LOCATION SAN SABA                TX+OK

Established Series
Rev. CLN;GLL:JMG
01/2017

SAN SABA SERIES

The San Saba series consists of moderately deep, moderately well drained, very slowly permeable soils that formed in calcareous clayey slope alluvium and/or residuum over hard limestone. These nearly level to gently sloping soils occur on ridges on hills. Slope ranges from 0 to 5 percent. Mean annual precipitation is about 838 mm (33 in), and mean annual air temperature is 19.4 degrees C (66 degrees F).

TAXONOMIC CLASS: Fine, smectitic, thermic Leptic Udic Haplusterts

TYPICAL PEDON: San Saba clay--cropland.
(Colors are for dry soil unless otherwise stated.)

Ap--0 to 10 cm (0 to 4 in); dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; moderate fine and medium granular structure; extremely hard, very firm; few fine roots; very slightly effervescent; slightly alkaline; clear smooth boundary. Thickness is 10 to 15 cm (4 to 6 in)

A--10 to 48 cm (4 to 19 in); very dark gray (10YR 3/1) clay, black (10YR 2/1) moist; moderate medium angular blocky structure; extremely hard, very firm; few fine roots; streaks of dark gray in old crack fillings; common pressure faces; few fine iron-manganese concretions; very slightly effervescent; slightly alkaline; gradual wavy boundary. Combined thickness of the A horizons is 25 to 66 cm (10 to 26 in)

Bss--48 to 89 cm (19 to 35 in); dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; common prominent slickensides and wedge shaped peds tilted 30 to 45 degrees from horizontal, these part to moderate fine angular blocky structure; extremely hard, very firm; few calcium carbonate concretions; few fine iron-manganese concretions; slightly effervescent; moderately alkaline; abrupt smooth boundary. Thickness is 30 to 76 cm (12 to 30 in)

R--89 to 97 cm (35 to 38 in); gray indurated fractured limestone; fractures about 8 to 20 inches apart; hardness of about 3 Mohs scale.

TYPE LOCATION: Bell County, Texas; from junction of Interstate 35 and Texas Highway 36 in Temple; 6 miles northwest on Texas Highway 36 to Texas Highway 317; 1.1 miles north on Texas Highway 317 to private road; 1,600 feet west of junction with private road.
USGS topographic quadrangle: Moffat, TX;
Latitude: 31 degrees, 10 minutes, 32.18 seconds, N;
Longitude: 97 degrees, 25 minutes, 7.70 seconds, W;
Datum: WGS84.
UTM Easting 650681.98 m, UTM Northing 3450140.28 m; UTM Zone 14.

RANGE IN CHARACTERISTICS:
Soil moisture: a Udic-ustic soil moisture regime
Depth to lithic contact: 61 to 100 cm (24 to 40 in)
Thickness of mollic epipedon: 25 to 91 cm (10 to 36 in)
Depth to slickensides: 10 to 66 cm (4 to 26 in)
Vertic features: When dry, cracks range from 2.5 to 8 cm (1 to 3 in) wide and extend from the surface to depths of51 cm (20 in) or more. Cracks open and close on the average more than once each year, and remain open from 90 to 150 cumulative days in most years.
Gilgai microrelief: Undisturbed areas have knolls 8 to 15 cm [3 to 6 in] higher than depressions and distance between the center of knolls and center of the depressions ranges from 6 to 12 feet.

Particle-size control section (weighted average)
Clay content: 45 to 60 percent
Rock fragments: Some pedons contain 5 to 10 percent fragments of limestone ranging from 13 to 51 mm (0.5 to 2 in) in diameter.

A horizon
Hue: 10YR
Value: 3 to 4 dry, 3.5 or less moist
Chroma: 1
Texture: clay
Clay content: 45 to 60 percent
Rock fragments: 0 to 10 percent; 2-51 mm; strongly cemented to indurated limestone
Effervescence: dominantly very slight to strong, but some pedons are noneffervescent to depths of 51 cm (20 in)
Reaction (pH): slightly alkaline or moderately alkaline (7.4 to 8.4)

Bss horizon
Hue: 10YR to 5Y
Value: 4 to 5
Chroma: 1 to 3; Most pedons that have chroma of 2 or 3 are distinctly mottled with gray.
Texture: clay or silty clay
Clay content: 45 to 60 percent
Rock fragments: 0 to 10 percent; 2-51 mm; strongly cemented to indurated limestone
Effervescence: slight to violent
Reaction (pH): slightly alkaline or moderately alkaline (7.4 to 8.4)

R layer
Kind: coarsely fractured, indurated limestone that may be interbedded with clay or chalk

COMPETING SERIES: These are the Crawford, Dalco, and Greenvine soils in the same family and the similar Anhalt, Dephalt, and Vertel series. Anhalt, Crawford and Dephalt soils: have hue of 7.5YR or redder throughout
Anhalt soils: contains more than 60 percent clay content in the particle-size control section
Dalco soils: have a paralithic contact with chalk
Greenvine soils: have a paralithic contact with tuffaceous siltstone or sandstone
Vertel soils: contains more than 60 percent clay content in the particle-size control section and have a paralithic contact with shale

GEOGRAPHIC SETTING:
Parent Material: calcareous clayey slope alluvium and/or residuum derived from clayey marl and limestone underlain by hard limestone
Landscape: hills
Landform: head slopes, footslopes and toeslopes of ridges
Slope: 0 to 5 percent, but predominantly from 0.5 to 2 percent
Mean annual precipitation range: 762 to 1016 mm (30 to 40 in)
Thornthwaite P-E index: 44 to 64
Mean annual air temperature range: 17.2 to 20.0 degrees C (63 to 68 degrees F)
Frost free period: 225 to 260 days
Elevation: 182.9 to 396.2 m (600 to 1300 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Crawford series and the Bolar, Denton, Eckrant, Krum, Purves, and Slidell series.
Bolar soils: contain more than 40 percent carbonates, do not have slickensides, and occur on similar positions
Crawford soils: occurs on slightly higher positions
Denton soils: are deep to bedrock, have a fine-silty particle-size control section, and occur on slightly higher positions
Eckrant soils: are less than 51 cm (20 in) deep to bedrock, have more than 35 percent fragments in the particle-size control section, and occur on similar positions
Krum and Slidell soils: are very deep to bedrock and occur on slightly lower positions
Purves soils: are less than 51 cm (20 in) deep to bedrock and occur on similar positions

DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very slow. Runoff is high on slopes less than 1 percent and very high on slopes from 1 to 5 percent.

USE AND VEGETATION: In cultivation, pasture and range. Cultivated crops are mostly grain sorghum, corn, small grain, and cotton. Native rangeland is mid and tall grasses with a widely spaced overstory of live oak. Most pasture areas are planted to coastal bermudagrass.

DISTRIBUTION AND EXTENT: Central Texas and southern Oklahoma; LRR J and limited acreage in LRR I, MLRA 85 and small areas of MLRAs 81C and 84B. This series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: San Saba County, Texas; 1916.

REMARKS:
Edited 01/2017 (RFG-TRD): Converted to tabular format and added metric units. Updated competing series, geographic setting, and associated soils sections.

Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 89 cm (0 to 35 in), moist chroma of less than 1.5 in the upper 12 inches in more than half of each pedon.
Vertic features - 48 to 89 cm (19 to 35 in). High shrink-swell potential and cracks that are 1.5 to 3 cm (1/2 to 1 in) wide at a depth 30 cm (12 in) or more during dry periods in most years.
Lithic contact - 89 cm (35 in).

ADDITIONAL DATA: None

Taxonomic Version: Keys to Soil Taxonomy, 12th Edition, 2014

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National Cooperative Soil Survey
U.S.A.