LOCATION MCINTYRE COEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive Lamellic Haplocryalfs
TYPICAL PEDON: McIntyre loam, forested. (Colors are for dry soil unless otherwise stated.)
01--2 to 1 inch; undecomposed organic material consisting mainly of needles, bark, and twigs.
02--1 inch to 0; partially decomposed organic material like that of the horizon above.
A1--0 to 12 inches; brown (10YR 4/3) loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure that parts to moderate very fine granules; soft, very friable; 5 percent gravel; medium acid; clear wavy boundary. (6 to 15 inches thick)
A2--12 to 16 inches; very pale brown (10YR 7/3) very fine sandy loam, brown (10YR 5/3) moist; weak thick platy structure that parts to very fine granules; soft, very friable; 5 percent gravel; strongly acid; clear wavy boundary. (3 to 6 inches thick)
A&B--16 to 25 inches; pale yellow (10YR 8/4) to light yellowish brown (10YR 6/4) sandy loam with imbedded nodules and lamellae of slightly brighter colored clay loam or sandy clay loam, light yellowish brown (10YR 6/4) to dark yellowish brown (10YR 4/4) moist; lamellae become thicker and more numerous with depth and total more than 6 inches in thickness; moderate medium subangular blocky structure; slightly hard, very friable; 5 percent gravel; thin patchy clay films in the lamellae; strongly acid; clear wavy boundary. (8 to 19 inches thick)
C--25 to 30 inches; very pale brown (10YR 7/3) very fine sandy loam, pale brown (10YR 6/3) moist; weak very fine granular structure; soft, very friable; 20 percent gravel and sandstone fragments; strongly acid; abrupt wavy boundary.
R--30 inches; sandstone. The surface of the rock is thinly coated with clay-like materials. (Several feet thick).
TYPE LOCATION: Gunnison County, Colorado; near the center of Sec. 33, T. 13 S., R. 83 W.
RANGE IN CHARACTERISTICS: The thickness of the mollic epipedon ranges from 7 to 15 inches, thickness of solum ranges from 20 to 40 inches, and depth to bedrock ranges from 20 to 40 inches. Organic carbon in the mollic epipedon ranges from .7 to 4 percent, and decreases uniformly with increasing depth. Rock fragments are typically 5 to 10 percent but range from 1 to 15 percent with most being angular sandstone pebbles.
The A1 horizon has hue of 10YR or 2.5Y, value of 3 through 5 dry, 2 or 3 moist, and chroma of 2 or 3. It has weak subangular blocky or granular structure. This horizon is soft or slightly hard. It ranges from pH 5.5 to 6.5 and is usually less acid than the rest of the profile.
The A2 horizon has hue of 10YR or 7.5YR, value of 6 through 8 dry, 4 through 6 moist, and chroma of 2 through 4. Usually this horizon has weak platy structure but is subangular blocky in some pedons. It is soft or slightly hard. It ranges from pH 4.5 to 5.8.
The A&B horizon has hue of 10YR or 7.5YR, value of 6 through 8 dry, 4 or 5 moist, and chroma of 3 or 4. Colors are variable with the finer textured lamellae being somewhat redder in color or brighter in chroma than the remainder of the soil mass. Usually the horizon has a subangular blocky structure, but structure varies in both grade and class, and between different parts of the horizon depending upon the amount of clay accumulated. The soil mass is typically sandy loam with lamellae of loam, sandy clay loam, or clay loam. Lamellae range in thickness from 1/2 to 1 1/2 inches and total more than 6 inches in total thickness. The horizon ranges from pH 4.5 to 5.5 and at least some part of the horizon has base saturation of less than 60 percent.
COMPETING SERIES: These are the Anvik, Bear Basin, Celaya, Paintrock, Quietus, and Slopman series, all of which have continuous B2t horizons which are fine-loamy.
GEOGRAPHIC SETTING: The McIntyre soils are on mountain side slopes and ridges. Slope gradients range from 2 to 50 or more percent. The soils formed in medium to moderately coarse textured parent materials weathered from underlying sandstone bedrock. At the type location the average annual precipitation is 20 inches with generally uniform distribution throughout the year. The average annual temperature is 32 degrees F., and the average summer temperature is 48 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Schofield and Tongue River soils, which lack mollic epipedons.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: These soils are used as native pastureland, for recreational purposes, and have a limited value for forestry. Native vegetation is mainly a widely spaced cover of spruce and fir or aspen with a good understory of Thurber fescue, columbine, lupine, and peavine.
DISTRIBUTION AND EXTENT: High mountainous areas of central Colorado. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Gunnison County, Colorado, 1975.
REMARKS: This series was previously placed in the fine-loamy family. Because of a letter written by J. Melvin Williams, Head, Soil Correlation Staff, SCS, West Technical Service Center, dated April 12, 1974. Subject: "Family particle-size classes for soils with argillic horizons that result from lamellae", it has been placed in the coarse-loamy family. Last updated by the state 1/75.