Digital representation of a map showing the thickness and character of Quaternary sediments in the glaciated United States east of the Rocky Mountains [electronic resource] / U.S. Department of the Interior, U.S. Geological Survey ; by David R. Sollar and Patricia H. Packard.
Imprint
[Reston, VA] : The Survey ; [Denver, CO : For sale by the Survey], 1998.
Contains vector-based digital geologic maps of surficial deposits in parts of 23 states where continental glaciation occurred during Quaternary. Map compilation was based on about 850 sources.