MAGNETIC PROPERTIES OF STREAM SEDIMENT AS A POLLUTION PROXY WITHIN THE KILLBUCK WATERSHED, NORTHEASTERN OHIO

The magnetic properties of river channel mud collected within the Killbuck watershed, Northern, Ohio were studied to determine if magnetic properties could serve as a pollution proxy. Over 80 km of streams flowing through various land uses ranging from rural farmland to the urban City of Wooster, were sampled and measured for magnetic concentration, domain size, and minerology. The samples from rural settings had lower concentration of ferrimagnetic particles than samples located close to the City of Wooster or near roadways and metal manufacturing sites. The samples from the urban areas also had coarser magnetic domain sizes compared to sediments from rural sediments. Low-coercivity magnetic minerals dominates the magnetic composition. The magnetic properties of the urban samples are characteristics of particles produced by combustion processes. Environmental Scanning Electron Microscopy (ESEM) of magnetic extracts from urban samples revealed abundant iron rich spherules and iron scale. Generally the samples to the east of the city had higher magnetic concentrations than those west of the city. A possible explanation for this spatial distribution that the prevailing winds from the west disperse combustion particles to the east. This study has found that magnetic properties provide a rapid and inexpensive means of identifying increased concentrations of combustion products and may help identify potential areas where trace metals and other forms of pollution may be located.