Georgetown Inlier
A block of very old crust in north Queensland that began life as part of North America. Its oldest sediments carry the zircon fingerprint of north-west Laurentia; it rifted away about 1,680 million years ago and was welded onto Australia about 1,600 million years ago, as the supercontinent Nuna came together.
Dated events and their evidence
- about 1,700,000,000 years ago mainstream
the lowest sedimentary units of the inlier are laid down, about 1,700-1,650 million years ago, from sediment whose zircon ages match north-west Laurentia source - about 1,680,000,000 years ago mainstream
the Georgetown block is rifted off western Laurentia as a ribbon of continental crust, about 1,680 million years ago source - about 1,600,000,000 years ago mainstream
the block collides with Australia, about 1,600 million years ago, during the assembly of the supercontinent Nuna source
Where
18.2922° S, 143.5480° E
The point is Wikipedia's position for the town of Georgetown, which gives the inlier its name; the inlier itself is a broad area of old rock in the north Queensland savannah around it.
Sources
- https://doi.org/10.1130/G39980.1
- https://doi.org/10.1130/B38303.1
- https://en.wikipedia.org/wiki/Georgetown,_Queensland
- https://ozgeology.com/blogs/news/queensland-was-once-connected-to-canada-the-georgetown-inlier
Each event carries Aion's own evidence grade (mainstream, disputed or speculative). This page repeats what the globe shows for this place.