Secrets from the Lady of the Lake: an 11,000 year history of episodic talus erosion and resedimentation in the Brecon Beacons

QRA 2020 ADM: Quaternary Earth System processes and feedbacks: challenges for society

Episodic erosion and resedimentation of talus is evident in the form of buried in situ organic-rich horizons intercalated with stacked sediment units. Radiocarbon dating of 35 samples recovered from debris cones and lake cores suggests that gully erosion and redeposition of talus represents asynchronous debris flow and slopewash activity within the past 8-9 cal kyr, though a marked increase in magnitude and frequency of erosional events is interpreted to have occurred at ~4.4-4.0 cal kyr BP. There is some support for possible clustering of events at ~4.8-4.2, ~2.2-1.8 and at ~0.7-0.3 cal kyr BP.