LOCATION INARAJAN GU+PBEstablished Series
TAXONOMIC CLASS: Very-fine, mixed, semiactive, nonacid, isohyperthermic Vertic Endoaquepts
TYPICAL PEDON: Inarajan clay, on a level native pasture under sedges and weeds (Hyptis, etc.). (Colors are for moist soil unless otherwise stated. Textures are apparent field textures.)
A--0 to 10 inches; dark gray (5Y 4/1) clay, with many fine red (2.5YR 4/6) mottles; moderate medium subangular blocky structure; very firm, very sticky and very plastic; many very fine through medium roots; common very fine, few fine and medium pores; continuous vertical cracks less than 0.5 inch wide; strongly acid (pH 5.3); gradual smooth boundary. (8 to 16 inches thick)
C1--10 to 16 inches; 50 percent dark yellowish brown and yellowish brown (10YR 4/4, 5/4), and 50 percent gray (5Y 5/1) clay; some of the gray material occur as fillings and wormcasts in coarse pores; moderate fine subangular blocky structure; firm, very sticky and very plastic; common very fine roots and few fine and medium roots; many very fine, common fine and medium and few coarse pores; pressure cutans on faces of peds; many wormcasts; common thin vertical cracks; medium acid (pH 5.8); clear smooth boundary. (4 to 24 inches thick)
C2--16 to 26 inches; gray (5Y 5/1) clay, with many medium dark yellowish brown and yellowish brown (10YR 4/4, 5/4) mottles; moderate fine angular blocky structure; firm, very sticky and very plastic; few very fine roots; common very fine through medium and few coarse pores, many with black streaks; few fine black manganese nodules; pressure cutans on faces of peds; few slickensides ; common thin vertical cracks; slightly acid (pH 6.5); abrupt wavy boundary. (4 to 20 inches thick)
C3--26 to 29 inches; variegated yellowish brown (10YR 5/4) and yellowish red (5YR 4/8) clay in a very fine pattern, with common fine and medium gray (5Y 5/1) mottles completely coating pore walls; massive; friable, sticky and plastic; few very fine roots; common very fine through medium and few coarse pores; slightly acid (pH 6.5); abrupt smooth boundary. (3 to 20 inches thick)
C4--29 to 32 inches; about 60 percent gray (5Y 5/1) and about 40 percent reddish yellow (7.5YR 6/8) clay; massive; friable, sticky and plastic; few very fine roots; many very fine, common fine, few medium and coarse pores; neutral (pH 6.8); clear smooth boundary. (3 to 16 inches thick)
C5--32 to 40 inches; reddish yellow (7.5YR 6/8) clay, with common fine gray (5Y 5/1) mottles lining pores; massive; friable, slightly sticky and slightly plastic; few very fine roots; many very fine, common fine and few medium pores, neutral (pH 6.8); clear wavy boundary. (0 to 16 inches thick)
C6--40 to 57 inches; 60 percent gray (5Y 5/1), 30 percent light olive brown (2.5Y 5/4) clay, and common fine streaks of yellowish red (5YR 4/6); moderate fine angular blocky structure; friable, sticky and plastic; few very fine roots; common very fine and few fine and medium pores; pressure cutans and small slickensides on faces of peds; neutral (pH 7.1).
TYPE LOCATION: Guam; about 1,300 feet WNW of Inarajan village, about 650 feet S of the Inarajan River, 80 feet N of a corral on the Alfred Flores Ranch; lat. 13 degrees 16 minutes 45 seconds N. and long. 144 degrees 44 minutes 25 seconds E.
RANGE IN CHARACTERISTICS:
Soil moisture - The soil is saturated most of the time between July and November. The A horizon is dry most of the time between March and June. A water table fluctuates between 20 and 40 inches between July and December, gradually receding during the dry season.
Flooding - Brief, occasional to common, dominantly between June and November, but may coincide with a typhoon at any time of year.
Soil temperature - 77 to 86 degrees F., with less than 4 degrees F. fluctuation between summer and winter.
Depth to bedrock - Dominantly over 60 inches, but in some pedons is as shallow as 40 inches over limestone.
Shrink-swell features - Hummocky microrelief is not always present. Surface cracks range from 0.5 to 2 inches wide, and from 8 to 20 inches deep, but are less than 0.5 inch wide at a depth of 20 inches.
A horizon - Matrix color: 10YR 2/1, 3/1, 3/2, 4/1, 2.5Y 4/2, 5Y 4/1, 5/1.
Mottle colors: 2/5YR 4/6, 5YR 4/4, 4/6, 7.5YR 4/4.
Texture: Dominantly clay and silty clay, but ranges to sandy clay loam in some areas.
Reaction: Strongly acid to neutral.
C horizon - Color: Both high and low chroma colors are present, either as matrix or as mottles. Common high chroma colors are 5YR 4/6, 4/8, 7.5YR 4/4, 5/6, 6/8, 10YR 4/3, 3/4, 4/4, 4/6, 5/4, 5/6, 7/6, 2.5Y 5/4. Common low chroma colors are 10YR 4/1, 4/2, 5/1, 5/2, 2.5Y 5/2, 5Y 4/1, 5/1. Texture: Dominantly clay or silty clay, may include strata of fine sandy loam, sandy clay loam, silty clay loam, or clay loam. Rock fragments: 0 to 5 percent pebbles, mostly below 40 inches. Reaction: Slightly acid to moderately alkaline. Strata in some pedons are calcareous.
COMPETING SERIES: None.
GEOGRAPHIC SETTING: Nearly level to gently sloping valley bottoms and coastal plains. Slopes range from 0 to 4 percent. These soils formed in alluvium. Elevation ranges from 0 to 330 feet. Mean annual precipitation is 80 to 100 inches, most of which falls between June and November. The mean annual temperature is 79 degrees F., with less than 4 degrees F. difference between summer and winter.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Pulantat, Shioya, and Ylig soils. Pulantat soils are shallow. Shioya soils are sandy. Ylig soils have low chroma mottles lower in the profile, occur in upstream valley heads and uplands, and are acidic.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; very slow or slow runoff; slow permeability. There is a seasonal, fluctuating water table from June through December.
USE AND VEGETATION: Most areas are farmed in the dry season; some areas are used for wildlife habitat and watershed. Areas not under cultivation are in water-tolerant forest and grasslands. Small areas are used for aquaculture by diking and ponding.
DISTRIBUTION AND EXTENT: Guam; this series is inextensive, with about 4,300 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Guam; July 1985.