Underlying all archaeological investigations in riverine environments, there needs to be as full an understanding as possible of the history of the fluvial system in question because fluvial history influences taphonomy and archaeology. Detailed investigation of five sites on the Holocene floodplain of the Exe River, southwest England, has extended our knowledge of channel change and fluvial sedimentation in this area. New dating from optically stimulated luminescence (OSL) has been combined with previous radiocarbon dates from the Upper and Lower Exe, and the resulting chronology is in approximate agreement with the phases of fluvial change described from southern Britain that appear to relate to Holocene climate shifts. Over the mid–late Holocene, avulsion and reoccupation of former channels have occurred, while in historic time, channel systems have been relatively stable, with some oscillation around channel bars or islands. The recognition of this change in channel behavior in the very late Holocene at a classic site has solved what had been a “floodplain paradox”—a contradiction between the rates of historical channel lateral migration and archaeology found on, and in, UK floodplains. The reoccupation of former channels allows lateral deposits to be stacked and is part of floodplain aggradation by overbank and bed sedimentation. This has significant implications for the preservation of archaeological material, including artifacts. Mesolithic artifacts have been found on the valley floors within the Exe catchment; their preservation has, to a large extent, been controlled by the style of Late Glacial and Holocene floodplain development.

Abstract Deposits of proximal dust-derived alluvium (alluvial loess) within the catchments of the now semi-arid Flinders Ranges in South Australia record regionally synchronous intervals of fluvial entrainment, aggradation and down-cutting spanning the last glacial cycle. Today, these floodplain remnants are deeply entrenched and laterally eroded by ephemeral traction load streams. The north–south aligned ranges are strategically situated within the present-day transitional zone, receiving both topographically enhanced winter rainfall from the SW and convectional downpours from summer monsoonal incursions from the north. We develop a regional chronostratigraphy of depositional and erosional events emphasizing the Last Glacial Maximum (LGM). Based on 124 ages (94 accelerator mass spectrometry radiocarbon and 30 optically stimulated luminescence) from the most significant terrace remnants on both sides of the Ranges, we conclude that the last glacial cycle including the LGM was characterized by major environmental changes. Two pronounced periods of pedogenesis between c . 36 and 30 ka were followed by widespread erosion and reworking. A short-lived interval of climatic stability before c . 24 ka was followed by conditions in which large amounts of proximal dust (loess) were deposited across the catchments. These loess mantles were rapidly redistributed and episodically transported downstream by floods. The termination of this regime c . 18–16 ka was marked by rapid incision.