Comparison Between the Lennard Shelf MVT Province of Western Australia and the Carlin Trend of Nevada: Implications for Genesis and Exploration

ABSTRACT
A comparison between the Lennard Shelf zinc and lead
province of Western Australia and the Carlin Gold Trend of Nevada
is presented, prompted by recent facies analysis of host-rocks in the
Carlin Trend (Armstrong et al., 1998) and by the recognition of
ÒsedexÓ style barite-zinc mineralization in the northern portion of
the Carlin Trend (Emsbo et al., 1999).
Major listric rift-bounding faults were the pathways for metalliferous
brines from the Fitzroy Trough and controlled the development
of the carbonate facies, which were to become the sites for the
MVT zinc and lead deposits of the Lennard Shelf. Basinal fluids
transported hydrocarbons, lead and zinc and deposited dolomite
and ferroan dolomite. Similar mineral phases present on the Carlin
Trend were deposited from fluids in a framework of carbonate
facies and structure analogous with the Lennard Shelf and were
therefore also probably controlled by early basin structures. The
main epigenetic gold mineralization overprints these phases in a
number of deposits suggesting that the pathways for the gold-bearing
fluids were the same fundamental features. Hence, the location
of the basin architecture faults such as rifts and accommodation
zones are important tools to define potential target areas for Carlinstyle
gold mineralization.