LOCATION JANTILL WAEstablished Series
TYPICAL PEDON: Jantill stony ashy sandy loam - forestland, on a north-facing 35 percent slope at an elevation of 6,050 feet in a lodgepole pine, subalpine fir, Engelmann spruce forest. (Colors are for dry soil unless other wise stated).
Oe--0 to 2 inches; moderately decomposed needles, twigs, and leaves; abrupt smooth boundary. (1 to 3 inches thick)
C--2 to 3 inches; light gray (10YR 7/1) stony ashy silt loam, grayish brown (10YR 5/2) moist; moderate fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine and few coarse roots; common very fine and fine tubular pores; 10 percent pebbles, 5 percent cobbles, and 5 percent stones; moderately acid (pH 5.6); clear wavy boundary. (0 to 2 inches thick)
2A--3 to 6 inches; light yellowish brown (10YR 6/4) stony ashy sandy loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic, and weakly smeary; many very fine and fine and common medium and coarse roots; common very fine and fine irregular pores; 10 percent pebbles, 5 percent cobbles, and 5 percent stones; NaF pH 10.5; moderately acid (pH 5.6); clear smooth boundary. (3 to 6 inches thick)
2Bw--6 to 13 inches; light yellowish brown (10YR 6/4) stony ashy sandy loam, brown (10YR 4/3) moist; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic, and weakly smeary; many very fine and fine and common medium and few coarse roots; common very fine and fine irregular pores; 15 percent pebbles, 5 percent cobbles, and 5 percent stones; NaF pH 10.5; moderately acid (pH 5.6); clear smooth boundary (4 to 8 inches thick)
3C1--13 to 29 inches; light brownish gray (2.5Y 6/2) very stony loamy sand; grayish brown (2.5Y 5/2) moist; common fine and medium distinct yellowish brown (10YR 5/6) moist stains; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; 25 percent pebbles, 15 percent cobbles, and 15 percent stones; slightly acid (pH 6.2); gradual wavy boundary.
3C2--29 to 62 inches; light gray (2.5Y 7/2) very stony loamy sand; grayish brown (2.5Y 5/2) moist; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; 30 percent pebbles, 15 percent cobbles, and 20 percent stones; slightly acid (pH 6.2).
TYPE LOCATION: Okanogan National Forest, Okanogan County, Washington; about 1 mile north of Mt. Bonaparte, 600 feet east and 300 feet south of the northwest corner of section 13, T. 38 N., R. 29 E. (Latitude 48 degrees, 47 minutes, 52 seconds N., Longitude 119 degrees, 07 minutes, 06 seconds W.)
RANGE IN CHARACTERISTICS: The average annual soil temperature is 37 to 42 degrees F. The average annual summer soil temperature is 42 to 46 degrees F. These soils are usually moist but are dry in the moisture control section for 30 to 45 consecutive days following the summer solstice. The volcanic ash mantle is 7 to 14 inches thick and has an estimated moist bulk density of 0.80 to 1.00 g/cc, volcanic glass content of 30 to 60 percent, acid-oxalate extractable iron of more than 2.0 percent, and 15-bar water retention of 5 to 12 percent for air dried samples. The particle-size control section averages 35 to 65 percent rock fragments.
The C horizon has values of 7 or 8 dry, 5 or 6 moist, and chromas of 1 or 2 dry. It is absent in some pedons.
The 2A horizon has chromas of 3 or 4 dry or moist. Reaction is moderately acid to slightly acid.
The 2Bw horizon has chroma of 3 to 6 dry and 3 or 4 moist. It is stony ashy sandy loam or gravelly ashy sandy loam. It has 10 to 30 percent pebbles, 0 to 5 percent cobbles, and 0 to 15 percent stones. Reaction is moderately acid to slightly acid.
The 3C horizon has hue of 10YR or 2.5Y, value of 6 or 7 dry, 5 or 6 moist, and chroma of 2 or 3 dry or moist. It is very stony loamy sand, very cobbly loamy sand, or extremely gravelly loamy coarse sand. It has 20 to 60 percent pebbles, 5 to 20 percent cobbles, and 0 to 20 percent stones.
COMPETING SERIES: These are the Bromas, Littlesalmon, Roman, Sitdown, and Upsata series.Bromas soils are 20 to 40 inches deep to a paralithic contact. Littlesalmon soils are 40 to 60 inches to a paralithic contact. Roman soils have a cambic horizon from 2 to 24 inches. Sitdown sois are dry for greater than 45 consecutive days following the summer solstice. Upsata soils lack very stony substratums.
GEOGRAPHIC SETTING: Jantill soils are on north-facing backslopes and footslopes of glaciated mountains at elevations of 4,900 to 6,800 feet. Slopes are 15 to 65 percent. These soils formed in till and some outwash from granitic rock with a mantle of volcanic ash 7 to 14 inches thick. The climate is characterized by cold, wet winters and cool, moist summers. The average annual precipitation ranges from 35 to 40 inches. The mean January temperature is about 20 degrees F, mean July temperature is about 58 degrees F, and the average annual air temperature is about 35 to 40 degrees F. The frost-free period is 60 to 85 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Buhrig, Manley, Myerscreek, and Wellsfar soils. Buhrig soils are on shoulders and ridges and are 20 to 40 inches to bedrock. Manley soils are on backslopes and footslopes and have a volcanic ash mantle greater than 14 inches over dense till. Myerscreek soils are on backslopes and footslopes and have a volcanic ash mantle 7 to 14 inches thick over dense till. Wellsfar soils are on shoulders and ridges and have a paralithic contact at 20 to 40 inches.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; medium to rapid runoff; moderately rapid permeability through the volcanic ash mantle, and rapid to very rapid below.
USE AND VEGETATION: Timber production, wildlife habitat, watershed, and recreation. Native vegetation is subalpine fir, Engelmann spruce, lodgepole pine, and western larch with an understory of cascades azalea, grouse whortleberry, sidebells wintergreen, blue huckleberry, whortleberry, northwestern sedge, and rattlesnake plantain.
DISTRIBUTION AND EXTENT: Northcentral Washington. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Okanogan National Forest, Okanogan County, Washington; 2005.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Mt. St. Helens "T" or "W" ash layer from approximately 450 years ago - C horizon
Ochric epipedon
Cambic horizon - 6 to 13 inches
Andic properties - 3 to 13 inches
PSCS - zone from 12 to 42 inches