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A craton is an ancient part of the Earth's continental crust which has been more or less stable since Precambrian times. Cratons whose ancient rocks are widely exposed at the surface, often with relatively subdued relief, are known as shields.
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 oldest dated rocks of the Baltic Shield are 3.5 Ga old. [10]
Cratons of South America and Africa during the Triassic Period when the two continents were joined as part of the Pangea supercontinent. 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 ...
The degree of certainty to which the identified landmasses can be regarded as independent entities reduces as geologists look further back in time. The list includes cratons, supercratons, microcontinents, continents and supercontinents. For the Archean to Paleoproterozoic cores of most of the continents see also list of shields and cratons.
The Dharwar Craton is an Archean continental crust craton formed between 3.6-2.5 billion years ago , which is located in southern India and considered the oldest part of the Indian peninsula. [ 2 ] Studies in the 2010s suggest that the craton can be separated into three crustal blocks since they show different accretionary history (i.e., the ...
The four main sequences include from oldest to youngest, the Central Slaver Cover Group, Kam Group, Banting Group, and Jackson Lake Formation. [13] The Yellowknife Supergroup has been used to represent the general stratigraphy of the greenstone belts in the Slave Craton, including belts in the Eastern Slave, in order to interpret the processes ...
The Pilbara and Kaapvaal cratons contain well-preserved Archaean microfossils. Drilling has revealed traces of microbial life and photosynthesis from the Archaean in both Africa and Australia. [19] The oldest widely accepted evidence of photosynthesis by early life forms is molecular fossils found in 2.7 Ga-old shales in the Pilbara Craton.
Some of the Yilgarn regolith is the oldest in the world, recording weathering events as early as the Cretaceous Period. This has been created by the generally subtropical latitudes and conditions of the Yilgarn craton, with minimal to no glaciation and generally flat topographical relief resulting in comparatively minor erosion.