Dolerite erratics resting on a broken rock platform of old red Sandstone at St Brides Haven in Pembrokeshire. They are washed by high tides. There is no stratigraphic context, but they were most likely transported into this location by the ice of the Irish Sea Ice Stream in the late Devensian glaciation.
The Baggy Point "giant erratic" and the pink granite erratic at Saunton. These are sealed by sandrock at the base of the local Pleistocene stratigraphic succession -- and this means they were probably in place on the rock platform before the Ipswichian interglacial. Like the St Brides erratics, these big boulders are probably washed out from ancient glacial deposits, just like the rounded "boulder bed" boulders seen at Whitesands in Pembrokeshire.
Erratic boulders resting on the rock platform at Whitesands. Here the raised beach is not visible, and the boulders are sealed in slope breccia assumed to date from the Early or Mid Devensian.
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