Maesyprior
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Geology & landscape
Geological Period: Quaternary
Landscape processes: Glacial
Description
Description At Maesyprior a system of well-developed glacial meltwater channels provides important evidence concerning the nature of late Pleistocene geomorphological processes in central South Wales. The channels have been used to reconstruct the pattern of glacial drainage during ice-sheet wastage. The oldest channels, which begin and end abruptly, may have been superimposed across spurs by englacial streams. Other channels with marked up-and-down profiles are thought to have been cut later by subglacial streams flowing under hydrostatic pressure. With progressive ice thinning, channel locations became more controlled by the underlying relief and eventually the meltwater cut channels along the existing valley floor and sides. The meltwater channels have features that cannot be reconciled with either an ice marginal origin or lake overflows, but provide an important demonstration of subglacial meltwater flow patterns.