LOCATION KIRVIN                  TX+AR LA OK

Established Series
GLL;RD;Rev.KLG, TR
10/2011

KIRVIN SERIES

The Kirvin series consists of deep, well drained soils. These gently sloping to moderately steep soils formed in stratified sandstone and shale derived from marine sediments on uplands of the Claiborne geological group. Slopes are dominantly 2 to 8 percent but range from 1 to 15 percent. Mean annual precipitation is about 1118 mm (44 in) and mean annual air temperature is about 18 degrees C (65 degrees F).

TAXONOMIC CLASS: Fine, mixed, semiactive, thermic Typic Hapludults

TYPICAL PEDON: Kirvin very fine sandy loam, elevation is 125 m (410 ft) (Elevation estimated from topographic software, following location directions below) (Colors are for moist soil unless otherwise stated.)

A--0 to 10 cm (0 to 4 in); brown (10YR 4/3) very fine sandy loam; weak fine granular structure; soft, very friable; common fine and few medium and coarse roots; about 10 percent by volume ironstone gravel; strongly acid; clear smooth boundary (8 to 20 cm [3 to 8 in]thick)

E--10 to 28 cm (4 to 11 in); pale brown (10YR 6/3) very fine sandy loam; weak fine subangular blocky structure; soft, very friable; common fine and few medium and coarse roots; about 5 percent by volume ironstone gravel; strongly acid; clear wavy boundary (0 to 30 cm [0 to 12 in]thick)

Bt1--28 to 58 cm (11 to 23 in); red (2.5YR 4/6) clay; moderate fine and medium angular blocky structure; hard, firm; few fine and medium roots; thin continuous clay films; about 3 percent by volume of ironstone fragments less than 3 inches across; very strongly acid; clear wavy boundary

Bt2--58 to 104 cm (23 to 41 in); red (2.5YR 4/6) clay; moderate medium angular blocky structure; hard, firm; few fine and medium roots; thin continuous clay films; common fine prominent strong brown (7.5YR 5/6) lithochromic mottles; very strongly acid; clear wavy boundary (64 to 114 cm [25 to 45 in]thick)

BCt--104 to 119 cm (41 to 47 in); yellowish red (5YR 5/8) clay; moderate coarse angular blocky structure; hard, firm; few fine and medium roots; red clay films on surface of peds; few flakes of mica; few weathered sandstone and shale fragments; common fine prominent distinct light brownish gray (10YR 6/2) and yellowish brown (10YR 5/8) lithochromic mottles; extremely acid; clear wavy boundary

Cd--119 to 163 cm (47 to 64 in); stratified layers of red (2.5YR 4/6) and yellowish red (5YR 5/8) weakly consolidated sandstone with sandy clay loam texture and light brownish gray (10YR 6/2) platy shale with clay texture, layers are mainly less than 1 inch thick; very hard, friable; few fine and medium roots mainly along vertical fractures; few flakes of mica; extremely acid (0 to 38 cm [0 to 15 in]thick)

TYPE LOCATION: Smith County, Texas; from TX 110, 6.8 miles southeast on FR 346; 100 feet north of road in woodland. (Latitude: 32 degrees, 11 minutes, 5.50 seconds N; Longitude: 95 degrees, 8 minutes, 0.61 seconds W. (Coordinates estimated from location directions and topographic software) Troup West, TX, TOPOGRAPHIC QUADRANGLE; NAD 83).

RANGE IN CHARACTERISTICS:
Soil Moisture: An udic soil moisture regime. The soil moisture control section is not dry in any part for as long as 90 cumulative days in normal years.

Mean annual soil temperature: 19 to 21 degrees C (66 to 70 degrees F)
Depth to argillic horizon: 8 to 51 cm (3 to 20 in)
Depth to redox concentrations: 33 to 76 cm (13 to 30 in)
Thickness of the solum, 100 to 150 cm (40 to 60 in)
Depth to densic layer: 100 to 150 cm (40 to 60 in)

Particle-size control section (weighted average):
Clay content: 35 to 50 percent
CEC/clay ratio: 0.24 to 0.40

A Horizon
Hue: 7.5YR or 10YR
Value: 3 to 5
Chroma: 2 to 4.
Texture: Fine sandy loam, very fine sandy loam or their gravelly counterparts; a graded phase which also includes sandy clay loam or clay loam surface textures is recognized
Clay content: 2 to 15 percent
Rock fragments: 1 to 50 percent ironstone gravel
Reaction: very strongly acid to neutral (4.5 to 7.3)

E Horizon
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 2 to 4
Texture: Fine sandy loam, very fine sandy loam, or their gravelly counterparts
Clay content: 2 to 15 percent
Rock fragments: 1 to 50 percent ironstone gravel
Reaction: very strongly acid to slightly acid (4.5 to 6.5) unless limed

Bt Horizon
Hue: 2.5YR or 5YR
Value: 3 to 5
Chroma: 4 to 8
Texture: clay, sandy clay or clay loam
Clay content: 35 to 60 percent
Clay films: on ped faces
Lithochromic mottles: none to common, fine or medium in shades of brown
Rock fragments: grayish platy shale fragments are in the lower part of some pedons
Base saturation: less than 35 percent
Reaction: extremely acid to strongly acid (3.6 to 5.5)

BCt Horizon
Hue: 2.5YR, 5YR, 7.5YR, 10YR
Value: 3 to 5
Chroma: 4 to 8
Texture: fine sandy loam, sandy clay loam, clay loam or clay
Clay content: 25 to 50 percent
Clay films: on ped faces
Lithochromic mottles: none to common, fine or medium in shades of gray or brown
Rock fragments: none to common sandstone or shale materials
Base saturation: Less than 35 percent
Reaction: extremely aicd or very strongly acid (3.6 to 5.0)

C/Bt Horizon (where present)
Hue: 2.5YR, 5YR, 7.5YR, 10YR
Value: 3 to 5
Chroma: 4 to 8
Texture: Fine sandy loam or sandy clay loam in the sandstone materials, and clay loam or clay in the shale materials. The amount of sandstone or shale materials is variable and there may none of either in some pedons.
Clay content: variable
Clay films: on faces of peds (Bt)
Reaction: extremely acid to strongly acid (3.6 to 5.5)

Cd Horizon
Hue: 2.5YR, 5YR, 7.5YR, 10YR
Value: 3 to 5
Chroma: 1 to 8
Texture: Fine sandy loam or sandy clay loam in the sandstone materials, and clay loam or clay in the shale materials. The amount of sandstone or shale materials is variable and there may none of either in some pedons.
Clay content: variable
Reaction: extremely acid to strongly acid (3.6 to 5.5)

COMPETING SERIES: These are the Albertville (AL), Badin (NC), Bengal (OK), Bonwier (TX) the Brockroad (VA), Carnasaw (OK), Catharpin (VA), Coghill (TN), Corryton (TN), Cunningham (GA), Cuthbert (TX), Galilee (TX), Luverne (AL), Marbledale (TN), Masada (VA), Mayodan (NC), McQueen (AL), Nason (VA), Peakin (NC), Sweatman (TX), Tatum (NC), Townley (AL), Uwharrie (NC) and Vance (NC) series.
Albertville soils: have a Bt horizon with hue yellower than 5YR
Badin soils: are underlain by fine-grained metavolcanic bedrock at a depth of 50 to 100 cm (20 to 40 in)
Bengal soils: have an irregular lower boundary over tilted shaly bedrock of Pennsylvanian age
Bonwier soils: soils formed in Pleistocene age parent materials
Brockroad soils: have a 2Bt horizon and do not have ironstone fragments
Carnasaw soils: have an irregular lower boundary over tilted shaly bedrock of Pennsylvanian age
Catharpin soils: have a 2Bt horizon and do not have ironstone fragments
Coghill soils: formed in residuum from Ordovician-aged limestones, shales, and sandstones and have a solum that is 50 to 100 cm (20 to 40 in) thick
Corryton soils: formed in residuum weathered from Cambrian and Ordovician aged shales
Cunningham soils: have base saturation of more than 35 percent in upper part of the Bt horizon and have a solum that ranges from 50 to 100 cm (20 to 40 in) thick
Cuthbert soils: have a solum that ranges from 50 to 100 cm (20 to 40 in) thick
Galilee soils: formed in Pleistocene age parent materials
Luverne soils: do not have ironstone fragments
Marbledale soils: formed in alluvium and do not have shale or sandstone layers
Masada soils: formed in alluvium and do not have shale or sandstone layers
Mayodan soils: formed in materials weathered from Triassic age sandstone, mudstone, shale, and siltstone
McQueen soils: formed in alluvium and do not have shale or sandstone layers
Nason soils: formed in residuum from sericite schist or phyllite
Peakin soils: have a seasonal high water table at a depth of 3.0 to 6.0 feet
Sweatman soils: have a solum that ranges from 50 to 100 cm (20 to 40 in) thick and have more than 30 percent silt in the particle-size control section
Tatum soils: formed in residuum from sericite schist or phyllite
Townley soils: have a solum that is 50 to 100 cm (20 to 40 in) thick
Uwharrie soils: formed in residuum weathered from fine grained metamorphic or igneous pyroclastic rocks
Vance soils: formed in residuum weathered from felsic crystalline rock, primarily aplitic granite, and have a solum that ranges from 20 to 40 inches thick

GEOGRAPHIC SETTING:
Parent material: weakly consolidated loamy and shaly materials derived from the Claiborne geologic group of the Tertiary System
Landscape: Coastal Plain
Landform: convex interfluves
Slope: mainly 2 to 8 percent but ranges from 1 to 15 percent
Mean annual air temperature range: 18 to 20 degrees C (64 to 68 degrees F)
Mean annual precipitation range: 1016 to 1219 mm (40 to 48 in)
Frost-free period: 235 to 270 days
Elevation: 44.8 to 198 m (160 to 650 ft)
Thornthwaite annual P-E indices: exceeds 64

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cuthbert (TX), Bowie (TX), Nacogdoches (TX) Redsprings (TX), Sacul (TX), Tenaha (TX) and Trawick (TX) series.
Cuthbert soils: have a 50 to 100 cm (20 to 40 inch) solum and are typically on sideslopes above drainageways
Bowie soils: Bowie soils are fine-loamy, are on lower concave positions and have a solum thickness of 150 cm (60 inch)
Nacogdoches soils: are alfisols, occur in higher positions on the landscape, and have a solum thickness of 150 cm (60 inch)
Redsprings soils: are alfisols, occur in higher positions on the landscape, and have a solum thickness of 100 to 150 cm (40 to 60 in)
Sacul soils: have grayish iron depletions and aquic conditions in the upper part of the Bt horizon and occur on concave or plane surfaces
Tenaha soils: have a sandy epipedon 20 to 40 inches thick and are commonly on side slopes above drainageways
Trawick soils: are alfisols, occur in higher positions on the landscape, and have a solum thickness of 100 to 150 cm (40 to 60 in)

DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium on slopes of less than 5 percent, and high slopes of 5 to 15 percent.

USE AND VEGETATION: Used primarily for pastureland and woodland. Forests consist of shortleaf, slash, and loblolly pine, red oak, sweetgum, and other hardwood trees.

DISTRIBUTION AND EXTENT: Southern Coastal plains of Texas, Louisiana, Oklahoma, and Arkansas; MLRA 133B; the series is of large extent.

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

SERIES ESTABLISHED: Freestone County, Texas, 1918.

REMARKS: The series was updated in 2002 to allow very strongly acid reaction in the A horizon and strongly acid reaction in the C or Cd horizon based on documentation collected in Shelby County, Texas. The series was updated in 2004 to allow a BCt horizon below the Bt horizon in some pedons.

Diagnostic horizons and features recognized in this pedon are:
Particle size control section: 28 to 78 (11 to 31 in). (Bt horizons)
Ochric epipedon: 0 to 28 cm (0 to 11 in). (A and E horizons)
Argillic horizon: 28 to 119 cm (11 to 47 in). (Bt and BCt horizons)

Additional Comments:

The assignment of the cation-exchange activity class is supported by laboratory data number S72TEX-212-1 from Smith County, Texas.

ADDITIONAL DATA: NSSL data from OSD type location, S72TEX-212-1. Particle-size analysis tests have been performed at various soil survey offices on over 50 pedons.

TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006

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National Cooperative Soil Survey
U.S.A.