These soils are adjacent to and higher lying than the Navan soils. Aztalan soils have mollic epipedons and Mosel soils do not have mollic epipedons. Colwood soils formed in stratified silt and sand while Poy soils have finer textured horizons in the upper part of the solum. Poy and Colwood soils occupy a similar setting as the Navan soils. Surface runoff is slow or ponded.
Permeability is slow or moderately slow.
In some places these soils are subject to common flooding. Most of the more extensive areas have been drained and are in cropland. Other areas have been retained primarily in pasture. The soil formed under a mixed swamp hardwood and grass vegetation. The Navan soils are of moderate extent.