CHARACTERIZATION OF WETLAND SOIL AND SEDIMENTS AT STARLING NATURE SANCTUARY, MARION COUNTY, INDIANA

The Scott Starling Nature Sanctuary is situated on the floodplain of Fishback Creek in Marion County, Indiana. The area has been primarily used for agriculture during most of the 19th century, and is now undergoing restoration. The central portion of the sanctuary shows evidence for containing a natural wetland prior to agricultural use, and shows characteristics of being a wetland today. Characterization of the soil and sediments underlying the sanctuary may be useful for determining whether wetland conditions were present before modification for agricultural use and, if so, what type of wetlands existed. Characterization is also essential for determining the current hydrological conditions and for effective restoration to pre-agricultural conditions.

The Fishback Creek valley is incised through Wisconsinan-aged glacial deposits and into Illinoian-aged glacial deposits, both of which are primarily till. The floodplain deposits lie on the eroded Illinoian till and consist of a gravel lag layer overlain by sandy alluvium with a cap of silt and clay from overbank flood deposits and colluvial slopewash. The upper 40 cm of the deposits show evidence of 19th century agricultural use.

Soil characterization was accomplished by examination and description of soil cores. Correlation was accomplished by using multiple transects of soil cores. Aerial photography was used to plan locations of wells and cores, determine locations of agricultural tiles, and determine the current drainage pattern. Soil and sediment cores were used to characterize the stratigraphic and hydrogeologic setting of the sanctuary. Monitoring wells were installed to determine the hydrologic regime and groundwater quality of the sanctuary. Data regarding the location of groundwater seeps, monitoring wells, and agricultural tiles as well as the boundaries of vegetation types and standing water at various hydroperiods were collected using survey-grade GPS for later input and analysis in a GIS