LOCATION TIGLEY ID

Established Series
Rev. CJW-BDG-EMM
07/2013

TIGLEY SERIES

The Tigley series consists of very deep, well drained soils on foothills, dissected terraces, escarpments, and breaklands. They formed in colluvium and tertiary alluvium derived dominantly from metasedimentary rock, with a mantle of loess and minor amounts of volcanic ash. Slopes are 15 to 80 percent. Permeability is moderately slow. The average annual air temperature is about 44 degrees F and the average annual precipitation is about 34 inches.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, frigid Vitrandic Hapludalfs

TYPICAL PEDON: Tigley gravelly ashy loam, forest; on a southwest-facing convex slope of 52 percent at 3,280 feet elevation. When described on September 10, 1981, the soil was slightly moist throughout. (Colors are for dry soil unless otherwise stated.)

Oi--0 to 0.5 inch; slightly decomposed needles, leaves, and twigs.

Oe--0.5 to 1 inch; decomposed organic matter mixed with Mt. St. Helens volcanic ash.

A--1 to 4 inches; grayish brown (10YR 5/2) gravelly ashy loam, very dark grayish brown (10YR 3/2) moist; weak very fine and fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and common fine and medium roots; many very fine and common fine tubular and irregular pores; 10 percent gravel and 5 percent cobbles; neutral (pH 6.8); clear wavy boundary. (2 to 6 inches thick)

BA--4 to 11 inches; yellowish brown (10YR 5/4) gravelly ashy loam, dark yellowish brown (10YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine, fine, and few medium and coarse roots; common very fine and few fine tubular and irregular pores; 15 percent gravel and 5 percent cobbles; slightly acid (pH 6.5); gradual wavy boundary. (0 to 11 inches thick)

Bt1--11 to 20 inches; light reddish brown (5YR 6/4) cobbly loam, reddish brown (5YR 4/4) moist; moderate fine and medium angular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and few fine and medium roots; common very fine and few fine tubular pores; common faint clay films on faces of peds and few faint and distinct clay films lining pores; few faint pinkish white (5YR 8/2) coatings on faces of peds; 10 percent gravel and 10 percent cobbles; strongly acid (pH 5.5); clear wavy boundary. (8 to 13 inches thick)

Bt2--20 to 34 inches; reddish yellow (5YR 6/6) extremely cobbly loam, yellowish red (5YR 4/6) moist; moderate fine and medium angular blocky structure; hard, firm, slightly sticky and slightly plastic; common very fine and few fine roots; common very fine and few fine tubular pores; common faint clay films on faces of peds and few faint and distinct clay films lining pores; few faint pinkish white (5YR 8/2) coatings on faces of peds; 30 percent gravel, 30 percent cobbles, and 10 percent stones; strongly acid (pH 5.5); clear wavy boundary. (14 to 24 inches thick)

Bt3--34 to 50 inches; mixed reddish yellow (5YR 6/6) and red (2.5YR 5/6) very cobbly loam, yellowish red (5YR 4/6) and dark red (2.5YR 3/6) moist; moderate fine and medium angular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; common very fine, and few fine and medium tubular pores; few faint and distinct clay films on faces of peds and lining pores; few faint pinkish white (5YR 8/2) coatings on faces of peds; 20 percent gravel, 20 percent cobbles, and 5 percent stones; strongly acid (pH 5.5); clear wavy boundary. (10 to 26 inches thick)

Bt4--50 to 60 inches; mixed reddish yellow (5YR 6/6) and red (2.5YR 5/6) very cobbly loam, yellowish red (5YR 4/6) and dark red (2.5YR 3/6) moist; weak medium angular blocky structure; hard, firm, slightly sticky and slightly plastic; few very fine and fine roots; common very fine and few fine tubular pores; common faint and few distinct clay films on faces of peds and lining pores; 15 percent soft fragments of decomposed metasedimentary rock; 20 percent gravel, 25 percent cobbles, and 5 percent stones; strongly acid (pH 5.4).

TYPE LOCATION: Benewah County, Idaho; about 1.6 miles southwest of St. Joe Baldy along USFS Road 551, about 2,650 feet west and 550 feet north of the southeast corner of sec. 11, T. 46 N., R. 1 W.; Latitude 47 degrees, 20 minutes, 34 seconds N., Longitude 116 degrees, 25 minutes, 33 seconds W., NAD 83; USGS St. Joe Baldy topographic quadrangle.

RANGE IN CHARACTERISTICS:

Soil moisture - usually dry for 30 to 40 consecutive days August to September, moist mid-September through July
Average annual soil temperature - 43 to 47 degrees F
Average summer soil temperature - 48 to 52 degrees F with an O horizon
Depth to bedrock - greater than 60 inches
Solum thickness - greater than 60 inches

Volcanic ash influence - 7 to 12 inches thick
Volcanic glass content - 5 to 20 percent (estimated)
Acid-oxalate extractable Al + 1/2 Fe - 0.4 to 1.0 percent (estimated)
Moist bulk density - 1.0 to 1.2 g/cc (estimated)
Phosphate retention - 25 to 55 percent (estimated)

A horizon
Hue - 10YR and 7.5YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 2 to 4 dry or moist
Texture - ashy loam or ashy silt loam
Rock fragments - 15 to 70 percent
Clay content - 10 to 15 percent
Reaction - slightly acid or neutral

BA horizon (or Bw horizon when present)
Hue - 10YR or 7.5YR
Value - 5 or 6 dry, 3 or 4 moist
Chroma - 3 or 4 dry, 2 to 4 moist
Texture - loam or silt loam
Rock fragments - 15 to 30 percent
Clay content - 10 to 15 percent
Reaction - moderately acid to neutral

Bt horizon
Hue - 10YR, 7.5YR, 5YR, or 2.5YR
Value - 5 to 8 dry, 3 to 6 moist
Chroma - 3 to 8 dry or moist
Texture - loam, silt loam, or silty clay loam
Rock fragments - 20 to 45 percent in the upper part, 45 to 75 percent in the lower part, and averages more than 35 percent
Clay content - 18 to 28 percent
Base saturation - 20 to 35 percent
Reaction - very strongly acid to slightly acid

COMPETING SERIES: This is the Beaverdump series.

Beaverdump soils: have 2Bt/E horizons and formed in alluvium and glacial outwash.

GEOGRAPHIC SETTING: Tigley soils are on south-facing foothills, dissected terraces, escarpments, and breaklands. Slopes range from 15 to 80 percent. These soils formed in colluvium and old alluvium derived dominantly from metasedimentary rock, with a mantle of loess and minor amounts of volcanic ash. Elevation ranges from 2,160 to 4,200 feet. The average annual air temperature ranges from 42 to 46 degrees F, and the average annual precipitation is 30 to 45 inches. The average frost-free period is from 80 to 120 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ahrs, Hugus, Lotuspoint, and Pinecreek soils. Ahrs soils are on east and west-facing adjacent mountain slopes and do not have an argillic horizon. Hugus soils are on north-facing foothills and terrace slopes, and have a thick volcanic ash mantle. Lotuspoint soils are on south-facing canyonsides and ridges, and have hard bedrock at 20 to 40 inches and are mesic. Pinecreek soils are on south-facing adjacent mountain slopes and do not have argillic horizons.

DRAINAGE AND PERMEABILITY: Well drained; very rapid runoff; moderately slow permeability.

USE AND VEGETATION: These soils are used for timber production, livestock grazing, recreation, wildlife habitat, and watershed. Potential natural vegetation is mainly grand fir, Douglas-fir, western white pine, ponderosa pine, and western larch with an understory of queencup beadlily, goldthread, longtube twinflower, starry false-Solomons-seal, American trailplant, myrtle pachystima, creambush oceanspray, common snowberry, baldhip rose, pine reedgrass, and Columbia brome.

DISTRIBUTION AND EXTENT: Northern Idaho; MLRA 43A. This soil is moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: St. Joe Area, Shoshone County Idaho, 1993.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from 0 to 4 inches (Oi, Oe, and A horizons)
Argillic horizon - the zone from 11 to 60 inches (Bt1, Bt2, Bt3, and Bt4 horizons)
Volcanic ash influence - the zone from 1 to 11 inches (A and BA horizons)
Particle-size control section - the zone from 11 to 31 inches (Bt1 and part of the Bt2 horizon)

Parent material of the Tigley series mapped in West Benewah County is metasedimentary colluvium. The tertiary alluvium and colluvium parent materials are mapped in East Benewah and Shoshone Counties.

National Cooperative Soil Survey
U.S.A.