Archival Blackline Bedrock Geologic Contacts Drawn on 1:24,000 Scale Topographic Map of Mount Tom Quadrangle. Map contains geologic contacts drawn in black felt-tip pen on a 1:24,000 scale topographic map of the Mount Tom quadrangle by Peter Robinson and students from the 1960's through the 1970's for compilation of the 1983, 1:250,000-scake statewide bedrock geologic map of Massachusetts.