LOCATION HALEMAUMAU HIEstablished Series
TAXONOMIC CLASS: Ashy, glassy, isothermic Typic Ustivitrands
TYPICAL PEDON: Halemaumau gravelly ashy sandy loam, on a dissected 10 percent side slope under scattered ohia trees and shrubs at an elevation of 1,170 meters (3,840 feet). Colors are for moist soil unless otherwise noted. Colors are lithochromic at depths below 25 centimeters (10 inches). When described on 1/13/97 the soil was slightly moist throughout. All textures are "apparent field textures". pH was determined by adjusting field organic dye values via regression to approximate pH in 1:1 water.
A--0 to 8 centimeters (0 to 3 inches); very dark gray (10YR 3/1) gravelly ashy sandy loam; strong medium platy structure parting to moderate fine granular; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; 20 percent gravel; extremely acid (pH 4.0); abrupt wavy boundary. (3 to 13 centimeters (1 to 5 inches) thick)
C1--8 to 25 centimeters (3 to 10 inches); very dark grayish brown (10YR 3/2) ashy loamy sand; massive; slightly hard, very friable, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; 8 percent, gravel sized rounded, soft to hard, accretionary lapili throughout; 2 percent gravel sized cinders; neutral (pH 7.2); abrupt wavy boundary.
Cd--25 to 29 centimeters (10 to 12 inches); very dark grayish brown (2.5Y 3/2) ashy loamy very fine sand; strong fine platy structure due to geologic stratification; very hard, very firm, brittle, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; 5 percent, gravel sized rounded, soft to hard accretionary lapili; neutral (pH 7.2); abrupt wavy boundary.
C2--29 to 33 centimeters (12 to 13 inches); 90 percent very dark gray (7.5YR 3/1) and 10 percent dusky red (10R 3/3) ashy loamy fine sand; moderate fine platy structure due to geologic stratification; slightly hard, very friable, nonsticky and nonplastic; common very fine and fine roots; many very fine and fine interstitial pores; neutral (pH 7.2); abrupt wavy boundary.
C3--33 to 38 centimeters (13 to 15 inches); very dark grayish brown (2.5Y 3/2) ashy loamy fine sand; massive; hard, firm, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; neutral (pH 7.2); abrupt wavy boundary.
C4--38 to 41 centimeters (15 to 16 inches); 90 percent very dark gray (7.5YR 3/1) and 10 percent dusky red (10R 3/3) ashy fine sand; weak fine platy structure due to geologic stratification; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; many very fine and fine interstitial pores; neutral (pH 7.2); abrupt wavy boundary.
C5--41 to 43 centimeters (16 to 17 inches); very dark grayish brown (2.5Y 3/2) ashy loamy fine sand; massive; hard, firm, nonsticky and nonplastic; few very fine and fine roots; many very fine and fine interstitial pores; neutral (pH 7.2); abrupt wavy boundary.
C6--43 to 46 centimeters (17 to 18 inches); 90 percent black (N 2/0) and 10 percent dusky red (10R 3/3) ashy fine sand; massive; soft, very friable, nonsticky and nonplastic; common very fine and fine and few medium roots; many very fine and fine interstitial pores; 2 percent yellow green coarse sand-size olivine crystals; neutral (pH 7.2); abrupt wavy boundary.
C7--46 to 48 centimeters (18 to 19 inches); 70 percent very dark grayish brown (2.5Y 3/2) and 30 percent black (N 2/0) ashy loamy sand and ashy coarse sand; moderate fine platy structure due to geologic stratification; soft, very friable, nonsticky and nonplastic; many very fine and fine and common medium and few coarse and very coarse roots; many very fine and fine interstitial pores; 2 percent yellow-green coarse sand-size olivine crystals; neutral (pH 7.2); abrupt wavy boundary.
C8--48 to 61 centimeters (19 to 24 inches); 50 percent black (N 2/0) and 50 percent dark olive gray (5Y 3/2) ashy coarse sand; single grain; loose when moist or dry, nonsticky and nonplastic; few very fine and fine roots; many very fine, fine and medium interstitial pores; 10 percent gravel-size dark olive gray (5Y 3/2) pumice; neutral (pH 7.2); clear wavy boundary. (Combined thickness of C horizons 51 to 74 centimeters (20 to 29 inches)).
2C--61 to 71 centimeters (24 to 28 inches); reticulite (pumice-like volcanic glass); abrupt wavy boundary. (0 to 13 centimeters (0 to 5 inches) thick)
3R--71 centimeters (28 inches), hard unweathered pahoehoe bedrock.
TYPE LOCATION: Hawaii Volcanoes National Park; drive 0.7 miles southeast of Namakani Paio Campground on Highway 11, and walk due south 270 yards to type location; Kilauea Crater Quadrangle, lat. 19 degrees 25 minutes 19.2 seconds N., 155 degrees 18 minutes and 19.2 degrees W.( +/- 65 feet position calculated based on digitized point using ArcMap 9.2 software, Old Hawaiii datum)
RANGE IN CHARACTERISTICS:
Depth to bedrock: 50 to 100 centimeters (20 to 40 inches).
Mean annual soil temperature: 15 to 20 degrees C. (59 to 68 degrees F.)
Soil Surface: Up to 30 percent of the pedons have a brittle crust, 1.5 centimeters (0.5 inch) thick. The crust has one to ten percent thin white coatings on the underside that does not effervesce with hydrochloric acid.
A horizon
Hue: 2.5YR to 10YR
Value: 2 to 3 moist.
Texture: Gravelly ashy sandy loam and extremely gravelly ashy coarse sand; and less commonly gravelly ashy loam or gravelly ashy fine sandy loam.
Rock fragments: 0 to 35 percent gravel sized cinders or pumice at surface or at depth.
Soil reaction: Strongly acid to extremely acid.
Some pedons have as much as thirty percent of the soil surface covered by a reddish brown (5YR 4/3) brittle crust 1 centimeter (0.5 inches) thick
C horizon
Hue: 2.5YR to 10YR, 2.5Y, 5Y, or N.
Value: 0, 2, or 3 moist.
Texture: Ashy loam, ashy very fine sandy loam, ashy fine sandy loam, ashy sandy loam, ashy loamy fine sand, ashy loamy sand, ashy fine sand, ashy sand, and ashy coarse sand.
Soil reaction: Slightly acid to slightly alkaline.
Accretionary lapili: 2 to 5 percent in most pedons.
Olivine crystals: Occur in some pedons.
2C Horizon
Reticulite: Occurs in most pedons.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Halemaumau soils formed in the Kilauea Volcano, Keanakakoi surge and airfall pyroclastic deposits over pahoehoe lava. They are mainly on Kilauea pahoehoe flows less than 750 years old at elevations from 1,070 to 1,250 meters (3,500 to 4,100 feet). Slopes range from 2 to 20 percent. The mean annual rainfall is 1270 to 2032 millimeters (50 to 80 inches), with about 90 percent of the rainfall occurring between October and May. The mean annual pan evaporation is 1,270 to 1,780 centimeters (50 to 70 inches). The mean annual air temperature is 13 to 18 degrees C. (55 to 65 degrees F.)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Alahapa, Heake, Kilauea, Lithic Ustipsamments, and Lithic Ustorthents soils. Alahapa soils are fragmental `a`a soils. Heake, Lithic Ustipsamments, and Lithic Ustorthents soils are less than 50 centimeters (20 inches) deep to bedrock. Kilauea soils are deep, more than 100 centimeters (40 inches) to bedrock.
DRAINAGE AND PERMEABILITY: Well drained. In areas with surface crust, runoff is very high and permeability is very slow. In areas without surface crust, runoff is low and permeability is rapid. Permeability is very slow in the underlying bedrock.
USE AND VEGETATION: These soils are used for National Park Service land. Vegetation is aalii (Dodonaea viscosa), bamboo orchid (Arundina graminifolia), broomsedge (Andropogon virginicus), bushy beardgrass (Schizachyrium condensatum), ohelo (Vaccinium reticulatum), ohia lehua (Metrosideros polymorpha), pukiawe (Styphelia tameiameiae), ulei or rose family (Osteomeles anthyllidifolia), and uki sedge (Machaerina angustifolia).
DISTRIBUTION AND EXTENT: Island of Hawaii, within Hawaii Volcanoes National Park; MLRA 161. The series is of small extent, approximately 650 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Island of Hawaii, Hawaii County, Hawaii, Proposed in 1996. Established in 2008. The name is from Halemaumau Crater.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the soil surface to a depth to 8 centimeters (3 inches) (A horizon).
Andic soil properties - from the soil surface to 71 centimeters (28 inches) (C and 2C horizons).
Depth to bedrock - 71 centimeters (28 inches).
Soil temperature - mean summer and mean winter soil temperatures differ by less than 6 degrees C. (11 degrees F.) (Iso temperature regime).
Soil moisture - dry in some or all parts for a four-month period from June to September in most years (Ustic moisture regime).
The Halemaumau soil with a cindery control section is a taxajunct.
Edit Log: 12/03 KH. Added "ashy" modifier to textures; changed soil reaction in Range in Characteristics.
2/01 KH. Minimum slope range changed from 10 to 2 percent. Rock fragments added to Range in Characteristics of A horizon. Previous high runoff and moderately rapid permeability changed to separate classes for areas with and without surface crust.
Okinas removed in 2008 for simplicity under direction of the State Soil Scientist.
Minor changes made by state 5/09
ADDITIONAL DATA: Nearby Heake soil NSSL sample S97HI-001-002.
Penetrometer readings made by inserting penetrometer horizontally into "in situ" soil:
C1 horizon = 0.5 tons/square foot
Cd horizon = 4.0 tons/square foot
C3 horizon = 2.5 tons/square foot
C5 horizon = 2.0 tons/square foot