Monument record 15392 - Englesea Basin Mire

<1> Leah, MD; Wells, CE; Appleby, C; Huckerby, E, 1997, The Wetlands of Cheshire (North West Wetlands Survey 4), p.125, 188-9 (Monograph). SCH3260.

Englesea basin mire was investigated by the North West Wetlands project, an archaeological and paleoecological study of the varied wetlands of Cheshire, undertaken between 1993-95. It lies within a series of wetlands lying between Crewe and the Shropshire border, with a further outlying group to the north-east, between Crewe and Alsager. Within this area, a variety of wetland types is represented from numerous small basin mires, often less than 1 hectare in extent, to the valley mire deposits found alongside some of the minor rivers and streams. Larger mosses (circa 10-20 hectares) such as White Moss, Oakhanger Moss and Wybunbury Moss, also occur. The underlying geology is masked by drift deposits made up of both till and fluvio-glacial sands and gravels. In places these deposits have resulted in the flat landscape characteristic of the Cheshire Plain, but in some areas, particularly to the south of Crewe, a much more varied and irregular topography occurs. Many wetlands developed in kettle holes left in the surface of these glacial deposits, although the role of subsidence of salt solution hollows also played a part in some cases, such as Wybunbury.

Englesea is a deep basin mire of circa 5 hectares situated in the south-eastern part of the Englesea Valley. It comprises over 7m of organic deposits lying under a wet, wooded fen carr. The deposit stratigraphy consists of a long sequence of wood peats interrupted at irregular intervals by Sphagnum or Phragmites/sedge peats and intercalated with several silty clay bands. These suggest that it may represent a salt solution hollow which has undergone periodic flooding as a result of slumping. Eight peat samples were examined, these show that despite the depth of the deposit, it only began developing at the Flandrian I/II transition. The limited pollen investigation shows clear evidence of anthropogenic clearance in the prehistoric period associated with a silt clay band. Charcoal and cultural indicator species (ie: herbs, cereal-type and Cannabis-type pollen) were present and from this it seems likely that at least some of the silt clay bands are the result of inwash from clearance which affected the immediate catchment area. In addition, a Sphagnum band recorded at circa 5m was associated with macropscopic charcoal, perhaps indicating that some of the more open environments represented in the stratigraphic record may have owed their presence to causes other than solution slump-induced flooding. Further study at this site is likely to provide a record of vegetation change and human impact spanning the later mesolithic onwards, although the higher level peats are likely truncated.