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A cratonic sequence (also known as megasequence, Sloss sequence or supersequence) in geology is a very large-scale lithostratigraphic sequence in the rock record that represents a complete cycle of marine transgression and regression on a craton (block of continental crust) over geologic time.
The Sauk sequence was the earliest of the six cratonic sequences that have occurred during the Phanerozoic in North America. It was followed by the Tippecanoe , Kaskaskia , Absaroka , Zuñi , and Tejas sequences.
The Zuñi sequence was the major cratonic sequence after the Absaroka sequence that began in the latest Jurassic, peaked in the late Cretaceous, and ended by the start of the following Paleocene. [1] Though it was not the final major transgression , it was the last complete sequence to cover the North American craton ; the following Tejas ...
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 Tippecanoe sequence was the cratonic sequence or the marine transgression following the Sauk sequence; it extended from roughly the Middle Ordovician to the Early Devonian. The Tippecanoe is bound by two Unconformities , at the base by the Knox Unconformity, and at its top the Wallbridge Unconformity.
The division of these sequences were originally constructed in the Appalachian Basin and Cordilleran Basin of North America. Eventually these sequences were correlated in Russia and South America. [3] The transgressive-regressive units show gaps in the rock records which indicate times of continual erosion and very little deposition. Local ...
Laurentia basement rocks. Laurentia or the North American Craton is a large continental craton that forms the ancient geological core of North America.Many times in its past, Laurentia has been a separate continent, as it is now in the form of North America, although originally it also included the cratonic areas of Greenland and the Hebridean terrane in northwest Scotland.
Approximate location of Mesoproterozoic (older than 1.3 Ga) cratons in South America and Africa. The São Luís and Luís Alves cratonic fragments are shown. Gondwana and the Kuungan orogen. Listed by modern continent and Gondwana, include: