The problem of recognizing melt‐out till

Abstract

Deposition of till by melt‐out was described as early as a hundred years ago, and today the criteria which provide evidence to support an interpretation of melt‐out till are available. The most important criteria are (P 1 ) the presence of unlithified, sorted and stratified sediments within or interstratified with the till(s). (P 2 ) the presence of a statistically preferred orientation of stone axes closely related to ice‐flow condition, and (P 3 ) a configuration of till with a recognizable textural or lithological property closely related to the configruation of englacial debris with regard to P 1 . Based on P 1 and P 2 and on regional aspects, tills composing ridges transverse to the dircetion of ice flow are interpreted as mult‐out till and flow till. The interpretation of till genesis must be based on the balnce of probability, as absolute proof is unrealistic in most cases.