Petrochemistry of the claret creek ring complex,northeast Queensland

The Claret Creek Ring Complex is one of several calc‐alkaline ring complexes in a Carboniferous epizonal batholith emplaced into continental crust at the junction of the Precambrian Georgetown Inlier and the adjacent Palaeozoic Tasman Geo‐syncline, northeast Queensland. Rhyolite ash‐flow sheets plus rhyolite and dacite ring dykes are intruded by two comagmatic central stocks of microgranite and grano‐diorite‐tonalite. The complex may be chemically distinguished from the surrounding, contemporaneous batholith by its low K/Na, Rb/Sr and Th/K ratios. The origin and variation of its magmas is explained by invoking progressive partial melting of low K/Na basaltic andesites. Close relatives to the magma source‐rock are preserved as microdiorite xenoliths, which have contaminated their host granodiorite‐tonalite stock.