LOCATION CASABE PREstablished Series
TAXONOMIC CLASS: Clayey, magnesic, isohyperthermic, shallow Ustic Haplargids
TYPICAL PEDON: Casabe clay--naturalized pastureland (Colors are for moist soil).
A--0 to 7 inches; very dark grayish brown (10YR 3/2) clay; strong medium and coarse granular structure; very hard, extremely firm; slightly sticky, very plastic; many prominent pressure faces on faces of peds; many very fine and fine roots; many very fine and fine irregular pores; about 12 percent, by volume, angular pebbles; neutral; clear wavy boundary. (4 to 9 inches thick)
Bt--7 to 16 inches; very dark grayish brown (10YR 3/2) paragravelly clay; strong fine and medium subangular blocky structure; very hard, extremely firm; slightly sticky, very plastic; many prominent clay film on faces of peds; common very fine and fine roots; common very fine and fine irregular pores; about 10 percent, by volume, angular parapebbles; neutral; abrupt wavy boundary. (5 to 11 inches thick)
Cr--16 to 38 inches; hard fractured and moderately weathered serpentinite bedrock. (3 to 40 inches thick)
R--38+ inches; hard fractured consolidated serpentinite bedrock.
TYPE LOCATION: Cabo Rojo, Puerto Rico. Approximately 2.9 miles southwest of the Boqueron community from the intersection of P.R. Hwy. 100 and P.R. Hwy. 101 on naturalized pastureland; USGS Puerto Real topographic quadrangle (1966); lat. 17 degrees 59 minutes 58.4 seconds N. and long. 67 degrees 11 minutes 45.8 seconds W.
RANGE IN CHARACTERISTICS: Depth to fractured and moderately weathered serpentinite rock ranges from 9 to 17 inches. Depth to hard fractured consolidated volcanic bedrock ranges from 14 to 41 inches. Reaction is neutral throughout. The combined total of rock fragments in the control section is less than 35 percent, by volume.
The A or Ap horizon has hue of 7.5YR or 10YR, value of 2 to 3, and chroma of 1 or 2. Content of rock fragments range from 5 to 12 percent, by volume. Texture is clay in the fine-earth fraction.
The Bt horizon has hue of 7.5YR or 10YR, value of 2 to 3, and chroma of 1 to 3. Content of rock fragments range from 5 to less than 35 percent, by volume. Texture is clay in the fine-earth fraction.
The Cr layer is composed of hard fractured and moderately weathered serpentinite. It can be excavated with difficulty with hand tools, and is rippable by mechanized equipment.
The R layer is composed of hard fractured consolidated serpentinite bedrock.
COMPETING SERIES: There are no known series in the same family.
GEOGRAPHIC SETTING: Casabe soils are on side slopes and summits of serpentinite hills and mountains on the Semiarid Mountains and Valleys MLRA. Slopes range from 5 to 60 percent. They formed in residuum that weathered from serpentinite. The climate is semiarid tropical. The average annual precipitation ranges from 16 to 35 inches and the average annual temperature ranges from 76 to 82 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bermeja (T), Cerro Mariquita (T), Costa (T), Esteli (T) and Pitahaya (T) series. Bermeja (T) and Cerro Mariquita (T) soils are shallow to volcanic bedrock and have coarser textured profiles. Costa (T) and Pitahaya (T) soils are shallow to limestone bedrock. Esteli (T) soil is shallow to soft limestone and has coarser textured profiles.
DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.
USE AND VEGETATION: Most areas of Casabe soils are on naturalized pastureland or urban development. The vegetation consists of drought tolerant, native and introduced grasses, shrubs and small trees.
DISTRIBUTION AND EXTENT: Side slopes and summits of serpentinite hills and mountains of southern Puerto Rico. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: Cabo Rojo Municipality, Puerto Rico; 2007.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 7 inches (A horizon).
Argillic horizon - the zone from 7 to 16 inches (Bt horizon).
Paralithic contact - the depth at 16 inches (Cr layer).
Lithic contact - the contact at 38 inches (R layer).
Casabe soils formed in the Serpentinite Formation (KJs).
Casabe soils were formerly included in the Aguilita series. A soil moisture study performed in the San German Area Soil Survey Update recognizes the Aridic Soil Moisture Regime in southern Puerto Rico.
Casabe soils are in MLRA 271.