Cosgrove, GIE orcid.org/0000-0002-2206-8714, Poyatos-Moré, M, Lee, DR orcid.org/0000-0003-4397-6030 et al. (3 more authors) (2020) Intra‐clinothem variability in sedimentary texture and process regime recorded down slope profiles. Sedimentology, 67 (1). pp. 431-456. ISSN 0037-0746
Abstract
Shelf‐margin clinothem successions can archive process interactions at the shelf to slope transition, and their architecture provides constraints on the interplay of factors that control basin‐margin evolution. However, detailed textural analysis and facies distributions from shelf to slope transitions remain poorly documented. This study uses quantitative grain‐size and sorting data from coeval shelf and slope deposits of a single clinothem that crops out along a 5 km long, dip‐parallel transect of the Eocene Sobrarbe Deltaic Complex (Ainsa Basin, south‐central Pyrenees, Spain). Systematic sampling of sandstone beds tied to measured sections has captured vertical and basinward changes in sedimentary texture and facies distributions at an intra‐clinothem scale. Two types of hyperpycnal flow‐related slope deposits, both rich in mica and terrestrial organic matter, are differentiated according to grain size, sorting and bed geometry: (i) sustained hyperpycnal flow deposits, which are physically linked to coarse channelized sediments in the shelf setting and which deposit sand down the complete slope profile; (ii) episodic hyperpycnal flow deposits, which are disconnected from, and incise into, shelf sands and which are associated with sediment bypass of the proximal slope and coarse‐grained sand deposition on the medial and distal slope. Both types of hyperpycnites are interbedded with relatively homogenous, organic‐free and mica‐free, well‐sorted, very fine‐grained sandstones, which are interpreted to be remobilized from wave‐dominated shelf environments; these wave‐dominated deposits are found only on the proximal and medial slope. Coarse‐grained sediment bypass into the deeper‐water slope settings is therefore dominated by episodic hyperpycnal flows, whilst sustained hyperpycnal flows and turbidity currents remobilizing wave‐dominated shelf deposits are responsible for the full range of grain sizes in the proximal and medial slope, thus facilitating clinoform progradation. This novel dataset highlights previously undocumented intra‐clinothem variability related to updip changes in the shelf process‐regime, which is therefore a key factor controlling downdip architecture and resulting sedimentary texture.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 The Authors. Sedimentology © 2019 International Association of Sedimentologists. This is the peer reviewed version of the following article: Cosgrove, G.I.E., Poyatos‐Moré, M., Lee, D.R., Hodgson, D.M., McCaffrey, W.D. and Mountney, N.P. (2020), Intra‐clinothem variability in sedimentary texture and process regime recorded down slope profiles. Sedimentology, 67: 431-456. doi:10.1111/sed.12648, which has been published in final form at https://doi.org/10.1111/sed.12648. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Bypass; clinothem; hyperpycnal; process regime; river dominated; texture; wave dominated |
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 GDF SUEZ E&P International SA No External Reference |
Depositing User: | Symplectic Publications |
Date Deposited: | 05 Jul 2019 11:14 |
Last Modified: | 08 Jul 2020 00:38 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1111/sed.12648 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:148175 |