On the interpretation of discrete debris accumulations associated with glaciers with special reference to the British Isles

Abstract

AbstractA selection of glacial deposits with distinct morphological or stratigraphic forms associated with glaciers is considered with respect to climatic signals and debris inputs at the time of formation. The relationships are by no means simple and consideration is given, in general terms, to the range of conditions that might apply to a range of depositional features now found ‘relict’ in the British Isles. These factors are spatial (including continentality) and altitudinal, as well as climate and climatic variability. Examples, mainly from present-day marginally glacierized environments, are given to illustrate the complexity of these interrelationships. Features included are: plateau glaciers and their outlets, where moraines of the outlet glaciers may not be representative of the overall behaviour; plateau glaciers and remnant blockfields related to time of formation; the formation of moraines and rock glaciers; and protalus ramparts and protalus lobes as functions of ice and debris input, as well as thermal regime. It is suggested that the relative amounts of ice and rock debris are important in the formation of certain features. Understanding these relationships is an on-going process and is required for effectively mapping an interpretation of past local- and medium-scale environmental conditions.