LOCATION WELOY GU+FM HI PBEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, mixed, isohyperthermic Typic Argiudolls
TYPICAL PEDON: Weloy gravelly silty clay loam - on a 53 percent west-facing slope in a broadleaf evergreen forest. (Colors are for moist soil.)
(About 5 percent of the surface covered is covered with hard schist pebbles and cobbles.)
O1--1 inch to 0; undecomposed and partially decomposed forest litter; abrupt smooth boundary.
A1--0 to 4 inches; very dark grayish brown (10YR 3/2) gravelly silty clay loam; strong very fine and fine granular structure; friable, slightly sticky and slightly plastic; many very fine and fine roots, common medium roots, and few coarse roots; many very fine tubular and interstitial pores and common fine tubular pores; approximately 25 percent by volume subangular to subrounded, moderately hard and hard schist pebbles .08 to 2 inches in size and 5 percent by volume soft cobbles 4 inches in size; medium acid (pH 5.7, 1:1 water); gradual wavy boundary. (3 to 10 inches thick)
A3--4 to 13 inches; dark brown (10YR 3/3) very gravelly clay loam; strong medium and coarse subangular blocky structure parting to strong very fine subangular blocky; friable, sticky and plastic; few very fine and fine roots; many very fine and fine tubular and interstitial pores; approximately 40 percent by volume moderately hard to hard, subangular to subrounded schist pebbles .4 to 3 inches in size; slightly acid (pH 6.2, 1:1 water); clear wavy boundary. (4 to 10 inches thick)
B2t--13 to 22 inches; yellowish brown (10YR 5/6) and dark yellowish brown (10YR 4/4) very gravelly clay; moderate fine and medium angular blocky; firm, sticky and very plastic; few very fine, fine, and medium roots; common very fine tubular and interstitial pores; common thin coatings on faces of peds and lining pores; horizon ranges from 2 inches thick over lithic material with fingers from 3 inches wide at top to 1 inch at bottom between next horizon, extending to a depth of 18 inches; approximately 40 percent by volume moderately hard to hard, subangular to subrounded schist pebbles .4 to 3 inches in size; slightly acid (pH 6.4, 1:1 water); abrupt irregular boundary. (8 to 16 inches thick)
Cr--22 inches; light olive brown (2.5Y 5/6) weathered schist that crushes with difficulty to sandy clay loam, and grayish green (5G 4/2) hard schist; black (2.5Y 2/0) manganese stains along fractures and dark yellowish brown (10YR 4/4) weathering rind; fractures in nearly vertical plane with one intrusion of hard schist 6 inches across; easily dug with spade; few fine and medium roots along fractures; common very fine and fine tubular pores following interstices; many thin coatings on faces of peds; weathered schist is slightly acid (pH 6.4, 1:1 water).
TYPE LOCATION: Weloy Municipality, Yap Island and State, Federated States of Micronesia; about .5 mile by road N. of the village of Okau, then about 1.8 mile E. on overland road and 98 feet S. of road on trail through forest; lat. 9 degrees 32 minutes 36.38 seconds N. and long. 138 degrees 6 minutes 12.46 seconds E.
RANGE IN CHARACTERISTICS: The thickness of the solum and the depth to bedrock range from 20 to 24 inches.
The A1 horizon has hue of 10YR or 2.5Y, value of 2 or 3, and chroma of 2 or 3. It is gravelly silty clay loam, gravelly clay loam, gravelly silt loam, or very gravelly silt loam. It is 10 to 30 percent moderately hard and hard schist pebbles .08 to 3 inches in size. The horizon is 5 to 15 percent cobbles 3 to 6 inches in size. Reaction in 1:1 water is slightly acid or medium acid.
The B2t horizon has moist color in hue of 7.5YR, 10YR, or 5Y, value of 4 or 5, and chroma of 3 through 8. It is clay loam, silty clay, or clay and is gravelly or very gravelly. The horizon is 15 to 40 percent gravel 1 to 3 inches in size and 5 to 15 percent cobbles 3 to 6 inches in size. Total coarse fragment content ranges from 20 to 50 percent and averages more than 35 percent by volume in the particle-size control section. Reaction in 1:1 water is medium acid or slightly acid.
COMPETING SERIES: These are the Gitam, Rumung, and Tabecheding series. All of these soils lack a mollic epipedon.
GEOGRAPHIC SETTING: Weloy soils are on hills and low mountains that have convex relief. Slopes are 2 to 75 percent. The soils formed in uptilted hard and soft green, chlorite, or talc schist or volcanic breccia containing schist fragments. Elevation ranges from 3 to 453 feet. The mean annual temperature is 81 degrees F., and does not vary by more than 34 degrees F from month to month. The mean annual maximum temperature is 88 degrees F., and the mean annual minimum temperature is 75 degrees F. The mean annual rainfall is about 122 inches (and presumably is higher in the higher elevations) and varies from 90 to 149 inches from year to year, with the driest months (February, March, and April) averaging 6 inches per month.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Gitam, Rumung, and Yap soils. Gitam soils are moderately deep to a paralithic contact, and have a high water table, and an ochric epipedon. Rumung soils are shallow to a lithic contact and have an ochric epipedon. Yap soils are very deep, formed in volcanic saprolite, and have an oxic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow through very rapid runoff; moderate permeability.
USE AND VEGETATION: Most areas are in broadleaf evergreen forest and are used for hunting and a minor amount of timber harvesting for village use.
DISTRIBUTION AND EXTENT: Weloy soils are inextensive in Yap.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Weloy Municipality, Yap Island and State, Federated States of Micronesia, 1981.
REMARKS: The Weloy soils typically have a calcium-magnesium imbalance in the B horizon; 1:1.5 for the typical pedon. These soils will be classified Argic Tropudolls when the subgroup is approved.
ADDITIONAL DATA: National Soil Survey Lab Data No. S80 TQ-639-02 and Military Geology of Yap Islands, Caroline Islands, 1960, used to define the series.