Zealandia
A continent of 4.9 million square kilometres in the south-west Pacific, 94% of it under the sea. New Zealand and New Caledonia are its highest parts. It was once about 5% of Gondwana; stretched and thinned in the Late Cretaceous, it broke away as a ribbon continent some 4,000 km long and sank, and in 2017 geologists argued it should count as a continent of its own.
Dated events and their evidence
- about 500,000,000 years ago mainstream
the oldest known rocks of Zealandia form: Middle Cambrian limestones of the Takaka Terrane and granites of the Jacquiery Suite, 490-505 million years old source - about 105,000,000 years ago mainstream
widespread stretching and thinning of the crust along the south-east margin of Gondwana, about 105 to 85 million years ago, before the breakup; the thinned crust later sinks, which is why 94% of Zealandia is now under water source - about 85,000,000 years ago mainstream
seafloor spreading begins to split Gondwana, and Zealandia separates in the Late Cretaceous as a ribbon continent some 4,000 km long; Wikipedia dates the breakaway to 83-79 million years ago source - 1995 CE mainstream
Luyendyk proposes the name Zealandia for New Zealand, the Chatham Rise, the Campbell Plateau and the Lord Howe Rise source - 2017 CE mainstream
February: Mortimer and ten co-authors argue in GSA Today that Zealandia, isolated from Australia and large enough, should be recognised as a geological continent source
Where
40.0000° S, 170.0000° E
The point is Wikipedia's centre for Zealandia; the continent spans about 4.9 million km² of the south-west Pacific, from New Caledonia in the north to the Campbell Plateau in the south.
Sources
Each event carries Aion's own evidence grade (mainstream, disputed or speculative). This page repeats what the globe shows for this place.