16. fine-silty, mixed, superactive, mesic Oxyaquic Argixeroll
(Southwick series)

This soil belongs to the Southwick series and has developed in loess under ponderosa pine forest. The relatively open canopy and dense understory associated with ponderosa pine forest in this area are responsible for development of a mollic epipedon.

The A-Bw horizon sequence has formed mostly in Holocene loess while the Btb horizon represents the upper part of a late-Wisconsinan paleosol. The Btb horizon is hydraulically restrictive with a saturated hydraulic conductivity of ~0.1 cm/day. Water is perched above this horizon for a period extending from late November through May.

(scale is in decimeters)