GEOLOGIC MAP OF SERENA 7.5 MINUTE QUADRANGLE, LASALLE COUNTY ILLINOIS

The Serena 7.5 minute quadrangle is located in LaSalle County, Illinois. It occupies the area between 88°37'30" and 88°45' west longitudes, and 41°22'30" and 41°30' north latitudes. Work was supported by grants from the U.S. Geological Survey EDMAP and the Illinois State Geological Survey. Soils were classified by content and formation. Parent materials were interpreted based on these parameters and elevations. Prominent formations included Cahokia Alluvium, bedded silts and clays from lake sediment of the Equality Formation, and bedded sands and gravels from river sediment of the Henry Formation. Peoria silt was grouped and mapped as soils forming in loess greater than 1.5 meters. The Yorkville (silty clay loam) and Batestown (coarser loam) members of the Lemont Formation were grouped together as till units. Bedrock units such as shale, sandstone, and limestone from the Pennsylvian Carbondale and Ordivicain St. Peter Formations were defined by field methods. The compiled soils map was digitzed in Canvas 10.0. Once the surface map is digitized, it can be geo-rectified and brought into Global Mapper and layered with DEM, DRG, aerial photo, or other representation of the quadrangle for comparison or enhancement.