Pegmont: A Stratiform Lead-Zinc Deposit in the Precambrian of Northwest Queensland

Stratiform lead-zinc mineralization at the Pegmont prospect occurs as a 4-6 m thick body interbedded within arkose, schist, amphibolite, and pegmatite of the Kuridala Formation in the Eastern Belt of the Lower Proterozoic of northwest Queensland.The overall structure of the body is that of a strongly crumpled east-dipping sheet. In detail it is subjected to complex and irregular deformation.Gossaneous outcrops of the mineralised body are anomalous in Pb-Zn-Ag content and have been traced, discontinuously, over about 36 km2 in a NNE-trending belt.Below the zone of oxidation, which reaches 25-40 m below the surface, the primary sulphides are galena, sphalerite, and pyrite.Drilling on a 2 km2 area near the discovery outcrops indicates fairly uniform grades of lead and zinc.Changes in thickness of the mineralised body are gradual.