LOCATION CRISTAL PR

Established Series
BCD-HRM Rev. SRT/MMR
04/2018

CRISTAL SERIES

The Cristal series consists of very deep, somewhat poorly drained soils on concave positions of mountain coves and lower side slopes of volcanic hills and mountains of deeply dissected uplands. They formed in a mixture of alluvium and colluvium. Near the type location, the mean annual rainfall is about 90 inches and the mean annual temperature is about 75 degrees F. Slopes range from 5 to 55 percent.

TAXONOMIC CLASS: Very-fine, parasesquic, isohyperthermic Aquic Hapludox

TYPICAL PEDON: Cristal clay loam - forest in Caribbean National Forest. (Colors are for moist soil conditions.)

A--0 to 2 inches; dark brown (10YR 4/3) clay loam; moderate fine granular structure; friable; many fine, medium and coarse roots, about 10 percent, by volume, cobbles; very strongly acid; clear smooth boundary. (1 to 8 inches thick)

Bw1--2 to 15 inches; pale brown (10YR 6/3) clay; weak medium subangular blocky structure; firm; few fine, medium, and coarse roots; common medium distinct very dark brown (10YR 2/2) and yellowish red (5YR 5/6) masses of iron accumulation and light brownish gray (10YR 6/2) areas of iron depletions; very strongly acid; clear smooth boundary.

Bw2--15 to 26 inches; yellowish brown (10YR 5/6) gravelly clay; weak medium subangular blocky structure; firm; few fine roots; about 15 percent, by volume, pebbles; few fine roots; common medium distinct very pale brown (10YR 6/3) and yellowish red (5YR 5/6) masses of iron accumulation and common distinct light gray (10YR 7/2) areas of iron accumulations; very strongly acid; very strongly acid; gradual smooth boundary.

Bw3--26 to 39 inches; strong brown (7.5YR 5/6) clay; weak fine subangular blocky structure; firm; common medium distinct yellow (10YR 7/6), red (2.5YR 5/6), and very dark brown (10YR 2/2) masses of iron accumulation; very strongly acid; gradual smooth boundary. (Combined thickness of the Bw horizons is 20 to 40 inches).

C--39 to 60 inches; yellowish red (5YR 5/8) clay loam; massive; friable; many medium distinct yellow (10YR 7/6) and very dark brown (10YR 2.2) masses of iron accumulation; very strongly acid.

TYPE LOCATION: Caribbean National Forest, Puerto Rico. Approximately 1,000 ft south of the junction of Rd 988 and the Virgilio (#5) trail (a little past the grove of royal palms and then downhill to the north about 20 ft). Farjardo topographic quadrangle; lat. 18 degrees 19 minutes 41 seconds N.; long. 65 degrees 42 minutes 30 seconds W.; PRD 1940.

RANGE IN CHARACTERISTICS: Thickness of the solum ranges from 30 to 50 inches. Reaction ranges from strongly acid to extremely acid throughout. Rock fragments range from 0 to 30 percent, by volume, throughout the profile.

The A horizon has hue of 10YR or 2.5Y, value of 2 to 4, and chroma of 3; or it is neutral with value of 2 to 4. Texture is loam, silty clay loam, clay loam, clay or their gravelly, cobbly, or stony analogs.

The Bw horizons have hue of 7.5YR to 5Y, value of 4 to 6, and chroma of 1 to 4. Redoximorphic features in shades of gray, brown, yellow, and red range from common to many. Texture is silty clay loam, silty clay, clay loam, clay, or their gravelly analogs.

The C horizon has hue of 5YR to 5GY, value of 4 to 6 and chroma of 3 to 8; or there is no dominant hue and is multicolored in shades of gray, brown, yellow, and red. Texture is sandy loam, silt loam, loam, silty clay loam, clay loam, or their gravelly analogs.

COMPETING SERIES: There are no competing series in the same family.

GEOGRAPHIC SETTING: Cristal soils are on concave areas of mountain coves and lower side slopes of volcanic hills and mountains of deeply dissected uplands. Slopes range from 5 to 55 percent. The climate is humid tropical. The average annual precipitation ranges from 80 to 100 inches and the average annual temperature ranges from 71 to 79 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the Humatas and Zarzal soils. The well drained Humatas soils have argillic horizons and a mixed mineralogy. The well drained Zarzal soils are Oxisols.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained; moderately slowly permeability.

USE AND VEGETATION: Native forest land that is used for recreation and research. Native and introduced woody species.

DISTRIBUTION AND EXTENT: Caribbean National Forest in Puerto Rico. The series is of minor extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Raleigh, North Carolina.

SERIES ESTABLISHED: Caribbean National Forest and Luquillo Experimental Forest, Puerto Rico, 1992.

REMARKS: Diagnostic horizons and features recognized in this pedon:

Ochric epipedon - zone from 0 to 2 inches (A horizon).

Cambic horizon - zone from 2 to 39 inches (Bw horizons).

Aquic feature - Perched water table with redoximorphic accumulations and depletions beginning at 2 inches.

These soils typically have an organic surface layer overlying residuum from volcanic sandstone rocks that been effected by soil creep in the upper part.

MLRA: 270.

National Cooperative Soil Survey
U.S.A.