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The Yilgarn Craton is a large craton that constitutes a major part of the Western Australian land mass. It is bounded by a mixture of sedimentary basins and Proterozoic fold and thrust belts . Zircon grains in the Jack Hills , Narryer terrane have been dated at ~4.27 Ga , with one detrital zircon dated as old as 4.4 Ga. [ 1 ]
A craton (/ ˈ k r eɪ t ɒ n / KRAYT-on, / ˈ k r æ t ɒ n / KRAT-on, or / ˈ k r eɪ t ən / KRAY-tən; [1] [2] [3] from Ancient Greek: κράτος kratos "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle.
The Yilgarn Craton, of Archaean age; The Pilbara Craton of Archaean to Proterozoic age; The Gawler Craton and Willyama Block, of Archaean to Proterozoic age. These are in turn flanked by several Proterozoic orogenic belts and sedimentary basins, notably the Musgrave Block of granulite gneiss and igneous rocks
The Yarrabubba impact structure is the eroded remnant of an impact crater, situated in the northern Yilgarn Craton near Yarrabubba Station between the towns of Sandstone and Meekatharra, Mid West Western Australia. [2] [3] With an age of 2.229 billion years, it is the oldest known impact structure on Earth. [1]
Nevertheless, the oldest cratons on Earth include the Kaapvaal Craton, the Western Gneiss terrane of the Yilgarn Craton (~2.9 – >3.2 Ga), the Pilbara Craton (~3.4 Ga), and portions of the Canadian Shield (~2.4 – >3.6 Ga). Parts of Dharwar Craton in India are greater than 3.0 Ga.
East European Craton, the core of Baltica. Volgo-Uralian Craton, Russia (3.0–2.7 Ga) Baltic Shield, part of the East European Craton; Fennoscandian Shield, the exposed Northwestern part of the Baltic Shield in Norway, Sweden and Finland (3.1 Ga) Karelian Craton, part of the Fennoscandian Shield in Southeast Finland and Karelia Russia, (3.4 Ga)
The Narryer Gneiss terrane has undergone many high-grade polyphase deformation events, with the most notable being at 2600 to 2700 Ma associated with granite-greenstone magmatism in the Yilgarn Craton, following an event at ~3350 Ma of amphibolite facies, resulting in widespread re-equilibration of geochronometers, preceded by a deformation ...
The Lake Zot Dolerite is similar to the Defiance Dolerite and other regionally important subvolcanic doleritic sill complexes throughout the Yilgarn Craton. Within the Widgiemooltha Dome area, the Lake Zot Dolerite can attain greater than 300 metres (984 ft) thickness and is intrusive into the hangingwall basalt and Widgiemooltha Chert above the Widgiemooltha Komatiite.