New Caledonia Trough

[3] The trough is between 200 and 300 km (120 and 190 mi) wide,[1] and traverses a number of sedimentary basins within the submerged continent of Zealandia.

[12] The timings and drivers of the formation of the trough have accordingly become the subject of research orientated to test this hypothesis and the Zealandia concept but the more recent tectonics could be explained in more than one way.

[14] There is evidence from studies of its northern aspects that it may have had a two-stage process with more recent Eocene to Oligocene formation timings.

The recent tectonics have been modelled at both the New Caledonian and New Zealand ends of the trough and will be commented on first, before consideration of the geology known of the relevant basins and the consensus stratigraphy.

[20] Pacific basin subducting slab dipped southwest beneath the eastern margin of Gondwana in the period from 260 to 110 million years ago.

[22] By the Late Cretaceous (83.5 million years ago) the New Caledonia Trough was established as an extension basin but can be regarded as a failed rift compared to the eastern opening of the Tasman Sea from the Australian plate that started about this time.

[26] This basins stratigraphy west of New Caledonia is consistent with foreland loading and tilting associated with Eocene and younger southwest verging thrusts along its eastern margin.

[c][28] It is based on the three regional tectonic phases of Zealandia and is:[29] Aotea Basin (deepwater Taranaki Basin)[14] sampling has shown a transition at 68 – 66 million years ago (Late Cretaceous) from sediments from land plants to a Paleocene fully oceanic environment by 63.5 – 56 million years ago.

[29] An area studied in detail of the Lord Howe raise western edge has volcanic seamounts and a canynon entering the basin.