LOCATION JIMMERSON CA

Established Series
Rev. DWB/CAF/JJJ
12/2022

JIMMERSON SERIES

The Jimmerson series consists of very deep, well drained soils formed in old tephra deposits and material from lava flow. They are on lava plateaus and hills. Slope is 2 to 50 percent. The mean annual precipitation is about 30 inches and the mean annual temperature is about 47 degrees F.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Vitrandic Palexeralfs

TYPICAL PEDON: Jimmerson loam on a north facing slope of 3 percent under a cover of ponderosa pine, white fir, incense cedar, black oak, prostrate ceanothus and greenleap manzanita at an elevation of 3410 feet. (Colors are for dry soil unless otherwise stated. When described on June 5, 1981 the soil was dry throughout.)

0i--1 to 0 inches; slightly decomposed pine needles, oak leaves and twigs. (0 to 4 inches thick)

A1--0 to 2 inches; reddish brown (5YR 5/4) loam, dark reddish brown (5YR 3/4) moist; strong fine granular structure; hard, friable, nonsticky and nonplastic; common fine roots; many fine interstitial pores; 14 percent gravel; moderately acid (pH 5.9); abrupt smooth boundary. (1 to 6 inches thick)

A2--2 to 5 inches; yellowish red (5YR 4/6) loam, dark reddish brown (5YR 3/4) moist; moderate fine subangular blocky structure; hard, friable, nonsticky and nonplastic; many fine roots; many fine interstitial pores; 12 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (2 to 6 inches thick)

Bt1--5 to 11 inches; yellowish red (5YR 5/6) loam, dark reddish brown (5YR 3/4) moist; strong fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many fine roots, common fine tubular and interstitial pores; few thin clay films in pores; 8 percent gravel; slightly acid (pH 6.2); clear wavy boundary. (6 to 21 inches thick)

Bt2--11 to 19 inches; yellowish red (5YR 5/6) loam, reddish brown (5YR 4/4) moist; moderate fine subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many fine and coarse roots; many fine and few medium tubular pores; few moderately thick clay films in pores; slightly acid (pH 6.3); clear smooth boundary. (8 to 12 inches thick)

Bt3--19 to 24 inches; strong brown (7.5YR 5/6) loam, reddish brown (5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and plastic; many coarse and common fine and medium roots; many very fine and common fine tubular pores; few moderately thick clay films in pores; 5 percent gravel; slightly acid (pH 6.5); abrupt wavy boundary. (5 to 16 inches thick)

2Bt4--24 to 36 inches; strong brown (7.5YR 5/6) clay loam, brown (7.5 5/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and plastic; common fine and medium roots; common very fine tubular pores; common thick clay films in pores and common thin clay films on peds; 5 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (9 to 18 inches thick)

2Bt5--36 to 50 inches; strong brown (7.5YR 5/6) clay loam, strong brown (7.5YR 4/6) moist; moderate medium angular blocky structure; very hard, firm, sticky and plastic; few fine and medium roots; common very fine tubular pores; common moderately thick clay films in pores and common moderately thick and few thick clay films on peds; neutral (pH 6.7); gradual wavy boundary. (12 to 30 inches thick)

2Bt6--50 to 62 inches; strong brown (7.5YR 5/6) cobbly clay loam, strong brown (7.5YR 4/6) moist; moderate fine angular blocky structure; very hard, firm, sticky and plastic; common very fine roots; few very fine tubular pores; many moderately thick clay films in pores and on peds; 15 percent cobbles and 10 percent gravel; slightly acid (pH 6.5); gradual wavy boundary. (9 to 18 inches thick)

2Bt7--62 to 70 inches; strong brown (7.5YR 5/6) clay loam, strong brown (7.5YR 4/6) moist; strong fine angular blocky structure; very hard, firm, sticky and plastic; few very fine roots; few very fine tubular pores; many moderately thick clay films in pores and on peds; neutral (pH 6.6).

TYPE LOCATION: Shasta County, California, about 1.5 miles northwest of Burney at the intersection of Hwy 299 and Timber Drive, 900 feet from the first dirt road past the power line off of Timber Drive and 200 feet on the east side of the dirt road; 1,700 feet east and 800 feet south of the northwest corner of sec. 18, T. 35 N., R. 3 E., Burney NW (Burney) quadrangle (7.5 minute series).

RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 47 to 50 degrees F. The soil moisture control section (8 to 21 inches) is moist in all parts from about early December until early April and usually is dry in all parts from early July until early November (120 to 130 days). The soil temperature is above 41 degrees F. from about early March to late December and is above 47 degrees F. from mid April to mid November. The clay in the control section ranges from 18 to 30 percent.

The A horizon color is 7.5YR 4/2, 4/4, 4/6, 5/4, 5/6; 5YR 5/4, 4/6, or 4/4. Moist color is 7.5YR 3/4; 5YR 3/4. Horizons with mollic colors are too thin to qualify for a mollic epipedon. Base saturation (ammonium acetate) ranges from 50 to 60 percent and ranges from 50 to 55 percent by sum of cations. It is loam or stony sandy loam. Rock fragments, mostly stones and gravel, range from 0 to 30 percent. It ranges from moderately acid through neutral. The percent clay ranges from 12 to 20 percent with a small amount of halloysite clay. NaF pH ranges from 9.6 to 10.0. Glass content ranges from 10 to 15 percent. Aluminum plus 1/2 iron (ammonium oxalate) range from 1 to 1.5. Bulk density range from 1.0 to 1.5 g/cm3.

The Bt horizon color is 7.5YR 4/4, 5/4, 4/6, 5/6, 5/8, 6/6, 6/8; 5YR 4/4, 4/6 or 5/6 dry and is 10YR 4/6; 7.5YR 3/4, 5/4, 4/4, 4/6; 5YR 3/4, 4/4, 4/6; 2.5YR 3/4, 4/6, or 3/6 moist. Chroma of 6 to 8 occur in at least the lower part of the Bt horizon. It is loam, clay loam, silty clay loam, cobbly loam or cobbly clay loam with 18 to 35 percent clay in the upper part with an average of 18 to 30 percent in the control section; and clay loam, silty clay loam, clay, cobbly clay or cobbly clay loam with 35 to 50 percent clay in the lower part with halloysite as the dominant clay. Rock fragments, mostly cobbles and gravel, range from 0 to 30 percent. It ranges from moderately acid through neutral. Base saturation (ammonium acetate) ranges from 55 to 75 percent, with some part 75 to 80 percent, and ranges 45 to 60 percent by sum of cations. NaF pH ranges from 9.1 to 9.6.

Andic property data (see remarks for explanation):
Depth B.D. pH NaF Glass Alo Feo 15 barH20
0-2 1.00 9.7 12 1.2 0.7 21.0
2-5 1.10 10.0 ND 1.1 0.7 14.2
5-11 1.20 9.6 13 0.8 0.7 14.6
11-19 1.26 9.4 ND 0.5 0.5 15.2
19-24 1.31 9.1 5 0.4 0.7 16.3
24-36 1.46 9.2 ND 0.4 0.6 20.5
36-50 1.44 9.5 1 0.4 0.5 22.9
50-62 1.46 9.4 ND 0.4 0.5 22.5
62-70 1.24 9.4 TR 0.4 0.5 23.1

COMPETING SERIES: There are no other series in this family.

GEOGRAPHIC SETTING: Jimmerson soils are on lava flow plateaus and hills. Slopes are 2 to 50 percent. The soils formed in old tephra deposits and material weathered from lava flow. Elevation is 3,300 to 4,500 feet. The climate is subhumid with warm dry summers and cold moist winters. Mean annual precipitation is 25 to 35 inches including 30 to 50 inches of snow. The mean annual temperature is about 45 to 48 degrees F. Frost-free period is 80 to 100 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Winnibulli (T), Chirpchatter (T), Hunsinger (T), and Wyntoon soils. Winnibulli soils have a mollic epipedon, have a weakly cemented horizon within 40 to 60 inches and have a seasonal high watertable. Chirpchatter soils have a mollic epipedon and have a 20 percent decrease of clay from the maximum within 60 inches. Hunsinger soils are loamy-skeletal, have a mollic epipedon, and have a 20 percent decrease of clay from the maximum within 60 inches. Wyntoon soil are on lava plateaus and hills, have stronger andic properties to a depth of 9 inches.

DRAINAGE AND PERMEABILITY: Well drained; slow to rapid runoff; and slow permeability.

USE AND VEGETATION: Jimmerson soils are used for timber production. Vegetation is ponderosa pine, Douglas fir, sugar pine, white fir and incense cedar with an understory of greenleaf manzanita, prostrate ceanothus, gooseberry, deerbrush and snowbrush.

DISTRIBUTION AND EXTENT: Northeastern California, MLRA 22B. These soils are moderately extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Shasta County, Intermountain Soil Survey Area, California 1994. Source of name is Jimmerson Mountain, Modoc County, California.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon - the zone from 0 to 5 inches (A1, A2)

Argillic horizon - the zone from 11 to 70 inches (Bt1, Bt2,Bt3, 2Bt4, 2Bt5, 2Bt6, 2Bt7)

Meets Vitrandic subgroups criteria in upper 11 inches. Bulk density values too high for placement in Andic subgroup.

Andic properties data definitions:

B.D.: bulk density of the less than 2mm fraction on an oven dry basis.

pH NaF: pH of soil mixed with saturated sodium floride solution.

Glass: percent volcanic glass.

Alo: acid-oxalate-extractable aluminum of the less than 2mm fraction.

Feo: acid-oxalate-extractable iron of the less than 2mm fraction.

15 bar H20: dried 1500 kPa water retention as a percent.

Data elements with a * are estimated.

NC: not calculated.

ND: not done.

ADDITIONAL DATA: Complete lab characterization of pedon. Pedon S-81-CA-089- 004 (Lincoln Lab); Pedon 81-45-200X (Davis Lab). (unpublished)

National Cooperative Soil Survey
U.S.A.