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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 sequence dates from the late Proterozoic through the early Ordovician periods, though the marine transgression did not begin in earnest until the middle Cambrian. [2] It is one of the most striking cratonic sequences in the geological record, spreading sheets of sandstone across basement rock deep into the interiors of many continents.
The Kaskaskia sequence was a cratonic sequence that began in the mid-Devonian, peaked early in the Mississippian, and ended by mid-Mississippian time. A major unconformity separates it from the lower Tippecanoe sequence , called the "Wallbridge Unconformity".
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 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 ...
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 Absaroka sequence was a cratonic sequence that extended from the end of the Mississippian through the Permian periods. There is an unconformity between the Absaroka and the lower Kaskaskia sequence. This unconformity divides the Carboniferous into the Mississippian and Pennsylvanian periods in North America.
He is known as a pioneer in the discipline of sequence stratigraphy, [5] and for his descriptions of cratonic sequences or "Sloss sequences" in ancient North America. As a whole, these sequences are large-scale cycles in sedimentary rock records that indicate broad patterns of environmental change over geologic time – specifically marine ...