|
 |
The Curnamona Province comprises two major groups of rocks. Late Palaeoproterozoic metasedimentary and metavolcanic rocks (the Willyama Supergroup) and intrusives crop out in the Willyama Inliers, occur beneath younger cover in the southern Benagerie Ridge, and may be present in the Mount Painter Inliers. These rocks were intensely deformed, metamorphosed and hydrothermally altered in the ~1640 – 1580 Ma Olarian Orogeny. Mesoproterozoic (~1600 – 1580 Ma, equivalent to the Hiltaba Suite in the Gawler Craton) intrusives occur in the Willyama Inliers and southern Benagerie Ridge, and Mesoproterozoic sediments, volcanics and intrusives occur in the Mount Painter and Mount Babbage Inliers and northern Benagerie Ridge.
These younger rocks were metamorphosed and deformed by the Delamerian Orogeny and, possibly, at least locally, by a Mesoproterozoic deformation in the Mount Painter Inliers but are undeformed in the centre of the province. The Willyama Supergroup and intrusives are extensively mineralised, and in New South Wales host the giant Broken Hill Pb-Zn-Ag orebody. Sedimentary and low-grade metasedimentary rocks of Neoproterozoic and Cambrian age, as well as Tertiary and Quaternary sediments, cover older basement across much of the province. Tertiary palaeochannel sediments host economic uranium deposits at Beverley and Honeymoon.
