Tectonic, structural and depositional controls on zinc-lead mineralisation on the Lennard Shelf, Canning Basin

Summary

The distribution of lithofacies in the Devonian limestones of the Lennard Shelf is controlled by basement-hosted faults, with reef and platform facies confined to palaeohighs.

Geophysical data show the Lennard Shelf to be defined by strike-extensive NW-trending listric normal faults that parallel the basin margin, but are offset within NE-trending accommodation zones, e.g., the Fossil Downs Graben. Initiation of deformation was contemporaneous with Middle Devonian sedimentation and continued into the Upper Devonian or early Carboniferous. Depositional sites for MVT mineralisation on the Lennard Shelf were examined.

Keywords: MVT mineralisation, faulting, evaporites, karsting, Lennard Shelf, Canning Basin