Environmental changes during the Upper Pleistocene–Holocene in Mediterranean NE Spain as recorded by the mineralogy and geochemistry of alluvial records

Abstract Landscape evolution and environmental conditions from Last Glacial Maximum (LGM) to Late Holocene times were reconstructed from the mineralogical and geochemical characteristics of the alluvial morphochronostratigraphy, recorded in Bardenas Reales Natural Park (Ebro Basin, NE Spain). Alluvial architecture includes a LGM-Holocene gravelly unit (≈22–9 ka BP), a Lower Holocene silty–muddy unit (≈9–7 ka BP), and an Upper Holocene sandy unit (≈5–0.1 ka BP). Increases in illite–smectite mixed layers, kaolinite, chlorite and modified Chemical Index of Alteration (CIA*), as well as the decrease in illite FWHM(E), are indicators of minor increases in the chemical weathering of the alluvial …