Moraine ridges formed from subglacial frozen‐on sediment slabs and their differentiation from push moraines

Throughout the 1980s the annual cycle of ice‐front activity along the stationary north margin of the ice‐cap Myrdalsjökull, southern Iceland, produced a complex ridge, 4 m high, composed of imbricately stacked slabs of frozen, clast‐paved lodgement till dipping up‐glacier. Further observations in 19...

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Bibliographic Details
Published in:Boreas
Main Author: KRÜGER, JOHANNES
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1996
Subjects:
Online Access:http://dx.doi.org/10.1111/j.1502-3885.1996.tb00835.x
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.1996.tb00835.x
https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.1996.tb00835.x
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Summary:Throughout the 1980s the annual cycle of ice‐front activity along the stationary north margin of the ice‐cap Myrdalsjökull, southern Iceland, produced a complex ridge, 4 m high, composed of imbricately stacked slabs of frozen, clast‐paved lodgement till dipping up‐glacier. Further observations in 1994 revealed that glaciofluvial processes and associated deposits may be involved in the final stage of ridge production depending on local climate and meltwater drainage pattern. It is concluded that at the margin of Myrdalsjökull the progressive stacking of subglacial frozen‐on sediment slabs to form a moraine ridge is a fundamentally similar mechanism to that involved in the incremental double‐layer model reported from Styggesdalsbreen, southern Norway. This study has also identified internal characteristics which are of potential use for distinguishing between moraine ridges formed by this mechanism and push moraines formed by proglacial thrusting.