Mohammed, M, Paton, D, Collier, REL et al. (2 more authors) (2017) Interaction of crustal heterogeneity and lithospheric processes in determining passive margin architecture on the southern Namibian margin. Geological Society Special Publications, 438. pp. 177-193. ISSN 0305-8719
Abstract
The influence of pre-rift crustal heterogeneity and structure on the evolution of a continental rift and its subsequent passive margin is explored. The absence of thick Aptian salts in the Namibian South Atlantic allows imaging of sufficient resolution to distinguish different pre-rift basement seismic facies. Aspects of the pre-rift basement geometry were characterized and compared with the geometries of the Cretaceous rift basin structure and with subsequent post-rift margin architectural elements. Half-graben depocentres migrated westwards within the continental synrift phase at the same time as basin-bounding faults became established as hard-linked arrays with lengths of c. 100 km. The rift–drift transition phase, marked by seaward-dipping reflectors, gave way to the early post-rift progradation of clastic sediments off the Namibian coast. In the Late Cretaceous, these shelf clastic sediments were much thicker in the south, reflecting the dominance of the newly formed Orange River catchment as the main entry point for sediments on the South African–Namibian margin. Tertiary clastic sediments largely bypassed the pre-existing shelf area, revealing a marked basinwards shift in sedimentation. The thickness of post-rift megasequences does not vary simply according to the location of synrift half-graben and thinned continental crust. Instead, the Namibian margin exemplifies a margin influenced by a complex interplay of crustal thinning, pre-rift basement heterogeneity, volcanic bodies and transient dynamic uplift events on the evolution of lithospheric strain and depositional architecture.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 The Author(s). Published by The Geological Society of London. All rights reserved. This is an author produced version of a paper published in Geological Society Special Publications. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | South Atlantic, Lithospheric Stretching, Passive Margin, Basement Heterogeneity |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Environment (Leeds) > School of Earth and Environment (Leeds) > Institute for Applied Geosciences (IAG) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Oct 2015 12:53 |
Last Modified: | 12 Apr 2017 14:05 |
Published Version: | https://doi.org/10.1144/SP438.9 |
Status: | Published |
Publisher: | Geological Society |
Identification Number: | 10.1144/SP438.9 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:90623 |