Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.446577
Title: Post Oligocene sedimentation and salt tectonics of the Kwanza and Lower Congo Basins
Author: Ferreira, Hercinda C. G.
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 2007
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Abstract:
The present study was designed to test the hypothesis that post-rift development of ponded accommodation space – a type of salt-induced accommodation space – exerted a controlling factor on the characteristics and distribution of the post-Oligocene lithofacies deposited in parts of the Kwanza and Lower Congo Basins (Angolan margin) covered by this study. The tectonostratigraphic evolution of the area covered by the 3D reflection seismic survey suggests that, during the Early Miocene, the study area was subject to extensional salt deformation. A landward shift of the salt deformation domains occurred during Mid Miocene to Early Pliocene times. This shift in salt domains was coeval with deposition of lithofacies which have characteristics that resemble those deposited in ponded-basin and healed slope salt-induced accommodation space in the Gulf of Mexico. Lithofacies characteristic of deposition in healed slope accommodation space dominate the Mid Miocene to Early Pliocene sedimentary packages, and suggest that ponded accommodation space constituted less than 20% of the total accommodation available at the time of deposition. Seafloor profiles across the present day Angolan margin and central Gulf of Mexico suggest that partial bypass of the slope during deposition in healed slope accommodation space may result in large abyssal plain sediment accumulation. This substantial abyssal plain sedimentation may have buttressed the toe of the Angola Salt Nappe hindering its advance and therefore promoting the landward shift in salt deformation domains observed during this period. Thus, the analysis of the sedimentary packages deposited in the study area during the post-Oligocene to Recent suggests that healed slope accommodation space, rather than ponded accommodation, provided the dominant control on the characteristics and distribution of the lithofacies and consequent shifts in salt deformation domains along the Angolan margin.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.446577  DOI: Not available
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