Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.606477
Title: Tectonic evolution and extensional modelling of the SW South China Sea and its analogy with the Southern Beaufort Sea, Canada Basin, Arctic Ocean
Author: Lu, Li
ISNI:       0000 0004 5361 6335
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 2014
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Abstract:
Both the SW South China Sea and southern Beaufort Sea represent areas of extended continental crust, located on continental margins associated with oceanic spreading centres and zones of continent ocean transition (COT). Multichannel seismic reflection data are interpreted to characterize the COT in the SW South China Sea and the Southern Beaufort Sea. Based on the modelling and subsidence analysis, these two areas, SW South China Sea and southern Beaufort Sea, are compared with each other and the process of formation of hyper-extended crust in marginal oceanic basins can be conceptually modelled. It is noted that the initial weak thinning of the continental crust happened and the ductile middle/lower crust is coupled with the brittle upper crust. As extension continued, the continental crust is thinned down to ~10km, which is in accord with depth-dependent lithosphere thinning. Major crustal thinning is unlikely to result from brittle, high-angle normal fault in the upper crust. The degrees of lower crustal extension are so high and very high amounts of lower crustal extension, presumably achieved by ductile flow, would be required to have affected the crust within the COT. The seafloor spreading centre existed in the area adjacent to the research regions, so the extension within the COT occurred prior to the onset of seafloor spreading and the lower ductile flow is away from the continent and towards the oceanic crust. The interpretations require that the continental lithosphere prior to seafloor spreading must have been very weak given the evidence for significant lower crustal flow, inferred shallow depth of the brittle ductile transition and the fact that the COT continued to extend after the cessation of seafloor spreading.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.606477  DOI: Not available
Keywords: Geology ; Structural ; China Sea ; Beaufort Sea
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