LOCATION SANTA MARTA PREstablished Series
TAXONOMIC CLASS: Fine, magnesic, isohyperthermic Typic Hapludalfs
TYPICAL PEDON: Santa Marta gravelly clay loam--forestland (Colors are for moist conditions unless otherwise indicated).
Ap--0 to 8 inches; dark brown (7.5YR 3/3) gravelly clay loam, brown (7.5YR 4/3) dry; weak fine and medium granular structure; soft, very friable; slightly sticky, slightly plastic; many very fine, fine, and medium roots, common coarse roots; many very fine, fine, and few medium and coarse interstitial pores; about 20 percent, by volume, pebbles; neutral; clear wavy boundary. (5 to 9 inches thick)
Bt1--8 to 21 inches; dark reddish brown (5YR 3/4) paragravelly clay, reddish brown (5YR 4/3) dry; weak fine and medium subangular blocky structure; soft, friable; moderately sticky, moderately plastic; common faint and few distinct clay films on faces of peds and pores; common fine and medium roots, few coarse roots; many very fine and fine, few medium and coarse irregular tubular pores; about 20 percent, by volume, paragravel; slightly acid; clear wavy boundary.
Bt2--21 to 37 inches; dark reddish brown (2.5YR 3/4) very paragravelly clay, yellowish red (5YR 4/6) dry; weak fine subangular blocky structure; soft, very friable; slightly sticky, moderately plastic; few distinct clay films on faces of peds; common medium roots, few coarse roots; many very fine, few medium and coarse irregular pores; slightly acid; abrupt irregular boundary. (Combined thickness of the Bt horizons ranges from 15 to 31 inches)
Cr--37 to 57 inches; highly fractured serpentinite bedrock that can be excavated by hand tools.
R--57+ inches; hard consolidated serpentinite bedrock.
TYPE LOCATION: San German, Puerto Rico. Approximately 1.0 mile northwest of downtown San German from the intersection of P.R. Hwy. 102 and P.R. Hwy. 347, about 0.5 mile northwest of the Water Company Aqueduct near to Interamerican University-San German Campus, and about 300 feet north of paved road on forestland. USGS San German topographic quadrangle (1966); lat. 18 degrees 05 minutes 31 seconds N.; long. 67 degrees 03 minutes 23 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 20 to 40 inches. Reaction ranges from strongly acid to neutral throughout.
The A or Ap horizon has hue of 2.5YR to 7.5YR, value of 3 to 5, and chroma of 3 to 6. Content of pebbles ranges from 5 to 20 percent, by volume. Texture is clay loam or clay in the fine-earth fraction.
The Bt horizon has hue of 2.5YR or 5YR, value of 3 or 4, and chroma of 4 to 6. Content of paragravels range from 15 to 30 percent, by volume. Texture is paragravelly clay loam or paragravelly clay.
The Cr horizon is composed of highly fractured serpentinite bedrock. It can be excavated with difficulty with hand tools, and is rippable by mechanical equipment.
The R horizon is composed of hard consolidated serpentinite bedrock.
COMPETING SERIES: These are no known series in the same family.
GEOGRAPHIC SETTING: Santa Marta soils are on side slopes of serpentinite hills and mountains of Humid Mountains and Valleys MLRA. Slopes range from 20 to 40 percent. They formed in residuum that weathered from serpentinite. The climate is humid tropical. The average annual temperature ranges from 75 to 79 degrees F., and the average annual precipitation ranges from 43 to 75 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include El Cacique (T), La Taina (T), Maresua, Nipe, and Rosario series. All these soils are on similar positions. El Cacique (T) and La Taina (T) soils are shallow to serpentinite bedrock and are Mollisols. In addition, La Taina soils are clayey-skeletal. Maresua soils are moderately deep, and have fine-loamy control sections, and are Mollisols. Nipe and Rosario soils are Oxisols. In addition, Nipe soils are very deep and Rosario soils are shallow
DRAINAGE AND PERMEABILITY: Well drained; moderate permeability.
USE AND VEGETATION: Most areas of Santa Marta soils are on naturalized pastureland and are used for grazing. The vegetation consists of mahogany, maricao doncella and algarrobo trees. The understory vegetation includes cariaquillo, leucaena, escambron and carrasco shrubs, along with lamina and guinea grass.
DISTRIBUTION AND EXTENT: Side slopes of humid serpentinite hills and mountains of the Humid Mountains and Valleys MLRA. The series is of minor extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES ESTABLISHED: San German, Puerto Rico; 1963. The name is from the Santa Marta hills, where it was originally recognized.
REMARKS: Diagnostic horizons and features recognized in this pedon:
Ochric epipedon - the zone from 0 to 8 inches (Ap horizon).
Argillic horizon - the zone from 8 to 37 inches (Bt1 and Bt2 horizons).
Paralithic contact - The contact at 37 inches (Cr horizon).
Santa Marta soils are in MLRA 270.