Search results
Results from the WOW.Com Content Network
The Pilbara Craton is an old and stable part of the continental lithosphere located in the Pilbara region of Western Australia. The Pilbara Craton is one of only two pristine Archaean 3.8–2.7 Ga (billion years ago) crusts identified on the Earth, along with the Kaapvaal Craton in South Africa .
The cratons appear to have been assembled to form the greater Australian landmass in the late Archaean to Mesoproterozoic, ~2400 Ma to 1,600 Ma. Chiefly the Glenburgh Orogeny is partly responsible for the assembly of the West Australian landmass by joining the Yilgarn and Pilbara cratons. The Glenburgh Orogeny is exposed in the rocks of the ...
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 ]
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.
The Capricorn orogeny was an orogenic event in what is now Western Australia, following the collision of the Pilbara Craton and the Glenburgh Terrane with the Yilgarn Craton during the Glenburgh orogeny. Spanning one billion years, the Capricorn orogeny is marked by widespread deformation and intracratonal reworking.
The Australian Shield is fractured into a number of distinct blocks, including two cratons - the Pilbara Craton in the North and the Yilgarn Craton in the Southwest. These two cratons are the oldest part of the shield, both of which have been dated at more than 2.3 billion years old. [5]
The Kaapvaal craton is marked by dramatic events such as the intrusion of the Bushveld Complex (2.045 Ga) and the Vredefort impact event (2.025 Ga), and no traces of these events have been found in the Pilbara craton, clearly indicating that the two cratons were separated before 2.05 Ga. [10] Furthermore, geochronological and palaeomagnetic ...
The Archean rocks from the Pilbara craton contain some of the first evidence of life, primitive cyanobacterial mats known as stromatolites. Soft-bodied organisms from the Ediacaran collectively known as the Ediacaran biota are found in sandstone around the Flinders Ranges in South Australia, notably at a site known as Wilpena Pound.