Papua new Guinea analogue for the late Permian environment of northeastern New South Wales, Australia

Abstract

The late Cenozoic Moresby Arc System of Papua New Guinea is explored as an analogue of the late Permian Tamworth Arc System in northeastern New South Wales. Matched elements are the northeastern Sydney Basin with the Aure Trough; the Glen Innes Basin (new name) with the Cape Vogel Basin; and the median basement zone of the Tamworth Arc System with the Owen Stanley Mountain Arc of the Moresby Arc System, involving the recognition of a Permian Tamworth Mountain Arc. The Tamworth Mountain Arc, the crest of which is inferred to have lain just southwest of the trace of the Peel Fault, shed voluminous dominantly epiclastic detritus southwest into the Sydney Basin and lesser amounts to the northeast where the remnants of the Glen Innes Basin suggest a fill dominated by pyroclastic ashflow tuffs in and around cauldron complexes close to sea-level. The two arc systems share a gross pattern of development involving inception of a major arcuate fault with accompanying tectonic emplacement of ultramafics and outflow of basalt in the fore-arc trough, followed by progressive uplift of a mountain arc feeding concomitantly subsiding flanking basins, with concurrent volcanism most active in the back-arc basin.