Palaeogeography of the South Australian Craton within Nuna

Integrated
geochronology, isotopic and REE geochemical analysis from the northern Gawler
Craton were used to test if major boundaries interpreted from geophysical
datasets (Baines et al., 2011) truly represent sutures between allochthonous
crustal blocks. The northern Gawler Craton appears to be underlain at least in
part by Neoarchaean substrate (Reid et al., 2014)
that is isotopically similar to basement rocks in southern Gawler Craton and
the North Australian Craton. The correlation of Neoarchaean basement in both
the southern and northern Gawler Craton (Reid et al., 2014) and lack of
systematic isotopic and REE variations suggest that these boundaries separate
autochthonous crustal blocks that have been attenuated (and possibly rifted
from each other) and re-amalgamated in the Late Palaeoproterozoic to Mesoproterozoic.
A modern analogue for this is the SW Pacific in which continental ribbons (e.g.
Lord Howe Rise) have been separated from the Australian plate.