Provenance comparisons between the Nambucca Block, Eastern Australia and the Torlesse Composite Terrane, New Zealand: Connections and implications from detrital zircon age patterns

Detrital zircon U-Pb LAM-ICPMS age patterns for sandstones from the mid-Permian -Triassic part (Rakaia Terrane) of the accretionary wedge forming the Torlesse Composite Terrane in Otago, New Zealand, and from the early Permian Nambucca Block of the New England Orogen, eastern Australia, constrain the development of the early Gondwana margin. In Otago, the Triassic Torlesse samples have a major (64%), younger group of Permian-Early Triassic age components at ca 280, 255 and 240 Ma, and a minor (30%) older age group with a Precambrian-early Paleozoic range (ca 1000, 600 and 500 Ma). In Permian sandstones nearby, the younger, Late Permian age components are diminished (30%) with respect to the older Precambrian-early Paleozoic age group, which now also contains major (50%) and unusual Carboniferous age components at ca 350-330 Ma. Sandstones from the Nambucca Block, an early Permian extensional basin in the southern New England Orogen, follow the Torlesse pattern: the youngest. Early Permian age components are minor (