The Lady D occurrence is located on the northeastern slope of Mount Brenton, approximately 3 kilometres northeast of Holyoak Lake.
Regionally, the area is underlain by chert, siliceous argillite and siliciclastic rocks of the Mississippian to Pennsylvanian Forth Lake Formation (Buttle Lake Group) and calc-alkaline volcanics of the Devonian Nitinat Formation (Sicker Group). Gabbroic to dioritic intrusive rocks of the Late Triassic Mount Hall Gabbro intrude the previous formations, while granodioritic intrusive rocks of the Early to Middle Jurassic Island Plutonic Suite are exposed to the northwest.
An exhalative iron formation is associated with a jasper unit. The unit is mapped at the contact of cherty tuffs above, and intermediate volcanics below. It appears to pinch and swell, with observed thicknesses up to 10 metres.
Work done on the showing in 1953 by Ladysmith Development Ltd. indicated that the iron zone extended along strike for 540 metres (Buckham, 1953, Map A).
In 1986, massive magnetite up to 8 metres thick was intersected in a drillhole by Utah Mines Limited. Up to 2.5 per cent pyrite was present along fractures. Drillhole JC-86-2, located approximately 1.8 kilometres northwest of the plotted location of the Lady D occurrence, yielded 0.24 per cent copper and 0.115 gram per tonne gold over 1.3 metres (225.0 to 226.3 metres down hole) of andesite ash tuff hosting quartz veins with chalcopyrite (Assessment Report 15442).
An old adit and dump in the same area showed samples of massive magnetite breccia containing up to 20 per cent pyrite with traces of chalcopyrite. Assay values were up to 0.05 per cent copper and 0.74 grams per tonne gold (Assessment Report 15749, page 14). Another nearby drillhole intersected similar mineralization. Moderate quartz veining with pyrite is present in the footwall andesite.
Zones of crackle brecciation occurring in the andesite contain magnetite, pyrite, chalcopyrite and malachite. One of these masses (probably to the northwest of the iron zone?) assayed 8.6 per cent copper, 42.86 grams per tonne silver and 3.22 grams per tonne gold (Assessment Report 15749, page 11).
Work History
A historical adit, likely dating to the first half of the 19th century, is reported in the occurrence area.
In 1953, Ladysmith Development Ltd. explored the occurrence.
During 1984 through 1986, BHP-Utah Mines completed programs of geochemical (rock, silt and soil) sampling, airborne and ground geophysical surveys, geological mapping and 16 diamond drill holes, totalling 6317 metres, on the JRM claims.
In 2001, Homegold Resources Ltd. conducted a program of geological mapping, prospecting and minor rock sampling on the area as the Holyoak 1-7 and 13-14 claims.
In 2020, 911 Mining Co. conducted a program of prospecting and geochemical (rock and silt) sampling on the area as the Mount Sicker property. In 2022, Sasquatch Resources Corp. completed a program of prospecting, geological mapping, drillcore and rock sampling and a 418.2 line-kilometre airborne electromagnetic survey on the area as part of the Mount Sicker property.
