Evolution and Sedimentary Cover of the Phanerozoic Craton

Peter Burgess

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Although the term craton is often taken as synonomous with tectonic quiescence, the North American craton is not simply an unchanging, stable platform accumulating strata and influenced only by changes in global sea-level. Rather, viewed on a timescale of tens to hundreds of millions of years at least, it is a dynamic tectonic environment influenced by various plate tectonic, mantle, denudational and depositional processes. The Sloss cratonic sequences record the history of this dynamic tectonic environment, in the form of episodes of transgression, regression and erosion and non-deposition, generated on a timescale of tens of millions of years. These sequences occur across the craton, on areas of platform, as well as in the four main intracratonic basins, yet their origins remain relatively poorly understood. Long-term eustatic oscillations must certainly have contributed to development of the transgressive and regressive sequence elements, but basic observations of tilted strata and angular sequence-bounding unconformities show eustasy cannot have been the only responsible mechanism. Variations in dynamic topography generated by subducting lithospheric slabs, and by thermal insulation of mantle beneath supercontinents, can explain much of the large-scale sequence architecture but more detailed plate tectonic reconstructions and associated mantle convection models are necessary to further test and develop these explanations. Intraplate stress also seems likely to have played a large role in generating the cratonic
sequences by reactivating pre-existing structures and driving subsidence and uplift. Variations in intraplate stress through time can be related, to some degree at least, to tectonic events occurring on the cratonic margins and on other adjacent plate margins. Given present available evidence and theory, the North American intracratonic basins seem most likely to be due to a combination of mantle downwelling and focused intraplate stress variations, in some cases with an element of long-wavelength tilting due to subduction-induced dynamic topography, and in some cases with an initial trigger by lithospheric stretching. Although taken together all these mechanisms provide a plausible explanation for the development of the North American cratonic sequences, they are certainly not definitive, conclusive explanations. Much work remains to be done to test, and to confirm or refute these ideas.
Original languageEnglish
Title of host publicationSedimentary Basins of the World: North America
EditorsAndrew Miall
PublisherElsevier Science Publishers B.V. (North-Holland)
Pages31-63
Number of pages28
Publication statusPublished - 2008

Publication series

NameSedimentary basins of the world

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