Convergent tectonics in the Huon Peninsula region, Papua New Guinea

Davies, H. L.; Lock, Jo; Tiffin, D L; Honza, Eiichi; Okuda, Y.; Murakami, Fumitoshi; Kisimoto, Kiyoyuki

doi:10.1007/bf02238044

Cited by 35 publications

(13 citation statements)

References 6 publications

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“…It is less clear what happened following the cessation of arc continent collision. Many workers have suggested that southward subduction of the Solomon Sea oceanic lithosphere initiated on the Trobriand Trough (Figure ) [ Davies et al ., ; Taylor et al ., ; Taylor and Huchon , ], leading to the Miocene onset of arc volcanism across the Papuan Peninsula and D'Entrecasteaux Islands [ Dow , ; Smith , ; Smith and Milsom , ; van Ufford and Cloos , ]. There is little to no evidence for active subduction (or a subducted slab) at the Trobriand Trough today [ Abers and Roecker , ; Kirchoff‐Stein , ; Hall and Spakman , ; Abers et al ., ], indicating that if subduction at the Trobriand Trough occurred in the past, it likely ceased sometime in the Miocene or Pliocene.…”

Section: Tectonic Settingmentioning

confidence: 99%

Continental breakup and UHP rock exhumation in action: GPS results from the Woodlark Rift, Papua New Guinea

Wallace

Ellis

Little

et al. 2014

Geochem Geophys Geosyst

291

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We show results from a network of campaign Global Positioning System (GPS) sites in the Woodlark Rift, southeastern Papua New Guinea, in a transition from seafloor spreading to continental rifting. GPS velocities indicate anticlockwise rotation (at 2–2.7°/Myr, relative to Australia) of crustal blocks north of the rift, producing 10–15 mm/yr of extension in the continental rift, increasing to 20–40 mm/yr of seafloor spreading at the Woodlark Spreading Center. Extension in the continental rift is distributed among multiple structures. These data demonstrate that low‐angle normal faults in the continents, such as the Mai'iu Fault, can slip at high rates nearing 10 mm/yr. Extensional deformation observed in the D'Entrecasteaux Islands, the site of the world's only actively exhuming Ultra‐High Pressure (UHP) rock terrane, supports the idea that extensional processes play a critical role in UHP rock exhumation. GPS data do not require significant interseismic coupling on faults in the region, suggesting that much of the deformation may be aseismic. Westward transfer of deformation from the Woodlark Spreading Center to the main plate boundary fault in the continental rift (the Mai'iu fault) is accommodated by clockwise rotation of a tectonic block beneath Goodenough Bay, and by dextral strike slip on transfer faults within (and surrounding) Normanby Island. Contemporary extension rates in the Woodlark Spreading Center are 30–50% slower than those from seafloor spreading‐derived magnetic anomalies. The 0.5 Ma to present seafloor spreading estimates for the Woodlark Basin may be overestimated, and a reevaluation of these data in the context of the GPS rates is warranted.

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Section: Tectonic Settingmentioning

confidence: 99%

Continental breakup and UHP rock exhumation in action: GPS results from the Woodlark Rift, Papua New Guinea

Wallace

Ellis

Little

et al. 2014

Geochem Geophys Geosyst

291

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“…The Australian continent is moving north-east and colliding with the Pacific plate at a rate of~110 mm per year [Johnson and Molnar, 1972;Davies et al, 1987]. The convergence creates one of the most seismically active regions on Earth, with earthquakes of magnitude up to 8.0.…”

Section: Tectonic Settingsmentioning

confidence: 99%

Centroid moment tensor catalogue using a 3‐D continental scale Earth model: Application to earthquakes in Papua New Guinea and the Solomon Islands

2017

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Although both earthquake mechanism and 3‐D Earth structure contribute to the seismic wavefield, the latter is usually assumed to be layered in source studies, which may limit the quality of the source estimate. To overcome this limitation, we implement a method that takes advantage of a 3‐D heterogeneous Earth model, recently developed for the Australasian region. We calculate centroid moment tensors (CMTs) for earthquakes in Papua New Guinea (PNG) and the Solomon Islands. Our method is based on a library of Green's functions for each source‐station pair for selected Geoscience Australia and Global Seismic Network stations in the region, and distributed on a 3‐D grid covering the seismicity down to 50 km depth. For the calculation of Green's functions, we utilize a spectral‐element method for the solution of the seismic wave equation. Seismic moment tensors were calculated using least squares inversion, and the 3‐D location of the centroid is found by grid search. Through several synthetic tests, we confirm a trade‐off between the location and the correct input moment tensor components when using a 1‐D Earth model to invert synthetics produced in a 3‐D heterogeneous Earth. Our CMT catalogue for PNG in comparison to the global CMT shows a meaningful increase in the double‐couple percentage (up to 70%). Another significant difference that we observe is in the mechanism of events with depth shallower then 15 km and Mw < 6, which contributes to accurate tectonic interpretation of the region.

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“…A reversal of subduction polarity has been proposed in eastern Papua New Guinea in the early Miocene (possibly late Oligocene) as northward subduction of the Australian continental margin [ Pigram et al ., ] stalled and continued convergence of the Australia and Pacific plates became accommodated primarily by southward subduction of Solomon Sea oceanic crust along the Trobriand trench [ Davies and Smith , ; Davies et al ., ; Honza et al ., ., Davies and Warren , ; Quarles van Ufford and Cloos , ] (Figure ). Subduction along the Trobriand trench has been cited as a possible source for Miocene arc magmatism throughout the Papuan Peninsula that intruded continental basement and the PUB [ Taylor and Huchon , ; Quarles van Ufford and Cloos , ].…”

Section: Tectonic Setting Of Eastern Papua New Guineamentioning

confidence: 99%

Evaluating upper versus lower crustal extension through structural reconstructions and subsidence analysis of basins adjacent to the D'Entrecasteaux Islands, eastern Papua New Guinea

Fitz

Mann

2013

Geochem Geophys Geosyst

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[1] The D'Entrecasteaux Island (DEI) gneiss domes are fault-bounded domes with~2.5 km of relief exposing ultrahigh-pressure (UHP) and high-pressure (HP) metamorphic gneisses and migmatites exhumed in an Oligocene-Miocene arc-continent collision and subduction zone subject to late Miocene to recent continental extension. Multichannel seismic reflection data and well data show the Trobriand basin formed as a fore-arc basin caused by southward Miocene subduction at the Trobriand trench. Subduction slowed at~8 Ma as the margin transitioned to an extensional tectonic environment. Since then, the Trobriand basin has subsided 1-2.5 km as a broad sag basin with few normal faults deforming the basin fill. South of the DEI, the Goodenough rift basin developed after extension began (~8 Ma) as the hanging wall of the north-dipping Owen-Stanley normal fault that bounds the basin's southern margin. The lack of upper crustal extension accompanying subsidence in the Trobriand and Goodenough basins suggests depth-dependent lithospheric extension since 8 Ma has accompanied uplift of the DEI gneiss domes. Structural reconstructions of seismic profiles show 2.3-13.4 km of basin extension in the upper crust, while syn-rift basin subsidence values indicate at least 20.7-23.6 km of extension occurred in the entire crust since~8 Ma. Results indicating thinning is preferentially accommodated in the lower crust surrounding the DEI are used to constrain a schematic model of uplift of the DEI domes involving vertical exhumation of buoyant, postorogenic lower crust, far-field extension from slab rollback, and an inverted two-layer crustal density structure.

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Convergent tectonics in the Huon Peninsula region, Papua New Guinea

Cited by 35 publications

References 6 publications

Continental breakup and UHP rock exhumation in action: GPS results from the Woodlark Rift, Papua New Guinea

Continental breakup and UHP rock exhumation in action: GPS results from the Woodlark Rift, Papua New Guinea

Centroid moment tensor catalogue using a 3‐D continental scale Earth model: Application to earthquakes in Papua New Guinea and the Solomon Islands

Evaluating upper versus lower crustal extension through structural reconstructions and subsidence analysis of basins adjacent to the D'Entrecasteaux Islands, eastern Papua New Guinea

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