LOCATION TASSI AZ

Established Series
Rev. AAD/PDC/WWJ
08/2019

TASSI SERIES

The Tassi series consists of shallow and very shallow to petrocalcic horizon, well drained soils that formed in mixed alluvium from sedimentary formations. Tassi soils are on structural benches, mesas and plateaus, and have slopes of 5 to 15 percent. The mean annual precipitation is about 12 inches and the mean annual air temperature is about 53 degrees F.
TAXONOMIC CLASS: Loamy, mixed, superactive, mesic, shallow Ustic Petrocalcids
TYPICAL PEDON: Tassi very gravelly loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 1 inch; light brown (7.5YR 6/3) very gravelly loam, brown (7.5YR 4/3) moist; weak thin platy and granular structure; soft, very friable, slightly sticky and slightly plastic; many fine and very fine and few medium roots; many fine vesicular and common fine irregular pores; 40 percent gravel; strongly effervescent with disseminated calcium carbonate, 19 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); abrupt smooth boundary. (1 to 3 inches thick)
Bk1--1 to 5 inches; light brown (7.5YR 6/4) gravelly loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine and very fine roots; common fine and very fine tubular and interstitial pores; 15 percent gravel; violently effervescent with disseminated calcium carbonate, 30 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); abrupt smooth boundary. (0 to 6 inches thick)
Bk2--5 to 10 inches; light brown (7.5YR 6/4) gravelly loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable, sticky and slightly plastic; common fine and very fine roots; common fine and very fine tubular and interstitial pores; 20 percent gravel; violently effervescent with disseminated calcium carbonate and few fine accumulations, 32 percent calcium carbonate equivalent; moderately alkaline (pH 8.2); abrupt smooth boundary. (3 to 10 inches thick)
Bkm1--10 to 12 inches; white (N8/) and pinkish white (7.5YR 8/2) indurated, calcium carbonate cemented hardpan with a 1 to 2 centimeter thick laminar cap; abrupt wavy boundary. (1 to 2 inches thick)
Bkm2--12 to 28 inches; white (N8/) and pinkish white (7.5YR 8/2) moderately to strongly calcium carbonate cemented hardpan; abrupt smooth boundary. (10 to 30 inches thick)
2R--28 inches; limestone.

TYPE LOCATION: Mohave County, Arizona; on the Grand Wash Bench about 12 miles southwest of Poverty Mountain; about 565 feet south and 2240 feet west of the northeast corner of section 32, T.34 N., R.13 W.; about 36 degrees, 18 minutes, 2 seconds north latitude and 113 degrees, 42 minutes, 28 seconds west longitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during July through September and December through February. Driest during May and June. Ustic aridic soil moisture regime.
Rock Fragments: Averages 15 to 35 percent rock fragments; ranges from 10 to 30 percent gravel and 0 to 5 percent cobble
Soil Temperature: 54 to 57 degrees F.
Organic Matter: 0.5 to 1 percent in the upper 1 to 3 inches
Depth to Petrocalcic Horizon: 5 to 20 inches
Depth to Lithic Contact: 20 to 40 inches
A horizon
Hue: 5YR, 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: sandy loam, loam
Reaction: slightly to moderately alkaline
Effervescence: slightly to strongly effervescent, 5 to 20 percent calcium carbonate equivalent
Rock fragments: 15 to 45 percent gravel, 0 to 5 percent cobble
Bk horizon
Hue: 5YR, 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4, dry or moist
Texture: loam, sandy loam (5 to 18 percent clay)
Effervescence: strongly to violently effervescent, 15 to 35 percent calcium carbonate equivalent
COMPETING SERIES: These are the Pastern (UT), Pastura (NM), Promontory (AZ), and Rolie (AZ) series. Esplin, Pastern, Pastura, and Rolie soils do not have bedrock within 60 inches of the surface. Promontory soils have rhyolite bedrock below the hardpan. In addition, Pastura soils are in the Western Great Plains (LRR-G) and are moist in May and June.
GEOGRAPHIC SETTING: Tassi soils are on structural benches, mesas and plateaus, and have slopes of 1 to 15 percent. These soils formed in mixed alluvium derived dominantly from sedimentary formations. Elevations range from 4500 to 6000 feet. The mean annual air temperature is 52 to 55 degrees F. Mean annual precipitation is 10 to 14 inches. The frost-free period is 150 to 165 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Rizno, Mellenthin and Strych soils. Rizno and Mellenthin soils are shallow to a lithic contact. Strych soils are very deep and contain more than 35 percent rock fragments.
DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability.
USE AND VEGETATION: Tassi soils are used for livestock grazing, recreation and wildlife habitat. The present vegetation is blackbrush, Wyoming big sagebrush, Stansbury cliffrose, green Mormon-tea, needleandthread, desert needlegrass, Indian ricegrass and bottlebrush squirreltail.
DISTRIBUTION AND EXTENT: Northwestern Arizona. The series is of limited extent. MLRA is 35. Name derived from Tassi Wash on the Grand Gulch Bench Quad.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Mohave County; Soil survey of the Shivwits Area, Arizona, Part of Mohave County; 1994.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 1 inch (A horizon)
Petrocalcic horizon - The zone from 10 to 28 inches (Bkm1, Bkm2 horizons)
Lithic contact - The boundary at 28 inches (2R horizon)
Classified according to Soil Taxonomy Second Edition, 1999.
Formerly classified as Ustollic Paleorthids.
Removed Esplin from competing series section because it changed to the Ustalfic Petrocalcids subgroup, tdc 08/2019.

National Cooperative Soil Survey
U.S.A.