Thermal regime controls the erosion potential of the ice. Plateau surfaces above valley-head outlets, cleared of blockfield and with striae-adorned bedrock, indicate warm-based plateau ice cover. More extensive blockfield stripping, bedrock abrasion and roche moutonnée formation indicates ice cover with a larger and more persistent warm-based component. Extensive evidence of erosion may fingerprint the provenance of ice as local (erosional elements indicating radial ice flow), or ice sheet (erosional elements are parallel/subparallel across plateaux). In the valleys erosional elements, for example trimlines, abraded bedrock, roches moutonnées, may be present.
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