The influence of climate on the tectonic evolution of mountain belts

Abstract

Simple physical arguments, analogue experiments and numerical experiments all suggest that the internal dynamics of actively deforming collisional mountain ranges are influenced by climate. However, obtaining definitive field evidence of a significant impact of climate on mountain building has proved challenging. Spatial correlations between intense precipitation or glaciation and zones of rapid rock-uplift have indeed been documented in numerous mountain ranges, and are consistent with model predictions. More compelling evidence — such as tectonic changes in response to (rather than just coincident with) climate change — has, however, rarely been documented. Triggered by a climate-driven increase in erosion rate, friction-dominated mountain ranges are expected to show a number of simultaneous responses: a decrease in the width of the range, a temporary increase in sediment yield, a persistent increase in the rate of rock uplift and a reduction in the subsidence rate of surrounding basins. The most convincing field evidence for such a coordinated response of a mountain range to climate change comes from the European Alps and the St Elias range of Alaska. Field studies and experimental research during the past two decades have provided considerable evidence for a significant influence of climate on tectonics. Recent advances suggest that model predictions can guide future fieldwork aimed at substantiating this view.