Influence of rock avalanches upon the formation of moraines and their subsequent palaeoclimatic interpretation: a critical appraisal

Abstract

We provide a critical appraisal of the impact of rock avalanches on the formation of moraines, and implications for their subsequent palaeoclimatic interpretation. First we present a conceptual model of how rock avalanche deposits could inflfl uence moraine formation by mountain glaciers during the Holocene, followed by a brief literature review on empirical studies that may reveal evidence of this influence. We summarise results from our own work addressing the possible inflfl uence of rock avalanches on glaciers in the Southern Alps of New Zealand. From analysis of available techniques for definite indication of which moraines are suitable for paleoclimatic interpretation, we suggest that future approaches must include microsedimentological studies. This is the basis for futures strategies to resolve the potential uncertainties in palaeoclimatic interpretations of moraines in tectonically active mountain ranges.