Medici, G, Boulesteix, K, Mountney, NP et al. (2 more authors) (2015) Palaeoenvironment of braided fluvial systems in different tectonic realms of the Triassic Sherwood Sandstone Group, UK. Sedimentary Geology, 329. 188 - 210. ISSN 0037-0738
Abstract
Fluvial successions comprising the fills of sedimentary basins occur in a variety of tectonic realms related to extensional, compressional and strike-slip settings, as well as on slowly subsiding, passive basin margins. A major rifting phase affected NW Europe during the Triassic and resulted in the generation of numerous sedimentary basins. In the UK, much of the fill of these basins is represented by fluvial and aeolian successions of the Sherwood Sandstone Group. Additionally, regions that experienced slow rates of Mesozoic subsidence unrelated to Triassic rifting also acted as sites of accumulation of the Sherwood Sandstone Group, one well-exposed example being the eastern England Shelf. The fluvial depositional architecture of deposits of the Sherwood Sandstone Group of the eastern England Shelf (a shelf-edge basin) is compared with similar fluvial deposits of the St Bees Sandstone Formation, eastern Irish Sea Basin (a half-graben). The two studied successions represent the preserved deposits of braided fluvial systems that were influenced by common allogenic factors (climate, sediment source, delivery style); differences in preserved sedimentary style principally reflect their different tectonics settings. Analysis of lithofacies and architectural elements demonstrates that both studied successions are characterized by amalgamated channel-fill elements that are recorded predominantly by downstream-accreting sandy barforms. The different tectonic settings in which the two braided-fluvial systems accumulated exerted a dominant control on preserved sedimentary style and long-term preservation potential. On the eastern England Shelf, the vertical stacking of pebbly units and the general absence of fine-grained units reflect a slow rate of sediment accommodation generation (18–19.4 m/Myr). In this shelf-edge basin, successive fluvial cycles repeatedly reworked the uppermost parts of earlier fluvial deposits such that only the lowermost channel lags tend to be preserved. By contrast, in the eastern Irish Sea Basin of west Cumbria, the rate of sediment accommodation generation was substantially greater (119 m/Myr) such that space was available to preserve complete fluvial cycles, including silty drape units that cap the channelized deposits.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015, Elsevier. This is an author produced version of a paper published in Sedimentary Geology. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Fluvial; Tectonics; Lithofacies; Architectural elements; Stacking pattern |
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) |
Funding Information: | Funder Grant number Total E&P UK Ltd Not Known Shell International Not Known |
Depositing User: | Symplectic Publications |
Date Deposited: | 29 Oct 2015 12:54 |
Last Modified: | 24 Apr 2017 03:33 |
Published Version: | http://dx.doi.org/10.1016/j.sedgeo.2015.09.012 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.sedgeo.2015.09.012 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:91257 |