LOCATION JACKMILL                ID

Established Series
IRD: WGH/TDT
09/2018

JACKMILL SERIES


The Jackmill series consists of very deep, well drained soils formed in colluvium and slope alluvium from rhyolite, quartzite and sandstone with loess influence. Jackmill soils are on fan remnants and have slopes of 2 to 60 percent. The mean annual precipitation is about 430 mm and the mean annual air temperature is about 1.4 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive Xeric Haplocryolls

TYPICAL PEDON: Jackmill gravelly loam on a fan remnant with 2 percent slope at an elevation of 2,378 meters. There were 5 percent gravel and 5 percent cobbles on the surface. (Colors are for dry soil unless otherwise noted.)

A--0 to 5 cm; brown (10YR 4/3) gravelly loam, very dark brown (7.5YR 2.5/2) moist; moderate very fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and common fine roots throughout; many very fine interstitial pores; 10 percent gravel and 5 percent cobbles; neutral (pH 6.6); abrupt smooth boundary. (5 to 38 cm thick)

AB--5 to 15 cm; brown (7.5YR 4/3) very gravelly loam, very dark brown (7.5YR 2.5/3) moist; moderate fine and medium subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common very fine and fine roots throughout; common very fine irregular pores; 35 percent gravel and 5 percent cobbles; neutral (pH 6.6); clear wavy boundary. (0 to 10 cm thick)

Bw--15 to 30 cm; brown (7.5YR 5/4) very gravelly loam, dark brown (7.5YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, very friable, moderately sticky and slightly plastic; common very fine and fine roots throughout; many very fine irregular and tubular pores; 35 percent gravel and 10 percent cobbles; neutral (pH 6.8); clear wavy boundary.

Bt--30 to 55 cm; strong brown (7.5YR 4/6) extremely gravelly sandy loam, brown (7.5YR 4/4) moist; moderate fine and medium subangular blocky structure; very hard, very friable, slightly sticky and nonplastic; many very fine and common fine roots matted around rock fragments; many very fine tubular and common very fine irregular pores; few discontinuous clay films bridging between sand grains; 40 percent gravel and 20 percent cobbles; neutral (pH 7.0); clear wavy boundary. (Combined thickness of the Bw and Bt horizons is 0 to 40 cm)

Bq--55 to 76 cm; strong brown (7.5YR 5/6) very gravelly sandy loam, strong brown (7.5YR 4/6) moist; weak fine and medium subangular blocky structure; very hard, very friable, slightly sticky and nonplastic; few very fine and fine roots matted around rock fragments; common very fine irregular pores; few discontinuous silica coats on rock fragments; 35 percent gravel and 20 percent cobbles; neutral (pH 7.2); clear wavy boundary. (15 to 21 cm thick)

2Cq--76 to 152 cm; light brown (7.5YR 6/4) extremely gravelly loamy sand, brown (7.5YR 4/4) moist; single grain; loose, nonsticky and nonplastic; few very fine roots matted around rock fragments; many fine interstitial pores; common discontinuous silica coats on rock fragments; 50 percent gravel and 25 percent cobbles; slightly alkaline (pH 7.4).

TYPE LOCATION: Clark County, Idaho; about 4.5 km north and 4.5 km east of the Edie school; about 330 meters south and 680 meters east of the northwest corner of section 35, T. 13 N., R. 33 E.; Edie Creek USGS topographic quadrangle; lat. 44 degrees, 24 minutes, and 51.8 seconds N. and long. 112 degrees, 32 minutes, 49.4 seconds W., NAD83.

RANGE IN CHARACTERISTICS:
Mollic epipedon thickness: 28 to 40 cm
Particle size control section weighted average rock fragments: 55 to 75 percent
Particle size control section weighted average clay: 8 to 15 percent
Depth to the Bq horizon: 28 to 70 cm
Depth to lithologic discontinuity (2Cq horizon): 60 to 90 cm
Reaction: slightly acid to slightly alkaline
Soil moisture regime: xeric
Mean annual soil temperature: 1.1 to 3.3 degrees C.
Mean summer soil temperature: 12.7 to 14.4 degrees C.

A horizon
Hue: 10YR or 7.5YR
Value: 3 to 5 dry, 2 to 4 moist
Chroma: 2 or 3, dry or moist

AB horizon
Hue: 10YR or 7.5YR
Value: 3 to 5 dry, 2 to 4 moist
Chroma: 2 or 3, dry or moist
Texture: GRV-L or GRV-SL
Total coarse fragments: 35 to 55 percent with 30 to 45 percent gravel and 5 to 10 percent cobbles

Bw horizon and Bt horizon
Hue: 10YR or 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 4 to 6 dry, 3 or 4 moist
Texture: GRV-L, GRX-L, GRV-SL or GRX-SL
Clay content: 10 to 20 percent
Total coarse fragments: 45 to 70 percent with 35 to 50 percent gravel and 10 to 20 percent cobbles

Bq horizon
Hue: 10YR or 7.5YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 3 to 6 dry or moist
Texture: GRV-L, GRX-L, GRV-SL or GRX-SL
Clay content: 10 to 20 percent
Total coarse fragments: 45 to 65 percent with 35 to 45 percent gravel and 10 to 20 percent cobbles

2Cq horizon
Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6 dry or moist
Texture: GRX-COS or GRX-LS
Clay content: 5 to 12 percent
Total coarse fragments: 65 to 80 percent with 45 to 50 percent gravel and 20 to 30 percent cobbles

2C horizon (when present)
Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 to 6, dry or moist
Texture: GRX-COS or GRX-LS
Total coarse fragments: 70 to 85 percent with 45 to 55 gravel and 25 to 30 cobbles

COMPETING SERIES: These are the Basinpeak, Berrycreek, Decram, Fairydell, Foxmount, Gaia, Klug, Krackle, Lag, Middlehill, Rockabin, Steepshrub, Sup, Timmercrek, and Wareagle series. The Basinpeak soils have 18 to 25 percent clay in the particle-size control section. Berrycreek, Lag, Sheepshrub, Timmercrek,and Wareagle soils have an O horizon. Decram, Foxmount, Krackle, Middlehill, and Rockabin soils are moderately deep. Fairydell soils have 20 to 25 percent clay in the particle-size control section and are slighty to strongly effervescent in the lower part of the subsoil and substratum. Gaia and Sup soils lack a cambic horizon and the silica accumulation. Klug soils lack the silica accumulation and the coarse textured (coarse sand or loamy sand) in the lower part of the particle-size control section.

GEOGRAPHIC SETTING:
Landscape: mountains
Landform: fan remnant
Elevation: 1,920 to 2,392 meters
Slope: 2 to 60 percent
Parent material: colluvium and slope alluvium from rhyolite, quartzite and sandstone with loess influence
Mean annual air temperature: 0.6 to 2.8 degrees C.
Mean annual precipitation: 406 to 457 mm
Frost free period: 35 to 45 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ediebench, Latigo, Poso Windicreek, and Zeebar soil. Ediebench soils are very deep, fine, smectitc soils and are on mountains, fan remnants, and hillslopes. Latigo soils are loamy-skeletal and formed in calcareous loess and slope alluvium from material weathered from rhyolite and are on hillslopes, fan remnants and structural benches. Poso soils are loamy-skeletal and formed in residuum and slope alluvium derived dominantly from calcareous sandstone conglomerate and are on nearly level to extremely steep fan remnant ridges. Windicreek soils are loamy-skeletal and are on nearly level to very steep fan remnants derived dominantly from calcareous sandstone conglomerate. Zeebar soils are loamy-skeletal and are formed in colluvium from quartzite, basalt and tuff and are on mountains, hillslopes, ridges and fan remnants.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage class: well
Saturated hydraulic conductivity: moderately high in the upper part to very high in the lower part

USE AND VEGETATION:
Major uses: Rangeland and wildlife habitat
Dominant native vegetation: mountain big sagebrush, Idaho fescue, bluebunch wheatgrass, and arrowleaf balsamroot

DISTRIBUTION AND EXTENT:
Distribution: East-central Idaho; MLRA 12.
Extent: the series is not extensive

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Portland, Oregon

SERIES PROPOSED: Clark County Area, Idaho, 2018.

REMARKS:
Diagnostic horizons and soil characteristics recognized in this pedon are:
Mollic epipedon: from a depth of 0 to 30 cm
Cambic horizon: from a depth of 30 to 76 cm
Particle size control section: from a depth of 25 to 100 cm averages about 11% clay and about 62% rock fragments
Soil temperature regime: cryic
Soil moisture regime: xeric

ADDITIONAL DATA:
Typical pedon was not sampled.


National Cooperative Soil Survey
U.S.A.