Drumlin formation within the Bustarfell drumlin field, northeast Iceland: integrating sedimentological and ground-penetrating radar data

Nína Aradóttir*, Ívar Örn Benediktsson, Ólafur Ingólfsson, Erik Sturkell, Skafti Brynjólfsson, Wesley R. Farnsworth, Emrys Phillips

*Corresponding author af dette arbejde

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

5 Citationer (Scopus)
2 Downloads (Pure)

Abstract

Drumlins are important bedforms of former glaciated landscapes as they demonstrate past ice-flow directions and elucidate processes that operated at the ice/bed interface. Recently mapped drumlins and other streamlined subglacial bedforms in northeast Iceland reveal the flow-sets of cross-cutting palaeo-ice streams that were active within the Iceland Ice Sheet (IIS) during and following the Last Glacial Maximum. Here we study the Bustarfell drumlin field within the Vopnafjörður–Jökuldalsheiði flow-set. The internal architecture of two drumlins was investigated using sedimentological analysis and ground-penetrating radar (GPR, 50 and 100 MHz) to illuminate subglacial processes that contributed to drumlin formation, as well as the history and dynamics of the IIS. On the stoss side of one of the drumlins, two subglacial traction till units were identified, separated by a thick unit of deformed glaciofluvial sand and gravel. The core of glaciofluvial material suggests that the drumlin formed around well-drained patches (sticky spots) in the subglacial bed that retarded the ice flow locally through increased basal drag and encouraged till deposition. Furthermore, our GPR data indicate a combination of erosional and depositional processes. We suggest that the glaciofluvial sediments were deposited as small ice-marginal fans on the Bustarfell plateau, possibly during the Bølling–Allerød interstadial, and that the drumlins were formed around these fans during a subsequent readvance during the Younger Dryas.

OriginalsprogEngelsk
TidsskriftJournal of Quaternary Science
Vol/bind38
Udgave nummer3
Sider (fra-til)386-402
Antal sider17
ISSN0267-8179
DOI
StatusUdgivet - 2023

Bibliografisk note

Funding Information:
This project has been funded through grants from the University of Iceland Research Fund (to ÓI), the Energy Research Fund of Landsvirkjun (to NA and ÍÖB) and the Icelandic Road and Coastal Administration (to ÍÖB). We would like to thank all our colleagues and graduate students for their great company during fieldwork, constructive discussions and helpful feedback during the project, especially for the help collecting the GPR data. Bragi Vagnsson, farmer at Bustarfell, kindly gave us the permission to excavate in drumlin Thury. The authors thank Adam Booth and an anonymous reviewer for their constructive comments, which improved the manuscript.

Publisher Copyright:
© 2022 John Wiley & Sons, Ltd.

Citationsformater