The Observatory Gravels and the Travellers' Rest Pit, Cambridge, England

An examination of the past descriptions of the Pleistocene Observatory Gravels and the sediments of the Travellers' Rest Pit ofNWCambridge has illustrated their relation to the local landscape in terms of sedimentation and age. The Travellers' Rest Pit sediments, which include gravels and 'loams', represent aggradation and alluviation/colluviation in a former drainage way which resulted from diversion to the west of the Cam valley drainage by glaciation in the Fenland in the Late Wolstonian Substage. The drainageway may have carried both Cam valley catchment waters and proglacial waters. The Travellers' Rest Pit gravels and 'loams' now lie on a ridge of Gault and Chalk Marl. The Observatory Gravels occur on the western slope of this ridge, at a lower level than the sediments of the Travellers' Rest Pit, and are associated with the incision of the Washpit Brook valley, on Gault Formation bedrock to the west of the Observatory slope, at a later date. The periglacial ground-ice structures and palaeontology of the Travellers' Rest Pit sediments are described. The Palaeolithic archaeology contained within the sequence, bears comparison with Palaeolithic finds elsewhere in Late Wolstonian proglacial gravels of the Fenland margins.