Paper No. 41
Presentation Time: 9:00 AM-6:00 PM
FE RATIOS IN SOILS FROM A PIEDMONT TERRACE CHRONOSEQUENCE, CATAWBA RIVER, NORTH CAROLINA
Soil chronosequence data can provide important contaminant transport, erosion, hydrologic, ecologic and geochronologic information to environmental and geologic studies. The Catawba River has been listed as one of the most endangered rivers in the United States according to the Environmental News Service (2008). Little is known, however, about soil development-age relationships for Piedmont landscapes of the eastern United States. The ratio between amorphous and crystalline iron oxide have been shown to have a strong correlation with age in other environments. This study intends to establish a soil-age relationship of iron in soil samples taken from five terraces along the Catawba River near Charlotte, North Carolina. Terrace ages have been assigned based on empirical correlations of terrace height above the modern channel for numerous channels on the eastern seaboard (Mills, 2000): Qt1: 42m – 1470 ± 180 ka; Qt2: 28m – 610 ±75 ka; Qt3: 14m – 128 ±16 ka;Qt4: 10m – 50 ±6 ka; Qt5: 3m – 4 ± 0.5 ka.
Three pits were dug and described on each terrace (Aquino et al., 2012). Three samples per horizon were collected from each pit in order to assess the chemical variability within each horizon for a total of 217 samples. Samples were prepared for Fe using the dithionate-citrate-bicarbonate and oxalic acid extraction methods of Mehra and Jackson (1960) and McKeague and Day (1966), respectively. Extracted samples were then analyzed on a Perkin-Elmer AAnalyst 200 Spectometer with the flame technique. Preliminary results (Layzell et al., 2012) indicate that Fe ratios show strong soil-time trends for terraces of the Catawba River.