Variations in esker morphology and internal architecture record time-transgressive deposition during ice margin retreat in Northern Ireland

STOKER, B, LIVINGSTONE, S, BARR, I, RUFFELL, A, STORRAR, Robert and ROBERSON, S (2021). Variations in esker morphology and internal architecture record time-transgressive deposition during ice margin retreat in Northern Ireland. Proceedings of the Geologists' Association.

[img] PDF
Stoker et al PGA.pdf - Accepted Version
Restricted to Repository staff only until 19 April 2022.
Creative Commons Attribution Non-commercial No Derivatives.

Download (5MB)
Official URL: https://www.sciencedirect.com/science/article/abs/...
Link to published version:: https://doi.org/10.1016/j.pgeola.2021.03.002
Related URLs:

    Abstract

    The architecture and evolution of the subglacial hydrological system plays a key role in modulating ice flow. Eskers provide an opportunity to understand subglacial hydrology at a broader perspective than contemporary studies. Recent research has established a morphogenetic classification for eskers, but these studies have been limited to topographically simple regions of a single ice sheet. We present an updated map of esker distribution in Northern Ireland based on 5-m resolution elevation data. We also present a high-resolution map of the glacial geomorphology of SW Northern Ireland, based on ~ 0.4-m resolution elevation data. Ground Penetrating Radar data from four sites along the > 20-km long Evishanoran Esker system in central Northern Ireland are combined with geomorphological observations to provide insight into depositional processes and controls on esker formation. Esker architecture indicates two styles of deposition, including an initial high energy flow event in a subglacial conduit and delta foreset deposition close to the ice sheet margin during ice margin retreat. These delta foreset deposits can be used to reconstruct former ice margins. We identify that local topographic complexity and geological structures (e.g., faults) are important controls on esker formation. The broad-scale esker architecture remains the same despite variable esker planform morphology, suggesting hydrological conditions alone cannot explain esker morphology. This study provides further evidence that morphogenetic relationships cannot be based solely on remote sensing data and must be supported by robust field observations, especially where post-glacial processes may distort esker morphology (e.g., peat infilling).

    Item Type: Article
    Uncontrolled Keywords: 0403 Geology; 2101 Archaeology
    Identification Number: https://doi.org/10.1016/j.pgeola.2021.03.002
    SWORD Depositor: Symplectic Elements
    Depositing User: Symplectic Elements
    Date Deposited: 21 Apr 2021 09:24
    Last Modified: 21 Apr 2021 09:30
    URI: http://shura.shu.ac.uk/id/eprint/28540

    Actions (login required)

    View Item View Item

    Downloads

    Downloads per month over past year

    View more statistics