Craven, B. orcid.org/0000-0002-9290-8723 and Lloyd, G.E. orcid.org/0000-0002-7859-2486 (2024) Reconciling onshore and offshore geological mapping: lessons from north Cornwall, SW England. Geological Society Special Publications, 541. ISSN 0305-8719
Abstract
We present the first detailed stratigraphic and structural geological map of offshore north Cornwall and Devon, SW England, based on freely available bathymetric data. Although the bathymetry is often spectacular, revealing fold and fault structures exposed on the seabed at a range of scales and with high resolution, interpretation is not as straightforward as it might appear and depends critically upon both accuracy and knowledge of the onshore geology. Unfortunately, onshore stratigraphic controls are limited and restricted to several thin ‘named shales’ whose coastal outcrops are not always well constrained. In addition, the structure is markedly non-cylindrical on local to regional scales, making seaward projection problematic, while the impact of early thrusting on the stratigraphy has often been previously neglected. We therefore developed a workflow to handle the problems we encountered, including: recognition of vertical to horizontal and 3D to 2D projections; variations in bathymetric data characteristics; prediction of expected seabed outcrop geometries based on coastal structures; incorporation of non-cylindrical effects; and problems with quantitative GIS terrain profiles and structural measurements that result in an absence of such measurements. The geological map produced should therefore be viewed as a step forward, but as forming a base for further detailed bathymetric mapping.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2023 The Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/). |
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) > Inst of Geophysics and Tectonics (IGT) (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 04 Dec 2023 13:08 |
Last Modified: | 04 Dec 2023 13:08 |
Status: | Published |
Publisher: | The Geological Society |
Identification Number: | 10.1144/sp541-2022-314 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:206148 |