The petrology, geochronology and tectono-magmatic setting of igneous rocks in the Suckling-Dayman metamorphic core complex, Papua New Guinea
| dc.contributor.author | Ӧsterle, J. E. | |
| dc.contributor.author | Little, T. A. | |
| dc.contributor.author | Seward, D. | |
| dc.contributor.author | Stockli, D. F. | |
| dc.contributor.author | Gamble, John A. | |
| dc.contributor.funder | Marsden Fund | en |
| dc.date.accessioned | 2020-03-05T12:33:03Z | |
| dc.date.available | 2020-03-05T12:33:03Z | |
| dc.date.issued | 2020-03-03 | |
| dc.date.updated | 2020-03-05T12:15:35Z | |
| dc.description.abstract | Southeastern Papua New Guinea has hosted magmatism throughout the Cenozoic, with the latest phase being concurrent with active extension in the Woodlark Rift. There, the Suckling-Dayman metamorphic core complex (SDMCC) has exhumed middle-crustal rocks in the past few million years along a still-active low-angle normal fault, the Mai'iu Fault. Uplift of the SDMCC has exposed metasedimentary and metaigneous rocks of Late Cretaceous-Pleistocene age that record an evolution from oceanic spreading to subduction, to collision, and finally to subduction-inversion and extensional exhumation. We present new petrographic, whole-rock geochemical and geochronologic (outcrop and detrital zircon UPb) data from the SDMCC to reconstruct its long-term evolution. The dominant footwall-lithology of the SDMCC, the Goropu Metabasalt, has a MORB composition. Detrital zircons from metasedimentary beds intercalated with these basalts yield U–Pb-based maximum estimates for deposition of ~103 and ~72 Ma, suggesting a Late Cretaceous spreading age of the oceanic protolith. Bulk compositions of low-grade tholeiitic meta-gabbroic and -tonalitic rocks (Yau Igneous Complex) that intrude the Goropu Metabasalt reveal both enriched and depleted light rare earth element patterns. Zircon UPb ages from the Yau Igneous Complex range between ~60 and ~57 Ma, providing a minimum age for the formation of the Goropu Metabasalt. Much younger syn-extensional granitoids in the mafic footwall of the SDMCC have calc-alkaline to high-K compositions and UPb ages on zircon between ~3.7 and ~2.0 Ma. Our data indicate that the Mai'iu Fault had re-activated a Paleogene thrust as an extensional detachment fault by 3.7 ± 0.2 Ma. UPb ages of detrital zircons in modern streams draining the footwall of the SDMCC are essentially restricted to the ages revealed by the Paleocene and Plio-Pleistocene intrusions. Xenocrystic zircons in the Plio-Pleistocene granitoids imply that the crust underlying the metabasaltic carapace of the SDMCC consists chiefly of Australian-continent derived sedimentary rocks. | en |
| dc.description.sponsorship | Marsden Fund (Marsden Grant VUW1310 and NSF Grant EAR-1524729) | en |
| dc.description.status | Peer reviewed | en |
| dc.description.version | Accepted Version | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.citation | Ӧsterle, J. E., Little, T. A., Seward, D., Stockli, D. F. and Gamble, J. (2020) 'The petrology, geochronology and tectono-magmatic setting of igneous rocks in the Suckling-Dayman metamorphic core complex, Papua New Guinea', Gondwana Research, doi: 10.1016/j.gr.2020.01.014 | en |
| dc.identifier.doi | 10.1016/j.gr.2020.01.014 | en |
| dc.identifier.endpage | 86 | en |
| dc.identifier.issn | 1342-937X | |
| dc.identifier.journaltitle | Gondwana Research | en |
| dc.identifier.startpage | 1 | en |
| dc.identifier.uri | https://hdl.handle.net/10468/9725 | |
| dc.language.iso | en | en |
| dc.publisher | Elsevier | en |
| dc.relation.uri | http://www.sciencedirect.com/science/article/pii/S1342937X20300666 | |
| dc.rights | © 2020 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. This manuscript version is made available under the CC BY-NC-ND 4.0 licence. | en |
| dc.rights.uri | https://creativecommons.org/licenses/by-nc-nd/4.0/ | en |
| dc.subject | Zircon | en |
| dc.subject | Southwest Pacific | en |
| dc.subject | Gondwana | en |
| dc.subject | U–Pb depth-profile dating | en |
| dc.subject | Suckling-Dayman metamorphic core complex | en |
| dc.title | The petrology, geochronology and tectono-magmatic setting of igneous rocks in the Suckling-Dayman metamorphic core complex, Papua New Guinea | en |
| dc.type | Article (peer-reviewed) | en |
