Century is a shale hosted zinc, lead, silver deposit developed within
gently folded, Proterozoic Lawn Hill Formation shales and siltstones,
approximately 250 kilometres north-northwest of Mount Isa, comprising
118 million tonnes of stratiform mineralisation, averaging 10.2 per cent
,,inc, 1.5 per cent lead and 36 grams per tonne silver. The deposit is
largely overlain by Cambrian limestone and younger Proterozoic
sedimentary rocks, outcropping at only two places. Small discordant lode
lead-silver deposits formed the basis of relatively small scale mining
activity in the area for almost 100 years, exploration tenement covering
the deposit being granted to CRAE exactly 100 years after the first
mining leases were pegged in the area in 1887.
Stratiform mineralisation occurs within three distinct blocks, bounded
by normal faults and the unconformity between Lawn Hill Formation and
overlying Cambrian limestones. The Termite Range Fault, a major
northwest trending, regional scale fault system occurs adjacent to the
northeast deposit boundary, while the Magazine Hill Fault, possibly a
component of the east trending Little Range Fault system, forms the
southern boundary of the deposit.