LOCATION CAMATTA CAEstablished Series
The Camatta series are very shallow and shallow, well drained soils that formed in alluvial material from calcareous sediments. Camatta soils are on high stream terraces and have slopes of 5 to 30 percent. Mean annual precipitation is about 254 millimeters (10 inches) and the mean annual air temperature is about 16 degrees C (60 degrees F).
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Xeric Petrocalcids
TYPICAL PEDON: Camatta loam, rangeland. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 18 centimeters (0 to 7 inches); pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine and common fine tubular pores; strongly effervescent, disseminated lime; moderately alkaline (pH 8.0); clear smooth boundary. (10 to 20 centimeters (4 to 8 inches) thick)
A--18 to 31 centimeters (7 to 12 inches); pale brown (10YR 6/3) loam, brown (10YR 4/3) moist; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine and common fine tubular pores; strongly effervescent, disseminated lime; moderately alkaline (pH 8.0); abrupt wavy boundary. (10 to 28 centimeters (4 to 11 inches) thick)
Bkm--31 to 51 centimeters (12 to 20 inches); white (10YR 8/1) indurated lime hardpan, very pale brown (10YR 8/3) moist; massive; the upper 1/2 inch is a laminar capping; violently effervescent, moderately alkaline (pH 8.0); gradual wavy boundary. (13 to 51 centimeters (5 to 20 inches) thick)
Bk--51 to 152 centimeters (20 to 60 inches); very pale brown (10YR 8/4) very fine sandy loam, brownish yellow (10YR 6/6) moist; moderate medium platy structure; weakly cemented, hard, friable, nonsticky and nonplastic; violently effervescent with lime segregated in seams and common medium and large concretions, calcium carbonates make up 60 percent of the soil mass by volume; moderately alkaline (pH 8.0).
TYPE LOCATION: San Luis Obispo County, California; near McDonald Canyon, about 800 feet west and 200 feet south of the northeast corner of Sec. 32, T.27S., R15E. USGS Camatta Canyon, California, Quad; latitude 32 degrees, 30 minutes, 00 seconds N and long. 120 degrees, 22 minutes, 28 seconds W.
RANGE IN CHARACTERISTICS: Depth to the indurated Bkm horizon (petrocalcic horizon) ranges from about 20 to 48 centimeters (8 to 19 inches). Mean annual soil temperature ranges from 15 to 17 degrees C (59 to 63 degrees F). The soils receive moisture from about December 15 to about May 15; about 6 out of 10 years they are not moist in some part between the depth of 20 centimeters (8 inches) and the petrocalcic horizon for 90 consecutive days and are moist in some part for 90 to 100 cumulative days. The calcium carbonate equivalent in the control section is about 15 to 35 percent. The electrical conductivity of the saturation extract at 25 degrees C. ranges from 1 to 1.5 dS/m (mmhos).
The A horizon is 10YR 6/2 or 6/3.
The Bkm horizon is 10YR 8/1, 8/3, 7/3. It is 13 to 51 centimeters (5 to 20 inches) thick. The uppermost 1 to 2.5 centimeters (1/2 to 1 inch) is a very dense laminate capping containing no pores. The Ckm horizon is stratified with thin laminae and strongly to weakly cemented materials, or alternating strata of the two.
The Bk horizon is a weakly cemented very fine sandy loam to loamy sand. It is 15 to 70 percent lime concretions and masses by volume. At least half of these concretions slake in water. The colors are similar to the Ckm horizon.
COMPETING SERIES: There are no other soils in this family. Soils in similiar families include the Bard, Cave, Crystal Springs, Domino, Las Vegas, Mormon Mesa, Pinal and Upton series. Bard, Cave, Las Vegas and Upton soils have an aridic moisture regime that does not border on xeric. Bard and Las Vegas soils also have carbonatic mineralogy. Crystal Springs soils have a mean annual soil temperature of 12 to 14 degrees C (53 to 57 degrees F) and have carbonatic mineralogy. Domino soils are 20 to 40 inches to the petrocalcid and are fine-loamy. Mormon Mesa soils have a petrocalcic horizon thicker than 122 centimeters (four feet) and have carbonatic mineralogy. Pinal soils have an indurated duripan.
GEOGRAPHIC SETTING: Camatta soils are on high stream terraces at elevations of 427 to 518 meters (1,400 to 1,700 feet). They formed in old mixed calcareous alluvium derived from sedimentary, granitic and basic igneous rocks sources. Slopes are 5 to 30percent. The climate is semiarid with warm, dry summers and cool, moist winters. The mean annual precipitation is 152 to 305 millimeters (6 to 12
Inches). The average January temperature is about 8 degrees C (46 degrees F), the average July temperature is about 23 degrees C (73 degrees F); the mean annual temperature is about 14 to 17 degrees C (57 to 62 degrees F). The average frost-free season is about 175 to 225 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Balcom,
Calleguas and
Polonio soils. Balcom soils have a solum 50 to 100 centimeters (20 to 40 inches) thick underlain by soft, calcareous
shale. Callegus soils have a solum 31 to 51 centimeters (12 to 20 inches) thick underlain by weathered calcareous shale. Polonio soils are very deep, well drained calcareous clay loam soils on alluvial fans.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: The soils are used for range and dry farmed grain. Vegetation is mainly redstem filaree, soft chess, red brome, foxtail barley and bur clover.
DISTRIBUTION AND EXTENT: South end of the Diablo Range, MLRA 15. Soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: San Luis Obispo County, California, Paso Robles Area, 1977.
Series reclassified on September, 1994. Competing series updated in November, 2001.