New Perspectives on Autochthonous Blockfield Development

The development of coarse blocky mantles in cold regions has played a central role in both the original definition of the periglacial facies by Lozinski and the establishment of a perception on the widespread efficacy of frost weathering among peri glacial geomorphologists. This paper challenges these notions as simplistic “geomyths” that limit the understanding of blocky weathering and blockfield development, whether in cold or warm regions. Mechanisms of block production increasingly appear to be the result of azonal weathering processes such as chemical weathering and thermal stress fatigue, with bedrock fractures a prequisite rather than an outcome of frost action. Observations from outside cold regions and the long-term landscape development associated with many blockfields further lead to broaden perspectives beyond simplistic frost action. Instead blockfields appear to be the result of complex process interactions and climatic histories that defy straightforward palaeoclimatic interpretations.