LOCATION ANGELSCREEK             CA

Established Series
MJE/AJP/TKK/JW
09/2018

ANGELSCREEK SERIES

The Angelscreek series consists of very deep, well drained soils formed in colluvium and/or residuum derived from agglomerate, tuff breccia, or latite. The Angelscreek soils are on lahars and sideslopes of lava plateaus. Slopes range from 1 to 60 percent. The mean annual precipitation is about 765 mm and the mean annual air temperature is about 16 degrees C.

TAXONOMIC CLASS: Loamy-skeletal, isotic, thermic Pachic Ultic Argixerolls

TYPICAL PEDON: Angelscreek loam on a southeast facing, convex, 1 percent slope under blue and live oak and annual grasses at an elevation of 502 meters. (Colors are for dry soils unless otherwise noted. When described on April 8, 2011 the soil was moist throughout.)

A--0 to 4 cm; brown (10YR 4/3) loam, very dark brown (10YR 2/2) moist; 35 percent sand; 46 percent silt; 19 percent clay; moderate fine granular structure; soft, friable, slightly sticky, slightly plastic; many very fine and fine roots throughout; common very fine tubular and irregular pores; 10 percent rounded indurated volcanic gravel, 3 percent rounded indurated volcanic cobbles; strongly acid (pH 5.1); abrupt wavy boundary. (1 to 20 cm thick)

ABt--4 to 20 cm; brown (10YR 5/3) loam, very dark brown (10YR 2/2) moist; 34 percent sand; 57 percent silt; 19 percent clay; moderate fine subangular blocky structure; soft, friable, slightly sticky, slightly plastic; many very fine and fine roots throughout; few very fine irregular pores; clay films on all faces of peds; 8 percent rounded indurated volcanic gravel, 5 percent rounded indurated volcanic cobbles; strongly acid (pH 5.3); clear smooth boundary. (5 to 35 cm thick)

Bt1--20 to 50 cm; brown (10YR 5/3) very cobbly loam, very dark brown (10YR 2/2) moist; 36 percent sand; 45 percent silt; 19 percent clay; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky, slightly plastic; common very fine, fine, and medium roots and few coarse roots throughout; common fine irregular pores; clay films on all faces of peds; 20 percent rounded indurated volcanic gravel, 30 percent rounded indurated volcanic cobbles; slightly acid (pH 6.1); clear wavy boundary.

Bt2--50 to 72 cm; brown (7.5YR 5/3) extremely cobbly loam, dark brown (7.5YR 3/3) moist; 37 percent sand; 37 percent silt; 26 percent clay; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky, moderately plastic; few very fine, fine, medium, and coarse roots throughout; few very fine tubular and irregular pores; clay films on all faces of peds; 35 percent rounded indurated volcanic gravel, 30 percent rounded indurated volcanic cobbles; slightly acid (pH 6.3); clear wavy boundary. (Combined thickness of the upper Bt horizons ranges from 50 to 100 cm.)

Bt3--72 to 92 cm; light brown (7.5YR 6/3) extremely cobbly clay loam, dark brown (7.5YR 3/4) moist; 34 percent sand; 31 percent silt; 35 percent clay; moderate medium subangular blocky structure; slightly hard, friable, moderately sticky, slightly plastic; few fine, medium, coarse, and very coarse roots throughout; few very fine irregular pores; clay films on all faces of peds; 35 percent rounded indurated volcanic gravel, 2 percent rounded weakly cemented volcanic gravel, 35 percent rounded indurated volcanic cobbles; slightly acid (pH 6.3); clear wavy boundary.

Bt4--92 to 152 cm; light brown (7.5YR 6/3) extremely cobbly clay loam, brown (7.5YR 4/3) moist; 42 percent sand; 29 percent silt; 29 percent clay; moderate medium subangular blocky structure; slightly hard, friable, very sticky, moderately plastic; common fine, medium, and coarse roots throughout; common fine tubular pores; clay films on all faces of peds; 35 percent rounded strongly cemented volcanic gravel, 10 percent rounded weakly cemented volcanic gravel, 30 percent rounded indurated volcanic cobbles, 5 percent rounded weakly cemented volcanic paracobbles, 2 percent rounded indurated volcanic stones; slightly acid (pH 6.4); clear wavy boundary. (Combined thickness of the lower Bt horizons ranges from 50 to 150 cm.)

TYPE LOCATION: Calaveras County, California, about 3.2 km (2 miles) north of Altaville, CA, USGS 7.5 minute topographic quadrangle: Angels Camp, California; WGS84 38.105278 latitude and -120.560556 longitude; UTM Zone 10 713884 meters E 4220291 meters N NAD83.

RANGE IN CHARACTERISTICS:
Soil temperature: The mean annual soil temperature at 50 cm is 16 to 17 degrees C and the difference between mean summer and mean winter soil temperature is greater than 6 degrees C. The soils have a thermic temperature regime.

Soil moisture: The soil moisture control section is dry in all parts from about May to October (about 180 days). The soils have a xeric soil moisture regime.

Diagnostic Feature(s):
Mollic epipedon thickness: 50 to 160 cm
Argillic horizon thickness: 75 to 195 cm

Organic matter in the epipedon: 1 to 6 percent

Reaction: Strongly to slightly acid in the surface horizon. Moderately acid to neutral in the control section.

Base saturation: Greater than 50 percent in the epipedon (by ammonium acetate).

Particle size control section weighted average:
Rock fragments: 35 to 80 percent, with 5 to 55 percent gravel, , 0 to 55 percent cobbles, and 0 to 10 percent stones.
Clay content: averages 15 to 35 percent clay
Base saturation: Less than or equal to 75 percent in one or more horizons between 25 and 75 cm (by sum of cations).

A horizon
Hue: 10YR, 7.5YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 1 to 3 dry, 1 to 3 moist
Texture: sandy loam, loam
Clay content: 10 to 27 percent
Rock fragments: 0 to 50 percent
0 to 25 percent gravel
0 to 20 percent cobbles
0 to 10 percent stones

ABt horizon
Hue: 10YR, 7.5YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 to 4 dry, 1 to 3 moist
Texture: sandy loam, loam
Clay content: 15 to 27 percent
Rock fragments: 0 to 60 percent
0 to 25 percent gravel
0 to 50 percent cobbles
0 to 10 percent stones

Bt1 horizon
Hue: 10YR, 7.5YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 to 4 dry, 2 or 3 moist
Texture: loam, clay loam
Clay content: 15 to 35 percent
Rock fragments: 15 to 80 percent
5 to 35 percent gravel
0 to 50 percent cobbles
0 to 10 percent stones

Bt2 horizon
Hue: 10YR, 7.5YR
Value: 4 or 5 dry, 2 to 4 moist
Chroma: 3 or 4 dry, 2 to 4 moist
Texture: loam, sandy clay loam, clay loam
Clay content: 15 to 40 percent
Rock fragments: 35 to 80 percent
10 to 60 percent gravel
10 to 55 percent cobbles
0 to 10 percent stones

Bt3 horizon
Hue: 10YR, 7.5YR
Value: 3 to 6 dry, 3 or 4 moist
Chroma: 3 or 4 dry, 2 to 4 moist
Texture: sandy clay loam, clay loam
Clay content: 20 to 40 percent
Rock fragments: 35 to 85 percent
10 to 60 percent gravel
10 to 55 percent cobbles
0 to 10 percent stones

Bt4 horizon (when present)
Hue: 10YR, 7.5YR
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 3 or 4 dry, 2 to 4 moist
Texture: clay loam, clay
Clay content: 27 to 45 percent
Rock fragments: 35 to 85 percent
15 to 65 percent gravel
15 to 60 percent cobbles
0 to 15 percent stones

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

GEOGRAPHIC SETTING: The Angelscreek soils are on lahars and sideslopes of lava plateaus. Slopes range from 1 to 60 percent. These soils formed in colluvium and/or residuum derived from agglomerate, tuff breccia (andesitic), or latite. Elevation is 150 to 800 meters. The climate is Mediterranean with warm, dry summers and cool, moist winters. The mean annual precipitation is 520 to 960 mm.The mean annual air temperature is 15 to 17 degrees C. The frost free season is 230 to 330 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Inks, Pentz, Shawsflat, Goldwall, and Toomes soils. The Inks soils are shallow to a lithic contact and are typically on summit or shoulder positions. Pentz soils have less than 35 percent fragments in the control section and are shallow to a paralithic contact. Shawsflat soils are moderately deep to a paralithic contact and lack an argillic horizon. Goldwall and Toomes are on the summits of lava plateaus and are very shallow and shallow respectively.

DRAINAGE AND PERMEABILITY: Well drained; moderately high to high saturated hydraulic conductivity in the epipedon and moderately low to high saturated hydraulic conductivity in the control section.

USE AND VEGETATION: This soil is used for recreation, livestock grazing, wildlife habitat, homesite development and viticulture. Vegetation consists mainly of hardwood species with grasses and forbs in the understory. Tree species include blue oak, live oak, foothill pine, and buckeye. Understory species include brome, ryegrass, wild oat, geranium, soft chess, and fescue.

DISTRIBUTION AND EXTENT: Sierra Nevada Foothills in California; MLRA 18. The series is not extensive.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES PROPOSED: Calaveras County, California, 2018. The name refers to Angels Creek found near the type location.

REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Mollic Epipedon 0 to 72 cm (A, ABt, and Bt1 horizon)
Argillic Horizon 50 to 152 cm (Bt2, Bt3, and Bt4 horizon)
Particle Size Control Section for this pedon: 50 to 100 cm (Bt2, Bt3, and upper part of Bt4).

ADDITIONAL DATA:
NASIS User Pedon ID: S2011CA009001
Pedon Purpose: laboratory sampling site
Lab Pedon #: 11N6749
Lab Source ID: SSL

Soil classified using the 12th Edition of the Keys to Soil Taxonomy.

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National Cooperative Soil Survey
U.S.A.