The internal fold and thrust belt play, Papua New Guinea

Abstract

Abstract The New Guinea Orogen is a complex megatectonic feature that originated in the zone of interaction between the Australian Plate to the south and the Pacific Plate to the north. In Papua New Guinea (PNG), it is 600 kilometres in length by up to 230 kilometres in width (Figure 1). It continues westwards into Irian Jaya with similar dimensions. In PNG, it is divided by fairly abrupt dogleg bends into three segments: two trending NNW and the middle one trending NW. Within the Orogen, and on the foreland to the southwest of it, Late Paleozoic Basement is overlain by rift and passive margin sequences of Triassic through Paleogene. The Neogene to Recent stratigraphic section comprises backarc and foreland basin sequences related to the collision between the Pacific and Australian Plates. Folding, thrusting, and uplift took place from the Late Miocene onwards. The region continues to be seismically active at the present day. More detailed accounts of the geology of the Orogen and of PNG in general are given in Dow (1977), Home et al. (1990), Smith (1990), Francis (1990), Struckmeyer et al. (1993), and Davies et al. (1996).