 Many coastal mosses were initiated by the process of glaciation, which sheared rock formations to a generally level terrain, while also gouging moderate sized craters that would pond.This description fits the fundamental situation of Portlethen Moss, where sphagnum would have flourished over millennia of evaporation, further intensifying the soil acidity, fueled by organic matter decaying, with little drainage outlet.A layer of sphagnum moss would have developed at the benthic level of the bog, and additional sphagnum layers floated in mats atop the bog.