LOCATION MCLEAN TX+NM
Established Series
Rev. RM-TCB
09/2022
MCLEAN SERIES
The McLean series consists of very deep, somewhat poorly drained, very slowly permeable soils that formed in clayey lacustrine deposits of Quaternary age. These nearly level soils are on the floor of playas 1.5 to 23 m (5 to 75 ft) below the surrounding plain and range in size from a few acres to more than 200 acres. Slope ranges from 0 to 1 percent. Mean annual precipitation is 483 mm (19 in), and mean annual temperature is 16 degrees C (61 degrees F).
TAXONOMIC CLASS: Fine, smectitic, thermic Udic Haplusterts
TYPICAL PEDON: McLean clay, midway between microhigh and microlow, 0.3 percent slope in playa basin, in rangeland, at an elevation of about 1,050 m (3,445 ft). (Colors are for dry soil unless otherwise stated.)
A1--0 to 10 cm (0 to 4 in); dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; moderate medium subangular blocky structure parting to moderate medium granular; hard, firm; very sticky and very plastic; common fine to coarse roots; cracks 5 cm (2 in) wide at the surface extend through the horizon; few fine black (10YR 2/1) iron-manganese concretions; moderately alkaline; clear smooth boundary.
A2--10 to 18 cm (4 to 7 in); dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; moderate medium subangular blocky structure; very hard, very firm; very sticky and very plastic; common fine to coarse roots; common fine to coarse pores; cracks 5 cm (2 in) wide extend through the horizon; few fine black (10YR 2/1) iron-manganese concretions; moderately alkaline; clear smooth boundary. (combined thickness of the A horizons is 13 to 38 cm .)
Bss1--18 to 38 cm (7 to 15 in); dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; strong coarse and very coarse wedge-shaped aggregates parting to strong fine and medium angular blocky structure; extremely hard, extremely firm; very sticky and very plastic; common fine to coarse roots; common fine to coarse pores; common prominent slickensides; cracks 2.5 cm (1 in) wide extend through the horizon; few fine black (10YR 2/1) iron-manganese concretions; few very fine calcium carbonate nodules; moderately alkaline; gradual wavy boundary.
Bss2--38 to 53 cm (15 to 21 in); dark gray (10YR 4/1) clay; very dark gray (10YR 3/1) moist; strong coarse and very coarse wedge-shaped aggregates parting to strong fine and medium angular blocky structure; extremely hard, extremely firm; very sticky and very plastic; common fine to coarse roots; common fine to coarse pores; common prominent slickensides; cracks 2.5 cm (1 in) wide extend through the horizon; few very fine calcium carbonate nodules; few fine distinct brown (7.5YR 4/4) masses of iron accumulation in pore linings; moderately alkaline; gradual wavy boundary.
Bss3--53 to 94 cm (21 to 37 in); dark gray (10YR 4/1) clay; very dark gray (10YR 3/1) moist; strong coarse and very coarse wedge-shaped aggregates parting to strong fine and medium angular blocky structure; extremely hard, extremely firm; very sticky and very plastic; common fine and medium roots; common fine to coarse pores; common prominent slickensides; cracks 1.3 cm (0.5 in) wide extend through the horizon; few very fine calcium carbonate nodules; few fine distinct brown (7.5YR 4/4) masses of iron accumulation in pore linings; moderately alkaline; gradual wavy boundary.
Bss4--94 to 107 cm (37 to 42 in); dark grayish brown (2.5Y 4/2) clay, very dark grayish brown (2.5Y 3/2) moist; strong coarse and very coarse wedge-shaped aggregates parting to strong fine and medium angular blocky structure; extremely hard, extremely firm; very sticky and very plastic; common very fine and fine roots; common very fine and fine pores; common prominent slickensides; cracks 1.3 cm (0.5 in) wide extend to a depth of 102 cm (40 in); few fine calcium carbonate nodules; few fine distinct reddish brown (5YR 4/4) masses of iron accumulation in pore linings; moderately alkaline; gradual wavy boundary.
Bss5--107 to 150 cm (42 to 59 in); dark grayish brown (2.5Y 4/2) clay, very dark grayish brown (2.5Y 3/2) moist; strong coarse and very coarse wedge-shaped aggregates parting to strong fine and medium angular blocky structure; extremely hard, extremely firm; very sticky and very plastic; common very fine and fine roots; common very fine to fine pores; common prominent slickensides; about 1 percent threads and fine nodules of calcium carbonate; common fine and medium distinct reddish brown (5YR 5/4) masses of iron accumulation in pore linings; slightly effervescent; moderately alkaline; clear wavy boundary. (combined thickness of the Bss horizons is 76 to 152 cm .)
Bkss1--150 to 183 cm (59 to 72 in); grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; strong coarse and very coarse wedge-shaped aggregates parting to strong fine and medium angular blocky structure; extremely hard, extremely firm; very sticky and very plastic; common very fine and fine roots; common very fine and fine pores; common prominent slickensides; about 3 percent fine masses and nodules of calcium carbonate; common fine distinct reddish brown (5YR 5/4) masses of iron accumulation in pore linings; slightly effervescent; moderately alkaline; clear wavy boundary.
Bkss2--183 to 203 cm (72 to 80 in); grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; strong medium and coarse wedge-shaped aggregates parting to strong fine and medium angular blocky structure; very hard, very firm; very sticky and very plastic; few very fine roots; common very fine and fine pores; common prominent slickensides; about 4 percent fine masses and nodules of calcium carbonate; common fine and medium distinct reddish brown (5YR 5/4) masses of iron accumulation in pore linings; strongly effervescent; moderately alkaline; gradual wavy boundary. (combined thickness of the Bkss horizons is 13 to 76 cm. )
2Bk--203 to 224 cm (80 to 88 in); light reddish brown (5YR 6/4) clay, reddish brown (5YR 5/4) moist; moderate fine and medium angular blocky structure; very hard, very firm; very sticky and very plastic; few very fine and fine roots; few very fine and fine pores; about 8 percent fine and medium masses and nodules of calcium carbonate; common medium distinct dark grayish brown (10YR 4/2) iron depletions on surfaces of peds; strongly effervescent; moderately alkaline.
TYPE LOCATION: Carson County, Texas; from the intersection of U.S. Highway 60 and Texas Highway 207 in Panhandle; approximately 6.9 kilometers (4.3 miles) southwest on U.S. Highway 60; 3.5 kilometers (2.2 miles) south on county road; 1.6 kilometers (1 mile) east down turn row; 483 m (0.3 mile) south into playa basin. Latitude: 35 degrees 16 minutes 42.00 seconds north and Longitude: 101 degrees 26 minutes 7.00 seconds west; Panhandle West, Texas USGS topographic quadrangle; NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: An ustic moisture regime bordering on udic. The soil moisture control section cracks and is dry in some or all parts more than 90 but less than 150 cumulative days in normal years. July through August and November through March are the driest months. Intermittently moist from September through October and April through June. These soils receive runoff from surrounding uplands and the soil moisture control section is moist for longer periods of time than is normal for the climate of the series province.
Mean annual soil temperature: 15 to 18 degrees C (59 to 64 degrees F).
Depth to secondary calcium carbonate: 25 cm (10 in) to more than 152 cm (60 in).
Depth to slickensides: 13 to 38 cm (5 to 15 in).
Solum thickness: more than 203 cm (80 in).
Particle-size control section: 50 to 60 percent silicate clay.
This is a cyclic soil and undisturbed areas have gilgai microrelief with microhighs 10 to 46 cm (4 to 18 inches) higher than microlows. Distance between the center of the microhigh and the center of the microlow is about 1.5 to 4.6 m (5 to 15 ft). The microhigh makes up about 25 percent, the intermediate, or area between the high and low, about 50 percent, and the microlow about 25 percent. Cracks open and close each year except during higher-than-normal rainfall years, and remain open for less than 150 cumulative days during most years. When dry, 1 to 7.6 cm (0.4 to 3 in) wide cracks extend from the surface to a depth of 102 cm (40 in) or more. Cracks are more prominent in the microlows. COLE is more than 0.07. Where redox features exceed 3 percent, they occur in less than 25 percent of each pedon. The range in characteristics represents 50 percent or more of each pedon unless otherwise stated.
A horizon:
Hue: 7.5YR or 10YR
Value: 3 or 4, 2 or 3 moist
Chroma: 1 or 2
Redoximorphic features: none or few in the form of iron-manganese concretions or oxidized rhizospheres
Texture: clay
Effervescence: none to strong
Reaction: slightly acid to moderately alkaline
Bw horizon: (where present)
Hue: 10YR or 2.5Y
Value: 3 or 4, 2 or 3 moist
Chroma: 1 or 2
Redoximorphic features: none or few in the form of iron-manganese concretions or oxidized rhizospheres
Texture: clay
Effervescence: none to strong
Reaction: neutral to moderately alkaline
Bss horizon:
Hue: 10YR or 2.5Y
Value: 3 to 6, 2 to 5 moist
Chroma: 1 or 2
Redoximorphic features: none to common in the form of iron-manganese concretions or oxidized rhizospheres
Texture: clay
Visible calcium carbonate: ranges from 0 to 2 percent by volume in the form of films, threads, and nodules
Effervescence: none to strong
Reaction: neutral to moderately alkaline
Bkss horizon:
Hue: 10YR or 2.5Y
Value: 4 to 8, 3 to 7 moist
Chroma: 1 or 2
Redoximorphic features: none to common in the form of iron-manganese concretions or oxidized rhizospheres
Texture: clay
Calcium carbonate equivalent: less than 15 percent
Visible calcium carbonate: 3 to 10 percent as threads, masses, and nodules
Effervescence: strong or violent
Reaction: moderately alkaline
2Bk or 2Bt horizon: (where present)
Hue: 5YR to 5Y
Value: 4 to 7, 3 to 6 moist
Chroma: 1 or 2
Redoximorphic features: none to common in the form of iron-manganese concretions or oxidized rhizospheres
Texture: clay
Calcium carbonate equivalent: less than 15 percent
Visible calcium carbonate: 3 to 10 percent as threads, masses, and nodules
Effervescence: strong or violent
Reaction: moderately alkaline
COMPETING SERIES: These are the
Bleiblerville,
Branyon,
Burleson,
Clarita,
Deport,
Dimebox,
Ellis,
Fairlie,
Heiden,
Houston Black,
Lazare,
Leson,
Luling,
Ovan,
Sanger,
Slidell,
Sparenberg, and the
Watonga series. Similar soils also include the
Chapel,
Lazbuddie,
Lockney,
Ranco, and
Randall series.
Bleiblerville,
Branyon,
Burleson,
Clarita,
Deport,
Dimebox,
Ellis,
Fairlie,
Heiden,
Houston Black,
Lazare,
Leson,
Luling,
Ovan,
Sanger,
Slidell, and
Watonga series: have mean annual soil temperature more than 18 degrees C (65 degrees F) and are moist for longer periods in the soil moisture control section.
Chapel series: have a calcic horizon within 102 cm (40 in) of the mineral soil surface.
Lazare series: formed in lacustrine sediments derived from alluvium of Pleistocene age and are in a slightly moister climate.
Lazbuddie and
Lockney series: have cracks that remain open for more than 150 cumulative days during most years.
Ranco series: have aquic conditions for some time during normal years and have less than 50 percent clay in the particle-size control section.
Randall series: have aquic conditions for some time during normal years and have cracks that remain open for 90 or more cumulative days during most years.
Sparenberg series: have less than 50 percent clay in the particle-size control section.
GEOGRAPHIC SETTING:
Parent material: clayey lacustrine sediments derived from the Blackwater Draw Formation of Pleistocene age.
Landform: in playas 1.5 to 23 m (5 to 75 ft) below the surrounding plain and range in size from a few acres to more than 200 acres.
Slopes: range from 0 to 1 percent.
Mean annual air temperature: 14 to 17 degrees C (57 to 62 degrees F).
Mean annual precipitation: 432 to 533 mm (17 to 21 in).
Frost-free period: 180 to 220 days.
Elevation: 975 to 1,463 m (3,200 to 4,800 ft).
Thornthwaite annual P-E Index Values: 30 to 34.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the similar
Lazbuddie,
Lockney,
Lofton and
Randall series and
Arch,
Drake,
Estacado,
Pep, and
Portales series.
Lazbuddie and
Lockney soils are on similar or slightly higher landscape positions and have cracks that remain open for more than cumulative days during most years.
Lofton soils are on slightly higher landscape positions and have an argillic horizon.
Randall soils are on similar landscape positions and have aquic conditions.
Arch soils are on slightly higher landscape positions and have 35 percent or less clay in the particle-size control section.
Drake soils are on calcareous eolian dunes and have 35 percent or less clay in the particle-size control section.
Estacado soils are on surrounding plains and have an argillic horizon.
Portales and
Pep soils are on slightly higher landscape positions and have 18 to 35 percent clay in the particle-size control section.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Very slow permeability. Surface runoff is negligible. These soils occasionally pond for brief to long periods.
USE AND VEGETATION: Used mainly for livestock grazing with some areas used for
crop production. Many areas are planted to wheat in the fall and utilized for
livestock pasture during the winter months, or during dry years, some areas are
cultivated to cotton or grain sorghum. Native vegetation varies according to
amount of water available. It includes western wheatgrass, buffalograss, blue
grama, vine mesquite, Texas blueweed, kochia, western ragweed, cocklebur,
sunflower, and mares-tail. Bur ragweed, sedges, spike rushes, bushy knotweed,
frog-fruit, and saltmarsh aster may occur in wetter areas. This soil has been
correlated to the Playa (R077CY027TX) ecological site in MLRA-77C.
DISTRIBUTION AND EXTENT: Southern High Plains, Southern Part (MLRA 77C in LRR H) of western Texas and eastern New Mexico. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: MLRA-77 Soil Survey; Carson County, Texas; 1995
REMARKS: These soils were formerly included in the Lipan and Randall series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 38 cm. (0 to 15 in) (A and Bss1 horizons)
Vertic features: 18 to 203 cm (7 to 80 in) (Bss & Bkss horizons) wedge-shaped aggregates and slickensides. Cracks open and close each year except during higher-than-normal rainfall years, and remain open for less than 150 cumulative days during most years. When dry, 1 to 7.6 cm (0.4 to 3 in) wide cracks extend from the surface to a depth of 102 cm (40 in) or more.
ADDITIONAL DATA: NSSL data (S94TX-065-001) from Carson County, Texas, NSSL data (S96TX-153-001), (S96TX-153-002) from Floyd County, Texas.
Taxonomic Version: Keys to Soil Taxonomy Twelfth Edition, 2014.
National Cooperative Soil Survey
U.S.A.