An example expert system for the interpretation of depositional environments

Open-File Report 85-30




During 1983 the U.S. EPA requested the U.S. Geological Survey and the Missouri Department of Natural Resources to study the geology, water movement, and sediment characteristics of Sugar, Romaine, and Rock Creek basins in Jefferson County, Missouri. The information was needed because the EPA had confirmed the presence of dioxin contamination at Bubbling Spring Horse Arena and on properties in Romaine and Rock Creek basins. Streambed sampling in the upstream reaches of Romaine Creek shows that dioxin is leaving the sites. Because dioxin strongly adsorbs onto fine sediments, it is believed to be transported with the sediments by water erosion. Sediment yields from two sampling sites along Romaine Creek generally were small during base-flow periods; however, instantaneous storm-runoff sediment discharges as large as 1.7 lbs/sec occurred at the downstream site. Typical instantaneous sediment discharges during storm-runoff sampling ranged from <0.1 to 0.5 lb/sec. More than 99% of the suspended sediment was of silt- or clay-size particles (fines); this was true for both base-flow and storm-runoff periods. Suspended sediment collected during the storm of October 20, 1983, was analyzed for dioxin. At the upstream site, the dioxin concentration was 15.3 parts per billion (ppb) in the sediment, but none was detected in the residual water layer at a detection limit of 1 ppb. No dioxin was detected at the downstream site in either the sediment or residual water layer at the 1 ppb detection limit. (Lantz-PTT)

Additional publication details

Publication type:
Publication Subtype:
USGS Numbered Series
An example expert system for the interpretation of depositional environments
Series title:
Open-File Report
Series number:
Year Published:
U.S. Geological Survey,
i, 15 p. :ill. ;28 cm.