Cliff-Top Eolian Sedimentation Reflecting Mid- to Late-Holocene Environmental Changes at Anticosti Island, Gulf of St. Lawrence, Eastern Canada

The study site (Cape Sandtop) consists of a 15 m high marine terrace exposed to strong easterly winds, at the eastern end of Anticosti Island in the Gulf of St. Lawrence (Quebec, Canada), where eolian sedimentation occurred. Sections at the terrace edge exposed thick, well-humified, buried organic deposits with many wood fragments. Sedimentological and plant-macrofossil analyses were conducted from four sections to provide a chronology of eolian activity and to evaluate the causal factors for the development of treeless plant communities. Plant remains indicate that Cape Sandtop was forested between 6520 and ca. 4740 cal YBP. After ca. 4740 cal YBP, the terrace experienced a rapid change from coastal conifer forests and treed fen to marshes. Sustained erosional activity by easterly winds along the upper limestone cliff' and the terrace edge started 1560 cal YBP and caused peat burial. The key factors responsible for cliff-top eolian sedimentation were relative sea level changes, increased exposure to easterly winds associated with higher elevation (15 m asl) of the marine terrace and sediment availability. In spite of its limited extent, this coastal site appeared as a system that was sensitive to environmental changes during the Mid- to Late-Holocene.