Purple Rose uranium occurrence, Surprise Lake, Atlin Mining Division, British Columbia, Canadai

Regional Level Types
Purple Rose uranium occurrence	Occurrence
Surprise Lake	Lake
Atlin Mining Division	Division
British Columbia	Province
Canada	Country

The Purple Rose uranium occurrence is located at the headwaters of Cracker Creek which drains eastward into the north end of Surprise Lake, about 24 kilometres north-east of Atlin, British Columbia.

The following quote is from B.C. Government site “Minfile”- Minfile No. 104N 005, current to 2015:
“The primary lithology in the area is that of a coarse grained to porphyritic alaskite to quartz monzonite belonging to the Late Cretaceous Surprise Lake batholith (Surprise Lake Plutonic Suite). These rocks have intruded volcanic and sedimentary sequences of the Mississippian to Triassic Kedahda Formation (Cache Creek Complex) composed of quartzite, limestone, and greenstone of the upper Mississippian to Permian Nakina Formation (Cache Creek Complex). Upper Mississippian to Permian Cache Creek Complex variably serpentinized ultramafic rocks (peridotite) have also been intruded by the Surprise Lake batholith in the Cracker Creek area.

The showing is associated with a northwest trending shear zone that is near the boundary of, but hosted entirely within, the alaskite to quartz monzonite body, near its contact with the sediments. The shear zone and associated mineralization has been traced over 500 metres. The alaskite is strongly "kaolinized" near the shear zone and the degree of alteration decreases away from the shear. Within the strongly altered alaskite, on the footwall of the shear zone, the uranium mineral zeunerite is found. This zone yielded the highest values of 0.075 per cent uranium and 0.011 per cent thorium oxide. Other minerals associated with the zeunerite are autunite, arsenopyrite, tetrahedrite, pyrite, galena, minor fluorite and vuggy quartz. One sample also assayed 1.06 per cent copper (Minister of Mines Annual Report 1955, pages 7 to 9).

In another area where the alaskite body comes in direct contact with limestone, the limestone is metamorphosed to a tremolite-garnet skarn with patchy magnetite and copper staining of malachite and azurite.”
Comments by Giles Peatfield regarding some of the minerals reported:
“Asbestos”: Kerr (1978) reported “Minor thread veins of chrysotile asbestos in serpentinized fractures in peridotite.”
Autunite: Kerr (1978) reported autunite, but gave no data regarding its identification. I would regard it as tentative.
Garnet: Kerr (1978) reported this in a magnetite/grossularite skarn, but gave no data regarding its specific identification.
Kasolite: Ballantyne, et al. (1978) reported kasolite, but gave no further information.
Metazeunerite: Holland (1956) stated that metazuenerite was “. . . identified in August, 1954, by E. W. Nuffield, of the University of Toronto, in material from the Purple Rose showings.” The Pacific Museum of Earth (University of British Columbia) has a specimen (No. S-74-3583) of metazeunerite from this locality.
Quartz: Holland (1956) made the point that at least some of the quartz was “smoky”.
Scheelite: Kerr (1978) listed scheelite as “possible”, in the above-mentioned magnetite/grossularite skarn in limestone, with azurite and malachite.
Scorodite: Brown (1955) noted that there were structures, with sparse arsenopyrite, pyrite and chalcopyrite mineralization, where the sulfides had been extensively altered to the secondary products, scorodite and limonite. He gave no firm data regarding the identification of scorodite.
Wolframite: Holland (1956) reported this in a narrow zone of kaolinized granite, with arsenopyrite and zeunerite.
Zeunerite: Holland (1956) stated that zeunerite was “. . . identified in August, 1954, by E. W. Nuffield, of the University of Toronto, in material from the Purple Rose showings.”

Other Databases

Link to British Columbia Minfile:	104N 005

Other Regions, Features and Areas containing this locality

References