The latest inland ice-retreat was temporarily halted because of a last, cold, thousand-year long period (the Younger Dryas stage, 12,500–11,500 years ago), and the margin of the enormous mass of ice remained in more or less the same position. During this cold period, the Younger Dryas ice marginal zone was formed. This Quaternary geological formation can be followed throughout Fennoscandinavia, and represents the passage to a warmer climate and, thus, the end of the ice-age. 

""Photo: Jesper Linder.