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. Pre-production mining commenced in the Drinkwater pit on May 31, 2011 and the Company achieved commercial production status effective January 1, 2012.
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.
2015 Mineral Ridge Operations Forecast:
- Production: 40,000 to 45,000 ounces of gold
- Total Cash Cost: US$800 to US$850 per ounce of gold sold
Production in 2015 is scheduled from the Mary and Mary LC pits, and from the Wedge, Bluelite, Solberry and Brodie satellite pits.
Key estimated parameters forming the basis for the 2015 forecast are:
- Average throughput: 2,700 short tons (2,450 metric tonnes) per day
- Average grade: 0.061 ounces per short ton (2.09 grams per tonne) gold
- Waste to ore ratio including development: 7.4 to 1
The Company expects these parameters to fluctuate throughout 2015 and as a result, these parameters should be treated as full-year averages and will not necessarily be reflective of quarterly operating results.
FIRST QUARTER 2015
Gold production in Q1 2015 totalled 11,952 ounces, representing a 16% increase over Q1 2014 and a new quarterly production record for the Mineral Ridge operation. Silver production totalled 6,319 ounces, representing a 23% increase over Q1 2014 and also a record high for Mineral Ridge.
A summary of the Q1 2015 operating results is presented in the Company's April 23, 2015
FOURTH QUARTER & YEAR ENDED DECEMBER 31, 2014
Total gold production in 2014 was 40,814 ounces, an increase of 4% over the year 2013. Gold production in Q4 2014 totalled 10,258 ounces, representing a decrease of 10% from Q4 2013 and a 9% decrease from Q3 2014. Production challenges occurred in the fourth quarter of 2014 as the Company experienced a delay in receiving its mine permit for the satellite deposits. The delay created a shortfall in scheduled tons and ounces mined from those pits and had to be made up by mining in the Mary LC area.
A summary of the Q4 2014 operating results is presented in the Company's January 15, 2015
THIRD QUARTER 2014
Production at Mineral Ridge in Q3 2014 totalled 11,228 ounces of gold and 4,911 ounces of silver at a total cash cost of US$859 per ounce of gold sold. Gold production for the first nine months of 2014 totals 30,556 ounces, representing an increase of 9.9% over the same period in 2013. As of September 30, 2014, total production at the Mineral Ridge Operation since declaring commercial production in January 2012 stands at 101,782 ounces of gold.
A summary of the Q3 2014 operating and financial results is presented in the Company's October 9, 2014
and November 20, 2014
news releases, with complete details provided in the Q3 2014 Financial Statements
and Management Discussion & Analysis
HIGHLIGHTS FOR THE THIRD QUARTER ("Q3") ENDED SEPTEMBER 30, 2014 AND SUBSEQUENT EVENTS
HIGHLIGHTS FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2014
- 11,228 ounces of gold produced compared to 9,632 during Q3 of 2013. In late June 2014, an additional carbon column was installed which increased the rate of processing of pregnant leach solution and thereby brought down leach pad inventory and consequently increased gold production.
- Revenue of $14.8 million compared to $14.4 million during Q3 of 2013, as a result of the sale of 3% more gold ounces in Q3 of 2014 than Q3 of 2013.
- Total cash cost per ounce of gold sold(1) of $859 compared to $729 during Q3 of 2013, mainly attributable to lower head grades.
- Mine operating earnings(1) of $1.2 million compared to $1.8 million during Q3 of 2013.
- Net earnings of $0.3 million ($0.00 basic and diluted per share), compared to $0.8 million ($0.00 basic and diluted per share) during Q3 of 2013.
- Adjusted net earnings(1) of $0.5 million ($0.00 basic and diluted per share) compared to $0.8 million ($0.00 basic and diluted per share) during Q3 of 2013.
- Adjusted EBITDA(1) of $3.4 million ($0.02 basic and diluted per share) compared to $5.2 million ($0.03 basic and diluted per share) during Q3 of 2013, mainly as a result of higher cash costs per ounce of gold sold.
- Cash flow from operating activities(1) of $5.0 million compared to $6.6 million during Q3 of 2013, mainly as a result of higher cash costs per ounce of gold sold.
- On November 5, 2014, the Company received 1,250,000 additional common shares of Gold Standard Ventures Corp. as bonus consideration pursuant to the sale agreement in respect of the Pinon property. The Company now holds 6,750,000 common shares of Gold Standard Ventures Corp.
(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 Q3 of 2014 for a complete definition and reconciliation to the IFRS results reported in the Company's financial statements for Q3 of 2014.
- 30,556 ounces of gold produced compared to 27,812 during the nine months ended September 30, 2013.
- Revenue of $38.6 million compared to $40.9 million during the nine months ended September 30, 2013, mainly due to a lower average realised gold price offset by an increase in the number of gold ounces sold.
- Total cash cost per ounce of gold sold(1) of $825 compared to $735 during the nine months ended September 30, 2013, mainly attributable to lower head grades.
- Mine operating earnings(1) of $3.6 million compared to $9.0 million during the nine months ended September 30, 2013.
- Net earnings of $1.3 million ($0.00 basic and diluted per share) compared to net loss of $4.9 million ($0.03 basic and diluted per share) mainly as a result of a non-cash impairment charges of $9.9 million ($0.06 basic and diluted per share) during the nine month period ended September 30, 2013.
- Adjusted net earnings(1) of $1.4 million ($0.00 basic and diluted per share) compared to $5.6 million ($0.02 basic and diluted per share) during the nine months ended September 30, 2013.
- Adjusted EBITDA ( ) of $10.8 million ($0.06 basic and diluted per share) compared to $20.4 million ($0.11 basic and diluted per share) during the nine months ended September 30, 2013, mainly as a result of lower revenue and higher cash costs per ounce of gold sold.
- Cash flow from operating activities(1) of $10.4 million, down from $18.1 million during the nine months ended September 30, 2013, mainly as a result of lower revenue and higher cash costs per ounce of gold sold.
- Sale of the Pinon property completed 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.
In its July 21, 2014
news release, the Company reported on an updated Life of Mine Plan ("LOM Plan") for the Mineral Ridge Operation that included the Drinkwater, Mary, Mary LC, and the five satellite deposits, Brodie, Bluelite, Solberry, Wedge and Oromonte. (see Mineral Reserve & Resource Estimates
). With completion of mining of the Drinkwater deposit in Q3 2014, Mary is now the main deposit currently in production.
Operations Area Map
(PDF 4.0 Mb)
Mary - Mary LC Deposit
The 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 - Mary LC and incorporation of the expanded pit design into the updated LOM Plan. Pre-stripping of the Mary LC pit commenced in the first quarter of 2014 and extraction of development ore was realized in the second quarter of 2014.
Infill and step-out drilling on the Mary LC post the March 31, 2014 cut-off date of the LOM Plan has focused on increasing the total mineral resources, upgrading resource categories, lowering the strip ratio and potentially increasing the mineral reserve estimate for the deposit.
Mary LC Drill Plan
(PDF 2.0 Mb)
The satellite Brodie, Bluelite, Solberry, Wedge and Oromonte 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. 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.
Brodie and Bluelite have been incorporated into the updated LOM (see Mineral Reserve & Resource Estimates
). Drilling has continued on both deposits as well the mineralized structural corridor that trends between, known as the NW Brodie trend. Results to date are very encouraging and are expected to increase and upgrade the current reserve and resource estimates for the Brodie and Bluelite deposits, and potentially allow for defining a new resource in the NW Brodie trend area.
Brodie Drill Plan
(PDF 1.5 Mb)
Bluelite Drill Plan
(PDF 1.3 Mb)
NW Brodie Trend Drill Plan
(PDF 1.0 Mb)
The Solberry deposit lies west of the Drinkwater pit and 600 meters (1,970 feet) northwest of the leach pad. Solberry has been incorporated into the updated LOM (see Mineral Reserve & Resource Estimates
). Results from a successful 2014 drill program at Solberry are expected to upgrade and expand the mineral resources currently defined for the deposit.
Solberry Drill Plan
(PDF 1.1 Mb)
The Wedge deposit is located 225 metres (740 feet) southwest of the Drinkwater pit and immediately adjacent to the leach pad. Wedge 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 1.0 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.
Oromonte Drill Plan
(PDF 1.0 Mb)
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 Physik target is situated approximately 300 meters southwest of the producing Mary LC pit. This is an entirely new target area on the Mineral Ridge property discovered by Scorpio Gold's exploration team using a combination of remote sensing, geophysics and structural interpretation.
Initial drill testing of the Physik target over a 200 meter strike length has intersected significant mineralization in 7 of 9 holes, with drill hole MR141107 returning 31.79 g/t gold over 4.57 meters within 15 meters of surface (see November 3, 2014
The mineralization is interpreted to lie along a northwest trend, which is the predominant structural trend common to all of the significant deposits on the property. The results from this early stage of drilling are considered to be highly encouraging. Follow-up drilling is planned in 2015 to determine if there is potential to define a mineral resource in this area.
In 2013, the Company commissioned an 810 line-km heli-borne VTEM plus
time domain survey over the Mineral Ridge property. Multiple targets were generated, including a circular annular magnetic anomaly in the area now known as the Physik target. The anomaly measures 680 meters by 740 meters in diameter and is interpreted as possible annular intrusion (ring dyke) with a magnetic high surrounding a central low signature. The Physik anomaly is readily identifiable in the TMI and RTP magnetic data sets in addition to the 1st vertical derivative magnetic data. A NW-SW trending fault is interpreted to lie along on the east edge of the anomaly. Interpretation of the possible ring dyke and fault structure is supported by an Aster multi-spectral satellite imagery survey undertaken in 2010.
Mineralization intersected to date lies within the central low area of the magnetic anomaly. The Company is currently waiting on a Mag 3-Dimensional inversion of the geophysical data, the results from which may provide discrete targeting of magnetic bodies, or the general magnetic framework (geometry) of the overall zone. Compilation of all data will direct planning of the 2015 exploration program at the Physik target.
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 and Life of Mine Plan was filed on SEDAR on September 3, 2014 and is also available here: View Technical Report (PDF 27.3 Mb)