Evidence for Subglacial Deformation and Deposition during a Complete Advance-Stagnation Cycle of Kötlujökull, Iceland – A Case Study

• Main Authors: Klint, K E S, Richardt, N, Krüger, Johannes
• Other Authors: Schomacker, A, Kjær, Kurt H
• Format: Book Part
• Language: English
• Published: Elsevier 2010
• Subjects: /dk/atira/pure/core/keywords/TheFacultyOfScience; Faculty of Science; Kötlujökull; glacier; Iceland
• Online Access: https://curis.ku.dk/portal/da/publications/evidence-for-subglacial-deformation-and-deposition-during-a-complete-advancestagnation-cycle-of-koetlujoekull-iceland--a-case-study(d378aaec-bdb8-4965-9b5e-d6a32572f0b8).html; https://doi.org/10.1016/S1571-0866(09)01309-8

A geological section, 70 m long and 3–4 m high, cut into dead-ice moraine in front of Kötlujökull, has been described. Five-sediment associations were recognized representing (1) proglacial glacio-fluvial sedimentation, (2) deposition and deformation in ice-marginal environment, (3) subglacial deformation and deposition from dynamically active ice, (4) subglacial deposition from stagnant ice and (5) supraglacial re-deposition in dead-ice environment during de-icing. This complete sedimentary sequence represents a single glacier advance-stagnation cycle. The melt-out till displays moderate consolidation, moderate content of fines and angular clasts, and a very strong clast fabric. The lodgement/deformation till displays strong to very strong consolidation, relatively high content of fines, low content of angular clasts, and a weak to strong clast fabric. The occurrence of water-escape structures below the basal till and complete lack of brittle deformations in the lodgement/deformation till suggest water-saturated subglacial conditions during the advance of Kötlujökull.