The Palaeozoic North American continent of Laurentia had a margin to the Iapetus Ocean which evolved from a late Precambrian/Cambrian rift to a passive margin and Mid/Late Palaeozoic orogenic belt. A number of sedimentary basins existed in the Laurentian continental interior, situated some distance from this margin. These intracratonic basins have proved controversial for a number of reasons; they are typically circular to sub-circular in outcrop and isopach maps and have prolonged patterns of subsidence. This dissertation describes detailed subsidence analysis of 3 intracratonic basins (the Illinois, Michigan, and Hudson Bay basins) and describes a pilot study of a fourth, the Williston Basin. It also describes the subsidence history of the Iapetean margin. It offers new insights into the mechanisms driving their subsidence and the relationships between the interior basins and the cratonic margins. North America was chosen for the study of intracratonic basins, as it offers excellent datasets and detailed stratigraphy. However, such basins exist on many continents and understanding of other basins should follow from this North American work. In order to investigate subsidence histories, a large database of stratigraphic sections has been compiled from outcrop and oil exploration boreholes. A standard backstripping technique has been applied and the resulting subsidence profiles interpreted in the light of existing structural frameworks, incorporating information such as seismic, gravity and magnetic anomaly data. In areas where independent evidence suggests that basin initiation was caused by lithospheric extension, subsidence data have been inverted for strain rate and the amount of extension quantified. Along the cratonic margin, new basinal areas are identified, such as central Texas and Alabama/Tennessee. An inferred rift arm, the Tobosa Basin of west Texas, is shown to have been absent during Early Palaeozoic times.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:597184 |
| Date | January 1997 |
| Creators | Butler, Andrew John |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://www.repository.cam.ac.uk/handle/1810/270453 |
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