The Brookbank Property is comprised of a group of mining leases and staked claims covering 17,870 hectares situated northeast of the town of Beardmore in north-central Ontario. The property lies north of Trans-Canada Highway 11 and is bisected by Provincial Highway 801.
Greenstone Gold Mines holds 100% interest in the mining lease where the Brookbank gold deposit is located, with the remaining portion of the Property subject to two Joint Venture (JV) agreements with Metalore Resources Limited (Metalore). The first JV is a Greenstone 74%/Metalore 26% split, with the second JV being a Greenstone 79%/Metalore 21% split.
The Brookbank Property is situated in the western part of the Beardmore-Geraldton Greenstone Belt, an ancient geological terrane extending from Lake Nipigon eastwards past the town of Longlac, a distance of more than 130 kilometers. The belt is mainly composed of volcanic and sedimentary rock formations that were deposited around 2.7 billion years ago. The Brookbank gold zone was discovered in the early 1940s and then comprehensively explored during the 1980s and 1990s.
The Brookbank deposit is a tabular, subvertically inclined body of disseminated gold mineralization hosted by intensely sheared, cobble-rich sedimentary rock in contact with iron- and magnesium-rich volcanic rocks. A ductile fault, or shear zone, was superimposed on the sedimentary-volcanic contact and acted as a structural conduit for the gold-bearing hydrothermal fluids . Disseminated grains and aggregates of pyrite are commonly present in the sheared rocks and contain economically significant concentrations of gold.
In addition to the Brookbank deposit, other zones of gold mineralization have been discovered on the property. A few kilometers east of the deposit are the Foxear and Irwin gold zones which are similar in appearance and origin to the Brookbank deposit. To the west, close to the southern shoreline of Knox Lake, are the Cherbourg prospects where gold is contained in quartz-carbonate veins hosted by similar volcanic rocks that form the hanging-wall of the Brookbank deposit.