Lateral shear-moraines and lateral marginal-moraines of palaeo-ice streams ...

• Main Authors: Batchelor, CL, Dowdeswell, JA
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier BV 2016
• Subjects: Palaeo-ice streams; Ice-stream lateral moraines; Cross-shelf troughs; Ice-sheet reconstruction; Ice Sheet
• Online Access: https://dx.doi.org/10.17863/cam.5862; https://www.repository.cam.ac.uk/handle/1810/260709

An understanding of the nature of sedimentation at ice-stream lateral margins is important in reconstructing the dynamics of former ice sheets and modelling the mechanisms by which sediment is transported beneath contemporary ice streams. Theories of the formation of ice-stream lateral moraines (ISLMs) have hitherto been based on a relatively limited number of terrestrial and marine examples. Here, an inventory of ISLMs is compiled from available studies, together with independent analysis of seismic-reflection and bathymetric datasets. The locations and dimensions of 70 ISLMs, alongside a synthesis of their key architectural and geomorphic characteristics, are presented. Two different types of ISLMs are identified. Type 1 ISLMs are up to 3.5 km wide and 60 m thick. They maintain a constant width, thickness and cross-sectional shape along their length. Type 1 ISLMs are interpreted and referred to as ice-stream $\textit{lateral shear-moraines}$ that form subglacially in the shear zone between ice streams and ...