average throughput: 2,840 short tons (2,580 metric tonnes) per day
- Average grade: 0.061 ounces per short ton (2.09 grams per tonne) gold
- Waste to ore ratio of Drinkwater and Mary/LC producing pits combined: 4.3 to 1
The Company expects these parameters to fluctuate throughout 2014 and as a result, these parameters should be treated as full-year averages and will not necessarily be reflective of quarterly operating results.
SECOND QUARTER 2014
Production at Mineral Ridge in Q2 2014 totalled 9,034 ounces of gold and 3,771 ounces of silver. Total gold production for the first half ("H1") of 2014 stands at 19,328 ounces; an increase of 6.3% from H1 of 2013. A summary of the Q2 production results is presented in the Company's July 14, 2014
FIRST QUARTER 2014
Production at Mineral Ridge in the first quarter of 2014 ("Q1") totalled 10,294 ounces of gold and 5,113 ounces of silver at a total cash cost of US$794 per ounce of gold sold A summary of the Q1 production and financial results is presented in the Company's April 23, 2014
and May 20, 2014
news releases, with complete details provided in the Q1 2014 Financial Statements
and Management Discussion & Analysis
Highlights for the First Quarter Ended March 31, 2014:
(1) This is a non-IFRS measure; refer to Non-IFRS Measures section of this press release and the Company's Management Discussion & Analysis for Q1 of 2014 for a complete definition and reconciliation to the IFRS results reported in the Company's financial statements for Q1 of 2014.
- 10,294 ounces of gold were produced at the Mineral Ridge mine during Q1 of 2014, compared to 7,411 ounces during Q1 of 2013. This 39% increase is primarily caused by the fact that production numbers for Q1 of 2013 were negatively impacted by the prior sale of approximately 1,878 ounces of gold and 759 ounces of silver as part of a sale of loaded carbon that accelerated production and revenue in Q4 of 2012.
- Increased revenues of $13.2 million compared to $11.7 million during Q1 of 2013, due to a 46% increase in ounces of gold sold offset by a lower average gold price during Q1 of 2014.
- Total cash cost per ounce of gold sold(1) of $794 compared to $774 during Q1 of 2013 representing a 3% increase.
- Higher production levels during Q1 of 2014 did not completely offset the decrease in the average gold price which consequently negatively impacted the following:
- Mine operating earnings(1) of $1.3 million compared to $3.6 million during Q1 of 2013, mainly due to the lower average gold price during Q1 of 2014.
- Net earnings and adjusted net earnings(1) of $0.4 million ($0.00 basic and diluted per share), compared to net earnings and adjusted net earnings of $2.1 million ($0.01 basic and diluted per share) during Q1 of 2013.
- Adjusted EBITDA(1) of $3.9 million ($0.02 basic and diluted per share) compared to $6.9 million ($0.04 basic and diluted per share) during Q1 of 2013.
- Receipt of approval for the new plan of operations at the Mineral Ridge mine in February 2014 which allows for the planned expansion of the Mary pit.
- Sale of the Pinon property on March 5, 2014, with approximately $5.2 million of the proceeds from such sale being applied to reduce the Company's long term debt to less than $6 million as at March 31, 2014.
The Drinkwater and Mary/LC are the two main deposits currently in production. On July 21, 2014, the Company reported an updated Life of Mine Plan ("LOM") for the Mineral Ridge Operation that includes the Drinkwater, Mary/LC, and the five satellite deposits, Brodie, Bluelite, Solberry, Wedge and Oromonte. (see Mineral Reserve & Resource Estimates
Operations Area Map
(PDF 3.9 Mb)
The Drinkwater deposit extends over a strike length exceeding 750 m (2,500 ft) and down dip extension of over 600 m (2,000 ft). It was partially mined by underground methods from the 1860s to the early 1940s and by open pit methods from 1989 to 1999. Scorpio Gold commenced pre-production mining in the Drinkwater pit on May 31, 2011 and achieved commercial production status effective January 1, 2012.
The Company's review of historical data indicated that mineralization was left behind in the high wall at the northwest end of the Drinkwater pit. Results from drilling in 2012-13 on the Drinkwater Highwall zone and its northwest trend confirmed this and have been modelled and incorporated into the Drinkwater mine plan for potential extraction.
The historic Mary deposit is located immediately southeast of the Drinkwater pit. Scorpio Gold commenced pre-stripping operations in the Mary pit in December 2011 and initial ore production in Q2 2012. Exploration drilling in 2011 indicated that the gold mineralization extended further southeast from the Mary zone to the adjacent Mary LC Zone, encompassing a strike length of 780 metres. Subsequent work determined that the Drinkwater, Mary and Mary LC zones were not isolated deposits but represented one continuous zone of mineralization.
Drilling in 2012 and 2013 was designed to support modification of the original Mary pit design to the southwest to include the continuation of mineralization into the Mary LC zone. A highly successful program led to completion of a mineral reserve and resource estimate for the Mary/LC and incorporation of the expanded pit design into the updated LOM. Development of the expanded pit commenced in 2014.
The satellite Brodie, Bluelite, Oromonte, Solberry and Wedge deposits are situated west and southwest of the Drinkwater pit and lie in close proximity to the leach pad. These deposits are part of a semi-continuous trend of mineralization within a shallow-dipping stratigraphic horizon. They lie on the western flank of an anticlinal fold structure and are considered to be related to mineralization within the Drinkwater-Mary trend, which lies on the eastern flank.
An unpdated LOM incorporating the Drinkwater, Mary/LC and satellite deposits was reported in the Company's July 21, 2014
news release. The cut-off date for the LOM study was March 31, 2014. Continued drilling on the satellite deposits post this cut-off date is designed to potentially upgrade and increase the reported mineral reserve and resource estimate and potentially extend life of mine.
Brodie & Bluelite Deposits
The Brodie and Bluelite deposits are located 975 metres (3,200 feet) and 1,100 metres (3,600 feet) southwest, respectively, of the Drinkwater pit. Drilling in 2011-12 targeted both deposits as well as the mineralized structural corridor that trends between them. Previous operators thought the Brodie and Bluelite deposits were separate mineralized bodies; however, results of Scorpio Gold's drilling has demonstrated they are one semi-continuous zone. The mineralized corridor encompasses a strike length of some 1,370 metres (4,500 feet) and is situated immediately adjacent to the leach pad.
The Brodie and Bluelite deposits have been incorporated into the updated LOM (see Mineral Reserve & Resource Estimates
). Results from the expansion drilling program post the March 31, 2014 cut-off date for the LOM study are very encouraging and are expected to increase and upgrade the current reserve and resource estimate for these deposits.
Brodie Drill Plan
(PDF 1.5 Mb)
Bluelite Drill Plan
(PDF 1.2 Mb)
The Oromonte deposit lies northwest of the Wedge deposit and 425 metres (1400 feet) west-southwest of the Drinkwater pit. A mineral resource estimate has been calculated for the deposit (see Mineral Reserve & Resource Estimates
) but currently there is no economic pit shell developed for Oromonte.
A higher-grade zone of mineralization intersected in 2011-2013 drilling lies below the current extent of the estimated resource,. The zone trends northerly and lies along the edge of a geophysical magnetic high. It has been intersected at 85 to 115 metres vertical depth and, although not accessible by open pit mining, may be amenable to underground extraction should further results support underground development. Historical underground workings are known to lie approximately 180 meters to the east. The significance of these drill results in context with their structural and geophysical setting will be evaluated for follow up in 2014.
The Solberry deposit lies west of the currently producing Drinkwater and Mary pits and 600 meters (1,970 feet) northwest of the leach pad. The Solberry deposit has been incorporated into the updated LOM (see Mineral Reserve & Resource Estimates
). Further drilling to potentially increase and upgrade the current reserve and resource estimate is planned in 2014.
Solberry Drill Plan
(PDF 1.1 Mb)
The Wedge deposit is located 225 metres (740 feet) southwest of the Drinkwater pit. The Wedge deposit has been incorporated into the updated LOM (see Mineral Reserve & Resource Estimates
). Results from the expansion drilling program post the March 31, 2014 cut-off date for the LOM study are very encouraging and are expected to increase and upgrade the current reserve and resource estimate for this deposit.
Wedge Drill Plan
(PDF 1.4 Mb)
Geology & Mineralization
The Mineral Ridge gold deposits are located on the northeast flank of the Silver Peak Mountain Range. This range lies in the southern reaches of the Great Basin, within the Walker Lane structural corridor. Walker Lane is a 100-km-wide region of right lateral, wrench-faulting which separates the Sierra Nevada batholith to the west and southwest and the Great Basin to the east and northeast.
Mineral Ridge is an anticlinal dome found on the eastern flank of the Silver Peak Range. It has been interpreted as an uplifted metamorphic core complex where unmetamorphosed and unfolded Cambrian strata are in detachment-fault contact with underlying deformed granitoids and Precambrian metamorphic rocks of the core complex. Auriferous quartz lenses of the central gold-quartz district are concordant with foliation in the metasedimentary host rocks of the Precambrian Wyman Formation. Transitional contacts were observed between quartz and alaskite (commonly pegmatitic), and between alaskite and peraluminous two-mica granite, strongly suggesting that the alaskite, quartz, and ore metals were derived hydrothermally from residual granite melt and aqueous fluids.
The property is located on a typical "Nevada Structural System" which is known to control gold mineralization.
To date, seven well-defined gold bearing structures have been documented on the property as follows:
- The North-Northeast Eagles Nest Fault
- The North-Northeast Coyote Fault
- The Northwest BW Normal Fault
- The North-Northwest Gillian Fault
- The Northeast Mary/Drinkwater Cross Fault
- The North-Northwest Mary/Drinkwater Cross Fault
- The North-Northwest Black Warrior Intersection Fault
The known mineralized zones occur over an area of approximately 4,300 m (14,000 ft) north-south and 4,600 m (15,000 ft) east-west. Individual zones can be as much as 43 m (140 ft) thick, usually consisting of a higher-grade 1.5 to 9.0 m wide halo surrounded by a lower-grade mineralized envelope. Two or more high-grade zones are commonly observed stacked on one another. Gold deposition is structurally controlled, and some of the highest grade material is found in mineralization shoots that are at an oblique angle to the direction of movement of the upper plate slab.
Gold is present as native gold and electrum, and generally occurs as rounded, angular, irregularly shaped and elongated inclusions and intergrowths in quartz, frequently associated with micaceous minerals or carbonates occupying interspatial spaces or fracture filling. Gold is also frequently associated with goethite, sometimes with relict pyrite, and on occasions intergrown with sphalerite, galena, anglesite/cerrusite and pyrite.
Mineral Reserve & Resource Estimates
On July 21, 2014, the Company reported on an updated Life of Mine Plan ("LOM") completed for the Drinkwater, Mary/LC, Brodie, Bluelite, Solberry, Wedge and Oromonte deposits.
The updated mine plan, which includes an updated mineral reserve estimate, projects mine life for Mineral Ridge extending into the 3rd quarter of 2016, or approximately 29 months as of the end of March 2014, the date of the LOM update. Average ore production over this time frame is estimated at 73,700 tons per month ("t/m") based on estimated Probable Mineral Reserves of 2.1 million tons ("Mt") grading 0.061 oz/ton gold (131,190 oz contained gold) within estimated Indicated Mineral Resources of 2.7 Mt grading 0.059 ounces per ton ("oz/ton") gold (160,300 oz contained gold). Expansion and infill drilling of the satellite deposits has continued since the March 31, 2014 cut-off date for the LOM and is expected to add to the resource base and potentially support further conversion of current mineral resources to mineral reserves.
This LOM is inclusive of the Drinkwater and Mary/LC deposits and the five satellite deposits, Brodie, Wedge, Bluelite, Solberry and Oromonte. An Inferred Mineral Resource estimate for the Brodie, Wedge, Bluelite, and Solberry deposits, dated June 1, 2013, was reported in the Company's August 16, 2013 news release. Development drilling over the past two years has allowed for an upgrade of the previous resource estimate to include Indicated Mineral Resources containing Probable Mineral Reserves. The updated Indicated Mineral Resource estimate for the five satellite deposits is 625,100 tons grading 0.061 oz/ton gold (38,360 oz contained gold), which includes a Probable Mineral Reserve for four of the deposits of 463,880 tons grading 0.065 oz/ton gold (30,050 oz contained gold).
Principal Outcomes - Life of Mine Study
- Estimated Probable Mineral Reserves: 2.1 Mt grading 0.061 oz/ton gold (131,190 oz contained gold).
- 2.5 year mine life at 73,700 t/m ore throughput as of March 31, 2014.
- Total gold production over projected life of mine is approximately 97,700 ounces gold which includes 85,300 recoverable ounces mined and 12,400 recoverable ounces gold in inventory as of March 31, 2014.
- Average total cash cost per ounce of gold sold of $1,074.
- After tax net present value until mine closure of $7.4 million (8% discount rate) using an average gold price of $1,300/oz.
- Key risks include:
- Current estimated reserves may not be realized causing a shortfall in gold production.
- Current water requirements for the heap leach solution would be in jeopardy if the main water well were to fail. The Company is currently rehabilitating a second water well to reduce this risk.
- Key opportunities include:
- Current estimated reserves may be exceeded, thus increasing gold production.
- There is potential to identify additional mineralization from drill-defined extensions to the known deposits, which may support Mineral Resource estimation updates and potentially be converted into Mineral Reserves.
- Exploration potential of other identified prospects on the Mineral Ridge property.
Mineral Reserves presented in Table 1 have demonstrated economic viability. All Mineral Reserves are classified as Probable Mineral Reserves with no Proven Mineral Reserves.
Table 1. Probable Mineral Reserves Estimate - March 31, 2014
Notes to Table 1:
Gold Grade (oz/ton)
Contained Gold (oz)
Strip Ratio (waste:ore)
Table 2. Indicated Mineral Resources Estimate - March 31, 2014
- The effective date of the Mineral Reserve estimate is March 31, 2014.
- The Mineral Reserve estimate was prepared by Jim Ashton, P.E., of Scorpio Gold and audited by independent qualified person, Randy Martin, SME-RM, of Welsh Hagen Associates.
- Mineral Reserves are reported at a 0.020 oz/ton gold cut-off grade.
- Mineral Reserves are contained within a designed pit with access ramps based on the Lerchs-Grossmann (LG) algorithm utilizing a $1,300 oz gold price. The optimization mining cost was $4.15/t of ore mined at Drinkwater, $3.79/t of ore mined at Mary/LC, $2.96/t of ore mined from the satellite deposits, $2.92/t for waste mined from the Drinkwater, $2.57/t for waste mined from the Mary/LC and satellite deposits, and $1.56/t of fill mined. An average processing cost of $11.29 was applied per ton processed. G&A costs were applied at $4.70 per ton processed. Shipping and refining costs of $28.82/oz gold produced were applied. A 65% metallurgical recovery was applied. Overall pit slope angles ranged from 45 degrees to 49 degrees.
- No economic pit was developed for the Oromonte deposit.
Table 3. Inferred Mineral Resources Estimate - March 31, 2014
Gold Grade (oz/ton)
Contained Gold (oz)
Notes to Tables 2 & 3:
Gold Grade (oz/ton)
Contained Gold (oz)
- Mineral Resources in Table 2 are reported inclusive of Mineral Reserves.
- The effective date of the Mineral Resource estimate is March 31, 2014.
- The Mineral Resource estimate was prepared by Jim Ashton, P.E., of Scorpio Gold and audited by independent qualified person, Randy Martin, SME-RM, of Welsh Hagen Associates.
- Mineral Resources are reported at or above a 0.020 oz/ton gold cut-off grade.
- Mineral Resources are reported using a long-term gold price of US$1,500/oz.
- Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
The Mineral Resource estimate is based on a total of 2,514 drill holes and 108,969 assay results collected between 1939 and 2014 from the Drinkwater, Mary, Brodie, Bluelite, Solberry, Wedge, and Oromonte deposits. The cut-off date for information used in the geologic model and Mineral Resource model was March 31, 2014.
Key Assumptions, Parameters & Methods Used:
- Mineral Resources reported are constrained within a conceptual Lerchs-Grossmann (LG) pit shell and are inclusive of Mineral Reserves.
- The economic parameters used to construct the Mineral Resource LG pit are the same as those used in the Mineral Reserve pit except that the price of gold was increased from $1,300 per ounce to a long-term gold price of $1,500 per ounce.
- The block model consists of 15 ft x 15 ft x 10 ft blocks estimated using inverse-distance to the second power methodology. Mineralized envelopes were constructed on 25 ft spaced sections using a 0.010 oz/ton gold assay grade as a guide. The envelopes were combined into wire-frames that defined the extent of mineralization for all the deposits.
- Extensive historical underground workings are present in the Drinkwater and Mary areas. Underground wire-frames were used to remove the percentage of the block contained within the mineralized envelope.
- A single bulk density factor of 13 cubic ft per short ton was assigned to all blocks that represent in-situ rock and used in the Mineral Resource estimates.
- In the Drinkwater area, assays were capped at a threshold of 1.6 oz/ton gold, in the Mary/LC and Oromonte areas assays were capped at a threshold of 1.0 oz/ton gold, in the Brodie, Bluelite, and Solberry area assays were capped at 0.650 oz/ton gold, and in the Wedge area assays were capped at 1.50 oz/ton.
- Mineralization pinches and swells, and is not easily mapped, and correlation between sections is often difficult, therefore outlier restriction was also applied to restrict gold interpolation at a threshold of 0.5 oz/ton gold and a distance of 60 ft for the Drinkwater and Mary/LC deposits and a distance of 40 ft for the satellite deposits.
The Mineral Resource and Mineral Reserve estimates were prepared by qualified person, Jim Ashton, P.E., of Scorpio Gold and audited by independent qualified person, Mr. Randy Martin, RM-SME of Welsh Hagen Associates. An independent technical report supporting the disclosure of the Mineral Resource and Mineral Reserve estimate is being prepared by Welsh Hagen Associates and will be filed on SEDAR within 45 days of the Company's July 21, 2014 news release.