Mid-Holocene environmental change within the southern Shap Fells, eastern Lake District, England

Radio-carbon dating of southern Shap Fells post-glacial deposits constrains periods of mid-Holocene subepoch hillslope erosion and the development of blanket peat. An organic-flecked blue solifluction clay was deposited between 5327 and 5272 cal BP, at the end of a cool climatic interval. Organic-rich silt sapropel was preserved within rock hollows at altitudes between 456 and 462 m asl from 5762 to 5651 cal BP, with blanket peat on level terrain at similar altitudes developing around 3350 to 3165 cal BP, i.e . within the Bronze Age. Despite a warmer and wetter climate at this time, at lower altitudes peat development was inhibited on steep unstable slopes. Instead, slope-washed grey silt was deposited on the blue clay initially between 2435 and 2309 cal BP, after which slope instability led to inter-bedding of silt and peat. Variable dates for peat initiation likely reflect local differences in nutrient and slope stability status, rather than climatic controls alone. Pollen records show a decline in woody heath as herbaceous grassland developed. Charcoal may indicate burning of shrub and tree cover during the Bronze Age to extend open high-level pasture for graziers. Partial woodland recovery was localized and may relate to a contraction in regional agricultural activity during the Iron Age.