Fluvial Geomorphology

Gregory Vandeberg

University of North Dakota

The Distribution of Metals in the Floodplain Soils of the Upper Blackfoot River , Montana

Gregory S. Vandeberg, Department of Geography, University of North Dakota, Grand Forks, ND 58202, Charles W. Martin, Department of Geography, and Gary M. Pierzynski, Department of Agronomy, Kansas State University, Manhattan, KS66506. Modeling of Heavy Metal Distribution in an Intermontane Gravel Bed Stream (Presented at Association of American Geographers, April 2005).

Metal mining and ore processing have impacted river systems in much of the world. Many of these activities have occurred in alpine settings with gravel and cobble bed river systems such as the upper Blackfoot River in western Montana. This paper investigates the distribution of metals in floodplain sediments in relation to distance from the source areas, geomorphic setting, textural classification and soil organic matter. Soil samples were collected along 20 transects in the upper 105 river km of the Blackfoot River, Montana. Samples were analyzed for total As, Cd, Cu, Mn, Pb and Zn using inductively coupled plasma spectroscopy. Samples were also analyzed for pH, soil organic matter and particle size distribution. Soil As levels dropped to median background values 14 km from the Blackfoot headwaters, followed by Cd and Pb (20 km), Mn and Zn (36 km) and Cu (67 km). Nonlinear regression equations and geostatistics were used to model the distribution of the metals. River kilometers (distance from mine areas) and stream power were found to be the best independent predictors of soil metal levels.

Temporal and Spatial Relations of Late Quaternary Valley and Piedmont Glaciers in Tom Miner Basin, Montana (see Glacial Geomorphology ).
As part of my masters thesis research, the relations of moriane elevations and outwash terrace gravels were used to determine the stratigraphic relationships between local Late Quaternary alpine glaciers and the northern Yellowstone outlet glacier. An outwash terrace (t3 in figure) extending from local glacial deposits in Horse Creek cuts deposits of the northern Yellowstone outlet glacier. This suggests that the northern Yellowstone outlet glacier had receded from the basin while local ice remained near maximum.

Last revised February 2007
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