Plio-Pleistocene river drainage evolution in New Guinea. Implications for reservoir mineralogy predictions

Abstract

The drainage of New Guinea has evolved rapidly since Pliocene time. Relief growth initiated in accreted oceanic terranes in the north and migrated into the Australian margin interior over time. The present-day drainage retains inherited elements of an ancient fluvial system that routed sediments from these northern terranes through the Central Highlands into foreland flexural basins, epicontinental seas, and deep oceanic basins. The rise of the Highlands and of the Papuan Peninsula spurred drainage reorganization, such that today little of the oceanic terranes still drains through the mountain range. This evolution has strongly affected the composition of the clastic sediments delivered to the shelves. The topography retains the memory of some of the most recent changes. Most of the relief of the Papuan Peninsula formed during the past 5 Ma, driven by tectonic removal of the load of the peninsular ophiolites, accompanied by contractional collapse along the Aure-Pocklington trough. In the eastern Central Highlands, rapid drainage reversal results from flexural back-tilting under the load of the colliding Huon-Finisterre Range. Northward reversal is also observed at the western end of the Highlands. In the south, the Fly platform has experienced recent, widespread, non-tectonic and non-flexural uplift of deep origin that will ultimately close the Torres Strait. The Quaternary drainage evolution will be used to calibrate the Badlands software developed by the Basin Genesis Hub, as a first step for simulating the evolution of topography and sediment delivery to the Australian shelf and Gulf of Papua in earlier times