Poyatos-Moré, M, Jones, GD, Brunt, RL et al. (3 more authors) (Cover date: October 2019) Clinoform architecture and along-strike variability through an exhumed erosional to accretionary basin margin transition. Basin Research, 31 (4). pp. 920-947. ISSN 0950-091X
Abstract
Exhumed basin margin‐scale clinothems provide important archives for understanding process interactions and reconstructing the physiography of sedimentary basins. However, studies of coeval shelf through slope to basin‐floor deposits are rarely documented, mainly due to outcrop or subsurface dataset limitations. Unit G from the Laingsburg depocentre (Karoo Basin, South Africa) is a rare example of a complete basin margin scale clinothem (>60 km long, 200 m‐high), with >10 km of depositional strike control, which allows a quasi‐3D study of a preserved shelf‐slope‐basin floor transition over a ca. 1200 km2 area. Sand‐prone, wave‐influenced topset deposits close to the shelf‐edge rollover zone can be physically mapped down dip for ca. 10 km as they thicken and transition into heterolithic foreset/slope deposits. These deposits progressively fine and thin over 10s of km farther down dip into sand‐starved bottomset/basin floor deposits. Only a few km along strike, the coeval foreset/slope deposits are bypass‐dominated with incisional features interpreted as minor slope conduits/gullies. The margin here is steeper, more channelized, and records a stepped profile with evidence of sand‐filled intraslope topography, a preserved base‐of‐slope transition zone and sand‐rich bottomset/basin‐floor deposits. Unit G is interpreted as part of a composite depositional sequence that records a change in basin margin style from an underlying incised slope with large sand‐rich basin‐floor fans to an overlying accretion‐dominated shelf with limited sand supply to slope and basin‐floor. The change in margin style is accompanied with decreased clinoform height/slope and increased shelf width. This is interpreted to reflect a transition in subsidence style from regional sag, driven by dynamic topography/inherited basement configuration, to early foreland basin flexural loading. Results of this study caution against reconstructing basin margin successions from partial datasets without accounting for temporal and spatial physiographic changes, with potential implications on predictive basin evolution models.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 The Authors. Basin Research © 2019 John Wiley & Sons Ltd, European Association of Geoscientists & Engineers and International Association of Sedimentologist. This article is protected by copyright. All rights reserved. This is the peer reviewed version of the following article: Poyatos-Moré, M, Jones, GD, Brunt, RL et al. (3 more authors) (2019) Clinoform architecture and along-strike variability through an exhumed erosional to accretionary basin margin transition. Basin Research, 31 (4). pp. 920-947. ISSN 0950-091X, which has been published in final form at https://doi.org/10.1111/bre.12351. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. |
Keywords: | clinoform; clinothem; facies analysis; seabed topography; sequence stratigraphy; shelf‐edge; strike variability |
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 Statoil SLOPE4 |
Depositing User: | Symplectic Publications |
Date Deposited: | 25 Feb 2019 10:15 |
Last Modified: | 25 Feb 2020 01:38 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1111/bre.12351 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:142913 |