Spodosols from Croatan Island, North Carolina, USA
This picture shows soil cores of Spodosols (a USDA Soil Taxonomy soil order) near the location where the official soil description of the Leon series (sandy, siliceous, thermic Aeric Alaquod) was described on Croatan Island on the coast of North Carolina.
Spodosols form in sandy soils in pine forests where humic acids from decomposing pine straw strip iron and aluminum from the A and E horizons leaving a “bleached” E horizon. These Fe and Al laden humic acids then accumulate in Bh (histic) and/or Bs (spodic) horizons creating a brown to red-colored horizon directly underlying the E horizon.
The picture was taken during the North Carolina State University Soil Geomorphology Tour in May 2012. You can see more pictures and read about the tour at ColbyDigsSoil.com: North Carolina Soil Geomorphology Tour.