LOCATION BLOCKER            OK
Established Series
Rev. JEH-RB
09/2003

BLOCKER SERIES


The Blocker Series consists of very shallow, well drained soils formed in reclaimed material from coal strip mines. These sloping to steep soils are on cutslopes of strip mines in the Arkansas Ridges and Valley land resource area. Slopes range from 5 to 20 percent. The mean annual soil temperature is about 56 degrees F. and mean annual precipitation is about 43 inches.

TAXONOMIC CLASS: Loamy, mixed, active, nonacid, thermic, shallow Alfic Udarents

TYPICAL PEDON: Blocker fine sandy loam, 10 percent slope, pasture.
(Colors are for moist soil unless otherwise stated.)

Ad--0 to 4 inches; dark brown (7.5YR 3/4) loam; platy and massive structure; hard, friable; about 20 percent by volume sandstone fragments less than 3 inches across; medium acid; abrupt smooth boundary. (0 to 5 inches thick)

Cd--4 to 7 inches; strong brown (7.5YR 5/6) clay loam; massive structure; extremely hard, very firm; about 20 percent by volume sandstone and shale fragments less than 3 inches across; neutral; abrupt smooth boundary. (1 to 9 inches thick)

Cr--7 to 10 inches; dark gray (2.5Y 4/0) shale; churned and slightly weathered; mildly alkaline.

TYPE LOCATION: Haskell County, Oklahoma; 800 feet west and 1200 feet north of the southeast corner of Sec. 20, T.8N., R.21E.

RANGE IN CHARACTERISTICS: Solum thickness and depth to unconsolidated bedrock is less than 10 inches. Reaction of the surface layer ranges from medium acid to neutral and the C horizon ranges from medium acid to neutral. Fragments of shale and sandstone range from 0 to 35 percent throughout the profile.

The Ad horizon has hue of 7.5YR and 10YR, value of 3, 4 or 5 and chroma of 3 or 4. Texture is a loam, fine sandy loam, silt loam, or silty clay loam.

The Cd horizon has hue of 5YR, 7.5YR and 10YR, value of 4 or 5 and chroma of 4 or 6. It is mottled in shades of red, brown, and gray. Texture is silty clay loam, clay loam, or loam.

The Cr horizon has hue of 2.5Y, value of 4, and chroma of 0 or 1. It is sometimes slightly weathered in the upper part.

COMPETING SERIES: The Lequire series is in the same family. Soils in similar families are the Kanima series and the tentative Cartersville, Emachaya and Whitefield series. Kanima soils have greater amounts of coarse fragments throughout the profile. Cartersville soils are deeper and do not have fragments of an argilic horizion within the profile. Emachaya, Lequire and Whitefield series have depth of reclaim material over shale that are greater than 10 inches.

GEOGRAPHIC SETTING: Blocker soils are sloping to steep upland cutslopes of reclaimed strip mines in the Arkansas Ridges and Valley land resource area. These soils are formed in the premine soils of the Hector, Linker and Enders series. They are mainly found on the cutslopes and highwall areas of the strip mine. The average annual temperature ranges from 54 to 57 degrees F., and the average annual precipitation ranges from 42 to 45 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing tentative series Cartersville, Lequire, Emachaya, Whitefield and Kanima soils. Cartersville soils are on less sloping areas near topsoil stockpile areas. Lequire soils are on similar areas and have more reclaim material placed over the shale. Emachaya and Whitefield soils are on areas that are less sloping and are deeper over shale material. Kanima soils are on adjacent, nonreclaimed areas.

DRAINAGE AND PERMEABILITY: Well drained. Runoff is rapid. Permeability is very slow.

USE AND VEGETATION: Used mainly for pasture or idleland. Vegetation is usually sparse with numerous rills and shallow gullies. Vegetation is mainly lovegrass or native grasses.

DISTRIBUTION AND EXTENT: Oklahoma and Arkansas. The series is not extensive with less than 5000 acres.

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

SERIES ESTABLISHED: Haskell County, Oklahoma; 1989.


National Cooperative Soil Survey
U.S.A.