The 10,252-hectare Willow property is located approximately 65 km southeast of Reno, Nevada and 13 km due west of Yerington, Nevada, in the Buckskin Mountain Range. The property was acquired in February of 2017 in an option agreement with Almadex Minerals. The Nev-Lorraine claims are contiguous and wrap around the far southeast corner of Willow. Nev-Lorraine is subject to a separate lease agreement with private landowners signed in February 2018.
Willow and Nev-Lorraine occur in the western portion of the historic Yerington Copper Camp. Both properties were explored in the 1960s to the early 1980s by Anaconda Mining, Bear Creek Mining and Conoco, to identify a porphyry copper deposit analogous to the nearby Yerington Mine which produced approximately 1.6 billion pounds of copper from 1952 to 1978 for Anaconda Mining. Year-round access from Yerington is along paved roads leading to well-maintained gravel roads that skirt the claims. A series of old drill roads provides good access to the entire combined property.
Four porphyry copper deposits and numerous Cu-Fe and Cu-Au skarns have been identified to date in the Yerington camp. The porphyry deposits are Yerington, Ann Mason, Bear and MacArthur. The main skarns are Pumpkin Hollow and the former Mason Valley, Bluestone and Malachite Mines. Abacus believes that its work to date has identified the presence of a fifth porphyry in the camp, something that Anaconda and other companies were searching for in the 1970’s. This represents the first major discovery in over forty years, although the deposit still remains to be delineated with further drilling.
The main producer in the camp was the Yerington porphyry deposit, mined from 1952-1976, which contained approximately 162 MT of 0.6% Cu. Recent exploration under the old pit has been carried out by Quaterra Resources, who also control the adjacent Bear and MacArthur porphyries. The Bear deposit contains > 500 MT of 0.4% Cu, while MacArthur has an M&I oxide resource of 159 MT at 0.212% Cu and was previously mined via an open pit. Quaterra initiated a Prefeasibility study on MacArthur in December of 2017. The other large porphyry in the camp is Ann Mason with an M&I resource of 1.4BT at 0.32% Cu, previously owned by Mason Resources. Mason Resources was acquired by Hudbay in 2018. The Ann Mason property is contiguous to Willow to the east.
Some of the earliest production at Yerington occurred from skarns. The Mason Valley, Bluestone and Malachite Mines produced approximately 3.8 Mt grading 1.5%--6.2% Cu from 1910-1931. The Pumpkin Hollow Skarn/Fe-oxide deposit recently commenced production in the southeast corner of the camp. It is owned by Nevada Copper and contains a P&P resource of 572 MT at 0.4% Cu.