Structure and evolution of the southern Solomon Sea region

Created 17/10/2025

Updated 17/10/2025

The evolution of the southern Solomon Sea region is deduced from a review of geological, geophysical, and bathymetric data, and previously unpublished seismic reflection profiles. Although the Solomon Sea is bounded to the north by a classical active arc-trench subduction system, the situation to the south is less certain. There, the Solomon Sea is bounded to the north by a classical active arc-trench Woodlark Rise. On seismic profiles, the Trobriand Trough has the appearance of an active trench, and it is associated with active andesite volcanoes. But it is virtually aseismic, indicating that it is inactive or that subduction is proceeding only slowly. If the Trough is active, then it forms the southwestern boundary of the Solomon Plate. If it is inactive, the plate boundary may be transitional, coinciding with a diffuse zone of shallow earthquakes on the Papuan peninsula. The southeastern boundary may be a postulated transform fault on the line of the Woodlark Rise. The lithosphere of the Solomon Sea Basin probably formed by back-arc spreading in the Early Tertiary. As a result of subduction to the northeast, northwest, and southwest, the lithosphere has been anticlinally folded about east-west and north-south axes, causing elevation of the Huon Peninsula and southern New Ireland, and the development of small flanking extensional basins. Miocene to Holocene volcanics of southeastern Papua mostly have the character of an arc-trench suite, and are probably related to Miocene-Quaternary subduction at the Trobriand Trough. The Trobriand Basin, an east-west trending basin south of the Trobriand Trough, contains up to 5000 m of Miocene and younger sediments, and probably developed as a fore-arc basin related to subduction at the Trobriand Trough. Seismic reflection profiles indicate that the Trobriand Basin extends further east than was previously recognised and is bounded southeastwards by rifting associated with the formation of the Woodlark Basin. The same rifting caused Plio-Quaternary elevation of the DEntrecasteaux Islands and Papuan peninsula, and the development of small rift basins, such as the Goodenough Basin, and is linked with rhyolite volcanism on Fergusson Island.

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Additional Info

Field Value
Title Structure and evolution of the southern Solomon Sea region
Language eng
Licence Not Specified
Landing Page https://data.gov.au/data/dataset/a0a13a94-f9f2-46f6-9836-bcc3c330c560
Contact Point
Geoscience Australia Data
clientservices@ga.gov.au
Reference Period 20/04/2018
Geospatial Coverage
Map data © OpenStreetMap contributors
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  "type": "Polygon"
}
Data Portal Geoscience Australia

Data Source

This dataset was originally found on Geoscience Australia "Structure and evolution of the southern Solomon Sea region". Please visit the source to access the original metadata of the dataset:
https://ecat.ga.gov.au/geonetwork/srv/eng/csw/dataset/structure-and-evolution-of-the-southern-solomon-sea-region