LOCATION MCELROY WAEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic, mesic Andic Dystroxerepts
TYPICAL PEDON: McElroy gravelly ashy loam - forested. (Colors are for dry soil unless otherwise noted. All textures are apparent field textures.)
Oi--0 to 1.5 inches; slightly decomposed needles, leaves and twigs.
A1--1.5 to 6 inches; strong brown (7.5YR 5/6) gravelly ashy loam, dark reddish brown (5YR 3/3) moist; weak very fine granular structure; slightly hard, friable, slightly sticky and nonplastic, weakly smeary; many very fine and fine roots; many fine irregular pores; 30 percent gravel; moderately acid (pH 5.9); clear smooth boundary. (4 to 7 inches thick)
A2--6 to 12 inches; strong brown (7.5YR 5/6) gravelly ashy loam, dark reddish brown (5YR 3/3) moist; weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic, weakly smeary; common very fine and fine roots; few very fine tubular and many fine irregular pores; 20 percent gravel; moderately acid (pH 5.6) clear wavy boundary. (5 to 8 inches thick)
2BA--12 to 24 inches; strong brown (7.5YR 5/6) gravelly loam, dark reddish brown (5YR 3/4) moist; weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine and fine roots; many fine irregular pores; 25 percent gravel; moderately acid (pH 5.8); abrupt smooth boundary. (6 to 12 inches thick)
2Bw1--24 to 39 inches; strong brown (7.5YR 5/6) very gravelly loam, dark reddish brown (5YR 3/4) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and few medium roots; many fine irregular and common very fine tubular pores; 40 percent gravel and 10 percent cobbles; moderately acid (pH 5.8); clear wavy boundary. (15 to 30 inches thick)
2Bw2--39 to 61 inches; strong brown (7.5YR 5/8) very gravelly loam, brown (7.5YR 4/4) moist; weak very fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few medium roots; common fine irregular and few very fine tubular pores; 45 percent gravel, 10 percent cobbles and 10 percent saprolitic paragravel; moderately acid (pH 5.6).
TYPE LOCATION: Klickitat County, Washington, about 5 miles west of Husum; 250 feet west of the southeast corner, section 32, T. 4 N., R. 10 E. Latitude 45 degrees 46 minutes 58 seconds N. and Longitude 121 degrees 34 minutes 10 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 48 to 50 degrees F. The soil moisture control section is dry in all parts for 45 to 60 consecutive days within the four months that follow the summer solstice in 6 or more years out of 10. Volcanic ash influence is 9 to 13 inches thick and has an estimated moist bulk density of 0.85 to 1.00 g/cc, volcanic glass content of 5 to 30 percent, acid oxalate extractable aluminum plus one-half iron of 1.0 to 2.0 percent, phosphate retention of 50 to 75 percent, and 15 bar water retention of 8 to 12 percent. On a weighted average in the particle-size control section, hard rock fragments range from 35 to 60 percent, and saprolitic paragravel from 0 to 10 percent. The umbric epipedon is 10 to 13 inches thick. Reaction is moderately acid to slightly acid throughout.
The A horizon has hue of 5YR or 7.5YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 3 to 5 dry, 2 or 3 moist. Texture is gravelly ashy loam or very stony ashy loam.
The 2BA horizon has hue of 7.5YR or 5YR, value of 4 or 5 dry, 2 or 3 moist and chroma of 4 to 6 moist and dry.
The 2Bw horizon has hue of 5YR or 7.5YR, value of 5 or 6 dry, 3 or 4 moist and chroma of 4 to 8 dry and moist. Texture is very gravelly loam, very cobbly loam or extremely gravelly loam. Rock fragments range from 35 to 55 percent gravel and 10 to 20 percent cobbles.
COMPETING SERIES: These are the Lydon (T), Lyre, Ovall, Schneider, Siouxon and Yedlick series. Lydon soils are 20 to 40 inches to a lithic contact (andesite), have a MAST of 52 to 59 degrees F., and are dry for 90 consecutive days following the summer solstice. Lyre soils are 20 to 40 inches to a sand or loamy sand 2C horizon with 50 to 70 percent rock fragments. Ovall soils are 20 to 40 inches to a lithic contact (andesite), have a MAST of 52 to 54 degrees F., and are dry for 60 to 75 consecutive days following the summer solstice. Schneider soils are 40 to 60 inches to a lithic contact, have an umbric epipedon 20 to 30 inches thick, and lack a surface mantle of ash. Siouxon soils have a mean annual soil temperature of 50 to 52 degrees F, and are 40 to 60 inches to a lithic contact (andesite). Yedlick soils are dry for 60 to 75 consecutive days following the summer solstice, have an ochric epipedon, and have 30 to 60 percent glass in the ash mantle.
GEOGRAPHIC SETTING: McElroy soils are on footslopes and backslopes of mountains at elevations of 400 to 2,600 feet. Slopes are 5 to 90 percent. The soils formed in colluvium and residuum from basalt with a mantle of volcanic ash. Summers are warm and dry; winters are cool and wet. The mean annual precipitation is 45 to 65 inches. The average January temperature is 26 degrees F. and the average July temperature is 65 degrees F. The mean annual temperature is 45 to 47 degrees F. The frost-free season is 100 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chemawa, Timberhead, and Underwood soils. Underwood soils are fine-loamy, have an argillic horizon and are on terraces. Chemawa soils are medial and are on mountains. Timberhead soils are frigid and are on backslopes of mountains.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: These soils are used mainly for timber production, watershed, some hay and pasture and livestock grazing. Vegetation is Douglas-fir, grand fir, bigleaf maple and vine maple with an understory of western hazel, deerfoot vanillaleaf, elk sedge, creambush oceanspray, Pacific dogwood, and poison-oak.
DISTRIBUTION AND EXTENT: Western Klickitat County and eastern Skamania County, Washington. MLRA 6. The series is moderately extensive.
MLRA OFFICE RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Skamania County, Washington, 1981.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Umbric epipedon - the zone from 1.5 to 12 inches
Cambic horizon - the zone from 12 to 61 inches
Particle-size control section - the zone from 11.5 to 41.5 inches