LOCATION LORELLA OR+CA IDEstablished Series
TAXONOMIC CLASS: Clayey-skeletal, smectitic, mesic Lithic Argixerolls
TYPICAL PEDON: Lorella very stony loam, rangeland. (Colors are for moist soil unless otherwise noted.)
A1--0 to 2 inches; very dark grayish brown (10YR 3/2) very stony loam, grayish brown (10YR 5/2) dry; weak thin platy structure parting to weak very fine granular; slightly hard, very friable, slightly sticky and slightly plastic; common very fine roots; many fine vesicular pores in upper 1 inch, many very fine pores below; about 60 percent gravel, cobbles and stones; neutral (pH 6.9); abrupt smooth boundary.
A2--2 to 5 inches; very dark grayish brown (10YR 3/2) very gravelly loam, grayish brown (10YR 5/2) dry; weak medium platy structure parting to weak fine granular; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; many very fine pores; about 50 percent gravel, cobbles and stones; neutral (pH 6.8); clear smooth boundary. (Combined thickness of the A horizon is 2 to 9 inches thick)
BA--5 to 10 inches; dark brown (10YR 3/3) very cobbly clay loam, dark grayish brown (10YR 4/2) dry; weak medium subangular blocky structure; hard, firm, sticky and plastic; common very fine roots; many very fine tubular pores; about 50 percent gravel, cobbles and stones; neutral (pH 6.7); clear smooth boundary. (0 to 5 inches thick)
Bt--10 to 19 inches; dark yellowish brown (10YR 4/4) very cobbly clay, pale brown (10YR 6/3) dry; moderate medium and fine angular blocky structure; very hard, very firm, very sticky and very plastic; few very fine roots; many very fine tubular pores; many stress cutans on faces of peds; about 55 percent gravel, cobbles and stones, some with opal coatings on underside; neutral (pH 6.8); abrupt smooth boundary. (4 to 15 inches thick)
R--19 inches; dark brown (10YR 4/3) fractured volcanic tuff; many distinct clay films on fracture surfaces.
TYPE LOCATION: Klamath County, Oregon; south slope of Bly Mountain; 2,730 feet east and 1,200 feet north of the SW corner sec. 27, T. 37 S., R. 11 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 54 degrees F. The soils are usually moist and are dry at depths between 4 to 12 inches for about 90 to 120 days consecutive days out of the 200 to 240 days when the soil temperature is above 41 degrees F. They are moist in some part or throughout from about October 10 to June 21. Solum thickness and depth to bedrock is 10 to 20 inches. The mollic epipedon may include all of part of the Bt horizon.
The A horizon has value of 2 or 3 moist, 4 or 5 dry, and chroma of 2 or 3 moist and dry. It has 5 to 35 percent gravel and 0 to 50 percent cobbles and stones. It is slightly acid to neutral.
The Bt horizon has hue of 10YR or 7.5YR, value of 2 through 4 moist, 4 through 6 dry, and chroma of 2 through 4 moist and dry. It is clay loam or clay and averages 35 to 50 percent clay. The horizon has 5 to 50 percent gravel, 10 to 45 percent cobbles and stones, and 35 to 60 percent total rock fragments. It is neutral to mildly alkaline.
COMPETING SERIES: These are the Gwinly, Laufer, Longcreek, Loomer, Pioche, Ruckles and Waterbury series. Gwinly soils are dry for 60 to 80 consecutive days. Laufer soils are dry for 80 to 90 consecutive days. Longcreek, Loomer Pioche and Ruckles soils have an aridic soil moisture regime. Waterbury soils are dry for 80 to 100 consecutive days and have 50 to 60 percent clay in the particle-size control section.
GEOGRAPHIC SETTING: Lorella soils are on sideslopes of mountains and hills and on convex slopes of escarpments. Elevations range from 3,500 to 6,000 feet. The soils formed in colluvium and residuum from tuff and basalt. The climate is characterized by dry summers and cool moist winters. The mean annual precipitation is 10 to 18 inches with most of the area above 12 inches. The mean January temperature is 28 degrees F; the mean July temperature is 67 degrees F; and the mean annual temperature is 45 to 51 degrees F. The frost-free period is 50 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Booth, Bullump, Calimus, Capona, Dehlinger, Harriman, Lasere, Stukel, and Woodcock soils. Booth, Calimus, Capona, Harriman, Lasere, and Stukel soils have less than 35 percent rock fragments. Booth soils have bedrock at depths of 20 to 40 inches, are frigid, and occur near the upper part of the elevational range on adjacent northerly slopes. Bullump soils are over 40 inches deep to bedrock, are frigid and are on north slopes. Calimus, Capona, and Dehlinger soils lack argillic horizon and are over 20 inches deep to bedrock. Harriman soils have a fine-loamy Bt horizons and have soft bedrock at depths of 40 or more inches. Lasere soils have bedrock at 20 to 40 inches. Stukel soils have an average of 10 to 18 percent clay. Woodcock soils are cryic, underlain by bedrock at depths over 60 inches, and also occur near the upper part of the elevational range on northerly aspects.
DRAINAGE AND PERMEABILITY: Well drained; slow permeability.
USE AND VEGETATION: Lorella soils are used for livestock grazing, pasture, water supply, and wildlife habitat. Vegetation is mainly western juniper, bluebunch wheatgrass, Idaho fescue, antelope bitterbrush, mountain big sagebrush and Wyoming big sagebrush on the drier extreme.
DISTRIBUTION AND EXTENT: South-central Oregon and adjacent parts of northern California, MLRA 21. Idaho has used the series in MLRA 10. The soils are extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Klamath County, Oregon, 1941.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: the zone from 0 to 10 inches (A1, A2, BA horizons)
Argillic horizon: the zone from 10 to 19 inches (Bt horizon)
Xeric soil moisture regime bordering on aridic.
Lithic contact: the boundary with hard bedrock at 19 inches.
ADDITIONAL DATA: Characterization data on 2 profiles (S66 Oreg. 18-9 and 18-10) reported in Riverside Soil Survey Laboratory report for Lorella soils sampled in Klamath County, Oregon, 1966. The typical pedon was sampled for characterization. Profile 18-10 is the type location.