LOCATION SPECK TX
Established Series
Rev. HCD-ALN-BJW
01/2017
SPECK SERIES
The Speck series consists of shallow, well drained, slowly permeable soils formed in residuum and colluvium derived from indurated limestone. These soils nearly level to moderately sloping soils occur on interfluves, side slopes, and base slopes of hills and ridges. Slope ranges from 0 to 8 percent. Mean annual precipitation is about 686 mm (27 in), and mean annual air temperature is about 18.3 degrees C (65 degrees F).
TAXONOMIC CLASS: Clayey, mixed, superactive, thermic Lithic Argiustolls
TYPICAL PEDON: Speck clay loam--rangeland.
(Colors are for dry soil unless otherwise stated.)
A--0 to 20 cm; (0 to 8 in); brown (7.5YR 4/2) clay loam, dark brown (7.5YR 3/2) moist; moderate fine subangular blocky and granular structure; hard, firm; few fine roots; few chert pebbles; slightly acid; clear smooth boundary. Thickness is 10 to 23 cm (4 to 9 in)
Bt--20 to 46 cm; (8 to 18 in); reddish brown (5YR 4/4) clay, dark reddish brown (5YR 3/4) moist; moderate fine angular blocky structure; very hard, very firm; few fine roots; few fine pores; common clay films on faces of peds; few fine calcium carbonate concretions in the lower 2 inches; neutral; abrupt wavy boundary. Thickness is 18 to 36 cm (7 to 14 in)
R--46 to 56 cm; (18 to 22 in); indurated limestone bedrock that is fractured with few calcium carbonate coatings in fractures; hardness of 3 or more on Moh's scale.
TYPE LOCATION: Coleman County, Texas; 14 miles S 37 degrees E of Coleman County Courthouse; in rangeland 225 feet east of a point on a ranch trail, which is 600 feet north of a fork in the trail and 1.6 miles east of intersection of private ranch trail and county road which intersection is 0.1 mile north and 1.5 miles east of intersection Farm Road 2633 and U. S. Highway 283.
RANGE IN CHARACTERISTICS:
Soil Moisture: Typic Ustic soil moisture regime. The soil moisture control section is dry in some or all parts for more than four-tenths and less than six-tenths of the cumulative days in normal years.
Depth to lithic bedrock: 36 to 51 cm, (14 to 20 in)
Thickness of the mollic epipedon: 18 to 48 cm (7 to 19 in)
Rock fragments on the surface and in the soil: 1 to 25 percent total; gravel are mostly angular chert fragments; cobbles and stones are mostly limestone
Particle-size control section (weighted average)
Clay content: 35 to 60 percent
Rock fragments: 1 to 25 percent
A Horizons
Hue: 5YR, 7.5YR, 10YR
Value: 2 to 4
Chroma: 2 to 3
Texture: clay loam, silty clay loam, clay, or their cobbly or stony counterparts
Effervescence: none
Reaction (pH): slightly acid to slightly alkaline (6.1 to 7.8)
Bt Horizon
Hue: 2.5YR, 5YR, 7.5YR
Value: 3 to 5
Chroma: 2 to 4
Texture: clay loam, clay, silty clay
Clay content: 35 to 60 percent
Identifiable secondary carbonate: occur in some pedons as concretions just above the limestone bedrock or as coatings on the surface of fragments and in fractures
Effervescence: typically none, but ranges to slight
Reaction (pH): neutral to moderately alkaline (6.6 to 8.4)
R layer
Texture: indurated limestone or limestone conglomerate with a hardness of more than 3 on Moh's scale
Cracks and fractures: fractured in some pedons
Identifiable secondary carbonate: when fractured, small amounts occur as coatings on the surface of fragments and in fractures
COMPETING SERIES: There are no series in the same family. Similar soils are the
Bexar,
Comfort,
Eckrant,
Harper,
Hensley,
Oglesby,
Purves,
Roughcreek,
Rowden,
Rumple,
Talpa, and
Tarpley series.
Bexar,
Rowden, and
Rumple soils: are 51 to 102 cm (20 to 40 in) deep to bedrock.
Comfort,
Eckrant, and
Roughcreek soils: have more than 35 percent rock fragments in the particle-size control section.
Harper,
Oglesby, and
Purves soils: have smectitic mineralogy and do not have an argillic horizon.
Hensley soils: do not have a mollic epipedon and are moist for longer periods.
Talpa soils: have less than 35 percent clay content in the particle-size control section and do not have an argillic horizon.
Tarpley soils: have more than 60 percent clay in the particle-size control section and smectitic mineralogy.
GEOGRAPHIC SETTING:
Parent material: reddish residuum and colluvium derived from indurated limestone
Landscape: Dissected plains or plateau
Landform: Interfluve, side slope, and base slope of hills and ridges
Slope: 0 to 8 percent
Mean annual precipitation: 559 to 762 mm (22 to 30 in)
Thornthwaite P-E Index: 32 to 46
Mean annual air temperature: 17.2 to 18.9 degrees C (63 to 66 degrees F)
Frost-free period: 210 to 240 days
Elevation: 381.0 to 762.0 m (1,250 to 2,500 ft)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Kavett,
Lueders,
Oplin,
Rowden, and
Tarrant series.
Kavett soils: occur on similar positions, have a petrocalcic horizon, and do not have an argillic horizon.
Lueders and
Oplin soils: occur on similar positions, have less than 35 percent clay content and more than 35 percent rock fragments in the particle-size control section, and do not have an argillic horizon.
Rowden soils: occur on similar positions and are 51 to 102 cm (20 to 40 in) deep to bedrock.
Tarrant soils: occur on similar positions, have more than 35 percent rock fragments in the particle-size control section, and do not have an argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is medium on slopes less than 1 percent, high on 1 to 5 percent slopes, and very high on 5 to 8 percent slopes.
USE AND VEGETATION: Used mainly for rangeland. Some areas are used for small grain and grain sorghums. Native vegetation consists of little bluestem, sideoats grama, Texas wintergrass, threeawn, and a few post oak and live oak trees.
DISTRIBUTION AND EXTENT: Central Texas; LRRs H & I, MLRA 78A - Rolling Limestone Prairie, MLRA 80B - Texas North-Central Prairies, MLRA 81 - Edwards Plateau. The soil is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Travis County, Texas; 1969.
REMARKS:
Edited 01/2017 (RFG-ROG): Changed to tabular format. Added metric measurements. Updated competing series, geographic setting, and associated soils sections.
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: 20 to 46 cm (8 to 18 in)
Mollic epipedon: 0 to 20 cm (0 to 8 in) (A horizon)
Argillic horizon: 20 to 46 cm (8 to 18 in) (Bt horizon)
Lithic contact: 46 cm (18 in) indurated limestone bedrock
ADDITIONAL DATA:
Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014
National Cooperative Soil Survey
U.S.A.