Magnetic Susceptibility Survey of Baton Rouge, Louisiana: 

Implications for Potential Heavy Metal Soil Contamination

Hannah Vedrines¹, Carl Richter¹, and William H. Schramm²

¹Department of Geology, University of Louisiana at Lafayette, P.O. Box 44530, Lafayette, Louisiana  70504

²Louisiana Department of Environmental Quality, P.O. Box 4314, Baton Rouge, Louisiana  70821

ABSTRACT

Magnetic susceptibility is useful for mapping anthropogenic heavy metal pollution in soil based on the idea that topsoil has more magnetic content than subsoil samples due to the settling of anthropogenic magnetic particles.  Magnetic susceptibility is also influenced from natural lithological heavy metal content as well as soil type, so it is crucial to distinguish the anthropogenically enhanced susceptibility from the natural susceptibility.  In this large-scale study, we sampled an area of 110 mi² (290 km²) in Baton Rouge, Louisiana, in small 1 mi² (2.6 km²) subsets, and attempted to cover a wide variety of areas from rural city outskirts to the more industrialized inner city.  Top- and sub-soil samples were collected in each square mile, field susceptibility measurements were obtained, and some areas were cored as well.  Laboratory measurements of magnetic susceptibility of the soil samples are currently being conducted, and statistical analyses of these data will follow.  Ultimately, we expect to be able to filter the anthropogenic signal from the natural signal, and use this to outline the soil contamination.

Vedrines, H., C. Richter, and W. H. Schramm, 2009, Magnetic susceptibility survey of Baton Rouge, Louisiana:  Implications for potential heavy metal soil contamination:  Gulf Coast Association of Geological Societies Transactions, v. 59,      p. 769-776.

AAPG Search and Discover Article #90093 © 2009 GCAGS 59th Annual Meeting, Shreveport, Louisiana