LOCATION HENCRATT CATentative Series
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Haploxerolls
TYPICAL PEDON: Hencratt cobbly fine sandy loam - grazed woodland (Colors for dry soil unless otherwise stated)
O--1 1/2 to 0 inches; litter of pine needles
A11--0 to 3 inches; very dark grayish brown (10YR 3/2) cobbly fine sandy loam, very dark brown (10YR 2/2) moist; weak very fine and fine granular structure; soft, very friable, nonsticky, nonplastic; abundant micro and very fine roots; many micro and very fine interstitial pores; neutral (pH 6.9) clear smooth boundary. (2 to 4 inches thick).
A12--3 to 9 inches; dark grayish brown (10YR 4/2) cobbly fine sandy loam, very dark grayish brown (10YR 3/2) moist; weak very fine and fine granular; soft, very friable, nonsticky, nonplastic; abundant micro and very fine roots; many micro and very fine interstitial pores; slightly acid (pH 6.4); diffuse wavy boundary. (4 to 7 inches thick).
A13--9 to 19 inches; dark brown (10YR 4/3) stony fine sandy loam, dark brown (10YR 3/3) moist; weak very fine and fine granular structure; slightly hard, very friable, slightly sticky, slightly plastic; abundant fine, very fine and medium roots; many micro and very fine interstitial pores; about 35 percent coarse fragments; neutral (pH 6.7); clear, broken boundary. (8 to 12 inches thick)
B2--19 to 38 inches; yellowish brown (10YR 5/4) very stony heavy sandy loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky, slightly plastic; abundant fine and medium roots; many fine and very fine tubular pores; few thin clay films in pores; about 50 percent coarse fragments; neutral (pH 6.7) clear wavy boundary. (12 to 20 inches thick).
C1--38 to 45 inches; light yellowish brown (10YR 6/4) very stony heavy sandy loam, dark yellowish brown (10YR 4/4) moist; moderate medium subangular blocky structure; slightly hard, friable; slightly sticky, slightly plastic; few fine and medium roots; many fine and very fine tubular pores; about 50 percent coarse fragments; neutral (pH 6.7).
C2--45 to 50 inches; weathered stratified tuff that becomes more strongly cemented with depth. Hardness of tuff is less than 3.
TYPE LOCATION: Lassen County, California about 11 miles south and 4 miles east of Adin near Lower McBridge Springs. In road cut about 2100 feet south of the north quarter corner of section 20; T37N, R10E.
RANGE IN CHARACTERISTICS: Solum thickness and depth to the paralithic contact (tuff) is about 24 to 60 inches. Gravels, cobbles and stones are throughout the profile and the control section usually contains about 35 to 50 percent coarse fragments. Mean annual soil temperature ranges from 47 to 50 degrees F. and mineralogy probably is ashy. The soils are dry most years during the summer for more than 60 days in the 7 to 20 inch zone.
The A horizon colors are in 10YR hues and have values of 3 to 5 dry and 2 to 4 moist. Chromas are 2 or 3 moist and dry. Texture ranges from sandy loam to loam and is gravelly, cobbly or stony. Structure is weak granular or weak subangular blocky, or the soils are massive. Consistence is soft, friable, or very friable, and nonsticky and nonplastic. Reaction is neutral or slightly acid and the thickness of the dark colored A horizons is less than 20 inches.
The B2 colors are in 10YR hues with values of 5 or 6 dry and 4 or 5 moist. Chromas are 3 or 4 moist or dry. Texture ranges from heavy sandy loamy to heavy loams that are very stony, gravelly or cobbly. Structure is loose to moderate subangular blocky and consistence is hard or slightly hard, friable, slightly sticky and slightly plastic. Reaction is slightly acid to mildly alkaline.
COMPETING SERIES: These include the Brief and Kilburn series in the same family and the Efwun and Surprise series in similar subgroups. The Brief and Kilburn soils both lack a paralithic contact at depths shallower than 40 inches. The Efwun soils lack a sambic horizon and are frigid. The Surprise soils lack a paralithic contact and have less than 35 percent coarse fragments in the control section.
GEOGRAPHIC SETTING: The Hencratt soils occur in mountainous uplands with slopes that are mostly less than 30 percent but are as step as 50 percent or more in places. Relief generally is smooth. The regolith is gravelly, cobbly and stratified stony tuff that ranges in texture from fine grained to breccia. Elevations range from about 4,500 feet to near 6,000 feet. The climate is semi-arid with mean annual rainfall of 15 to 20 inches with warm dry summers and cold moist winters. Mean annual temperature is about 46 degrees F., average January temperature about 26 degrees F., and average July temperature about 66 degrees F. Average frost free season is about 70 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: The Hencratt soils occur in the same general areas as the Bieber soils with duripans, the Gerig soils with argillic horizons, the reddish brown Letterbox soils, and the Packwood soils with duripans at shallow depths.
DRAINAGE AND PERMEABILITY: Excessively drained, moderately rapid to rapid permeability and slow to medium runoff.
USE AND VEGETATION: Native vegetation is Jeffrey pine, mountain mahogany, Idaho fescue, squirreltail and other bunch grasses. The soils are used for timber, grazing, and recreation.
DISTRIBUTION AND EXTENT: In northern California around the Modoc Plateau. The soils are moderately extensive. MLRA 23.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Soil Vegetation Survey of the Pit Soil Conservation District, Lassen County California 1952.
REMARKS: The Hencratt series was formerly classified in the Prairie soil group. As mapped, these soils may be in both the frigid temperature non and in the mesic. Also, the mineralogy may be ashy.
OSED scanned by SSQA. Last revised by state on 3/68.