LOCATION CARSTAIRS               WA

Established Series
Rev. LDG-CJM-RJE
06/2011

CARSTAIRS SERIES


The Carstairs series consists of very deep, somewhat excessively drained soils that formed in glacial outwash and volcanic ash. Carstairs soils are on glacial outwash terraces at elevations of l00 to 500 feet. Slopes are 0 to 8 percent. The mean annual precipitation is about 75 inches. Mean annual temperature is about 50 degrees F.

TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Andic Humixerepts

TYPICAL PEDON: Carstairs extremely gravelly medial loam - forested. (Colors are for moist soil unless otherwise noted.)

A--0 to 13 inches; dark reddish brown (5YR 2/2) extremely gravelly medial loam, very dark brown (10YR 2/2) dry; single grained; soft, very friable, nonsticky and nonplastic and weakly smeary; many fine roots; 65 percent water worn pebbles, mostly fine size; very strongly acid (pH 4.8); clear smooth boundary. (7 to 14 inches thick)

2Bw--13 to 24 inches; dark yellowish brown (10YR 4/4) extremely gravelly loamy sand, dark yellowish brown (10YR 4/4) dry; single grained; loose; many fine roots; 75 percent water worn pebbles, strongly acid (pH 5.4); clear smooth boundary. (7 to 15 inches thick)

2C--24 to 60 inches; dark grayish brown (2.5Y 4/2) extremely gravelly sand, grayish brown (2.5Y 5/2) dry; single grained; loose; 75 percent rounded pebbles; few fine roots to 36 inches; moderately acid (pH 5.8).

TYPE LOCATION: Mason County, Washington; 1/2 mile north of west side of Shelton at intersection of Johns Prairie Road and Brockdale Road; soil pit 25 feet from NW corner of intersection; SE1/4 sec. 7. T. 20 N., R. 3 W.

RANGE IN CHARACTERISTICS: Depth to extremely gravelly sand or loamy sand is 7 to 14 inches. Coarse fragments in the particle-size control section average 60 to 80 percent. These soils are usually moist but are dry in all parts between depths of l2 and 35 inches for about 45 to 60 consecutive days following the summer solstice. The umbric epipedon is 7 to 14 inches thick.

The A horizon has chroma of l or 2 moist or dry.

The 2Bw horizon has value of 4 or 5 dry, 3 or 4 moist and chroma of 3 or 4 moist or dry. It is extremely gravelly loamy sand or extremely gravelly sandy loam. It is moderately acid or strongly acid.

The 2C horizon has value of 4 or 5 dry or moist.

COMPETING SERIES: This is the Spanaway series. Spanaway soils are dry for more than 60 consecutive days and are moderately acid or strongly acid in the A horizon and slightly acid or neutral in the C horizon.

GEOGRAPHIC SETTING: Carstairs soils are on glacial outwash terraces at elevations of l00 to 500 feet. Slopes are 0 to 8 percent. The soils formed in very gravelly glacial outwash material. Mean January temperature is about 38 degrees F.; mean July temperature is about 63 degrees F. Annual precipitation ranges from 65 to l00 inches. The growing season (28 degrees F.) is 200 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Everett, Grove and the competing Spanaway soils. Everett and Grove soils have an ochric epipedon.

DRAINAGE AND PERMEABILITY: Excessively drained; slow runoff; rapid permeability.

USE AND VEGETATION: Used for woodland, suburban development, cropland and pasture. Native vegetation Douglas-fir, lodgepole pine, western hemlock, western redcedar, and red alder with an understory of salal, red huckleberry, trailing blackberry, western swordfern, western brackenfern, Oregongrape, Indian plum, vine maple, kinnikinnick, salmonberry, cascara buckthorn, oceanspray and blue elderberry.

DISTRIBUTION AND EXTENT: Central-western Washington. Series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon

SERIES ESTABLISHED: Mason County, Washington, l950.

REMARKS: Diagnostic horizon and features recognized in this pedon are:

Umbric epipedon from the surface to 13 inches. The zone from 0 to 13 inches is assumed to have andic soil properties. The particle-size class would be medial-skeletal over sandy or sandy-skeletal and isotic over mixed if such a family existed.


National Cooperative Soil Survey
U.S.A.