Newmont-GoldCorp recently announced the official opening of the Borden gold mine near Chapleau, Ontario (Borden Mine Opening) and that they had reached commercial production a week later.
Why is this significant for Labrador Gold Shareholders?
The Borden Gold Deposit, discovered in 2010 by Probe Mines, is located less than five kilometres to the northwest of Labrador Gold’s Borden Lake Extension (BLE) project acquired shortly after Probe Mines announced their discovery. We named it the Borden Lake Extension because it lies along the southeast trend of the Borden Gold zone. Newmont-Goldcorp is still finding mineralization while drilling to the southeast and has now reached the east side of Borden Lake. The last published reserves for the Borden Gold deposit were 0.95Moz of proven and probable grading 7.14g/t Au.
Previous work at BLE included geophysical and geochemical surveys over an area of complex magnetic anomalies along trend with the Borden Gold zone. A VLF-EM survey identified seven conductors sub-parallel to the southeast trend of the Borden Gold zone in the vicinity of the anomalous gold zones.
Bulk till samples were collected across the trend of the VLF anomalies and sent to Overburden Drilling Management for dense media separation and identification of minerals. Results showed gold grains in 18 of the 22 samples including 48 grains found in one of the samples. This result is significantly higher than the number of gold grains found in 240 regional till samples taken by the Ontario Geological Survey (maximum of 33 grains) including those immediately down ice of the Borden discovery outcrop (19 to 28 grains). The BLE samples with the highest numbers of gold grains, occur down ice (south southwest) of the projected trend of the Borden Lake gold zone. The occurrence of gold in the BLE till samples was the first indication of gold in close proximity to the Borden Lake gold zone since its discovery in 2010.
A spaciotemporal geochemical hydrocarbon (SGH) survey resulted in the definition of two targets closely associated with gold in till and VLF conductors.
Heavy mineral concentrates produced from the bulk till samples were analyzed for gold and ranged from below detection up to 386 ppb. In addition, gold was also analyzed in small till samples taken over a larger area and ranged from below detection up to 54ppb. Finally soil samples were taken across the trend of the VLF conductors and analyzed for Au using the partial digestion mobile metal ion (MMI) technique. Several anomalous samples are associated with other gold anomalies. Taken together, the results of the geochemical surveys define two anomalous zones one in the north extending over 1.3km northwest-southeast and another in the south extending over 1km north south. The area between these two zones has not been adequately sampled to determine continuity.
The two anomalous geochemical zones were covered with dipole-dipole IP/Resistivity survey grids to determine specific targets for drilling one in the north, covering gold grain in till samples from 1 to 12 and a second in the south covering gold grains in till from 3 to 48. Results indicate a chargeability anomaly approximately 230 metres up ice of the 48 gold grain sample that is open to the northwest and to the southeast. In addition, a second chargeability anomaly occurs on the south grid another 800 metres up ice of the 48 grain sample and approximately 450 to 600 metres north of a cluster of samples containing from three to seven gold grains.
During 2017, the Company drilled 1,665 metres in 13 holes to test the chargeability and geochemical anomalies occurring up ice of the high gold grain counts in till samples, including the sample that returned 48 gold grains. One of the chargeability anomalies occurs adjacent to a soil gas hydrocarbon (SGH) anomaly approximately 200 metres up ice of the sample containing 48 gold grains. A second chargeability anomaly, with a stronger response than the first occurs a further 500 metres up ice of the anomalous till samples. Both chargeability anomalies are approximately 400 metres long and remain open to the east and west.
While no significant gold mineralization was found, the rocks encountered were commonly altered, with hematite, silica (both pervasive and as veinlets) and chlorite being the predominant alteration styles. Sulphide mineralization, primarily in the form of disseminated pyrite, and in some cases pyrrhotite, was identified in some of the altered zones.
In addition, drilling intersected the same rocks as those described by Probe Mines during their drilling at Borden Lake, including biotite gneiss, garnet biotite gneiss as well as pegmatite that is commonly associated with the gold mineralization. Mafic metavolcanics rocks were also encountered, and these may be part of the Borden Lake Belt.
Given the start of production at the Borden Mine, follow up of past results at BLE is warranted. Till sampling to fill in gaps in the data where possible should be undertaken. VLF-EM data should be reprocessed using up to inversion softaware. Due to the amount of overburden in the region, further follow could use overburden drilling using a RAB drill on a grid pattern over the anomalous areas. Such overburden drilling was the key to discovery of New Gold’s Rainy River gold deposit in northwestern Ontario (4.2 Moz reserves as of December 2018).
This summary complete with figures can be found here.