Status: Available for Option


Willoughby is an intrusive-related, high grade Au-Ag prospect with some similarities to the nearby Red Mountain deposit (1,641,600 Mt @ 8.36 g Au/t, 26 g Ag/t Measured & Indicated, Arseneau, 2016); and, to the historic Silbak-Premier Gold Mine (produced 56,000 kg Au, 1,281,400 kg Ag, 1918-1976).

Location & Infrastructure

Golden Triangle, Northwest BC. The Willoughby property is located within the Skeena Mining Division of British Columbia, about 26 km east of the Town of Stewart. The Red Mountain Au-Ag deposit being developed by IDM is located about 7 km to the west across the Cambria Icefield.  Hwy 37A and the Stewart power line are located about 14 km to the north.

Land Status

Two Mineral Tenures comprising ~995 hectares owned 100% by Millrock. The Tenures are in good standing to at least August 11, 2019.

Geology & Mineralization

The property is situated within the Stikinia Terrane of the

Intermontane Tectonic Belt and is underlain by volcanic and sedimentary rocks of the favourable Jurassic Hazelton Group that host the majority of mineral deposits in the Golden Triangle. The wide diversity of deposit types include epithermal (Brucejack); VMS (Eskay Creek, Granduc, Barbra Ann, Todd); intrusion related (Red Mountain, Silbak Premier); and, porphyry (KSM, Red Chris, Treaty, Snowfields).  With a stratigraphic position similar to Red Mountain and a close spatial and possible genetic association with early Jurassic porphyritic intrusive rocks, Willoughby is considered to have excellent exploration potential.

Bond Gold Canada Inc. conducted the first detailed exploration program in 1989 and at least ten significant gold-bearing Zones (Main, North, NN, Edge,Upper Icefall, Lower Icefall, Kiwi, Ledge, Willoughby, Buffalo) were identified on or near the Willoughby nunatak. The multiphase mineralization is controlled by two dominant structural trends and their intersections. The 1989 drill program returned up to 24.99 g Au/t and 184.22 g Ag/t over a 20.5 m core interval from the North Zone. Other intersections of interest include:

  • 7.8 m grading 1.58 g Au/t and 78.59 g Ag/t from the North Zone
  • 10.50 m grading 7.56 g Au/t and 45.9 g Ag/t from the Main Zone
  • 13.5 m grading 1.76 g Au/t and 3.74 g Ag/t from the Main Zone
  • 25.5 m grading 2.46 g Au/t and 10.39 g Ag/t from the Willoughby Zone
  • 7.5 m grading 1.47 g Au/t and 1.12 g Ag/t from the Edge Zone

The semi-massive to massive sulfide mineralization at the North Zone occurs as irregular pods, lenses, and branching bodies of pyrite, pyrrhotite sphalerite, arsenopyrite, chalcopyrite, and galena. The centers of the sulfide pods are composed of massive pyrrhotite that grades laterally into massive and disseminated pyrite. The gold mineralization is associated with the early sulfide-rich phase dominated by pyrite, pyrrhotite, galena, bismuth-telluride and silver-telluride. The intense alteration halo consists of sericitization, chloritization, silicification, pyritization, and carbonatization surrounding the mineralization.

Bond concluded that the considerable vertical extent (> 350 m) of the precious metal mineralization so far encountered and a style of mineralization similar to that of the nearby Stewart Gold Camp suggest the possibility of the presence of several depth persistent ore shoots. Highlights of historic drilling by Camnor Resourses Ltd. in 1994 and 1995 continued to return values of interest:

  • 11.7 m grading 40.11 g Au/t and 109.71 g Ag/t in hole 94-15 on the North Zone
  • 12.2 m grading 10.94 g Au/t and 27.42 g Ag/t in hole 94-27 on the North Zone
  • 2.9 m grading 383 g Au/t and 213.6 g Ag/t in hole 95-36 on the North Zone
  • 5.9 m grading 16.32 g Au/t and 53.83 g Ag/t in hole 95-51 on the Wilby (Main) Zone
  • 13.0 m grading 13.37 g Au/t and 63.43 g Ag/t in hole 95-53 on the Wilby (Main) Zone

Exploration Status

Bond and Camnor completed 58 surface drill holes totalling 6476 m and ~90 m of underground development from 1989 to 1995. Little work has been carried out since that time.  However, in view of the auriferous sulfides and receding glaciers, Bonterra Resources Inc. commissioned a 310 km AeroTEM system electromagnetic and magnetic survey in 2007. According to Bonterra, the survey discovered two areas of EM conductivity that need to be evaluated as possible drill targets. Seven anomalous EM ‘picks’ occur underneath the Willoughby glacier on an east-southeast trend and may represent an extension of the best-developed known mineralization located at the base of the Willoughby nunatak. This EM anomaly is situated within an area of relatively low magnetic susceptibility, possibly due to hydrothermal alteration. This anomalous area warrants further investigation and may prove to be a viable drill target. A secondary anomalous EM area defined by five EM anomaly ‘picks’occurs in an under-explored area on the east side of the Patience claim. It is accessible as there is no glacier cover, and merits surface exploration work.

Proposed Exploration Program

The mineralization on Willoughby extends over a strike length of greater than one km and has a vertical extent of >350 m. The available historic data is being compiled by MILLROCK and the historic Bond and Camnor drill core should be located and reviewed in some detail, including confirmation sampling, whole rock analysis and magnetic susceptibility surveys. As indicated above, the 2007 AeroTEM survey has delineated a number of follow-up and potential drill targets.  Further processing and interpretation of the airborne survey data is required to fully delineate the structural controls and EM signatures of the mineralization. Much of Willoughby Property is steep with receding glaciers and requires detailed mapping, which could be partially achieved with drone orthophotography.  Follow-up detailed mapping of drill target areas is a prerequisite for the drilling for discovery component of the field program.

Agreement & Terms

Millrock is currently seeking potential joint venture partners for the project. If desired, Millrock can serve as operator on behalf of an earn-in joint venture partner. Qualifying exploration expenditures are eligible for a 20% Mineral Exploration Tax Rebate from the Province of BC.