The Lorna occurrence is located at an elevation of approximately 1640 metres near the top of a moderate hill, north of Pimainus Creek and approximately 2.5 kilometres north-northwest of the west end of the western most of the Pimainus Lakes.
The area is underlain by Border phase granitic rocks of the Upper Triassic to Lower Jurassic Guichon Creek Batholith comprising mainly hornblende-biotite quartz diorite with small, isolated areas of diorite, amphibolite and granodiorite. To the east, northwest-trending contacts with Highland Valley phase (Guichon and Chataway varieties), Bethlehem and Bethsaida phases (including Skeena variety) of the batholith occur.
Well-formed, subvertical to vertical regional joint set directions are 000 to 010 degrees and 090 to 110 degrees. The density of joints averages 10 per metre.
Copper mineralization is present as trace malachite, chalcopyrite or bornite associated with epidote veining and alteration along fractures in shear zones. Several of these occurrences are also exposed in Border phase rocks within 1500 metres to the east and south. Minor pyrite, sericite and limonite have also been mapped (Assessment Report 2700). Chalcopyrite and pyrite often occur as accessory minerals within the Border phase rocks.
To the southwest of the occurrence, on the former Act claims, trenching is reported to have exposed a biotite quartz diorite with magnetite and minor chalcopyrite along fractures.
In 1970, numerous zones of trace copper mineralization were identified in the occurrence area and their locations can be found in Assessment Report 2700, pg. 35.
Work History
Historical trenches and percussion drill holes, of unknown age, are reported on the former Lorna 28 claim and the former Lorna 20 and 22 claims to the south of the Lorna 28 claim. No descriptions or results of this work are known.
In 1967, Zenith Mining Corp. Ltd. completed a program of soil sampling and trenching on the area as the Lorna, Mars, Mat and Pam claims. The following year, a program of soil sampling was completed on the Mac and Zen claims, adjacent to the Lorna claims to the northeast. Also at this time, Taseko Mines Ltd. completed a program of soil sampling, trenching and a 12 line-kilometre induced polarization survey on the area immediately southwest of the occurrence as the Act claims. In 1969, Zenith Mining Corp. Ltd. completed a program of soil sampling and an induced polarization survey on the claims.
Also in 1969, Mollie Mac Mines Ltd. completed a program of soil sampling and an induced polarization survey on the area located immediately north of the occurrence as the Jon, Jonn, Brennan and Ban claims. In 1970, Dowa Mining Co. Ltd. completed a program of geological mapping, ground magnetic, electromagnetic and seismic surveys on the area as the Jon, Lorna, Mat and Pam claims of the Mac property.
In 1980, Cominco Ltd. completed 60.0 line-kilometres of ground magnetometer and induced polarization surveys on the area as the Island property. The following year, 22.9 line-kilometres of induced polarization surveys were completed on the property. In 1982, Cominco Ltd. completed an induced polarization survey on the area as the Island property.
In 2000, Highland Valley Copper completed 46.2 line-kilometres of induced polarization surveys on the area as the Pimainus Creek property. The following year, three diamond drill holes, totalling 877.2 metres, were completed on the property.