LOCATION FORTRAN WAEstablished Series
TAXONOMIC CLASS: Ashy over sandy or sandy-skeletal, glassy over mixed, mesic Typic Udivitrands
TYPICAL PEDON: Fortran cindery loamy sand, 65 to 120 percent slopes - forested on a 85 percent southeast facing slope at 1,200 feet elevation. (Colors are for moist soil unless otherwise noted. All textures are apparent field textures.)
Oi--3 to 1 inch; leaves, needles, and twigs.
Oa--l inch to 0; decomposed organic material.
A--0 to 3 inches; dark brown (l0YR 3/3) paragravelly loamy sand, brown (l0YR 5/3) dry; weak fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine, fine medium and coarse roots; many very fine and fine irregular pores; l5 percent pumice fragments and 5 percent pebbles; moderately acid (pH 5.8); clear wavy boundary. (2 to 4 inches thick)
Bw--3 to 11 inches; dark yellowish brown (l0YR 4/4) paragravelly sandy loam, light yellowish brown (l0YR 6/4) dry; weak fine subangular blocky structure; soft, very friable, nonsticky and non plastic; many very fine and fine roots and common medium and coarse roots; many fine irregular pores; l5 percent pumice fragments and 5 percent pebbles; moderately acid (pH 6.0); clear wavy boundary. (7 to 12 inches thick)
BC--11 to 17 inches; dark brown (l0YR 4/3) very gravelly sandy loam, brown (l0YR 5/3) dry; weak very fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine, fine, and medium roots; many very fine irregular pores; 30 percent pebbles, 5 percent cobbles, and 5 percent pumice fragments; slightly acid (pH 6.2); abrupt wavy boundary. (5 to 10 inches thick)
2C--17 to 60 inches; gray (5Y 5/l) extremely gravelly loamy sand, light gray (5Y 7/l) dry; massive hard, firm, nonsticky and nonplastic; few fine roots; few fine tubular pores; 55 percent pebbles, l0 percent cobbles, and 5 percent stones; slightly acid (pH 6.2).
TYPE LOCATION: Skamania County, Washington; about 1/2 mile east of Swift Creek dam, 2,000 feet north and 400 feet east of the southwest corner of sec. 21, T. 7 N., R. 5 E.
RANGE IN CHARACTERISTICS: Mean annual soil temperature is 49 to 51 degrees F. Depth to the 2C horizon ranges from 14 to 25 inches. The upper 14 to 25 inches of the soil is more than 60 percent volcanic ash and pumice in the fine earth fraction and 5 to 35 percent rock fragments.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist or dry. It has l5 to 25 percent pumice fragments and 0 to 5 percent pebbles.
The Bw horizon has value of 4 or 5, 5 or 6 dry, and chroma of 3 or 4 moist or dry It has weak, fine, or medium subangular blocky structure. Rock fragments range from 0 to 15 percent pebbles. Pumice fragments range from l5 to 35 percent.
The BC horizon has value of 3 or 4 moist, 5 or 6 dry, and chroma of 3 or 4 moist or dry.
The 2C horizon has hue of l0YR to 5Y. It has 40 to 60 percent pebbles, 5 to 15 percent cobbles, and 0 to 10 percent stones.
COMPETING SERIES: There are no competing series. The Domkey, Parmenter, Pinchot, Stepstone, and Thowson series are similar soils. Domkey, Parmenter, Stepstone, and Thowson soils have a xeric moisture regime. Pinchot soils are 25 to 40 inches deep to the sandy-skeletal material.
GEOGRAPHIC SETTING: Fortran soils are on terrace escarpments at elevation of 800 to 1,800 feet. These soils formed in pyroclastic flow and lahar material. Slopes are 65 to 120 percent. The climate is characterized by warm, dry summers and cool wet winters. Average annual precipitation is 90 to 110 inches. The mean January temperatures is about 32 degrees F., mean July temperature is about 63 degrees F, and the mean annual temperature is 50 to 53 degrees F. The frost-free season is 115 to 135 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cinnamon, Swift, Yalelake, and the competing Forsyth soils. Cinnamon and Yalelake soils are ashy over medial. Swift soils are ashy over loamy-skeletal and have a frigid temperature regime.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; very rapid runoff; moderately rapid permeability.
USE AND VEGETATION: Used for timber production, recreation, and wildlife habitat. The native vegetation is Douglas-fir, western redcedar, western hemlock red alder, and bigleaf maple. Understory species include vine maple, Pacific dogwood, western swordfern, western brackenfern, Oregon-grape, and salal.
DISTRIBUTION AND EXTENT: Northern Skamania County, Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skamania County, Washington, l987.
REMARKS: Diagnostic horizons and features recognized in this pedon are an ochric epipedon from the mineral surface to 3 inches, a cambic horizon from 3 to 17 inches that is more than 60 percent volcanic ash and pumice in the fine earth fraction and a lithologic change to sandy- skeletal material at 17 inches. kParticle-size control section is from the mineral soil surface to 40 inches with: from 0 to 17 inbches qualifying as ashy by weighted average and from 17 to 40 inches qualifying as sandy-skeletal. Classification changed 6/98 based on 1998 Keys to Soil Taxonomy.