Citation for published item:ivnsD hFtFeF nd oungD xFtFF nd ¡ y gofighD gF @PHIRA 9qlil geomorphology of terrestrilEterminting fst )ow loesGie strem mrgins in the southwest vurentide se heetF9D qeomorphologyFD PHR F ppF VTEIIQF Further information on publisher's website: httpXGGdxFdoiForgGIHFIHITGjFgeomorphFPHIQFHUFHQI Publisher's copyright statement: NOTICE: this is the author's version of a work that was accepted for publication in Geomorphology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reected in this document. Changes may have been made to this work since it was submitted for publication. A denitive version was subsequently published in Geomorphology, 204, 1 January 2014, 10.1016/j.geomorph.2013.07.031. Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. MTR Type 2 sequences are recessional push moraines similar to those developing at modern active temperate glacier snouts. MTR Type 3 ridges document moraine construction by incremental stagnation, because they occur in association with hummocky terrain. The close association of hummocky terrain with push moraine assemblages, indicates that they are the products of supraglacial controlled deposition on a polythermal ice sheet margin, where the Type 3 hummocks represent former ice-walled lake plains. The ice sheet marginal thermal regime switches indicated by the spatially variable landform assemblages in southern Alberta are consistent with palaeoglaciological reconstructions proposed for other ice stream lobate margins of the southern Laurentide Ice Sheet, where alternate cold, polythermal and temperate marginal conditions sequentially gave way to more dynamic and surging activity.