LOCATION MULDOON IDEstablished Series
The Muldoon series consists of deep to duripan, well drained soils that
formed in alluvium from mixed igneous and metamorphic rocks. Muldoon
soils are on fan terraces and footslopes to mountains and have slopes
of 2 to 15 percent. Permeability is moderately slow. The average
annual precipitation is about 14 inches, and the average annual
temperature is about 42 degrees F.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Ultic Argixerolls
TYPICAL PEDON: Muldoon loam - on a 10 percent slope at an elevation of
5,500 feet in rangeland. When described on November 7, 1979, the soil
was moist to 12 inches and dry below. (Colors are for dry soil unless
otherwise noted.)
A1--0 to 3 inches; brown (10YR 5/3) loam, very dark grayish brown
(10YR 3/2) moist; weak fine granular structure; soft, very friable,
slightly sticky and slightly plastic, many very fine and fine roots,
many very fine and fine interstitial pores, slightly acid (pH 6.2);
clear smooth boundary. (3 to 10 inches thick)
A2--3 to 7 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3)
moist; weak fine subangular blocky structure; soft, very friable; many
very fine and fine roots; many fine tubular pores; few thin clay films
on ped faces; slightly acid (pH 6.4); abrupt smooth boundary. (0 to 7
inches thick)
Bt1--7 to 11 inches; yellowish brown (10YR 5/4) clay loam, dark
brown (10YR 3/3) moist, weak fine and medium subangular blocky
structure; soft, very friable, sticky and plastic, many very fine, fine
and medium roots; many fine tubular pores; common thin clay films on
ped faces; slightly acid (pH 6.4); clear wavy boundary. (0 to 7 inches
thick)
Bt2--11 to 22 inches; yellowish brown (10YR 5/4) clay loam, dark
yellowish brown (10YR 3/4) moist; moderate medium subangular blocky
structure; hard, friable, very sticky and plastic, common fine and
medium roots; many fine tubular pores; many moderately thick clay films
on ped faces and lining pores; neutral (pH 6.8); gradual smooth
boundary. (8 to 13 inches thick)
Bt3--22 to 32 inches; yellowish brown (10YR 5/4) clay loam, dark
yellowish brown (10YR 3/4) moist; strong fine angular blocky structure;
very hard, firm, very sticky and very plastic; few fine and medium
roots; common very fine tubular pores; many thick clay films on ped
faces and lining pores; neutral (pH 6.8); gradual smooth boundary. (7
to 22 inches thick)
Bt4--32 to 45 inches; light yellowish brown (10YR 6/4) clay loam;
dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky
structure; hard, firm, very sticky and very plastic; few fine roots;
few very fine tubular pores; about 5 percent gravel; common moderately
thick clay films on ped faces and lining pores; neutral (pH 7.2); clear
smooth boundary. (0 to 13 inches thick)
2Bqm--45 to 56 inches; light yellowish brown (10YR 6/4) indurated
duripan dark yellowish brown (10YR 4/4) moist; massive; few very fine
tubular pores; weakly cemented plates; cemented with silica (veins of
silica within plates about 1 to 4 mm thick); neutral (pH 7.2).
TYPE LOCATION: Blaine County, Idaho about 11 miles north and 5 miles
west of Carey; 300 feet west and 450 feet south of the northeast corner
of section 35, T. 2 N., R. 20 E.
RANGE IN CHARACTERISTICS:
Depth to the base of the argillic - 40 to 60 inches
Average annual soil temperature - 42 to 46 degrees F.
Base saturation (upper 75 cm) by sum of cations - 50 to 75 percent
Soil moisture - dry 45 to 80 consecutive days following the summer
solstice
A1 Horizon
Color value, dry - 4 or 5
Chroma, moist or dry - 2 or 3
Bt1, Bt2, and Bt3 Horizons
Color hue - 10YR or 7.5YR
Color value, dry - 5 or 6
Color value, moist - 3 through 5
Chroma, moist - 3 or 4
Texture - CL, SICL
Sand content - less than 30 percent fine sand and coarser
Silt content - more than 40 percent of silt is fine silt
Clay content - 27 to 35 percent
Rock fragments - 0 to 5 percent
Reaction - Slightly acid to neutral
Bt4 Horizon
Color value, dry - 5 or 6
Chroma, moist - 3 or 4
Texture - CL, CB-CL
Clay content - 27 to 33 percent
Rock fragments - 5 to 30 percent
Reaction - Slightly acid to neutral
2Bqm Horizon
Structure - Massive or platy
Thickness of plates - 2 to 10 cm
Depth to cemented pan - 40 to 60 inches
Clay films - oriented clay is in fractures and on horizontal plate
faces
COMPETING SERIES: These are the Carmack, Elkcreek, Johnson,
Molyneux, Simonton, Suloaf, and Trojan series. Carmack, Johnson, and
Suloaf have O horizons and occur in a precipitation zone wetter than 16
inches. Carmack soils have moderately acid argillic horizons.
Elkcreek soils have bedrock at 20 to 40 inches. Johnson, Molyneux, and
Simonton have more than 30 percent fine sand and coarser. Trojan soils
are dry more than 80 consecutive days following the summer solstice.
Molyneux soils have more than 5 percent gravel in the upper part of the
argillic. Suloaf soils have gravelly textures in the upper part of the
argillic horizon.
GEOGRAPHIC SETTING: Muldoon soils are on fan terraces and foot slopes
to mountains. Slopes range from 2 to 15 percent. Elevation ranges
from 4,800 to 6,500 feet. The soil formed in alluvium from mixed
igneous and metamorphic rocks. The average annual precipitation is 12
to 16 inches, most of which falls as snow and early spring rain. The
average annual temperature is 40 degrees to 44 degrees F. The frost
free season is 60 to 90 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Peevywell, Goodington,
Starhope, Smelter, and Molyneux soils. Peevywell soils have a duripan
at a depth of 24 to 35 inches. Goodington, Smelter, and Starhope soils
have an abrupt increase in clay. Goodington soils are on lava plains.
Starhope soils are 20 to 40 inches deep. Smelter soils have fine silty
control sections. Starhope and Smelter soils occur on foothills and
mountainsides.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is slow to medium.
Permeability is moderately slow.
USE AND VEGETATION: Mainly used for rangeland. Vegetation is Mountain
big sagebrush, bluebunch wheatgrass, Idaho fescue, Nevada bluegrass,
and needlegrass.
DISTRIBUTION AND EXTENT: South-central Idaho. These soils are
inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Blaine County, Idaho, 1985.
REMARKS: Laboratory data S-81ID-013-008 indicated a fine-loamy family
was appropriate.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - extends from the soil surface to approximately 11
inches (A1, A2, and Bt1 horizons)
Argillic horizon is the zone from 7 to 45 inches (Bt1, Bt2, Bt3, and
Bt4 horizons)
Duripan occurs at 45 inches (2Bqm horizon)
National Cooperative Soil Survey