LOCATION NARU OKEstablished Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, active, thermic Udic Haplustalfs
TYPICAL PEDON: Naru cobbly loam--forest.
(Colors are for dry soil unless otherwise stated.)
A1--0 to 6 inches; brown (7.5YR 4/2) cobbly loam, dark brown (7.5YR 3/2) moist; moderate medium granular structure; soft,
friable; common fine and medium roots; content of coarse fragments
of limestone make up about 45 percent by volume; neutral; clear smooth boundary. (4 to 8 inches thick)
A2--6 to 15 inches; light brown (7.5YR 6/4) cobbly loam,
brown (7.5YR 5/4) moist; moderate medium granular structure; soft, friable; common fine and medium roots; content of coarse fragments
of limestone makes up about 45 percent by volume; neutral; clear
wavy boundary. (6 to 10 inches thick)
B2t--15 to 36 inches; reddish brown (5YR 5/4) cobbly loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable; few fine and medium roots; thick nearly continuous clay films on faces of peds; content of coarse
fragments of limestone makes up about 35 percent by volume;
neutral; clear wavy boundary. (16 to 22 inches thick)
IIC--36 to 58 inches; coarsely mottled dark reddish brown
(2.5YR 3/4), reddish brown (5YR 4/4), gray (10YR 6/1), and olive yellow (2.5Y 6/6) shaly clay; massive; very hard, very firm;
content of coarse fragments of limestone make up 10 percent by volume; calcareous; moderately alkaline; clear wavy boundary. (20
to 26 inches thick)
IIR--58 to 70 inches; light gray (N 7/0) indurated limestone conglomerate tilted less than 20 degrees from horizontal.
TYPE LOCATION: Murray County, Oklahoma; about 5 miles west and 4 miles south of Sulphur; 4,700 feet north and 4,000 feet east of
the southwest corner of sec. 26, T. 1 S., R. 2 E.
RANGE IN CHARACTERISTICS: Solum thickness and depth to IIC
horizon ranges from 30 to 40 inches. Depth to the IIR layer
ranges from 55 to 65 inches. Depth to secondary carbonates is
more than 36 inches.
The A1 horizon has hue of 7.5YR or 10YR, value of 4 or 5, and
chroma of 2 or 3. Texture is cobbly and very cobbly phases of
silt loam and loam. Reaction is medium acid to neutral. Content
of coarse fragments of limestone ranges from 35 to 70 percent by volume. About 15 to 30 percent by volume is less than 76 mm in diameter, and 20 to 40 percent by volume is more than 76 mm in diameter.
The A2 horizon has hue of 7.5YR or 10YR, value of 6 or 7, and
chroma of 2 to 6. Texture, reaction, and content of coarse
fragments is the same as the A1 horizon.
The B2t horizon has hue of 5YR, value of 4 or 5, and chroma of 4
to 8. Texture is cobbly or very cobbly phases of clay loam, silty clay loam, cobbly loam, or silt loam. Reaction is medium acid to neutral. Content of coarse fragments is the same as the A1
horizon.
The IIC horizon is coarsely mottled in shades of brown, red, gray, and yellow. The gray mottles are inherited from the parent
material and are not indicative of wetness. Content of coarse fragments less than 76 mm in diameter makes up 0 to 5 percent by volume. Some pedons are neutral to moderately alkaline and noncalcareous.
The IIR layer is indurated limestone conglomerate that is several feet thick and is tilted less than 20 degrees from horizontal. In some areas, minor amounts of granite fragments are present in the conglomerate.
COMPETING SERIES: This is the
Click series in the same family and
Cisco,
Cobb,
Grandfield,
Kopperl,
May,
Menard,
Oben, and
Rochelle series in similar families. Cisco, Cobb, Grandfield, and May
soils have less than 35 percent coarse fragments in the control section. In addition, Cisco soils have siliceous mineralogy.
Click and Kopperl soils have a solum more than 40 inches thick.
In addition, Kopperl soils have siliceous mineralogy. Menard and Rochelle soils have secondary carbonates within 35 inches and are
dry for longer periods of time. Oben soils have a solum less than
20 inches thick and have less than 35 percent coarse fragments.
GEOGRAPHIC SETTING: Naru soils are on sloping to steep side
slopes of low ridges or hills north of the Arbuckle Mountains in
the Grand Prairie. The upper part of these soils formed in colluvium, and the lower part formed in shaly clays and hard conglomerate of Pennsylvanian age. Slopes are 5 to 30 percent.
Mean annual precipitation ranges from 34 to 40 inches. Mean
annual temperature ranges from 62 to 64 degrees F. Thornthwaite annual P-E indices range from 54 to 64.
GEOGRAPHICALLY ASSOCIATED SOILS: These are
Bromide,
Chigley,
Grainola,
Rayford, and
Travertine series. Bromide soils are on similar areas on the landscape, but they do not have argillic horizons. Chigley and Grainola soils are usually on ridges and
upper side slopes, have more than 35 percent clay content in the control section, and have less than 35 percent coarse fragments in the control section. Rayford and Travertine soils usually occur
on ridges, and they have a solum less than 20 inches thick.
DRAINAGE AND PERMEABILITY: Naru soils are well drained. Runoff
is medium to rapid. Permeability is slow.
USE AND VEGETATION: Mainly used for range, recreation, and urban dwellings. The native vegetation is post oak, blackjack oak,
eastern redcedar, green ash, chinkapin oak, and shumard oak trees with an understory of tall grasses.
DISTRIBUTION AND EXTENT: Grand Prairie of Oklahoma near the
Arbuckle Mountains. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Murray County, Oklahoma; 1982.
REMARKS: These soils were formerly included in the Gilson series. The Gilson series is inactive.