Petrographic study of albitization associated with uranium mineralization in the Beaverlodge district of northern Saskatchewan
Jacklynn Adell Kennicott1, Guoxiang Chi
1 and Ken Ashton
2, (1)University of Regina, Department of Geology, Regina, SK, Canada, Geology, Regina, SK, Canada, (2)Saskatchewan Geological Survey, Regina, SK, Canada
Contact First Author: Jacklynn Adell Kennicott; kennicoj@uregina.ca
Previously Published Material: Kennicott, Jacklynn, Dr. Chi, Guoxiang, Dr. Ashton, Kenneth 2014. Petrographic study of albitization in the Beaverlodge area of northern Saskatchewan. Presented December 1-3, 2014 at the 45th Saskatchewan Geological Open House. Findingd are not under review or accepted.
English Abstract:
The Beaverlodge district is located in the southwest Rae craton of the Churchill province in northern Saskatchewan and is well known for its vein-type U mineralization. The mineralization is structurally controlled by major faults (e.g. Black Bay and St. Louis faults), many of which have an early ductile mylonitic history, although U tends to be concentrated in brittle secondary structures such as breccias, veins and fractures. Mineralization is found in variably deformed granites of differing ages, and Murmac Bay group supracrustal rocks, particularly amphibolites. The Martin group redbeds unconformably overlie the Murmac Bay group and are spatially associated with several deposits, but host only minor occurrences. Albitization occurs extensively as a replacement alteration of granitic rocks spanning several tens of meters in width and as millimeter-scale veins in albitites, partially altered granitic rocks and supracrustal rocks. Albitization has long been noted as having a spatial association with U mineralization in this area and in districts worldwide; however, a genetic relationship between the two is unclear.
Replacement albitites commonly form by the alteration of granitic rocks where dissolution of quartz and replacement of primary feldspars by albite has occurred. Voids believed to be the result of quartz dissolution, are filled with rutile, specular hematite, carbonate and minor albite. Rutile and specular hematite, often associated with carbonate, are also found interstitially and in veinlets. A range of carbonate and quartz veins, including at least one generation of U-mineralized veinlets with hematized albite margins and calcite ± dolomite cores, are found in many rock types. Relating the many generations of albite, carbonate, and U mineralization is an ongoing challenge. Although, the replacement albitization predates the main mineralizing event, mineralized albite-carbonate veins appear younger and coeval with at least one stage of U mineralization.
