LOCATION QUIENSABE CAEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Typic Argixerolls
TYPICAL PEDON: Quiensabe sandy clay loam - on a west-facing slope of 31 percent, under blue oak and annual grasses and forbs at an elevation of 1,550 feet. (Colors are for dry soil unless otherwise stated. When described on November 3, 1981 the soil was moist throughout.)
A1--0 to 4 inches; brown (10YR 5/3) sandy clay loam, dark brown (10YR 3/3) moist; moderate fine and medium subangular blocky structure; hard, friable, sticky and plastic; common very fine roots; common very fine tubular pores; 5 percent gravel 2 to 10 mm in size; 31 percent clay; neutral (pH 7.0); clear smooth boundary.
A2--4 to 14 inches; yellowish brown (10YR 5/4) sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; hard, friable, sticky and plastic; few very fine roots; common very fine and fine tubular pores; 5 percent gravel 2 to 10 mm in size; 2.8 percent organic matter; 34 percent clay; neutral (pH 7.0); clear smooth boundary. (Combined thickness of the A horizons is 8 to 17 inches)
Bt--14 to 22 inches; brown (7.5YR 4/4) gravelly clay, dry and moist; strong fine prismatic structure parting to strong fine angular blocky; hard, firm, sticky and very plastic; few very fine roots; common very fine tubular pores; many thick clay films on peds and bridging sand grains; 20 percent gravel 2 to 10 mm in size; 40 percent clay; neutral (pH 7.0); gradual smooth boundary. (6 to 15 inches thick)
C--22 to 27 inches; brown (7.5YR 4/4), light yellowish brown (10YR 6/4), and red (2.5YR 5/6) very gravelly clay loam, brown (7.5YR 4/4), yellowish brown (10YR 5/4), and red (2.5YR 4/6) moist; massive; hard, friable, sticky and very plastic; few medium roots, few very fine tubular and interstitial pores; many moderately thick clay films bridging sand grains; 40 percent gravel 2 to 20 mm in size; 35 percent clay; neutral (pH 7.0); clear smooth boundary. (4 to 8 inches thick)
2R--27 to 29 inches; unrelated fractured sandstone.
TYPE LOCATION: Merced County, California; about 20 miles SW of the city of Los Banos, 4,200 feet west of the south fork of Los Banos Creek, 2,200 feet north and 100 feet east of the NW corner of section 3, T. 13 S., R. 8 E.
RANGE IN CHARACTERISTICS: Depth to an unrelated lithic contact ranges from 20 to 40 inches. The mollic epipedon is 8 to 17 inches thick and is always at least one-third as thick as the depth of the solum. The moisture control section is moist throughout from about November 15 to June 1 and dry throughout from July 1 to October 15 most years. The soil temperature is below 47 degrees F. from December 15 to March 1. The average annual soil temperature is 59 degrees to 62 degrees F.
The A horizon dry color is 10YR 4/2, 5/2, 5/3, or 5/4. Moist colors are 10YR 2/2, 3/2, or 3/3. It is sandy clay loam or clay loam with 25 to 35 percent clay content. It has up to 10 percent gravel. Organic matter content ranges from 1 to 3 percent.
The Bt horizon dry color is 7.5YR 4/4, 6/4, 6/6; 10YR 5/3, 6/3, or 6/4. Moist colors are 7.5YR 4/4, 5/4, 5/6; 10YR 4/2, 4/3, 4/4, or 5/4. It is clay loam or gravelly clay with 35 to 45 percent clay content and 5 to 25 percent gravel. Clay increase in the Bt horizon is less than 15 percent (absolute) greater than the A horizon and has a clear boundary.
The C horizon is gravelly clay loam or very gravelly clay loam with 30 to 40 percent clay content and 15 to 50 percent gravel. This horizon rests abruptly upon unrelated fractured sandstone at a depth of 20 to 40 inches. Some pedons are underlain by consolidated volcanic sediments.
COMPETING SERIES: This is the Yorkville series in the same family and the Contra Costa, Franciscan, Gonzaga and Laveaga series in other families. Contra Costa soils have an ochric epipedon. Franciscan soils are fine-loamy. Gonzaga soils have an abrupt A/B boundary with more than 15 percent clay increase. Laveaga soils are 40 to 60 inches deep and have a mesic temperature regime. Yorkville soils are greater than 40 inches deep, moderately well drained and occur in fault gouge materials dominated by chlorite, vermiculite, and mica.
GEOGRAPHIC SETTING: Quiensabe soils are on hillslopes of high elevation dissected terraces of the Peckham Formation and have slopes of 30 to 50 percent. Elevations are 700 to 1,800 feet. The soils formed in mixed alluvium dominantly from sedimentary and metamorphic rock of the Franciscan Formation, and in some pedons dominantly from basic igneous rock of the Quiensabe Sabe Formation. The climate is subhumid with hot dry summers and cool moist winters. Mean annual precipitation is 13 to 21 inches. Mean January temperature is about 44 degrees F.; mean July temperature is about 72 degrees F.; mean annual temperature is about 61 degrees F. Frost-free season is 200 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Contra Costa and Franciscan soils and the Fifield and Orognen soils. Fifield soils are loamy-skeletal. Orognen soils are greater than 60 inches deep and lack a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained, rapid runoff, slow permeability.
USE AND VEGETATION: Used mainly for annual rangeland. Vegetation is blue oak, soft chess, wild oats, fescue, tarweed, and other annual grasses and forbs.
DISTRIBUTION AND EXTENT: Quiensabe soils are on high elevation terraces in the intermountain valleys of the Coast Range. They are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Merced County, California 1984.
REMARKS: Quiensabe soils were formerly included with and mapped as the Positas series in Los Banos Area, series 1939 report. They are being differentiated by having a mollic epipedon and not having at least 15 percent clay increase (absolute) in the B horizon over the A horizon. pH determined by colorimetric method using Thymol Blue and Hellige-Truog Triplex indicators. Texture determined by modified Bouyoucos method. Organic matter determined by Walkley-Black digestion method. Base saturation determined by KC1-triethanolamine extract (sum of cations).
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET
OSED scanned by SSQA. Last revised by state on 8/84.