The Mercur Project is located in the southern Oquirrh Mountains in Tooele County, Utah, about 32 miles southwest of Salt Lake City, Utah (Fig. 1). The Company controls approximately 6,200 hectares on primarily patented claims including Mercur, West, South and North Mercur (Fig. 2). Mercur is unique in the class of Carlin-type deposits in that it is the only large (>3 million ounce Au mined) Carlin-type district of the Basin and Range province that is located outside of the relatively small cluster of large, Carlin-type deposits in north-central Nevada. The Mercur district is an isolated occurrence about 240 miles east of the major Carlin-type deposits in Nevada. The Mercur district also ranks as the first Carlin-type deposit to have been discovered and commercially developed.
In December 2020, the Company commenced a 9,942 meter reverese circulation drilling program that was completed in October 2021. The focus of the program was to confirm mineralization based on historical drilling in the South Mercur and Main Mercur areas and to test new targets in the West Mercur area. In addition to the drill program, the Company completed geologic mapping, soil sampling, claim staking, and historical data review to delineate potential drill targets for the 2022/2023 drill program.
In 2022, the drill program will consist of approximately 8,760 meters of a combination of reverse circulation and core drilling. The core drilling will be focused on testing structural targets based on recent mapping and the results of the 2020 and 2021 reverse circulation programs, having the benefit of structural insights gained in the Carlin trend which has led to a clearer understanding of the potential of these large systems. Additional work will include further geologic mapping and sampling, metallurgical testing, a resource estimate and a scoping study or preliminary economic assessment.
The Mercur gold deposits can be classified as Carlin-type deposits. The gold mineralization is largely stratabound in a particular 240-foot thick host unit within the Mississippian-age Great Blue Formation. These favorable Mercur Member beds consist of mixed clastics and carbonates, capped by impermeable shales, in an otherwise monotonous, thick section of Upper Paleozoic shelf carbonate lithologies. Alteration includes early decalcification, followed by a pervasive silicification of the basal beds of the Mercur Member. This early stage jasperoid (the Silver Chert) yielded rich silver ores. Subsequent pervasive argillic, minor silicification and carbonaceous alteration marked the start of the main gold mineralization. Gold occurs as micron-size grains associated with arsenian pyrite, marcasite, orpiment, realgar, thallium minerals and organic matter disseminated throughout the host rocks. Younger and higher-grade gold-bearing veinlets of similar mineralogy cut the disseminated mineralization. The associated trace element suite includes As, Sb, Hg, Tl and Ag. Gold content generally is greater than the silver content, except locally in the Silver Chert, and base metal values are low throughout the district.
The Mercur deposits occur on the east limb of the broad, northwest-trending, doubly plunging Ophir anticline. The fold likely formed during the late Cretaceous Sevier orogeny in the upper plate of an east-directed thrust sheet. A complex network of faults, caused by several periods of post-folding extension, cuts the fold. Gold mineralization carries the best grades where certain faults intersect the favorable units of the Mercur Member beds. Tertiary-age felsic dikes, sills and breccia pipes that contain clasts of igneous rock occur throughout the Mercur district. The intrusive rocks display a general spatial relationship with the gold deposits. The main hydrothermal gold mineralization occurred after the intrusion of the igneous bodies. It is proposed that the Mercur gold deposits represent the late stage of distal hydrothermal activity related to a Tertiary-age magma source at depth.