Digital representation of a map showing the thickness and character of Quaternary sediments in the glaciated United States east of the Rocky Mountains

This CD-ROM contains vector-based digital geologic maps of the surficial deposits in parts of 23 states where continental glaciation occurred during the Quaternary. These maps, at 1:1,000,000-scale, include the texture of the surface sediments and the total thickness of Quaternary sediments. Map compilation was based on about 850 sources of information. These maps are also published in paper form, as U.S. Geological Survey Miscellaneous investigations Series Map I-1970-A, B, C, and D.