Integra’s primary focus is on the Triangle deposit, located 2 km away from the Sigma Mill. The March 2017 resource update at Triangle increased the indicated resource 100% and the inferred resource 105% on 117,734 meters of new drilling.
In late 2015 the Company completed installation of all surface infrastructure (road, power, water, sewage, gas and buildings) required prior to commencing an underground exploration program at Triangle at a cost of $5.6 million.
Integra signed a contract with Promec in June 2016 and construction on the Triangle ramp is underway. The ramp will descend at a rate of 170 meters per month and take 13-16 months to complete. This ramp will allow Integra to complete an underground exploration drill program and complete a bulk sample for metallurgical testing. For more information on the construction progress click here.
Steeply dipping C Structures carry bulk of resource, amenable to long-hole mining
Permitted through bulk sample, mining lease process underway
Gold mineralization at the Triangle Zone, highlighted by an abundance of quartz-tourmaline veins with minor amounts of pyrite, is interpreted to be predominantly hosted within a series of parallel, steeply-dipping shear structures identified as “C” zones. These high angle structures strike east-west and dip south at angles varying from 55 to 75 degrees. The associated “C Splay” structures, which dip from 20 to 45 degrees to the south with an east-southeast strike, are interpreted as second order structural splays developing from the more steeply dipping “C” structures. A third order of horizontal veining has also been identified and likely developing from the C structures; although distribution of this type of veining is not well defined in part due to drill spacing. All structures are gold mineralized although the “C” zones are generally thicker, steeper dipping and more continuous. The Company’s predictive model as it relates to the “C”, “C Flat” structures, and horizontal veining will continue to evolve as more drill data becomes available.
The Company’s geologists have now identified and modelled six “C” structures, C1 to C6, while recent and ongoing drilling indicates that additional gold bearing, steeply dipping shear structures are present at depth structurally below C6.
Styles of gold mineralization encountered at Triangle bear striking similarities to those hosting gold mineralization at the adjacent, historic Lamaque and Sigma Gold Mines. The Lamaque and Sigma Mines jointly produced over 9 M ounces of gold* and are located less than 2.5 km from the Triangle Deposit in the same geological and structural domain as Triangle. At the Lamaque Mine, 80% of the gold production came from mineralization hosted within the intrusive host rock, while mineralization at the adjacent Sigma Mine is split almost 50/50 between the intrusive phases and the volcanic country rocks often derived from sub-vertical shear zones similar to the “C” type structures of Triangle. At the Sigma Mine some of these shear zones have been identified to have a strike length of greater than 1 km, similar to strike lengths being tested at Triangle in the current program.
The Triangle Zone was discovered by drill testing an ovoid shaped magnetic anomalous zone which corresponded to a younger tonalite intrusion. The magnetic anomaly extends both east and west over a strike length of 700 metres and is up to 400 metres wide. In drill core the mineralized veins occur as part of a related vein clusters within the fractured and altered zones of the tonalite which intrudes the surrounding intermediate to mafic volcanics (mostly lapilli and blocky tuffs, undifferentiated pyroclastics and basalt).
Below is a brief overview of drill programs completed on the Triangle Zone:
In total, 123,233 m of drilling was completed at Lamaque in 2016, of which 104,820 m were completed on Triangle. All 2016 drill results from Triangle will be included in the resource estimate planned for Q1 2017.
The Triangle Zone was the main drill target in 2015, with drilling focused on testing the lateral extensions of mineralization to the east, west and south. To the east of Triangle, drilling focused on targets that remain open in the vicinity of the 2014 drill program which intersected multiple high grade mineralized zones, including 14.23 grams per tonne Gold (“g/t Au”) over 11 m in TM-14-32 (see press release dated May 21, 2014).
Drilling to the west of Triangle further tested areas targeted during the 2014 condemnation drilling for the proposed Triangle ramp access, which intersected gold mineralization grading up to 101.85 g/t Au over 1.6 m in TMC-14- 10 (see press release dated December 02, 2014).
To the south of Triangle, the Company intends to continue testing extensions of gold mineralization hosted in volcanic units. Drilling in the southern volcanics hosted within the Triangle Zone during 2014 returned significant assays, including 23.02 g/t Au over 5 m in TM-14-03A (see press release dated March 25, 2014).
During the winter of 2014, the Company completed a 25,040 meter drill program in 65 holes. The drill program concluded the following:
Results strongly support and validate the Company’s geological model of the Triangle Zone used for both resource estimation and mine planning in the PEA. Mineralized zones were intersected where the model predicted they would be.
Validation of near surface lateral extensions, primarily to the south of the Triangle Zone, with numerous drill holes intersecting high-grade mineralized shear zones hundreds of meters from the extent of the existing resource limit.
Wide, high-grade zones intersected outside of but in proximity to the lower portion of the Triangle Zone resource, showing strong similarities to lower, bulk tonnage sections of the adjacent Main Plug at the historic Lamaque Mine. Mining at the Main Plug began using traditional, selective narrow vein mining techniques but as production moved deeper, below 500 meters, there were wide zones with multiple veins sets stacked upon one another that they were able to apply much lower cost bulk mining methods. The Main Plug of the Lamaque Mine produced 3.7 million ounces* and is located within a few hundred meters of Integra’s Lamaque project border.
Between 2006 and 2011, validation and verification drilling, 8,209 meters in 23 diamond drill holes DDHs, aided in providing an understanding of the geological model. A resource calculation for this zone was completed in November 2011 and added high-grade ounces to the Lamaque Property resource. Subsequently, 4,500 meters of drilling was completed in 2012, and a further 7,000 meters drilled in 2013, all of which was incorporated into the Company’s then existing resource estimate.
1. Triangle: Effective date is March 17, 2017; specific gravity of 2.8 g/cm3; geologically constrained model with hard boundary; capping of 20 g/t Au on composites when estimated cells are more than 15 m from drill hole otherwise uncapped; composited to full length for each zone intersection before geostatistical analysis; 2 m minimum true thickness, if required diluted with in situ grade when assay results are available otherwise diluted with “zero” grade; ordinary kriging; 3 g/t cut-off calculated for official resource numbers
The mineral resources presented herein are not mineral reserves and thus do not have demonstrable economic viability. The mineral resources for the Lamaque Project were estimated in conformity with CIM “Estimation of Mineral Resources and Mineral Reserves Best Practices” guidelines and are reported in accordance with NI 43-101. The “Technical Report and Fall 2016 Mineral Resurce Estimate Update for the Lamaque Project” is available under the Company’s SEDAR profile or at the following link: https://integragold.com/site/assets/files/1183/43-101-fall-2015-mineral-resource-estimate-update-1473793352.pdf