LOCATION BIROME TXEstablished Series
TAXONOMIC CLASS: Fine, mixed, active, thermic Ultic Paleustalfs
TYPICAL PEDON: Birome fine sandy loam--wooded.
(Colors are for dry soil unless otherwise stated.)
A--0 to 3 inches; brown (7.5YR 5/4) fine sandy loam,
dark brown (7.5YR 4/4) moist; weak medium subangular blocky structure; hard, friable; few fine and medium roots; about
10 percent by volume sandstone fragments as much as 3 inches
across long axis; neutral; clear smooth boundary.
E--3 to 9 inches; light brown (7.5YR 6/4) fine sandy
loam, brown (7.5YR 5/4) moist; weak fine granular structure;
hard, friable; few fine roots; 5 to 10 percent by volume
sandstone fragments as much as 3 inches across long axis;
neutral; clear smooth boundary.
Bt1--9 to 15 inches; red (2.5YR 4/6) clay, dry and
moist; moderate medium prismatic structure parting to
moderate medium blocky; very hard, very firm, sticky and
plastic; few fine roots; many thick dark red (2.5YR 3/6)
clay films; medium acid; gradual smooth boundary.
Bt2--15 to 25 inches; yellowish red (5YR 5/6) clay loam,
yellowish red (5YR 4/6) moist; common fine distinct strong
brown (7.5YR 5/6) mottles; moderate medium prismatic
structure parting to moderate coarse blocky; very hard, very
firm, sticky and plastic; few fine roots; many thick red
(2.5YR 4/6) clay films on surface of peds; strongly acid;
gradual smooth boundary.
Bt3-25 to 35 inches; reddish yellow (7.5YR 6/6) clay
loam, strong brown (7.5YR 5/6) moist; common medium distinct
red (2.5YR 4/6) mottles; moderate medium prismatic structure
parting to moderate medium blocky; very hard, firm, sticky
and plastic; few fine roots; many thick clay films; strongly
acid; abrupt smooth boundary.
Cr--35 to 50 inches; weakly cemented fractured reddish
sandstone in upper part that decreases in amount of
fracturing as depth increases; clay flows and roots
penetrate fractures; sandstone hardens when exposed;
strongly acid.
TYPE LOCATION: Tarrant County, Texas; from the intersection
of Interstate Highway 35W and South Loop 820 in the city of
Fort Worth, 5.9 miles south on Interstate Highway 35W, 6.1
miles east on Farm Road 1187, and 100 feet south.
RANGE IN CHARACTERISTICS: The solum thickness and depth to
sandstone ranges 20 to 40 inches. Ironstone and sandstone
pebbles and sandstone fragments less than an inch to 3
inches thick and 3 to about 10 inches across the long axis
cover 0 to 20 percent of the soil surface. Pebbles and
fragments comprise 0 to 35 percent of the epipedon and 0 to
10 percent in the argillic horizon.
The A horizon has hue of 7.5YR and 10YR, value of 4 through
7, and chroma of 2 through 4. The E horizon is 1 to 3 units
higher in value and chroma than the A1 horizon. Texture is
loam, fine sandy loam or loamy fine sand and their gravelly
or stony counterparts. The reaction ranges from medium acid
through neutral.
The Bt horizon has hue of 2.5YR through 7.5YR, value of 4
through 6, and chroma of 4 through 8. Mottles in these
colors and in other shades of red and brown range from none
to common. The texture is clay, clay loam, or sandy clay.
Reaction is strongly acid or medium acid.
The BC horizon, when present, is in shades of red, brown, or
yellow and is typically mottled or has common to many
mottles in these colors. It is sandy clay loam or clay
loam. The reaction is strongly acid or medium acid. It is
slightly acid in some pedons. Sandstone and ironstone
fragments larger than 2 mm across range from 2 to 35 percent
by volume.
The Cr layer is weakly cemented sandstone and is typically
stratified with shaly or loamy materials. The strata are
reddish, yellowish, or grayish. The sandstone is fractured
or weakly consolidated and hardens upon exposure.
COMPETING SERIES: These are the
Bonti,
Castell,
Darst,
Jedd,
Rosanky,
Shatruce and
Travis series in the same family
and the
Aubrey,
Axtell and
Crosstell series in similar
families. Bonti soils have a lithic contact of sandstone at
a depth of 20 to 40 inches. Castell soils formed in gneiss. Shatruce soils formed in shaly materials. Darst soils
formed in siltstone or mudstone. Jedd soils have an
argillic horizon less than 16 inches thick and formed in the
Tertiary system. Rosanky and Travis soils have sola more
than 40 inches thick. Aubrey soils have base saturation of
more than 40 inches thick, montmorillonitic mineralogy and
vertic properties.
GEOGRAPHIC SETTING: Birome soils are on gently sloping to
moderately steep narrow ridges and low hills mainly in the
East Cross Timbers land resource area of north-central
Texas. Slopes range from about 2 to 20 percent. The soil
formed in loamy and clayey sediments high in iron in the
Cretaceous Period. Climate is moist subhumid. Mean annual precipitation ranges from 30 to 38 inches. Mean annual
temperature is 66 degrees to 68 degrees F. The Thornthwaite
annual P-E index is 52 to 62.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Aubrey and
Crosstell series and the
Rayex series. Rayex
soils have sola less than 20 inches thick. Aubrey and Rayex
soils are on positions similar to Birome soils. Crosstell
soils are mainly below on gently sloping, convex stream
divides.
DRAINAGE AND PERMEABILITY: Well drained; rapid runoff; slow permeability.
USE AND VEGETATION: Mostly in wooded pasture. Native
vegetation consists of little bluestem, purpletop, and
shrubs with an overstory of post oak and blackjack oak.
DISTRIBUTION AND EXTENT: Central Texas mainly in the East
Cross Timbers land resource area. The soils are of moderate
extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Hill County, Texas; 1975.
REMARKS: These soils were formerly included in the Bonti
series.
Diagnostic horizons and features recognized in this pedon
are:
Ochric epipedon - 0 to 9 inches, the Ap and E horizons.
Argillic horizon - 9 to 35 inches, the Bt horizon.
Paralithic contact of sandstone at a depth of 35 inches.
Ultic feature - Base saturation less than 75 percent
throughout the Bt horizon.