THE GEOLOGY AND NATURAL HISTORY OF COPPOCK PARK (MARSHALL CO., IOWA) AND IT’S ADJACENT LANDSCAPES

This research investigates a small area on the Southern Iowa Drift Plain; a landform region which is the product of erosional forces on Iowa’s Pre-Illinoian glacial plains and underlying sedimentary deposits. The resulting surface contains a deeply grooved rolling landscape. Coppock Park is a Marshall County Park along with its adjacent wooded landscapes; the area has approximately 50 acres of nearly unaltered land just six miles southeast of Marshalltown, Iowa. The adjacent property (just to the west of the park) contains various landforms, such as a valley and stream (Timber Creek), as well as some previously unmapped, Mississippian(?), bedrock exposures. The outcrops are accessible in a floodplain and are characterized as Oolitic Grainstones. Soil and parent material samples were collected from the area’s landform sediment assemblages formed over the Quaternary. Sample locations were marked using GIS software (ArcPad 10.2) and hardware (Trimble GeoXH). The majority of the soil samples were loess deposits of the Fayette Series which overlies eroded glacial till. X-Ray Fluorescence analysis of the soil reports that the average chemical composition is closely related to the composition of Peoria Loess, a form of loess common in the area. This project explored the geology of a previously undocumented area, as well as compliments previous research done on the Southern Iowa Drift Plain.