This section is from the book "British Wild Flowers - In Their Natural Haunts Vol5-6", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
As a whole peat deposits are not older than the Glacial epoch, and a great proportion of them belong to the Recent or present period coeval with the formation of the alluvium of our modern rivers. Hut the upland peat formed upon the highlands of England and Scotland, as shown by F. J. Lewis, may be said to be older, or of Glacial age. Thus in Kirkcudbrightshire and Ayrshire the succession is as follows: Recent peat, chiefly with Scirpus and Sphagnum, an Upper Turbarian or Sixth Glacial stage, an Upper Forestian bed with Pinus sylvestris, then Sphagnum, then Eriophorum, Lower Turbarian or Fifth Glacial stage, Arctic Willow and Empetrum, then Eriophorum, followed by Sphagnum, a Lower Forestian bed with White Birch, and below Willow and Ling, the Meck-lenburgian or Fourth Glacial stage with coarse sand and morainic material.
Thus forest beds alternate with peat beds. This is similar to the sequence of Pine, Oak, and Spruce in Sweden. The plants of the peat beds are arctic plants, and have travelled southward with the ice.