Askham Bog

Askham Bog formed in the Vale of York in a hollow which was flooded by meltwater from the last glacial retreat about 15,000 years ago. The bog's lowest layer is made up of sealed boulder clay, sand, and gravel. Above this is a distinct layer of organic deposits, which collectively reflect a series of biological and geological periods. The basal clay layer is covered by additional lake clay and nutrient-rich nekron mud, which is supplied by the surrounding moraines. Further up, there are layers of fen peat and sphagnum peat. The latter contains traces of Scorpidium and Eriophorum. The Nekron peat layer reflects a permanent shift to a relatively warm post-glacial climate. Formed during this…