Abstract

Located approximately 20 km north-east of Ottawa, Caverne de la Mine contains a fossiliferous infill of significant importance. The cave which likely acted simultaneously as a roost or burrow and as a natural trap, accumulated a large amount of animal remains in the form of bones and teeth. As proven elsewhere, such deposits are very useful for the paleoecological reconstruction of a locality. The upper portion of the infill (100 cm) has been previously studied and showed a relatively recent faunal composition dated at 5000 years B.P. It is characterised by the presence of Ursus americanus, Odocoileus virginianus, Procyon lotor, Peromyscus sp. and Eptesicus fuscus. The bottom portion of the infill (70 cm) dated between 5 020±70 and 8 230±80 years B.P. is presently being studied. Based on cranial elements recovered from this portion of the infill, twenty-two mammal species were identified to this date. The fossil assemblage contains a significant abundance and variety of micromammals, while larger mammals such as U. americanus and O. virginianus are entirely absent here. The fossil fauna contains two species, Microtus pinetorum (MNI= 7) and Dicrostonyx hudsonius (MNI= 1), which are exclusive of the modern local fauna. Today M. pinetorum inhabits the eastern portion of the continent, generally east of the Mississippi valley and south of the Great Lakes, while D. hudsonius largely occupies the Ungava peninsula and parts of Labrador. Their presence in the infill suggests that the local fauna underwent important adjustments since the beginning of the Holocene before attaining its modern form about 5000 years ago.