LOCATION SHERLOCK WA+MTEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, isotic Andic Haplocryalfs
TYPICAL PEDON: Sherlock silt loam under coniferous forest on 25 percent northwest slope at an elevation of 4,500 feet. (Colors are for dry soils unless otherwise stated.)
0a--0 to 1 inch; decomposed needles, leaves, twigs, bark mosses, and lichens; abrupt smooth boundary.
E--1 to 1.5 inches; gray (10YR 6/1) ashy very fine sandy loam, dark gray (10YR 4/1) moist; weak fine granular structure, soft, very friable, nonsticky and nonplastic; common fine and medium roots; 5 percent pebbles; moderately acid (pH 5.8); abrupt broken boundary. (0 to 2 inches thick)
Bwl--1.5 to 5 inches; yellowish brown (10YR 5/6) ashy silt loam, dark brown (7.5YR 3/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine, few medium and coarse roots; l0 percent pebbles; weakly smeary; moderately acid (pH 6.0); clear wavy boundary. (3 to 7 inches thick)
Bw2--5 to 10 inches; yellow (10YR 7/6) ashy silt loam, brown (7.5YR 4/4) moist; weak fine subangular blocky structure; soft, very friable nonsticky and nonplastic; common very fine and fine, few medium and coarse roots; l0 percent pebbles; moderately smeary; slightly acid (pH 6.4); abrupt wavy boundary. (4 to 7 inches thick)
2Btl--10 to 29 inches; light gray (2.5Y 7/2) very gravelly heavy silt loam, olive brown (2.5Y 4/4) moist; moderate medium subangular blocky structure; hard, firm, slightly sticky and moderately plastic; few very fine, fine and coarse roots; few distinct clay films on ped faces and lining pores; 30 percent pebbles, l0 percent cobbles; neutral (pH 6.8); clear wavy boundary. (6 to 25 inches thick)
2Bt2--29 to 60 inches; pale olive (5Y 6/3) very gravelly silty clay loam, olive (5Y 4/3) moist; moderate medium subangular blocky structure; very hard, very firm, very sticky, and moderately plastic; few very fine and fine roots; continuous prominent clay films on faces of peds and lining pores; 35 percent pebbles, l5 percent cobbles; neutral (pH 7.2).
TYPE LOCATION: Pend Oreille County, Washington; about 7.25 miles west and l.75 south of Boundary Dam; 500 feet north and l,650 feet east of the southwest corner, sec. l3, T. 40 N., R. 44 E.
RANGE IN CHARACTERISTICS: The average annual soil temperature at 20 inches ranges from 40 to 44 degrees F. These soils are dry in the moisture control section less than 45 consecutive days following summer solstice and are continual moist in winter and spring. The thickness of the solum ranges from 32 to greater than 60 inches. Thickness of the volcanic ash mantle and depth to the 2Bt horizon is 7 to l4 inches. The upper 7 to 14 inches is 30 to 60 percent volcanic glass. The upper 20 inches of the argillic horizon averages 20 to 35 percent clay and averages 35 to 60 percent coarse fragments.
The E horizon, when present, has value 6 or 7 when dry, 4 or 5 when moist, and chroma of l or 2 when dry or moist. Reaction is moderately acid or slightly acid. Some pedons have an A horizon and lack an E horizon.
The Bw horizon has hue of 5YR, 7.5YR or l0YR, a value of 4 to 7 dry, 3 or 4 moist, and chroma of 3 to 6 dry or moist. It is ashy loam, or ashy silt loam and modified by 0 to 30 percent pebbles. Reaction is moderately acid or slightly acid.
The 2Bt horizon has a hue of 7.5YR to 5Y, value of 5 through 7 dry, 3 or 4 moist, and chroma of 2 through 4 dry or moist. It is heavy silt loam, loam, clay loam, or silty clay loam, modified by 35 to 50 percent pebbles and 0 to l5 percent cobbles. Reaction is moderately acid to neutral.
COMPETING SERIES: These are the Ortellcreek and Pileup series. Ortellcreek soils have a glossic horizon and have the top of fragic materials at 35 to 45 inches. Pileup soils have a xeric moisture regime.
GEOGRAPHIC SETTING: Sherlock soils are on till plains and moraines on glaciated foothills and mountains. Slopes are 0 to 65 percent. They formed in glacial till of mixed igneous and metasedimentary rock material with a mantle of volcanic ash. Elevation is 3,900 to 6,500 feet. The soils are in a continental climate with cool, dry summers and cold, moist winters. The average annual precipitation is 35 to 60 inches. The average annual temperature is 39 to 42 degrees F. The frost-free season is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are Buhrig, Conto, Holloway, Huckleberry, Manley and Truefissure soils. All of these soils lack an argillic horizon, in addition Buhrig and Huckleberry soils are 20 to 40 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Well drained, slow to very rapid runoff. Permeability is moderately slow.
USE AND VEGETATION: Woodland, wildlife habitat, watershed, and recreation. Vegetation includes subalpine fir, western redcedar, western larch, grand fir, western hemlock, Douglas-fir, lodgepole pine, willow and alder, with an understory of common bear grass, princes pine, huckleberry, pachystima, kinnikinnick, and queencup beadlily.
DISTRIBUTION AND EXTENT: Northeastern Washington and Northwestern Montana. The series is small in extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: St. Regis-Ninemile Area, Mineral County, Montana, l970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon from the soil surface to 10 inches (O, E, Bw1 and Bw2 horizons);
Albic horizon the zone from 1 to 1.5 inches (E horizon);
Argillic horizon the zone from 10 to 60 inches (2Bt1 and 2Bt2 horizons).
The upper 10 inches of the mineral soil is estimated to be 30 to 60 percent volcanic glass, and an estimated acid-oxalate extractable aluminum plus one-half of the acid-oxalate extractable iron of more than 2.0 percent and 15-bar water retention of less than 12 percent for air dried samples.
This description reflects a change in classification from Loamy-skeletal, mixed, Andic Cryoboralfs to Loamy-skeletal, isotic Andic Haplocryalfs.The Bw horizon fails to be a spodic horizon only because of pH.