Bison remains from a Lake Agassiz spit complex in the Swan River valley, Manitoba: depositional environment and paleoecological implications

Abstract

Fossil bison remains have been recovered from gravels on an extensive spit complex situated between the Upper and Lower Campbell levels of Lake Agassiz in Swan River valley, western Manitoba. Three bone samples yielded radiocarbon dates of 10 300 ± 200 years BP (BGS-617), 9500 ± 150 years BP (BGS-840), and 9400 ± 125 years BP (BGS-887). These are the first dates obtained outside the southern basins of Lake Agassiz for the beginning of the Campbell phase.Local geomorphological evidence and the radiocarbon dates indicate that both Campbell beaches formed within a relatively short time during the Campbell phase. Aside from their geological significance, the bison remains and their depositional context are important for interpreting early Holocene ecology and Paleo-Indian occupation of the Swan River valley.