No stone left unturned : fluvial processes in the Pleistocene of northern Europe

• Main Author: Chu, Wei
• Published: University of Reading 2013
• Subjects: 936.401
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610970

This thesis explores the effects of fluvial processes on Pleistocene lithic artifacts and assemblages in northern Europe. Lithic artifacts are commonly found within fluvial sediments indicating that they have been subject to moving flow. Their incorporation into the bedload may result in changes to morphology and spatial context, thereby obscuring site interpretations. This has been well documented among numerous sites worldwide. This study reports on three experiments aimed at understanding the effects of fluvial processes on lithic artifacts. In the fluvial-field experiment, 456 painted and measured replica lithic artifacts were placed in nine different "scatters" along the River Glenderamackin (UK), where river flow and animal activity were monitored for 18 months. Artifacts were visited at four different times and each time their locations, orientations, and physical conditions were recorded. The results showed that artifact movement depends on lithic morphology and discard location (in the river channel or on the banks), with vegetation and burial playing critical roles in inhibiting transport. Artifact transport also resulted in characteristic edge micro-flaking. In the tumbling barrel experiment, 188 replica lithic artifacts were subjected to an environment simulating the effects of coarse-grained fluvial abrasion. The results showed that artifact lithic abrasion is affected by the amount, size, and lithology of the abrasive sediment as well as the artifact's lithology and shape. The last experiment reports on aspects of fme-grained fluvial abrasion. In this study, 27 artifacts were marked with nine microscopic observation areas and abraded in an annular flume with three different sediment sizes for up to 168 hours. When analyzed with a scanning electron microscope, the results showed that time, and sediment size and the artifact's entrainment mode have varying effects on artifact edge micro-flaking, surface texture, and ridge widths. The implications of these experiments are discussed along with previous experiments and applied to the sites of Happisburgh I (UK), Happisburgh 3 (UK), Pakefield (UK), and Caours (PR), questioning the formation of these sites and indicating that they were subject to post-depositional processes.