A granulometry and secondary mineral fingerprint of chemical weathering in periglacial landscapes and its application to blockfield origins

► Low clay/silt ratios indicate periglacial chemical weathering. ► Secondary mineral assemblages consistent with generally minor chemical weathering. ► Temperature and parent lithology exert primary control on clay and silt abundances. ► Secondary minerals controlled by climate, regolith residence time, and hydrology. ► Quaternary blockfield formation, rather than Neogene initiation, is indicated.