Invermay Mine, Giant Copper deposit, New Westminster Mining Division, British Columbia, Canadai

Regional Level Types
Invermay Mine	Mine
Giant Copper deposit	Deposit
New Westminster Mining Division	Division
British Columbia	Province
Canada	Country

The former Invermay Mine is on Silverdaisy Mountain, approximately 4 kilometres south-east of the junction of Silverdaisy Creek and the Skagit River. The area is within an enclave between the E. C. Manning and Skagit Valley Provincial Parks. The mine had very minor production of lead and zinc, with by-product silver and gold, between 1936 and 1947.
The following quote is from B.C. Government site “Minfile”- Minfile No. 092HSW 002, current to 2017:
“The area is underlain by steeply dipping and tightly folded rocks of the Lower and Middle Jurassic Ladner Group. The northwest- trending Hozameen fault is to the immediate west and separates the Ladner rocks from mafic volcanics and lesser sediments of the Permian-Jurassic Hozameen Complex, to the west.
The Ladner Group rocks in the area of interest are mainly argillites and siltstones with minor greywacke and felsic tuff. Intruding this package is the Invermay stock, a medium-grained diorite to granodiorite body thought to be Oligocene. Numerous dikes and sills ranging from diorite to pyroxenite also intrude.
An area of brecciated quartz diorite within the stock is reported to be the host for mineralization; three types of mineralization are indicated. Underground development explored a strong, relatively tight shear zone that strikes northeast with a near-vertical dip. Along this shear, a narrow mineralized zone contains quartz, galena, sphalerite and minor chalcopyrite. The width of this zone ranges from several centimetres up to 60 centimetres. Diamond drilling from the drifts revealed a second type of mineralization in a breccia consisting of fine disseminated chalcopyrite that assayed uniformly low- grade values in copper. A third type of mineralization consists of scattered pockets of jamesonite, pyrite, arsenopyrite and chalcopyrite in tourmaline-rich banded quartz diorite at the A and B adits.
Another mineralized breccia zone, referred to as the Tramline zone, is located approximately 2 kilometres to the northwest. It is described as a north east elongate zone of brecciated diorite with pyroxene dikes and weak copper mineralization.”
Comments by Giles Peatfield regarding some of the minerals reported:
Cubanite: Campbell (1965) reported what he thought were exsolution blebs to 45 microns diameter in chalcopyrite. I would class this as possible.
Jamesonite: This was X-ray confirmed by Dr. R. M. Thompson (Friesen, 1950).
Pentlandite: This was reported as possible by Campbell (1965), occurring “. . . as irregular flame-like bodies in pyrrhotite and having a size range of 4 – 20 [microns].” I would regard this as likely.
Tetrahedrite: Friesen noted that this mineral was X-ray confirmed by Dr. R. M. Thompson.

Other Databases

Link to British Columbia Minfile:	092HSW002

Other Regions, Features and Areas containing this locality

References