John Rodgers compiled the 1:125,000 scale, Bedrock Geological Map of Connecticut, published in 1985 on behalf of the Connecticut Geological and Natural History Survey of the Connecticut Department of Environmental Protection, in Cooperation with the U.S. Geological Survey. Published and unpublished 1:24,000 scale quadrangle bedrock mapping was used as source materials for the statewide compilation.

These source materials have been archived by the Connecticut Geological Survey and are made available here. The collection includes 116 paper quadrangles with mylar overlays constituting the master file set for geologic lines and unit designations compiled to the statewide map. Some quadrangles have multiple sheets depicting iterations of mapping. The authors for quadrangle scale source materials are listed on sheet 2 of the published state map.

This master file set of paper source materials illustrates the geologic lines and units selected for the statewide compilation and includes compiler notes in the margins regarding formation designations and structures. The mylar overlays contain the actual linework and labels that were included on the final version of the published statewide map. Consequently, paper and mylar map sets together chronicle the process of the statewide compilation.