Significant effort has been expended in an attempt to date hydro-
thermal activity that generated Carlin-type gold deposits (CTDs) in
the Great Basin of Nevada. Thus far, these efforts have been only
partially successful, because the relationship(s) between the dated
mineral and hydrothermal activity are equivocal in many cases.
Galkhaite, a trace component of at least four CTDs in Nevada, con-
tains significant amounts of Rb and virtually no Sr, making it an ideal
candidate for radiometric dating.At the Getchell deposit, galkhaite is
paragenetically late, but clearly associated with gold mineralization.
Our data place gold mineralization at Getchell at 39.0 ± 2.1 Ma. This
is the first unequivocally gold-related date produced for any of the
Carlin-type systems. Galkhaite also has been reported at the Carlin,
Rodeo, and Betze deposits and is likely present in other CTDs in
Nevada. This mineral may provide a solution to the conundrum of
dating of CTDs.
Sedimentary-rockhosted disseminated gold deposits, also known
as Carlin-type gold deposits (CTDs), are among the most economically