Hydrologic Indicators. These soils have formed in red parent materials from the Permian geologic period. Hydrologic indicators in the soil are often faint or absent. Where visible, the primary hydrologic indicators are 5 to 35 % redox concentrations (both iron and manganese) and redox depletions within 8 inches of the surface. Secondary indicators are the presence of oxidized rhizospheres. Another commonly observed indicator is the presence of partially decomposed plant materials (roots and stems) in the soil profile that have a characteristic charcoal appearance. Other indicators are the presence of water stained leaves in depressional areas that pond water for the longest periods of time, and fluted and buttressed tree trunks. High water marks and debris lines at the four to six foot level are common on trees near larger rivers.