LOCATION PINEAL CAEstablished Series
TAXONOMIC CLASS: Clayey, smectitic, mesic, shallow Natric Durixeralfs
TYPICAL PEDON: Pineal silt loam - range land (Colors are for dry soil unless otherwise noted.)
A1--0 to 4 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; weak fine and medium platy structure; hard, very friable, slightly sticky, slightly plastic; few very fine roots; few very fine interstitial pores; slightly acid (pH 6.2); clear smooth boundary. (2 to 4 inches thick)
A2--4 to 9 inches; light brownish gray (10YR 6/2) heavy loam, dark brown (7.5YR 4/2) moist; massive; hard, very friable, slightly sticky, slightly plastic; common very fine and few fine roots; few very fine tubular pores; clean quartz grains; neutral (pH 7.2); abrupt smooth boundary. (2 to 10 inches thick)
B2t--9 to 16 inches; brown (7.5YR 5/2) heavy clay loam, dark brown (7.5YR 4/2) moist; strong medium columnar structure; very hard, firm, sticky, plastic; few very fine roots; few very fine tubular pores; continuous moderately thick clay films on peds; 1 to 3 mm thick bleached caps; noneffervescent; moderately alkaline (pH 8.3); clear smooth boundary. (6 to 10 inches thick)
C1sicam--16 to 24 inches; pale brown (10YR 6/3) clay loam, dark brown (7.5YR 4/4) moist; massive; hard, friable, slightly sticky, slightly plastic; weakly cemented between the bands; common very fine and few fine roots; many very fine interstitial and very fine tubular pores; 2 mm thick indurated bands and about 10 percent.
C2sicam--24 to 30 inches; very pale brown (10YR 7/3) duripan that crushes to heavy loam, dark brown (7.5Y 4/4) moist; strong thick platy structure; extremely hard, extremely firm, slightly sticky, slightly plastic, strongly cemented; many very fine tubular pores; strongly effervescent, segregated lime as filaments; strongly alkaline (pH 8.5); clear smooth boundary. (4 to 20 inches thick)
C3--30 to 49 inches; very pale brown (10YR 7/3) crushes to heavy clay loam, dark brown (7.5YR 4/4) moist; massive; very hard, friable, very sticky, plastic; weakly cemented, many very fine tubular pores; noneffervescent; moderately alkaline (pH 8.0); gradual smooth boundary. (0 to 20 inches thick)
C4--49 to 60 inches; very pale brown (10YR 7/3) light clay loam; dark brown (7.5YR 4/4) moist; massive; slightly hard, friable, sticky, plastic; many very fine interstitial pores; noneffervescent; moderately alkaline (pH 8.0). (0 to over 15 inches thick)
TYPE LOCATION: Modoc County, California; about 5 miles south of Alturas; 1.5 miles south of Pine Creek road (County Rd 59) on old U.S. Highway 395; 43 feet south of an east-west fence and 50 feet east of the fence corner or the W1/4 corner of section 6, T.41N., R.13E.
RANGE IN CHARACTERISTICS: Depth to the duripan is 10 to 20 inches. Depth to weakly cemented or non-cemented C horizons is about 20 to 60 inches. The mean annual soil temperature is about 50 degrees to 55 degrees F. and the soil temperature usually is above warmer than 41 degrees F. March 15 to December 1. It is moist more than one-half the time when the soil temperature is warmer than 41 degrees F. The soil between depths of 4 to 12 inches or to the duripan is usually dry in all parts from August until October 15 and is moist in some or all parts all the rest of the year. The A1 and A2 horizons are similar and are very pale brown, pale brown, light gray, of light brown in 10YR hue. Moist colors are brown to very dark grayish brown (10YR 4/3, 4/2, 3/3, 3/2; 7.5YR 4/2, 3/2.) This horizon is massive or has weak platy structure and is slightly acid to strongly alkaline. Effervescence is lacking in some pedons or is as much as strongly effervescent in others. The upper part of the A horizon is very fine sandy loam, loam, or silt loam. The lower part is heavy loam or light clay loam. It lacks an abrupt texture change to the B2t horizon. The B2t horizon is brown, grayish brown, or dark grayish brown (10YR or 7.5YR hue) dry and is brown to very dark grayish brown moist (10YR 4/3, 4/2, 3/3, 3/2; 7.5YR 4/2, 3/2.) It is heavy clay loam, heavy silty clay loam or clay and has 35 to 45 percent clay. This horizon has prismatic or weak to strong columnar structure that in most pedons parts to strong angular blocks. It is moderately to very strongly alkaline and lacks effervescence or is as much as violently effervescent in some pedons may be weakly cemented and brittle in the lower part of the B2t horizon. This horizon is strongly to very strongly alkaline and has 15 to 30 percent exchangeable sodium. The Csicam horizon is very pale brown to light brownish gray (10YR 7/4 through 6/2) dry and yellowish brown and dark grayish brown to dark brown (10YR 5/4 through 3/3); and (7.5YR 5/4, 5/2, 4/4) moist. It is massive or has platy structure and has thin bands or plates that are strongly cemented or are indurated with silica and lime. The plates or thin bands are indurated in some part of the pedon. The soil material between the bands is less firm and only weakly to moderately cemented. After crushing this material the apparent texture is sandy loam, loam, silt loam or clay loam. Segregated lime mostly occurs as filaments. The lower part of the C horizon is similar in color to the Csicam horizons. It is only weakly cemented or cementation is lacking, and usually is massive but not indurated in any part. It commonly is moderately alkaline but noneffervescent. After crushing the apparent texture is heavy loam, clay loam, silty clay loam, or heavy clay loam. In some pedons the lower C horizons are absent.
COMPETING SERIES: These are the Alturas, Calder, Calneva, Lewis, Ocho, Standish, and Stearms series. Alturas soils have a mollic epipedon and lack a duripan. Calder soils have abrupt textural AB boundaries and lack indurated duripans. Calneva and Standish soils lack a duripan. Lewis and Stearns soils have a duripan at depths of 20 to 40 inches. Also, Lewis soils have a mean annual soil temperature of more than 59 degrees F. Ocho soils have an abrupt textural change from the A2 horizon to the B2t horizon and are somewhat poorly drained. They occur mostly in intermound areas of hummocky micro-relief.
SETTING: Pineal soils are on nearly level old lake bottoms or on basin rims, at elevations of 4,350 to 4,450 feet. They formed in alluvium derived mostly from extrusive igneous rock, tuff, and volcanic ash. The climate is cool semiarid mesothermal with warm dry summers and cold moist winters. Mean annual precipitation is 10 to 12 inches including 24 to 48 inches of snowfall. Average January temperature is 30 degrees F.; average July temperature is 68 degrees F.; mean annual temperature is 47 degrees to 50 degrees F.. The frost-free season is 80 to 90 days.
PRINCIPAL ASSOCIATED SOILS: These are the Balman, Barnard, Bieber, Buntingville, Modoc, Pasquetti and Pit soils. Balman soils have fine-loamy control sections, a calcic horizon, and lack a duripan. Barnard, Bieber, and Modoc soils have mollic epipedons, duripans, and aridic moisture regimes. Buntingville and Pasquetti soils have mollic epipedons, lack duripans, and have aquic moisture regimes. Pit soils are clayey throughout and have intersecting slickensides.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow or very slow runoff; slow or very slow permeability.
USE AND VEGETATION: Used for grazing. Vegetation is saltgrass, giant wildrye, cheatgrass, and rabbitbrush.
DISTRIBUTION AND EXTENT: Northeastern California, currently only in Modoc County. The soils are inextensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Modoc County (Alturas Area), California, 1974.
REMARKS: Pineal soils would have been classified as Solonetz soils. Differentiae from the Ocho series needs to
be studied again when the Ocho soils are being actively mapped.
OSED scanned by SSQA. Last revised by state on 6/74.