New Tectonic Reconstructions of New Guinea Derived from Biostratigraphy and Geochronology

Abstract

Biostratigraphic data from exploration wells in Papua, West Papua of Indonesia, Papua New Guinea and Australia were reviewed, revised and updated using modern stratigraphic interpretations. Revised stratigraphic interpretations were combined with zircon U-Pb geochronologic data to produce new tectonic reconstructions of the Indonesian provinces of West Papua and Papua. Zircon U-Pb geochronologic data used in this study include new results from the Papuan Peninsula, combined with existing datasets from West Papua, Papua New Guinea, eastern Australia and New Caledonia. Supplementary geochronologic data were used to provide independent validation of the biostratigraphic data. Findings from a compilation of biostratigraphic and zircon age data provide a framework to produce new tectonic models for the origin of New Guinea’s terranes. Two hypotheses are presented to explain observations from the biostratigraphic and geochronologic data. The ‘Allochthonous Terrane’ Model suggests that many of the terranes are allochthonous in nature and may have been derived from eastern Australia. The ‘Extended Rift’ Model suggests that the New Guinea Terranes may have been separated from north-eastern Australia by an elongate rift system far more extensive than previously described. These new tectonic models are essential for our geological understanding of the regional and can be used to drive successful petroleum exploration in this frontier area.