LOCATION PAMOA HIEstablished Series
TAXONOMIC CLASS: Very-fine, parasesquic, isohyperthermic Torrertic Haplustolls
TYPICAL PEDON: Pamoa silty clay - pasture. (Colors are for moist soil unless otherwise noted. All textures are "apparent field textures.")
A1--0 to 7 inches; dark reddish brown (5YR 3/3) moist and dry, silty clay, dark reddish brown (5YR 3/4) crushed moist; moderate very fine, fine and medium subangular blocky structure parting to moderate fine and medium granular; hard, friable, sticky and very plastic; many roots; few thin patchy coatings on peds; many manganese concretions; violent effervescence with hydrogen peroxide; neutral (pH 6.6); gradual wavy boundary. (6 to 8 inches thick)
B1--7 to 15 inches; dark reddish brown (5YR 3/4) moist and dry clay; moderate very fine and fine subangular blocky structure and pockets of loose very fine subangular blocky structure; slightly hard, friable, very sticky and very plastic; many roots; many very fine and fine tubular pores; few thin patchy coats on peds; many fine black concretions; strong effervescence with hydrogen peroxide; neutral (pH 6.6); clear wavy boundary. (5 to 8 inches thick)
B21--15 to 32 inches; dark reddish brown (5YR 3/4) moist and dry silty clay; moderate very fine, fine and medium subangular blocky structure; firm in place; hard, friable, sticky and plastic; many roots; many very fine pores, common fine tubular pores; common organic stains in root channels; many patchy stress faces; strong effervescence with hydrogen peroxide; slightly acid (pH 6.1); clear wavy boundary. (15 to 18 inches thick)
B22--32 to 40 inches; dark reddish brown (5YR 3/4) moist and dry clay; strong very fine and fine angular and subangular blocky structure; firm in place; hard, friable, sticky and plastic; many roots; many very fine pores; common fine tubular pores; continuous weakly grooved stress faces; common organic stains in root channels; strong effervescence with hydrogen peroxide; strongly acid (pH 5.1); gradual wavy boundary. (7 to 9 inches thick)
B23--40 to 62 inches; dark reddish brown (5YR 3/4) moist and dry clay; few fine distinct dark brown (7.5YR 4/2) mottles along some major root channels; moderate coarse subangular blocky structure parting to moderate and strong very fine and fine angular and subangular blocky; hard, friable, very sticky and very plastic; many roots; many very fine tubular pores; continuous stress faces and coatings on peds; many black stains; strong effervescence with hydrogen peroxide; very strongly acid (pH 4.8).
TYPE LOCATION: Island of Molokai, Maui County. Hawaii; about 3 miles east of Manualoa on Molokai Ranch, from the intersection of Highway 46 and Ilio Point road, south past FAA Omnirange station to gate, which is 1.1 miles south of the highway, 0.5 mile south of the gate.
RANGE IN CHARACTERISTICS: Few to many vertical tubular holes a few inches to 5 feet in diameter and 2 to 10 feet deep are throughout this soil. When dry the soil has a strong granular surface mulch that ranges from 1/2 to 2 inches in thickness, and cracks 1/2 to 2 inches wide and several feet deep. Mean annual soil temperature is about 72 degrees F. The soil is dry in some horizons for more than 90 cumulative days in most years. The solum is clay or silty clay. It has hue of 5YR or 2.5YR.
The A horizon has chroma of 2 or 3 moist.
The B horizon has value of 2 or 3 moist, and chroma of 3 through 6 either moist or dry.
COMPETING SERIES: These are the Honouliuli, Waihuna, and Waipahu series. Honouliuli soils have mixed mineralogy and are neutral or mildly alkaline throughout. Waihuna soils have mean annual soil temperature of less than 71.5 degrees F., and hue of 7.5YR or yellower throughout. Waipahu soils have prismatic structure and have 10YR hue throughout.
GEOGRAPHIC SETTING: Pamoa soils are on uplands at elevations of 100 to 1,500 feet. Slope is 5 to 20 inches. Annual rainfall is 15 to 30 inches. The soils formed in fine-textured old alluvium and residuum weathered from basalt. The average January temperature is about 69 degrees F.; average July temperature is about 76 degrees F., and the mean annual temperature is about 72 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hoolehua and Lahaina soils. Hoolehua and Lahaina soils do not have a granular surface mulch, wide cracks or slickensides.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability to depths of 40 inches and moderately slow below.
USE AND VEGETATION: Used for pasture and wildlife. Present vegetation is kiawe (Prosopis chilensis), ilima (Sida spp.), uhaloa (Waltheria indica), pitted beardgrass (Andropogon pertusus), piligrass (Heteropogon contortus) and fuzzytop (Andropogon barbinoides).
DISTRIBUTION AND EXTENT: Islands of Molokai, Lanai, and Oahu, Hawaii. The soil is inextensive, with a total of about 3,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Soil Survey of the Territory of Hawaii, 1949.
OSED scanned by SSQA. Last revised by state on 3/78.