The paragenesis and geochemistry of the Bellekeno Ag-Pb-Zn vein, Keno Hill district, Yukon, Canada
Date
Author
Institution
Degree Level
Degree
Department
Supervisor / Co-Supervisor and Their Department(s)
Examining Committee Member(s) and Their Department(s)
Citation for Previous Publication
Link to Related Item
Abstract
The Keno Hill district Ag-Pb-Zn deposit occurs within the Tombstone-Tungsten Belt, Yukon. Vein mineralization, dominated by siderite, sphalerite, and galena, is spatially associated with, but paragenetically later than, intrusion-related gold mineralization. A direct genetic link between the Keno Hill mineralization and the Roop Lakes stock cannot be demonstrated; however the age of Keno Hill mineralization and spatial geochemical variations of mineral chemistry suggests that some genetic or temporal relationship exists. Twelve distinct mineral assemblages record 5 different fluid compositions defining a cooling trend from >300˚C to <160˚C (Th). Fluids evolved and variably mixed; decreasing temperature and dilution appear to be the principal controls on silver and base-metal mineralization. Moderately saline fluids (<20 wt % NaCl equiv.) could be derived from either magmatic or formation waters, with some of the dissolved components derived from the surrounding country rock. A late stage, lower temperature fluid is of meteoric origin.