LOCATION CRITCHELL          CO
Established Series
Rev. GB
03/2003

CRITCHELL SERIES


The Critchell series consists of deep, well drained soils that formed in mixed, stratified alluvium derived from reddish brown sedimentary rocks. Critchell soils are on fans, terraces, and valley sidelsopes and have slopes of 0 to 15 percent. The mean annual precipitation is about 17 inches and the mean annual temperature is about 47 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Argiustolls

TYPICAL PEDON: Critchell gravelly sandy loam, nonirrigated cropland. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 6 inches; very dark grayish brown (10YR 3/2) gravelly sandy clay loam, very dark grayish brown (10YR 3/3) moist; weak fine granular structure; slightly hard, very friable, slightly sticky; 15 to 20 percent pebbles; neutral; clear smooth boundary. (4 to 8 inches thick)

BA--6 to 9 inches; dark grayish brown (10YR 4/2) gravelly sandy clay loam, very dark grayish brown (10YR 3/2) moist; weak coarse subangular blocky structure; hard, very friable, slightly sticky; very thin clay films on faces of peds; 15 to 25 percent pebbles; neutral; clear smooth boundary. (2 to 5 inches thick)

Bt1--9 to 15 inches; dark brown (7.5YR 4/2) gravelly sandy clay loam, dark brown (7.5YR 3/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, friable, sticky; moderately thick continuous clay films on faces of peds; 15 to 25 percent pebbles; neutral; clear smooth boundary. (5 to 10 inches thick)

Bt2--15 to 26 inches; reddish brown (5YR 5/2) gravelly sandy clay loam, reddish brown (5YR 4/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; very hard, friable, sticky; moderately thick continuous clay films on faces of peds; 15 to 25 percent pebbles; neutral; clear smooth boundary. (8 to 16 inches thick)

BC--26 to 35 inches; reddish brown (5YR 5/4) gravelly sandy clay loam, reddish brown (5YR 4/4) moist; weak moderate prismatic structure parting to weak moderate subangular blocky; very hard, friable, sticky; few thin clay films on the faces of peds; 20 to 30 percent pebbles; neutral; gradual smooth boundary. (3 to 10 inches thick)

C1--35 to 52 inches; light reddish brown (5YR 6/4) gravelly sandy loam, reddish brown (5YR 4/4) moist; weak coarse prismatic structure parting to weak coarse subangular blocky; hard, friable; 30 to 35 percent pebbles; mildly alkaline; gradual smooth boundary. (10 to 22 inches thick)

C2--52 to 60 inches; pink (5YR 7/4) gravelly coarse sandy loam, reddish brown (5YR 5/4) moist; massive; hard, very friable; 30 to 40 percent pebbles; mildly alkaline.

TYPE LOCATION: Jefferson County, Colorado; approximately one mile west of the spillway of Chatfield Dam; 75 feet east and 320 feet south of the center of section 2, T. 6 S., R. 69 W.

RANGE IN CHARACTERISTICS: Thickness of the mollic epipedon is 7 to 16 inches. Solum thickness is 24 to 48 inches. These soils are generally noncalcareous; but some pedons are calcareous below a depth of 40 inches. Rock fragments range from 15 to 35 percent by volume in a major part of the solum and C horizon above 40 inches and are mainly less than 3 inches in diameter. Reaction is neutral or mildly alkaline.

The A horizon has hue of 10YR through 5YR, value of 3 through 5, 2 or 3 moist, and chroma of 2 or 3. it is sandy loam or loam with stony and gravelly modifiers.

The Bt horizon has hue of 7.5YR through 2.5YR, value of 3 through 6 dry, 3 or 4 moist, and chroma of 2 through 4. It is gravelly sandy clay loam, gravelly loam or gravelly light clay loam and averages 18 to 35 percent clay.

The C horizon has hue of 7.5YR through 2.5YR. It is gravelly sandy loam, gravelly sandy clay loam or gravelly loam. Stratification is common in the lower part.

COMPETING SERIES: These are the Ascalon, Bresser, Capulin, Dagflat, Featherlegs, Hargreave, Harlan, Kirtley, Lavate, Noden, Palmer Canyon, Rosebud, Ryegate, Satanta, Sugardee, Wages and Wolf series. Ascalon, Capulin, Featherlegs, Harlan, Kirtley, Palmer Canyon, Satanta, Sugardee, Wages and Wolf soils have horizons that contain secondary lime. Dagflat, Hargreave, Kirtley, Rosebud and Ryegate soils have a lithic or paralithic contact at depths less than 40 inches. Bresser, Lavate and Noden soils have less than 15 percent rock fragments in the A and B horizons.

GEOGRAPHIC SETTING: Critchell soils are on alluvial fans, terraces and valley side slopes. Slopes are 0 to 15 percent. Elevations are 5,300 to 6,200 feet. The soils formed in mixed alluvium derived from reddish brown sedimentary rocks. The soils are in a warm semiarid climate with annual precipitation of 15 to 19 inches. The mean annual temperature is about 46 degrees to 48 degrees F. The frost-free season is 125 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Lavate soils and the Stapleton, Rednun, and Yoder soils. Rednun soils have more than 35 percent clay in the argillic horizon. Stapleton and Yoder soils have coarse-loamy control sections.

DRAINAGE AND PERMEABILITY: Well-drained; slow to medium runoff; moderate permeability.

USE AND VEGETATION: Soils are used for grazing land or as dry and irrigated cropland. Native vegetation is mainly blue grama, western wheatgrass, and some sagebrush, rabbit brush, pinyon and juniper.

DISTRIBUTION AND EXTENT: Foothill area of east-central Colorado. The series is of small extent.

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

SERIES ESTABLISHED: Jefferson County, Colorado, 1980, Golden Area Soil Survey.

REMARKS:
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.


National Cooperative Soil Survey
U.S.A.