LOCATION HIGHYORK                CA

Established Series
Rev. JWH/KP
10/2016

HIGHYORK SERIES

The Highyork series consists of very deep, somewhat poorly drained soils that formed in material weathered from chloritic schist and other metasedimentary rocks. Highyork soils are on mountains and have slopes of 15 to 50 percent. The mean annual precipitation is about 2160 millimeters and the mean annual temperature is about 11 degrees C.

TAXONOMIC CLASS: Fine, mixed, superactive, mesic Aquic Argixerolls

TYPICAL PEDON: Highyork silt loam on an east facing convex slope of 15 percent under grassland, at an elevation of 750 meters. (Colors are for dry soil unless otherwise noted.) When described on June 10, 2009, the soil was moist throughout.

A1--0 to 20 cm; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; moderately hard, friable, slightly sticky and slightly plastic; common very fine and fine roots throughout; common very fine and fine tubular pores; 3 percent very strongly cemented gravel; moderately acid (pH 5.8); clear smooth boundary. (15 to 35 cm thick)

A2--20 to 40 cm; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; moderately hard, friable, slightly sticky and moderately plastic; common very fine and fine roots throughout; common very fine tubular pores; 2 percent very strongly cemented gravel; moderately acid (pH 5.8); abrupt smooth boundary. (0 to 30 cm thick)

Bt1--40 to 65 cm; grayish brown (2.5Y 5/2) clay, dark grayish brown (2.5Y 4/2) moist; weak medium and coarse subangular blocky structure; extremely hard, firm, very sticky and very plastic; few very fine roots throughout; common very fine tubular pores; 30 percent distinct clay films on all faces of peds; 5 percent fine prominent irregular light olive brown (2.5Y 5/6) moist, iron-manganese masses and 5 percent fine faint irregular light olive brown (2.5Y 5/6) moist, iron depletions; neutral (pH 6.6); gradual wavy boundary. (20 to 50 cm thick)

Bt2--65 to 94 cm; gray (2.5Y 5/1) clay, dark gray (2.5Y 4/1) moist; weak coarse subangular blocky structure; extremely hard, firm, very sticky and very plastic; few very fine tubular pores; 20 percent distinct clay films on all faces of peds; 5 percent fine faint irregular dark gray (2.5Y 4/1) moist, iron depletions and 7 percent fine prominent irregular light olive brown (2.5Y 5/6), moist, iron-manganese masses; 3 percent very strongly cemented gravel; neutral (pH 6.8); gradual wavy boundary. (15 to 50 cm thick)

Btg1--94 to 110 cm; gray (5Y 5/1) clay, dark gray (5Y 4/1) moist; weak coarse subangular blocky structure; extremely hard, firm, very sticky and very plastic; few very fine tubular pores; 10 percent faint clay films on all faces of peds; 4 percent fine prominent irregular light olive brown (2.5Y 5/6) moist, iron-manganese masses; 3 percent very strongly cemented gravel; neutral (pH 7.0); gradual wavy boundary. (15 to 50 cm thick)

Btg2--110 to 180 cm; olive gray (5Y 5/2) clay loam, dark gray (5Y 4/1) moist; weak coarse subangular blocky structure; hard, firm, moderately sticky and moderately plastic; 4 percent fine prominent spherical light olive brown (2.5Y 5/6) moist, iron-manganese masses; 25 percent very strongly cemented gravel and 5 percent very strongly cemented cobbles; neutral (pH 7.0). (40 to 70 cm thick)

TYPE LOCATION: Humboldt County, California; about 3 kilometers south of Iaqua Butte; USGS 7.5 minute quadrangle Mad River Buttes, California; 40.6408333 latitude and -123.8702778 longitude; UTM zone 10 426408mE, 4499268mN, NAD 83.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil moisture control section is dry in all parts for 45 or more consecutive days after the summer solstice and moist in all parts from November through May. The soil has a xeric soil moisture regime.

Soil Temperature: The mean annual soil temperature at 50 centimeters is 10 to 15 degrees C. The difference between mean summer and mean winter temperature is 6 degrees or more C. The soil has a mesic soil temperature regime

Depth to Redoximorphic Features: 25 to 50 centimeters

Particle size control section (weighted average):
Rock fragments: 0 to 10 percent gravel, 0 to 5 percent cobbles
Pararock fragments: 0 to 10 percent
Clay content: 35 to 45 percent

Mollic epipedon: 25 to 100 centimeters thick

A horizon
Hue: 10YR or 2.5Y
Value: 4 or 5, 2 or 3 moist
Chroma: 1 or 2, dry or moist
Texture: loam, clay loam or silt loam
Rock fragments: 0 to 25 percent gravel
Clay content: 20 to 27 percent
Reaction: strongly to slightly acid

Upper Bt horizon
Hue: 10YR through 5Y
Value: 4 through 6, 2 through 4 moist
Chroma: 1 through 4, dry or moist
Texture of fine earth: clay loam, silty clay loam, and clay
Rock fragments: 0 to 25 percent gravel
Clay content: 35 to 45 percent
Reaction: moderately acid to neutral

Redoximorphic Features: fine and medium iron-manganese masses
Quantity: few to many
Hue: 10YR or 2.5Y
Value: 3 through 6
Chroma: 3 through 6

Redoximorphic features: fine and medium iron depletions
Quantity: few to common
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2

Lower Bt horizon
Hue: 10YR through 10Y and N
Value: 4 through 6, 2.5 through 4 moist
Chroma: 1 through 3, dry or moist
Texture of fine earth: clay loam, silty clay loam, and clay
Rock fragments: 0 to 34 percent gravel, 0 to 10 percent cobbles and stones
Pararock fragments: 0 to 34 percent paragravel
Clay content: 30 to 45 percent
Reaction: moderately acid to neutral

Redoximorphic Features: fine and medium iron-manganese masses
Quantity: few to many
Hue: 10YR or 2.5Y
Value: 4 through 6
Chroma: 3 through 8

Redoximorphic features: fine and medium iron depletions
Quantity: none to common
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2

C horizon (when present)
Hue: 2.5Y through 10Y and N
Value: 4 through 6, 2.5 through 4 moist
Chroma: 0 to 3, moist or dry
Texture of fine earth: clay loam, silty clay loam, and clay
Rock fragments: 5 to 34 percent percent gravel, 0 to 10 percent cobbles
Pararock fragments: 0 to 34 percent paragravel
Clay content: 30 to 45 percent
Reaction: neutral to moderately alkaline

Redoximorphic Features: fine and medium iron-manganese masses
Quantity: few to many
Hue: 10YR or 2.5Y
Value: 3 through 6
Chroma: 3 through 8

Redoximorphic features: fine and medium iron depletions
Quantity: none to common
Hue: 2.5Y or 5Y
Value: 4 or 5
Chroma: 1 or 2

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

GEOGRAPHIC SETTING: Highyork soils are on mountain slopes. Slopes range from 15 to 50 percent. Highyork soils are on concave to slightly convex slopes. Elevations range from 600 to 1100 meters. These soils formed in slope alluvium, colluvium, and residuum. Landscapes dominated by Highyork soils have hummocky relief, slips, and intermittent springs. The climate is subhumid with warm,dry summers and cool, wet winters. Mean annual precipitation is 1500 to 2550 millimeters. Mean January temperature is about 6 degrees C, mean July temperature is about 17 degrees C., and the mean annual temperature is 10 to 15 degrees C. Frost free period is about 200 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Coolyork, Elkcamp, and Airstrip soils. Coolyork soils are moderately well drained on linear to concave positions, under forest vegetation. Airstrip soils are on convex positons, contain more than 35 percent coarse fragments, and have lithic contact below 50 centimeters. Elkcamp soils contain less than 35 percent clay and are on hummocky slopes.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Somewhat poorly drained; very high runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: This soil is used for livestock grazing, watershed, and wildlife habitat. Vegetation is annual and perennial grass and forbs including soft brome, bristly dogstail grass, wildrye, medusahead, and western rush.

DISTRIBUTION AND EXTENT: Siskiyou-Trinity Area; MLRA 5. The soils are not extensive.

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

SERIES ESTABLISHED: Humboldt County, South Part, California, 2010. The name is coined.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from 0 to 40 centimeters (A1, A2 horizons)
Argillic horizon - the zone from 40 to 180 centimeters (Bt1, Bt2, Btg1, and Btg2 horizons)
Particle size control section - the zone from 40 to 90 centimeters (Bt1 and Bt2 horizons) averages 45 percent clay.
Aquic subgroup - the zone from 40 to 180 cm (Bt1, Bt2, Btg1, and Btg2 horizons)

ADDITIONAL DATA: NASIS Pedon ID: 09CA600241

Keys to Soil Taxonomy, 12th edition

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National Cooperative Soil Survey
U.S.A.