Mid- and late-Holocene vegetation history and tephra studies at Fenton Cottage, Lancashire, U.K.

The Over Wyre region of Lancashire, England, was formerly dominated by a complex of ombrotrophic intermediate raised mires, most of which have been severely damaged by agricultural activity during the last 250 years. The degree of truncation and desiccation of the remaining peats means that opportunities for studying environmental history in this part of lowland England are extremely rare. An exception occurs at Fenton Cottage where a relict, non-truncated portion of original mire survives and forms an environmental archive spanning the second half of the Holocene. The palaeoecological record shows that there has been a continual human influence on the development of the landscape since the mire began growing, with a particularly significant deforestation episode commencing in the late Iron Age. A major expansion of the mire system commenced in the late Bronze Age/early Iron Age and may have led to the abandonment of settlement in and around the peatlands during much of the Iron Age. The investigation also yielded the first tephra to be discovered in English peats. This took the form of a discrete layer of microscopic tephra, geochemically assigned to the Icelandic Hekla-4 eruption of ca. 2300 cal. B.C.. This was recorded inScheuchzeria palustris-dominated peat which formed during a period of freshwater flooding. The find represents the most southerly geographical location in the British Isles where Hekla-4 tephra has been detected to date. The study demonstrates the palaeoecological value of threatened relict lowland peat archives in agricultural landscapes and highlights the potential of tephrochronology as a tool for studying environmental changes and wetland archaeology in southern Britain.