Orebodies
Mount Isa contains two separate orebodies: a stratigraphically lower lead-zinc-silver ore horizon and an upper copper ore. Both are contained within the Lower Proterozoic Urquhart Shale. The Urquhart is 1,000 metres thick and is a grey dolomitic shale with tuffaceous horizons. Near the ore horizons the shale is pyritic. The orebodies are on one limb of a plunging anticline and are extensively faulted.
The ore occurs as en-echelon bodies parallel to the shale bedding. Orebodies may extend more than one kilometre along strike and three-fourths of a kilometre down dip. Thickness may reach 50 metres. The ores are considered to be syn-genetic with the host shale and interbedded volcanic material.
Read more about this topic: Mount Isa Mines