Summary:
The project includes five lead deposits – Magellan, Cano, Pinzon in the Magellan Hill area, and Pizarro and Drake in the Finlayson Range south of the Paroo Station Mine. Other small lead mineral occurrences (i.e. Cortez) are present across the local area.
The Paroo Station Mine area contains remnant discontinuous outliers of the Yelma Formation (Earaheedy Basin), forming low hills surrounded by shales of the Maraloou Formation (Yerrida Basin). The informally-named Magellan Hill – a mesa of approximately 5 × 2.5 km rises 25–50 m above the surrounding alluvial plain. A relatively thin (up to 60 m) sequence of the Yelma Formation sediments unconformably overlies the Maraloou shale. The Yelma sequence includes a basal fining-upwards clastic sandstone-siltstone sequence that is overlain by a silcretized quartz-clay collapse breccia with relics of dolostones at the base of the unit. The Yelma Formation is overprinted by surficial massive silcrete several meters thick and a thin colluvial soil.
At the Pizarro and Drake lead deposits south of the Magellan Hill group, lead mineralization occurs in sediments of the Yelma Formation and the underlying Juderina Formation (Yerrida Basin) (Looi, 2010).
The Magellan Hill group of lead deposits – Magellan, Cano and Pinzon – are contained in a mesa outcrop with dimensions of 5 × 2.5 km, comprising the Yelma Formation which hosts the lead mineralization, the majority of which is contained in a quartz-clay breccia and sediment sequence up to 35 m thick. The mineralized unit is described as an upper quartz-clay breccia with fragments of completely silicified carbonate with relict stromatolitic structures, siltstone, and euhedral and colloform banded quartz in a white clay-rich matrix up to 35 m thick (Sibbel, 2009).
The Magellan deposit extends for approximately 1,600 m in a NNE direction with an average width of approximately 900 m and an average vertical thickness of economic mineralization of approximately 12 m.
The Cano deposit lies along a north-west axis, extending for approximately 850 m with an average width of 430 m and an average vertical thickness of approximately 7 m.
The Pinzon deposit comprises two zones of mineralization, one trending in an N–NW direction and the second on a north-east trend. Both zones intersect in a V-shaped body and are approximately 1,000 m long by 200 m wide with an average vertical thickness of 5 m.
The Gama deposit has now been shown to coalesce with the eastern flank of Magellan and further extends for 1,200 m in a north-easterly direction with an average width of 300 m and an average thickness of approximately 5 m.
The Pizarro lead deposit is located 7.8 km SSW of the Paroo Station Mine, occurring within the Finlayson Range, a prominent east–west trending series of hills comprised of rocks of the Juderina Formation. While small areas of sub-cropping Yelma Formation quartz-clay breccia occur in the Pizarro area, much of the unit is covered by loamy colluvium deposits (Looi, 2010).
The deposit main mineralized trend strikes NNE over a length of approximately 1,950 m, with an average width of 230 m. A secondary trend extending 620 m north-west bisects and offsets the main trend by 270 m in a sinistral fashion. The trends are interpreted to be primary mineralizing structures or fluid pathways, possibly faults related to Yerrida and/ or Earaheedy basinal rifting. A smaller mineralized body, 300 m in diameter, lies 850 m to the north-west of Pizarro.
The Drake lead deposit is located 11 km south-west of the Paroo Station Mine, in the Finlayson Range. The main mineralized trend strikes north-east for approximately 680 m and is 200 m wide. A secondary, diffuse and lower grade lobate trend arcs south-east from the northern limits of the main trends.