LOCATION PANAMAKER WAEstablished Series
TAXONOMIC CLASS: Mixed, mesic Typic Xeropsamments
TYPICAL PEDON: Panamaker gravelly sand on a l percent slope at an elevation of 580 feet. Colors are for moist soil unless otherwise stated.
C1--0 to 3 inches; dark gray (l0YR 4/l) gravelly sand, light gray (l0YR 6/l) dry; single grain; loose, nonsticky and nonplastic; 20 percent pebbles; neutral (pH 7.0); clear wavy boundary.
C2--3 to 60 inches; dark gray (l0YR 4/l) sand, light gray (l0YR 6/l) dry; single grain; loose, nonsticky and nonplastic; 5 percent pebbles; neutral (pH 6.8).
TYPE LOCATION: Cowlitz County, Washington, about 3 miles east of Toutle, 350 feet east of southwest corner of section 27, T. l0N., R.1 E.
RANGE IN CHARACTERISTICS: These soils are usually moist but are dry for 45 to 60 consecutive days following summer solstice. The particle-size control section averages l5 to 30 percent volcanic glass and glass aggregates and 0 to l5 percent rock fragments. These soils are very strongly acid to neutral throughout.
The C horizon has hue of l0YR or 2.5Y, values of 2 to 4 moist, 5 to 7 dry and chroma of 1 or 2 moist or dry. Textures are stratified and range from fine sand to coarse sand with 0 to 20 percent rock fragments.
COMPETING SERIES: These are the Bisbee, Dart, Ewall, Preston, and Santaquim series. All of these soils average less than l5 percent volcanic glass in the particle-size control section. In addition these soils are dry more than 60 consecutive days.
GEOGRAPHIC SETTING: The Panamaker soils are on low river terraces and flood plains along the Toutle River at elevations of 200 to 600 feet. Panamaker soils formed in sandy dredge material from volcanic mudflows from the May l8, l980 eruption of Mt. St. Helens. The sandy materials are l0 to 25 feet in depth. The climate is characterized by cool, dry summer, and mild moist winters. Average annual precipitation is 45 to 80 inches. The mean annual temperature is about 50 degrees F. The growing season (28 degrees F.) is 200 to 240 days.
GEOGRAPHIC ASSOCIATED SOILS: These are the Carrolls, Cowlitz and Mountsolo soils. Carrolls soils have a water table in winter and are somewhat poorly drained. Cowlitz soils are somewhat excessively drained soils formed in gravelly dredge spoils. Mountsolo soils are somewhat poorly drained soils formed in gravelly mudflow material.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained, slow runoff; rapid permeability. This soil ranges from rare flooding to occasional brief periods of flooding from November through April.
USE AND VEGETATION: Areas have been revegetated with grass seedings. Natural revegetation by red alder and scotch-broom.
DISTRIBUTION AND EXTENT: Cowlitz County, Washington along the Cowlitz and Toutle Rivers. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Cowlitz County, Washington l989.
REMARKS: The only diagnostic feature recognized in this soil is the particle-size control section from l0 to 40 inches that is sandy throughout.