LOCATION OCHILTREE OK+KS TX

Tentative Series
SLM-CPH-JTB
03/2017

OCHILTREE SERIES

The Ochiltree series consists of very shallow, somewhat excessively drained, moderately rapid permeable soils that formed in loamy calcareous caliche colluvium from the Ash Hollow or Kimball Members, Ogallala Formation of Miocene-Pliocene age. These soils are on gently sloping to steep hillslopes in the Southern High Plains, Breaks (MLRA 77E). The slope ranges from 5 to 45 percent. Mean annual precipitation is about 530 mm (21 in), and mean annual air temperature is about 15 degrees C (59 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic, shallow Petrocalcic Calciustepts

TYPICAL PEDON: Ochiltree very gravelly fine sandy loam - on a 7 percent concave-linear slope in native rangeland at an elevation of 824 m (2704 ft).
(Colors are for dry soil unless otherwise stated.)
The surface is covered with about 20 percent cobbles and 15 percent gravels. The fragments are strongly to very strongly cemented caliche colluvium and very strongly cemented to indurated petrocalcic fragments.

Ak--0 to 21 cm (0 to 8 in); grayish brown (10YR 5/2) very gravelly fine sandy loam, dark grayish brown (10YR 4/2), moist; moderate medium granular structure; soft, friable; common fine and few medium roots; 2 percent 2 to 5 mm, 5 percent 5 to 20 mm, 34 percent 20 to 75 mm, and 10 percent 75 to 250 mm very strongly cemented caliche and petrocalcic fragments; violently effervescent (20 percent calcium carbonate equivalent); moderately alkaline, pH 7.9; diffuse wavy boundary. (10 to 23 cm thick [4 to 9 in])

Bkkm--21 to 49 cm (8 to 19 in); light brown (7.5YR 6/4), brown (7.5YR 5/3), moist; indurated petrocalcic; indurated by carbonates, stage IV calcium carbonate accumulation; few fine roots in cracks; violently effervescent (43 percent calcium carbonate equivalent); moderately alkaline, pH 8.3; diffuse wavy boundary. (20 to 94 cm thick [8 to 37 in])

Bk--49 to 93 cm (19 to 37 in); pink (7.5YR 7/3) extremely cobbly fine sandy loam, light brown (7.5YR 6/3), moist; moderate very coarse prismatic structure; extremely hard, slightly rigid; 3 percent 2 to 5 mm, 5 percent 5 to 20 mm, 39 percent 20 to 75 mm, and 32 percent 76 to 250 mm very strongly cemented caliche and petrocalcic fragments; violently effervescent (17 percent calcium carbonate equivalent); moderately alkaline, pH 8.2; diffuse wavy boundary. (35 to 66 cm thick [14 to 26 in])

BCk--93 to 180 cm (37 to 71 in); pink (7.5YR 8/3) extremely cobbly loamy fine sand, light brown (7.5YR 6/4), moist; moderate very coarse prismatic structure; very hard, extremely firm; common fine and common medium threadlike carbonate masses throughout; 2 percent 2 to 5 mm, 6 percent 5 to 20 mm, 30 percent 20 to 75 mm, and 26 percent 76 to 250 mm strongly cemented caliche and petrocalcic fragments; strongly effervescent (17 percent calcium carbonate); moderately alkaline, pH 8.2; (70 to 120 cm thick [28 to 48 in])

TYPE LOCATION: Beaver County, Oklahoma; From the intersection Highway 412 and Highway 23 at Elmwood, 2 miles north and 4 miles west; then 1830 ft (558 m) north and 755 ft (230 m) east of the southeast corner of Section 8, Township 2N Range 23E (Cimarron meridian).

USGS topographic quadrangle: Slapout, Oklahoma
Latitude: 36 degrees 39 minutes 1.17 seconds N
Longitude: 100 degrees 35 minutes 51.88 seconds W
Datum WGS84

Decimal Degrees:
Latitude: 36.6503258
Longitude: -100.5977478

UTM Northing: 4057272
UTM Easting: 357185
UTM zone 14S

RANGE IN CHARACTERISTICS:
Solum thickness: 50 to 100 cm (20 to 40 in)
Depth to secondary carbonates: 0 to 15 cm (0 to 6 in)
Depth to petrocalcic horizon: 15 to 25 cm (6 to 10 in)

Particle-size control section (weighted average):
Section range: From the soil surface to the top of the petrocalcic horizon
Silicate clay content: 8 to 16 percent
Calcium carbonate equivalent: 15 to 30 percent
Coarse Fragments: amount-40 to 65 percent; size-fine to coarse gravels, cobbles; kind-petrocalcic fragments, caliche, and colluvial carbonate nodules and concretions

Surface Fragments: amount-5 to 25 percent; size fine to coarse gravels, cobbles; kind-carbonate nodules, concretions, caliche, and petrocalcic fragments

Ak horizon:
Hue: 10YR
Value: 4 or 5, 3 or 4 moist
Chroma: 2 or 3 moist or dry
Texture: Fine sandy loam, sandy loam, loam, and their gravelly, very gravelly, cobbly and very cobbly counterparts
Coarse Fragments: amount-10 to 65 percent; size-fine to coarse gravel, cobbles; kind-carbonate nodules and concretions, caliche, and petrocalcic fragments
Identifiable calcium carbonate: amount-5 to 35 percent; size-fine to extremely coarse; kind-carbonate masses, nodules, concretions, caliche, and petrocalcic fragments
Calcium carbonate equivalent: 5 to 30 percent
Effervescence: Strong to violent
Reaction (pH): Slightly alkaline to moderately alkaline (7.4-8.4)

Upper Bk horizons (where present):
Hue: 7.5YR or 10YR
Value: 4 to 6, 4 or 5 moist
Chroma: 2 to 4 moist or dry
Texture: Fine sandy loam, sandy loam, loam, and their gravelly, very gravelly, cobbly and very cobbly counterparts
Coarse fragments: amount-15 to 75 percent; size-fine to coarse gravels, cobbles; kind-carbonate nodules, concretions, caliche, and petrocalcic fragments
Identifiable calcium carbonate: amount-5 to 45 percent; size-fine to extremely coarse; kind-carbonate masses, nodules, caliche, and petrocalcic fragments
Effervescence: Strong or violent
Calcium carbonate equivalent: 15 to 45 percent
Reaction (pH): Slightly alkaline to moderately alkaline (7.4-8.4)

Bkkm horizons:
Hue: 7.5YR or 10YR
Value: 6 to 8, 5 to 7 moist
Chroma: 2 to 4 moist or dry
Texture: Fractured indurated or very strongly cemented petrocalcic; fractures are greater than 10 cm apart horizontally and range in size from 2 to 15mm with fine sandy loam, sandy loam, or loam along voids created by fractures
Identifiable calcium carbonate: 75 to 95 as cemented petrocalcic, fractured petrocalcic, caliche, and carbonate nodules, masses, and concretions
Effervescence: Strong or violent
Calcium carbonate equivalent: 40 to 85 percent
Reaction (pH): Slightly alkaline to moderately alkaline (7.4-8.4)

Lower Bk horizons and Bkk horizons (where present):
Hue: 7.5YR or 10YR
Value: 6 to 8, 5 to 7 moist
Chroma: 2 to 4 moist or dry
Texture: Fine sandy loam, sandy loam, loam, and their gravelly, very gravelly, cobbly, very cobbly or extremely cobbly counterparts
Coarse fragments: amount-25 to 85 percent; size-fine to coarse gravel, cobbles; kind-carbonate nodules, concretions, caliche, and petrocalcic fragments
Identifiable calcium carbonate: amount-25 to 75 percent; size-fine to extremely coarse; kind-carbonate masses, nodules, concretions, caliche, and petrocalcic fragments
Effervescence: Strong or violent
Calcium carbonate equivalent: 15 to 65 percent
Reaction (pH): Slightly alkaline to moderately alkaline (7.4-8.4)

BCk or CBk horizons:
Hue: 7.5YR or 10YR
Value: 6 to 8 dry, 5 to 7 moist
Chroma: 2 to 6 moist or dry
Texture: Loamy fine sand, loamy sand, fine sandy loam, sandy loam and their cobbly, very cobbly or extremely cobbly counterparts
Coarse fragments: amount-15 to 75 percent; size-fine to coarse gravel, cobbles; kind-caliche and petrocalcic fragments
Identifiable calcium carbonate: amount-15 to 45 percent; size-fine to extremely coarse; kind-carbonate masses, nodules, concretions, caliche, and petrocalcic fragments
Effervescence: Strong or violent
Calcium carbonate equivalent: 10 to 35 percent
Reaction (pH): slightly alkaline to moderately alkaline (7.4-8.4)

COMPETING SERIES: There are no competing series. Similar series are the Laverne (TX), Plack (OK), Pastura (NM), and Potter (TX) soils.
Laverne soils: have a mollic epipedon, and a petrocalcic between 25 and 50 cm (10 to 20 in) of the soil surface
Plack soils: have a mollic epipedon, and have a mesic soil temperature regime.
Pastura soils: have mesic soil temperature regime.
Potter soils: have carbonatic mineralogy and do not have a petrocalcic horizon.

GEOGRAPHIC SETTING:
Parent Material: Calcareous, loamy colluvium derived from the Kimball or Ash Hollow Members of the Ogallala Formation of Mio-Pliocene age.
Landscape: Alluvial Plain Remnant
Landform: Hillslopes, scarps
Slope: 5 to 45 percent
Soil moisture: An ustic moisture regime bordering on aridic. The soil moisture control section is dry in some or all parts for more than 180 but less than 220 days, cumulative, in normal years. July through August and December through February are the driest months. These soils are intermittently moist in September through November and March through June.
Mean annual air temperature: 14 to 17 degrees C (57 to 63 degrees F)
Mean annual precipitation: 381 to 584 mm (15 to 23 in)
Frost-free period: 180 to 210 days
Elevation: 640 to 1371 m (2,100 to 4,500 ft)
Thornthwaite annual P-E Index: 25 to 36

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alopark (T), Catesby (T), Conlen, Laverne, Mansic, Mocane (T), Oklark, Oslo, Paloduro, Plack, and Slapout (T) series.

Alopark, Mansic, Mocane, and Oklark soils: occur on lower landscape positions and grade to loamy or sandy, and siliceous gravelly subsoils derived from the Laverne Member of Ogallala Formation.
Alopark soils: have a coarse-loamy particle-size family, and do not have a petrocalcic horizon
Mansic and Oklark soils: have a mollic epipedon, and do not have a petrocalcic horizon
Mocane soils: have a sandy particle-size family, and do not have a petrocalcic horizon

Catesby and Slapout soils occur on similar landscape positions in parent materials from the Kimball or Ash Hollow Members, Ogallala Formation.
Catesby soils: have a mollic epipedon, are very deep to root restriction, and do not have a petrocalcic horizon
Slapout soils: are very deep to root restriction, and do not have a petrocalcic horizon

Laverne soils: occur on adjacent structural benches, mesa and butte summits, and have a mollic epipedon, and a petrocalcic horizon between 25 cm (10 in) and 50 cm (20 in) of the soil surface.

Conlen, Oslo, and Plack soils: occur on higher landscapes in MLRA 77A, and have a cooler soil temperature regime.
Conlen soils: have a mollic epipedon, and carbonatic mineralogy, and do not have a petrocalcic horizon
Oslo soils: have a mollic epipedon, a fine-silty particle-size class, an argillic horizon, and do not have a petrocalcic horizon
Plack soils: have a mollic epipedon

DRAINAGE AND PERMEABILITY:
Drainage class: excessively
Permeability: moderately rapid in the upper part and very slow in the petrocalcic
Runoff: very high on 1 to 20 percent slopes

USE AND VEGETATION: These soils are used exclusively for livestock grazing. Native vegetation is predominantly purple threeawn, little bluestem, silver bluestem, side oats grama, yucca, and broom snakeweed.

DISTRIBUTION AND EXTENT: Southern High Plains, Breaks (MLRA-77E in LRR H) of the Texas and Oklahoma Panhandles, and counties in northwestern Oklahoma and southwestern Kansas. This soil is extensive.

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

SERIES PROPOSED: Beaver County, OK 2009. The name of the series comes from Ochiltree County, Texas.

REMARKS:
The Ochiltree series was formerly included in the Potter series. The series was separated based on the features of a petrocalcic horizon, mineralogy, and moisture regime.

Diagnostic horizons and features in this pedon are:
Ochric epipedon: 0 to 21 cm (0 to 8 in) (Ak horizon)
Petrocalcic horizon: 21 to 49 cm (8 to 19 in) (Bkkm horizon)
Calcic Horizon: 49 to 180 cm (19 to 71 in) (Bk, and BCk horizons)
Secondary carbonates: 0 to 180 cm (0 to 71 in) (all horizons)
Particle Size Control Section: 0 to 21 cm (0 to 8 in)

ADDITIONAL DATA: KSSL data available, S2009OK007002 (TL-Beaver County, Oklahoma)

TAXONOMIC VERSION: Keys to Soil Taxonomy, Twelfth Edition, 2014.

National Cooperative Soil Survey
U.S.A.