LOCATION GYPILL                  AZ

Established Series
Rev. AAD/DEW/PDC
04/2015

GYPILL SERIES

The Gypill series consists of very shallow and shallow, well drained soils that formed in materials weathered from gypsiferous mudstone, shale and gypsum rock. Gypill soils are on eroding hills and escarpments with slopes of 5 to 50 percent. The mean annual precipitation is about 9 inches and mean annual air temperature is about 64 degrees F.

TAXONOMIC CLASS: Loamy, gypsic, thermic, shallow Typic Torriorthents

TYPICAL PEDON: Gypill fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 2 inches; pink (7.5YR 7/4) fine sandy loam, brown (7.5YR 5/4) moist; moderate medium platy structure; soft, very friable, nonsticky and nonplastic; very few very fine roots; many fine and very fine vesicular pores; 2 percent gypsum; strongly effervescent, 33 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 2 inches thick)

Cy--2 to 6 inches; pale yellow (5Y 7/3) fine and medium sand sized dispersed crystalline gypsite with white (N 8/) 1 to 2 cm bands of harder more consolidated crystalline gypsite and 10 to 20 percent loamy material, pale olive and white (5Y 6/3 and N 8/) moist; slightly hard and hard, friable and firm, nonsticky and nonplastic; many fine and very fine irregular pores; 32 percent gypsum; slightly effervescent, 30 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); abrupt smooth boundary. (3 to 10 inches thick)

Cr1--6 to 10 inches; white, pink and light brownish gray (N 8/, 5YR 8/4, 2.5YR 6/2) stratified weathered gypsiferous materials (crystalline gypsite, siltstone and mudstone); very hard, very firm; 40 percent gypsum; noneffervescent; abrupt boundary. (0 to 10 inches thick)

Cr2--10 to 60 inches; hard gypsite.

TYPE LOCATION: Mohave County, Arizona; about 0.7 mile south of the Arizona - Utah state line on the Sunshine Trail, southeast of St. George, Utah; 100 feet south and 2800 feet east of the northwest corner of section 3, T.41 N., R.11 W.; Latitude 36 degrees 59 minutes 28 seconds N, Longitude 113 degrees 28 minutes 10 seconds W.

RANGE IN CHARACTERISTICS:

Soil Moisture: Intermittently moist in some part of the soil moisture control section during July - September and December - February. Driest during May and June. Typic aridic soil moisture regime.

Rock Fragments: less than 15 percent in the control section

Soil Temperature: 59 to 72 degrees F.

Depth to accumulation of gypsum: 1 to 2 inches (30 to 90 percent gypsum)

Depth to bedrock: 4 to 15 inches


A horizon

Hue: 5YR, 7.5YR, 10YR

Value: 5 through 7 dry, 4 through 6 moist

Chroma: 4 through 6, dry or moist

Gypsum: 1 to 20 percent

Calcium carbonate equivalent: 5 to 25 percent

Reaction: slightly or moderately alkaline


Cy horizon

Hue: 5YR, 7.5YR, 10YR, 2.5Y, 5Y

Value: 5 through 8 dry, 4 through 8 moist

Chroma: 2 through 6, dry or moist

Texture: sandy loam, loam; 50 to 90 percent sand sized crystalline gypsite (containing 3 to 10 percent clay)

Reaction: slightly or moderately alkaline

Gypsum: 30 to 90 percent

Calcium carbonate equivalent: 5 to 35 percent


Cr horizon

Highly gypsiferous bedding planes of reprecipitated geogenic gypsite. Not a gypsic horizon.


COMPETING SERIES: This is the Holloman (NM) series. Holloman soils contain more than 10 percent clay in the control section.

GEOGRAPHIC SETTING: Gypill soils are on eroding hills and escarpments with slopes of 5 to 50 percent. These soils formed in mixed colluvium, eolian and alluvial materials. Elevation ranges from 1600 to 4500 feet. Mean annual precipitation is 6 to 12 inches. The mean annual air temperature is 57 to 70 degrees F. The frost-free period is 180 to 240 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hobog and Nikey soils. Hobog soils are over limestone and loamy-skeletal. Nikey soils are very deep and coarse-loamy.

DRAINAGE AND PERMEABILITY: Well drained; rapid or very rapid runoff; moderate permeability.

USE AND VEGETATION: The Gypill soils are used for limited livestock grazing. Gypsum mines are common in the area. The present vegetation is mound saltbush, creosotebush, fourwing saltbush, gyp dropseed, big galleta, Mormon-tea and annuals.

DISTRIBUTION AND EXTENT: Northern Arizona. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: PHOENIX, ARIZONA

SERIES ESTABLISHED: Mohave County; Soil survey of Shivwits Area, Arizona, Part of Mohave County; 1994.

REMARKS: Bedrock originally proposed as a paralithic contact. Subsequently correlated as lithic due to textbook hardness of gypsum by Mohs scale. The lithology is gypsite which is a reprecipitated form of gypsum. Gypsite is not a single mineral and does disperse during shaking. Classification is corrected to the original field proposal.

Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - The zone from 0 to 2 inches (A horizon)

Paralithic contact - The boundary at 6 inches (Cr horizon)


ADDITIONAL DATA:

NSSL Reference sample S89AZ - 015 - 2

Responsibility for this series was transferred from Davis to Phoenix 4/2015. The last revision to the series was 5/1997. ET

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National Cooperative Soil Survey
U.S.A.