Quaternary Geology of the Indiana Portions of the Chicago and the Northern Half of the Kankakee 30- x 60-minute Quadrangles

The map of the Quaternary Geology of the Indiana portions of the Chicago 30- x 60-minute quadrangle and the northern half of the Kankakee 30- x 60-minute quadrangle displays unconsolidated Pleistocene glacial sediments deposited by the Lake Michigan Lobe of the Laurentide Ice Sheet and Holocene post-glacial sediments deposited by coastal, eolian, and fluvial processes in northwestern Indiana. Unconsolidated deposits were characterized through field observations; new and archived borehole data; lithologic information from the Indiana Department of Natural Resources water well database; and soils data from the U.S. Department of Agriculture, Natural Resource Conservation Service, Soil Survey Geographic (SSURGO) database. A light detection and ranging (LiDAR)-based digital elevation model was used in combination with geologic data to identify landforms and infer contacts between unconsolidated units. Glacial and proglacial deposits include diamicton, glaciofluvial, glaciolacustrine, and eolian sediments of Wisconsin Age which directly overlie Devonian and Silurian bedrock. Summary descriptions of mapped units are listed on the map sheet with detailed descriptions in the accompanying pamphlet. In addition to the map and pamphlet, a composite spatial data set that conforms to the standardized database schema known as GeMS (Geologic Map Schema) is also available for download. Metadata records associated with each element within the spatial data set contain detailed descriptions of their purpose, constituent entities, and attributes. This geologic map was funded in part through the U.S. Geological Survey Great Lakes Geologic Mapping Coalition program under Cooperative Agreement No. G21AC10762.