LOCATION ZIGZAG                  CO

Established Series
Rev. DKR/CSW/JWB
04/2011

ZIGZAG SERIES

The Zigzag series consists of shallow and very shallow, well drained soils that formed in slope alluvium and/or colluvium from sedimentary rocks over residuum derived from Mancos shale. Zigzag soils are on hills, knobs, and ridges. Slopes range from 3 to 80 percent. Mean annual precipitation is about 14 inches and the mean annual temperature is about 48 degrees F.

TAXONOMIC CLASS: Clayey, smectitic, calcareous, mesic, shallow Aridic Ustorthents

TYPICAL PEDON: Zigzag very channery clay loam, on a southwest facing, 23 percent slope in pinyon-juniper woodland at an elevation of 6,560 feet. (Colors are for dry soil unless otherwise noted.) The surface is covered by 15 percent gravel, 5 percent stones, and 40 percent channers.

A1--0 to 1 inch; light brownish gray (10YR 6/2) very channery clay loam, brown (10YR 4/3) moist; strong fine granular structure; soft, very friable, moderately sticky and moderately plastic; violently effervescent; 15 percent gravel, 40 percent channers, and 5 percent stones; moderately alkaline (pH 8.2); abrupt smooth boundary. (1 to 7 inches thick)

A2--1 to 5 inches; light brownish gray (10YR 6/2) clay loam, dark grayish brown (10YR 4/2) moist; strong fine granular structure; soft, very friable, moderately sticky and moderately plastic; violently effervescent; 10 percent gravel and 2 percent channers; moderately alkaline (pH 8.2); abrupt wavy boundary. (0 to 6 inches thick)

C1--5 to 14 inches; light brownish gray (10YR 6/2) clay, grayish brown (10YR 5/2) moist; moderate medium prismatic structure parting to weak coarse subangular blocky; very hard, very firm, very sticky and very plastic; violently effervescent; moderately alkaline (pH 8.2); abrupt wavy boundary. (5 to 15 inches thick)

C2--14 to 19 inches; light brownish gray (10YR 6/2) clay, brown (10YR 5/3) moist; massive; very hard, very firm, very sticky and very plastic; violently effervescent; moderately alkaline (pH 8.4); abrupt wavy boundary.

Cr--19 to 29 inches; Mancos shale.

TYPE LOCATION: Montezuma County, Colorado; about 160 feet west of the Vo-Tech school, on the north side of Hwy 160; located about 1,800 feet south and 1,050 feet west of the northeast corner of sec.25, T. 36 N., R. 15 W.; Point Lookout, CO USGS quad; lat. 37 degrees 21 minutes 07 seconds N. and long. 108 degrees 26 minutes 48 seconds W., NAD27

RANGE IN CHARACTERISTICS:

Soil moisture regime: The soil moisture control section is affected by precipitation that peaks from July to October and falls evenly throughout the remainder of the year; ustic bordering on aridic

Soil temperature regime: mesic

Mean annual soil temperature: 47 to 52 degrees F

Mean summer soil temperature: 63 to 67 degrees F

Surface rock fragments: 0 to 50 percent boulders, stones, cobbles, channers and/or gravel

Particle-size control section: 35 to 55 percent clay

Depth to paralithic contact: 4 to 20 inches to Mancos shale

Depth to calcareous material: 0 to 3 inches

A horizon:
Hue: 10YR to 5Y
Value: 5 or 6 (3 to 5 moist)
Chroma: 2 to 4
Texture: clay loam
Rock fragments: 10 to 60 percent
Calcium carbonate equivalent: 1 to 15 percent
Reaction: slightly or moderately alkaline

C horizon (Bw horizon in some pedons):
Hue: 10YR to 5Y
Value: 5 to 7 (4 or 5 moist)
Chroma: 2 to 4
Texture: clay loam, clay, silty clay loam, or silty clay
Rock fragments: 0 to 15 percent
Pararock fragments: 0 to 60 percent
Calcium carbonate equivalent: 1 to 15 percent
Reaction: slightly or moderately alkaline

COMPETING SERIES: These are Epsie and Samsil series.
Epsie soils have an E and Bky horizon.
Samsil soils have accumulations of carbonates, gypsum, and salts.

GEOGRAPHIC SETTING:

Parent material: slope alluvium and/or colluvium from sedimentary rocks over residuum derived from Mancos shale

Landform: ridges, knobs, and hills

Slopes: 3 to 80 percent

Elevation: 6,000 to 7,500 feet

Mean annual temperature: 45 to 50 degrees F

Mean annual precipitation: 12 to 16 inches

Precipitation is fairly evenly distributed throughout the year with July and August being slightly wetter and June being slightly dryer.

Frost-free period: 100 to 135 days

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Sideshow, Gladel, and Pulpit series. Sideshow soils are very deep. Gladel and Pulpit soils have bedrock between 20 and 40 inches.

DRAINAGE AND PERMEABILITY: well drained, high or very high runoff, slow permeability

USE AND VEGETATION: These soils are used mainly for grazing. The native vegetation is pinyon, juniper, western wheatgrass, and galleta.

DISTRIBUTION AND EXTENT: Southwest Colorado and central Utah. LRR D, MLRA 34B and 36. This series is of small extent.

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

SERIES ESTABLISHED: Cortez Area, Colorado, Parts of Dolores and Montezuma Counties 1997.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

ochric epipedon: The zone from 0 to 5 inches. (A1 and A2)

Particle-size control section: The zone from 10 to 19 inches. (C1, C2)

The series replaces the Zyme series in the 13 to 16 inch precipitation zone in southwest Colorado due to the moisture regime change from the Four Corners Climate Conference of 10/92.

Soil Taxonomy Eleventh Edition, 2010.

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National Cooperative Soil Survey
U.S.A.