In 1969, Placer Development Limited discovered the Eastmain Mine. The gold-silver-copper bearing A Zone was intersected while drill-testing an airborne geophysical conductor in an area devoid of outcrop. The discovery hole in the A zone, 1.5m @ 13.6 g/t Au, was associated with quartz veins containing semi / massive sulphides (pyrrhotite). In the 1970’s, further airborne surveys identified the B Zone, which was entirely undercover. Drilling was once again directed by geophysical interpretation, but an unsuccessful drill campaign resulted in the cessation of exploration work until the 1980’s. After re-staking by Placer in the 1980’s, further drill testing of newly identified airborne conductors successfully located two additional gold-rich zones (the B and C zones), although grid pattern drilling did not establish sufficient zone continuity. At this stage, Downhole Electromagnetics (DHEM) was trialed for the first time, with the goal of detecting the sulphide zones (and subsequently the coincident gold mineralization) at depth. DHEM methods were subsequently deemed successful, reporting a 71% success rate for drill hole targeting based on borehole geophysics. At this stage, Placer concluded that borehole Pulse Electromagnetics (PEM) could easily define the sulphide lenses at depth, and that “the only means to rapidly develop tonnage and new lenses is to stringently guide drilling programs with geophysics” (Placer Exploration Report, 1984). However, this remains the last time that any significant ground based EM surveys were carried out on the Eastmain property. The pioneering success of these geophysical surveys, along with the absence of further geophysical work at Eastmain since the 1980’s, forms the basis of the new exploration strategy that is now being executed by Benz.
Following further drilling and the declaration of a maiden resource the Eastmain mine was put into production by MSV resources in 1994. A total of 118,356 tonnes were mined at 10.58 g/t for 40,000 oz of recovered gold. Ore was trucked by ice road to the Copper Rand processing plant in Chibougamau (now owned by Dore Copper Mining), and recoveries were reported at 95%. Due to adverse ice road conditions, the mine was shut down in March 1995, and ceased indefinitely in November 1995 as continued low gold prices exacerbated operational difficulties at the mine.
In 2005 Eastmain Resources completed 3,200 line-kilometers of VTEM and magnetic airborne geophysical surveys at 100-metre line spacing over the Ruby Hill East, Ruby Hill West claim blocks and the Eastmain Mine property. The VTEM surveys clearly outlined the A, B and C Gold Zones on the Eastmain Mine property, and magnetic survey data also defined the key ultramafic marker unit on the Property. In 2004, Campbell Resources Inc. (“Campbell”) reported a measured and indicated mineral resource of 878,100 tonnes at 10 g/t Au for the Eastmain Mine Gold deposit containing 255,750 oz of gold and 4.1 million lbs of copper, including measured resources of 91,500 tons grading 0.268 oz/t gold and indicated resources of 786,600 tons at 0.294 oz/t gold (Campbell, 2004 Annual Report, available on SEDAR at www.sedar.ca). Several historical reports including a Feasibility Study prepared by MSV in 1990 and a report entitled Reserves/Resources Audit of Mining Property by MetChem in 2001, support Campbell’s disclosed estimate. In 2009, Eastmain completed soil geochemical surveys, prospecting and geological mapping on the Eastmain Mine Property. Anomalous gold ranging from 4.38 g/t gold to 43.6g/t gold was detected in rock sampling over a six-kilometer strike-length, coinciding with the Mine Tend, northwest of the Eastmain Mine Gold Deposit.
In 2007, Eastmain Resources acquired the Eastmain property from Campbell Resources as a secondary project. Despite several encouraging drill programs, the company remained focused on the 1.3m oz Eau Claire deposit. In 2009, Eastmain completed soil geochemical surveys, prospecting and geological mapping on the Eastmain Mine Property. Anomalous gold ranging from 4.38 g/t gold to 43.6 g/t gold was detected in rock sampling over a six-kilometer strike-length, coinciding with the Mine Tend, northwest of the Eastmain Mine Gold Deposit. In 2013 and 2014, a 5,483 line-km high-resolution helicopter-magnetic survey was conducted over the Eastmain Mine and the adjoining Ruby Hill East Properties. Mapping and prospecting programs were also completed. A total of 463 rock samples and 1,539 soil (B-Horizon) samples were collected. 97 samples returned values greater than 100 ppb Au, from which 35 assayed more than 1 g/t Au. The best value, returning 108.5 g/t Au, 196.0 g/t Ag and 4.22% Cu was from a boulder and probably originated from what is now the EM18-H2 trench. The best results, from an outcrop located in the Hillhouse Hill area, assayed 39.5 g/t Au, 3.3 g/t Ag and 0.46% Cu. 2014 field exploration work confirmed four high-grade target zones northwest of the Eastmain Mine Gold deposit. 249 rock samples were collected as part of the 2014 geological targeting program in search of additional Mineral Resources along the Mine Trend. Two of the areas (“Hillhouse” and “Julien”) coincided directly with the projected Eastmain Mine Trend and two targets (“Michel” and “Suzanna”) are located along secondary parallel structures, which may be a stratigraphic repetition of mineralization or a folded repetition of the mine sequence. The four showings are briefly described below.
As part of the Plan Nord economic development strategy launched by the Quebec government in 2011, a direct, all-season road (Route 167) leading directly to the Eastmain project was completed in 2016. The road was conceived as an access road for the Renard Diamond mine, located immediately North of Eastmain. Prior to the construction of Route 167, access to the Eastmain mine was only possible via helicopter, float plane or ice-road. In August 2019, Benz Mining Corp. entered into an option agreement with Eastmain Resources Inc. to acquire a 100% interest in property. Benz Mining has subsequently appointed a new board, new management, and a new technical team.
