LOCATION BEAM CAEstablished Series
The Beam series consists of shallow, well drained soils formed in material weathered from soft calcareous sandstone, shale or conglomerate. Beam soils are on hills and mountains and have slopes of 9 15 to 75 percent. The mean annual precipitation is about 200 millimeters (8 inches) and the mean annual temperature is about 16 degrees C (60 degrees F).
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Xeric Haplocambids
TYPICAL PEDON: Beam fine sandy loam - on an east-facing slope of 40 percent, under annual grass and native shrubs at 774 meters elevation. (Colors are for dry soil unless otherwise stated. When described on January 8, 1981 the soil was dry throughout.)
A--0 to 10 centimeters (0 to 4 inches); light gray (2.5Y 7/2) fine sandy loam, grayish brown (2.5Y 5/2) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and slightly plastic; common very fine roots; few very fine tubular and interstitial pores; electrical conductivity is 2.5 millimhos per centimeter; violently effervescent with disseminated lime; moderately alkaline (pH 8.0); gradual wavy boundary. (10 to 20 centimeters (4 to 8 inches) thick)
B--10 to 38 centimeters (4 to 15 inches); light gray (2.5Y 7/2) fine sandy loam, grayish brown (2.5Y 5/2) moist; massive; soft, very friable, nonsticky and slightly plastic; common very fine and few fine roots; common very fine tubular pores; electrical conductivity is 2.6 millimhos per centimeter; violently effervescent with disseminated lime; moderately alkaline (pH 8.0); clear wavy boundary. (15 to 30 centimeters (6 to 12 inches) thick)
Crk--38 to 58 centimeters (15 to 23 inches); variegated gray (N 6/0) and grayish brown (2.5Y 5/2) fractured fine grained sandstone, dark gray (N 4/0) moist; fine and medium and angular blocky fragments which slake in water after 15 minutes of shaking; common very fine roots in fractures; strongly effervescent with disseminated lime and lime segregated in seams and coatings on fracture faces.
TYPE LOCATION: San Luis Obispo County, California; approximately 2,750 feet northwest on Simmler-Soda Lake Road from intersection with Hurricane Road, then about 1,500 feet east on road to water tank, then uphill 212 feet southwest (magnetic bearing 230 degrees) of the metal pole south of concrete ruins; 850 feet east and 5 feet south of the northwest corner of sec. 27, T. 31 S., R. 21 E. Mount Diablo Base Line. USGS Panoramic Hill Quad; latitude 35 degrees, 12 minutes, 20 seconds N and long. 119 degrees, 42 minutes, 53 seconds W.
RANGE IN CHARACTERISTICS: Depth to soft calcareous sandstone or conglomerate is 25 to 50 centimeters (10 to 20 inches) . Mean annual soil temperature ranges from 16 to 20 degrees C (60 degrees to 68 degrees F). The moisture control section becomes moist in some or all parts between December 15 and January 15, and remains moist until mid-March. Soil temperature is always above 8 degrees C (47 degrees F). Clay content ranges from 12 to 20 percent. Gravel content is 0 to 10 percent by volume. Stones and cobbles on the surface range from 0 to 20 percent.
The A horizon has dry color of 10YR 6/2, 6/3, 6/4, 7/3; 2.5Y 7/2 and moist color of 10YR 4/2, 4/3, 4/4, 5/3; 2.5Y 5/2. Textures are fine sandy loam, sandy loam, loam, stony sandy loam and stony loam. It is slightly to violently effervescent. Electrical conductivity ranges from 1 to 4 millimhos per centimeter.
The C horizon has dry color of 10YR 6/3, 6/4, 7/3; 2.5Y 7/2 and moist color of 10YR 4/3, 5/4; 2/5Y 5/2. Textures are fine sandy loam and sandy loam. It is strongly to violently effervescent. Electrical conductivity ranges from 2 to 4 millimhos per centimeter.
COMPETING SERIES: This is the Calleguas series. Calleguas soils have at least 20 percent clay throughout and do not have an accumulation of carbonates in the Cr horizon.
GEOGRAPHIC SETTING: Beam soils are on hills and mountains and have slopes of 9 to 75 percent. The soil is formed in material weathered from soft calcareous sandstone, shale or conglomerate. Elevations are 549 to 1250 meters (1,800 to 4,100 feet). The climate is semiarid with hot dry summers and cool moist winters. Mean annual precipitation is 178 to 279 millimeters (7 to 11 inches). Average January temperature is about 8 degrees C (46 degrees F), the average July temperature is about 25 degrees C (77 degrees F)., and the mean annual temperature is about 14 to 17 degrees C (58 degrees to 62 degrees F). The average frost-free season is about 175 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Hillbrick, Jenks (T), Padres (T) and Panoza (T) soils. Hillbrick soils have a lithic contact. Jenks (T) and Panoza (T) soils are moderately deep. Padres soils are deep and are on alluvial plains.
DRAINAGE AND PERMEABILITY: Well drained medium runoff; moderately rapid permeability.
USE AND VEGETATION: This soil is used for livestock grazing and some dry-farmed small grain. Vegetation is mainly red brome, annual fescue, goldenbush and buckwheat.
DISTRIBUTION AND EXTENT: Hills and mountains of the Temblor and Caliente ranges in California in MLRA 15. The soils are moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: San Luis Obispo County, California; Carrizo Plain Area, 1982. Soil name was derived from Beam Flat.
REMARKS:
Ochric epipedon - 0 to 4 inches
Cambic horizon - 10 to 38 centimeters (4 to 15 inches); based on evidence of removal of carbonates from B horizon and accumulation in Cr horizon. The B horizon designation is given because of removal of carbonates even though there is no development of structure or color.
Calcareous class - pedon is violently effervescent throughout.
Electrical conductivity - NSSL 0 to 10 cm (0 to 4 in.) - 2.5 millimhos per centimeter; 10 to 38 centimeters (4 to 15 in.) - 2.6 millimhos per centimeter
Beam soils have an aridic bordering on xeric moisture regime.
This is a classification change from Typic Xerorthents, loamy, mixed (calcareous), thermic to Xeric Torriorthents, loamy, mixed (calcareous), thermic.
ADDITIONAL DATA: NSSL Soil Survey Sample No. 84CA-079-037 Laboratory Pedon number 84P 0932 (type location)
Last revised by the state on 2/86.