Black Diamond Vein occurrence, Surprise Lake, Atlin Mining Division, British Columbia, Canadai

Regional Level Types
Black Diamond Vein occurrence	Occurrence
Surprise Lake	Lake
Atlin Mining Division	Division
British Columbia	Province
Canada	Country

The Black Diamond Vein occurrence is located near the headwaters of Boulder Creek, which drains into Surprise Lake, about 22 kilometres north-east of Atlin, British Columbia.

There is a brief description of the occurrence and its history, on the British Columbia “Minfile” site, current to 2015; parts are quoted below:
“The Black Diamond prospect is hosted within, and very near the southern margin of, the Mount Leonard Boss; a small stock removed from the main body of the Late Cretaceous Surprise Lake batholith (Surprise Lake Plutonic Suite). The batholith covers 1100 square kilometres east and northeast of Atlin and is dated at 70.6 +/- 3.8 Ma (Map 52). The occurrence is hosted in grey to pink, equigranular, coarse grained quartz monzonite. The rock contains roughly equal amounts of potassium feldspar, plagioclase, and grey quartz. The showing lies very near the southern margin of the stock where it is in contact with metavolcanic and metasedimentary rocks of the Upper Paleozoic Cache Creek Complex.”
“The occurrence consists of a quartz vein which strikes northeast and dips 60 degrees to the northwest; it has been traced for about 4 kilometres. The vein contains disseminated patches or blebs of wolframite and arsenopyrite with minor muscovite, chalcopyrite, scheelite, molybdenite, cassiterite, fluorite and gold. The uranium oxide, zeunerite, has been reported to occur in the vein (Map 52).”

Additional comments by Giles Peatfield on this and other occurrences in the area:
Black Diamond Vein is one of several occurrences of tungsten ¬+ tin + molybdenum + base metal mineralization in the region immediately south of, but not necessarily related to, the Adanac molybdenum deposit (“Minfile” No. 104N 052). Others of interest are: Black Diamond South (“Minfile” No. 104N 053); Black Diamond North (“Minfile” No. 104N 054) and Silver Diamond (“Minfile” No. 104N 069). It is best to view these together, because the various reports available are not always perfectly clear as to which specific occurrence geological data refer to, and even the names given are not always consistent. As an example, a report (Read, 1957) which “Minfile” lists as referring to this occurrence almost certainly refers to material from Black Diamond South, q.v.

Comments by Giles Peatfield on some of the minerals reported from the locality:
A note of caution: Christopher and Pinsent (1982), in describing the YKR prospect south and west of the Adanac molybdenum deposit, listed a number of minerals that they described as occurring in “Vein mineralization [that] occurs mainly in the granitic rocks but has also been found in the contact zone.” It is not clear from their description that all the minerals occur in the Black Diamond Vein occurrence sensu stricto, or perhaps in other veins in the region. I have noted those minerals that are likely but not proven to exist here.
Cassiterite: Possible for the occurrence but not certain.
Fluorite: Possible for the occurrence but not certain.
Gold: Possible for the occurrence but not certain.
Molybdenite: Possible for the occurrence but not certain.
Muscovite: Possible for the occurrence but not certain.
Scheelite: Possible for the occurrence but not certain.
Zeunerite: Christopher and Pinsent (1982) stated that “Zeunerite has also been reported from the Black Diamond vein . . . .”, but gave no further details. It has been confirmed at the Purple Rose occurrence about two kilometres to the north-east.

Other Databases

Link to British Columbia Minfile:	104N 006

Other Regions, Features and Areas containing this locality

References