LOCATION SONADORA PREstablished Series
TAXONOMIC CLASS: Fine, smectitic, isohyperthermic Vertic Eutrudepts
TYPICAL PEDON: Sonadora clay loam - forested. (Colors are for moist conditions.)
A-- 0 to 1 inch; dark reddish brown (5YR 3/2) clay loam; moderate fine subangular blocky structure; friable; slightly sticky; plastic; many very fine, fine, and medium roots; strongly acid; abrupt smooth boundary. (1 to 6 inches thick.)
Bw1-- 1 to 4 inches; dark brown (10YR 3/3) clay; moderate fine and medium subangular blocky structure; firm; sticky, very plastic; about 0.2 inch cracks between peds; common very fine and fine roots; very strongly acid; clear smooth boundary.
Bw2-- 4 to 10 inches; dark brown (10YR 3/3 clay; strong medium and coarse subangular blocky structure; firm; sticky, very plastic; about 0.3 inch cracks between peds; few faint pressure faces on surfaces of peds; few very fine, fine, and coarse roots along structural faces; very strongly acid; clear wavy boundary.
Bw3-- 10 to 16 inches; dark brown (10YR 3/3) clay; strong coarse prismatic structure parting to medium subangular blocky; firm; sticky, very plastic; about 0.3 inch cracks between peds; common distinct pressure faces on surfaces of peds; few faint non-intersecting slickensides having polished and grooved surfaces; few fine, medium, and coarse roots along structural faces; very strongly acid; clear smooth boundary. (Combined thickness of the Bw horizons range from 8 to 15 inches.)
BC-- 16 to 21 inches; grayish brown (2.5Y 5/2) clay; moderate coarse subangular blocky structure; firm; sticky, plastic; few fine, medium, and coarse roots; about 15 percent, by volume, mudstone rock fragments; strongly acid; clear smooth boundary. (0 to 5 inches thick.)
C-- 21 to 36 inches; 35 percent grayish brown (10YR 5/2), 35 percent yellowish brown (10YR 5/6), and 30 percent very dark grayish brown (10YR 3/2) clay loam; massive; friable; sticky; slightly plastic; few very fine roots; strongly acid; clear smooth boundary.
R-- 36+ inches; horizontally fractured dark gray (10YR 4/1) mudstone bedrock.
TYPE LOCATION: Caribbean National Forest, Municipio De Rio Grande, Puerto Rico. Approximately 3,000 feet southeast of the garage at the El Verde Work Center, along trail number 21 to the second switchback and about 15 feet to the west. El Yunque topographic quadrangle. Lat 18 degrees 20 minutes 11 seconds N.; long. 66 degrees 49 minutes 16 seconds W.; PRD 1940.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 10 to 20 inches. Pebbles and/or cobbles range from 0 to 20 percent, by volume, throughout. Depth to mudstone bedrock ranges from 20 to 40 inches. Reaction ranges from very strongly acid to neutral in the A and Bw horizons and from strongly acid to neutral in the BC and C horizons.
The A horizon has hue of 5YR to 10YR, value of 2 or 3, and chroma from 2 or 3. Texture is loam, silty clay loam, clay loam, their gravelly or cobbly analogs.
The Bw horizon has hue from 10YR or 2.5Y, value of 3 to 6, and chroma of 2 to 6. Texture is clay loam, clay, their gravelly or cobbly analogs.
The BC horizon, where present, has hue from 10YR or 2.5Y, value of 4 to 6, and chroma of 2 to 6. Texture is clay loam, clay, their gravelly or cobbly analogs.
The C horizon has hue from 10YR or 2.5Y, value of 4 to 6, and chroma of 2 to 6; or there is no dominate color and is multicolored in shades of brown, yellow, and gray. Texture is loam, clay loam, their gravelly or cobbly analogs.
The Cr horizon, where present, has same range of colors as the C horizon. It is composed of highly weathered mudstone that has a loam or clay loam texture.
The R horizon is composed of mudstone bedrock.
COMPETING SERIES: There are no other series in the same family.
GEOGRAPHIC SETTING: Sonadora soils are on side slopes of lower hills and footslopes of strongly dissected uplands. They formed in residuum that weathered from calcareous mudstone of the Hato Puerco formation. Slopes range from 20 to 60 percent. The climate is humid tropical. The average annual temperature ranges from 75 to 77 degrees F., and the average annual precipitation ranges from 75 to 80 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the Caguabo soils. Caguabo soils have loamy-skeletal control sections and are shallow to bedrock.
DRAINAGE AND PERMEABILITY: Well drained; very slowly permeability.
USE AND VEGETATION: All areas of Sonadora soils are used for recreation, research, wildlife habitat, and watershed protection. Vegetation consists of native and introduced species.
DISTRIBUTION AND EXTENT: Highly dissected humid mountains of Puerto Rico. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.
SERIES PROPOSED: Caribbean National Forest. 1999.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 10 inches. (A, Bw1, and Bw2 horizons)
Cambic horizon - the zone from 1 to 16 inches. (Bw1, Bw2, and Bw3 horizons)
Vertic features - the zone from 1 to 16 inches. (Bw1, Bw2, and Bw3 horizon)
Depth to lithic contact - hard bedrock at 36 inches. (R layer)
MLRA: 270.