LOCATION MOONCREEK CA
Established Series
REV: BAL/ACF/ET
10/2016
MOONCREEK SERIES
The Mooncreek series consists of very deep, well drained soils formed in colluvium and residuum derived from sandstone and mudstone. These soils are on mountains and have slopes of 9 to 75 percent. Mean annual precipitation is 1500 millimeters (59 inches) and the mean annual temperature is 12 degrees C (54 degrees F).
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Xeric Palehumults
TYPICAL PEDON: Mooncreek gravelly clay loam - under a stand of Douglas-fir, tanoak, Pacific madrone and salal. When described on March 15, 2005 the soil was moist throughout. (Colors are for dry soil unless otherwise stated).
Oi--0 to 4 centimeters (0 to 2 inches); very dark gray (10YR 3/1) slightly decomposed plant material consisting of needles and leaves of Douglas-fir and tanoak; abrupt smooth boundary. (0 to 10 centimeters thick)
A--4 to 8 centimeters (2 to 3 inches); brown (7.5YR 4/3) gravelly clay loam, dark brown (7.5YR 3/4) moist; moderate fine granular structure; slightly hard, very friable, slightly sticky and slightly plastic; many very fine through medium roots; many very fine and fine tubular, and many medium interstitial pores; 18 percent gravel; very strongly acid (pH 4.7); clear smooth boundary. (3 to 35 centimeters thick)
ABt--8 to 16 centimeters (3 to 6 inches); brown (7.5YR 4/4) gravelly clay loam, dark brown (7.5YR 3/4) moist; moderate fine subangular blocky structure; slightly hard, very friable, moderately sticky and moderately plastic; many very fine through medium roots; many fine and medium, and common coarse tubular pores; few faint clay films on all faces of peds; 18 percent gravel; very strongly acid (pH 5.0); clear smooth boundary. (0 to 20 centimeters thick)
Bt1--16 to 54 centimeters (6 to 21 inches); brown (7.5YR 4/4) gravelly clay loam, brown (7.5YR 4/4) moist; strong fine medium subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many fine and medium and common coarse roots; many fine and medium, and common coarse tubular pores; few distinct clay films on all faces of peds; 18 percent gravel; extremely acid (pH 4.4); gradual smooth boundary.
Bt2--54 to 96 centimeters (21 to 38 inches); brownish yellow (10YR 6/6) gravelly clay loam, dark yellowish brown (10YR 4/6), moist; moderate fine and medium angular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; many fine and medium, and common coarse roots; many fine and medium tubular pores; common distinct clay films on all faces of peds; 20 percent gravel; extremely acid (pH 4.4); gradual smooth boundary. (Combined thickness of the upper Bt horizons is 25 to 100 centimeters)
Bt3--96 to 139 centimeters (38 to 55 inches); brownish yellow (10YR 6/6) gravelly clay loam, dark yellowish brown (10YR 4/6), moist; moderate fine and medium angular blocky structure; hard, firm, very sticky and very plastic; common medium and coarse roots; common fine and medium tubular pores; common distinct clay films on all faces of peds; 18 percent gravel; very strongly acid (pH 5.0); gradual smooth boundary.
Bt4--139 to 200 centimeters (55 to 80 inches); brownish yellow (10YR 6/6) gravelly clay loam, yellowish brown (10YR 5/6) moist; moderate fine and medium subangular blocky structure; hard, firm, very sticky and very plastic; common medium and coarse roots; common medium tubular pores; common distinct clay films on all faces of peds; few fine very weakly cemented strong brown (7.5YR 5/6), moist, iron-manganese masses; 16 percent gravel; very strongly acid (pH 4.5). (Combined thickness of the lower Bt horizons is 50 to 125 centimeters)
TYPE LOCATION: Humboldt County, California; USGS Hupa Mountain Quadrangle, CA.; WGS84 Decimal degrees 41.0383056 latitude and -123.77900 longitude; UTM Zone 10 434516mE, 4543297mN, NAD 83.
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is dry from July 1st to October 15th and moist in all parts from November 15 to June 1st. This soil has a xeric soil moisture regime.
Soil temperature: The mean annual soil temperature is 10 to 15 degrees C (50 to 59 degrees F). The difference between the mean summer and mean winter temperature is 6 degrees C or greater. This soil has a mesic soil temperature regime.
Soil reaction: very strongly acid to moderately acid throughout the soil profile.
Base saturation: less than 35 percent (by sum of cations) 125 centimeters below the top of the argillic horizon.
Organic matter: There are 12 kg/m2 or more organic carbon between the mineral soil surface and a depth of 100 cm.
Surface fragments: 0 to 5 percent gravel and 0 to 2 percent cobbles
Particle Size Control Section (weighted average):
Clay: 28 to 35 percent.
Rock fragments: 0 to 25 percent gravel and 0 to 10 percent cobbles.
A horizon
Hue: 7.5YR or 10YR
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4; dry or moist
Texture of the fine earth fraction: loam or clay loam
Clay content: 16 to 30 percent
Rock fragments: 15 to 45 percent gravel and 0 to 10 percent cobbles
Upper Bt horizons
Hue: 7.5YR or 10YR
Value: 4 through 6 dry; 4 or 5 moist
Chroma: 4 through 6; dry or moist
Texture of the fine earth fraction: silty clay loam or clay loam
Clay content: 28 to 35 percent
Rock fragments: 5 to 25 percent gravel and 0 to 20 percent cobbles
Lower Bt horizons
Hue: 7.5YR or 10YR
Value: 4 through 6 dry; 4 or 5 moist
Chroma: 4 through 6 dry or moist
Texture of the fine earth fraction: silty clay loam or clay loam
Clay content: 30 to 40 percent
Rock fragments: 0 to 25 percent gravel
Parafragments: 0 to 50 percent paragravels
COMPETING SERIES: There are no other series in this family.
GEOGRAPHIC SETTING: These soils occur on mountain slopes with slopes of 9 to 75 percent in linear slope positions. These soils formed in colluvium and residuum derived from slightly metamorphosed sandstone and mudstone. The elevation ranges from 18 to 1437 meters (59 to 4715 feet). The climate is subhumid with warm dry summers and cool moist winters. The mean annual precipitation is 1250 to 2030 millimeters (49 to 80 inches). Mean annual air temperature is about 12 degrees C (54 degrees F). Mean summer temperature is 14 degrees C (58 degrees F) and the mean winter temperature is 7 degrees C (44 degrees F). The mean annual temperature is 10 to 15 degrees C (50 to 59 degrees F). The frost free period is about 150 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Noisy and
Tossup series. The Tossup series is fine with greater than 35 percent clay in the particle size control section. Noisy soils are loamy-skeletal with greater than 35 percent rock fragments in the particle size control section. Tossup soils are generally on linear and concave slope positions. The Noisy soils are generally on convex slope positions.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high runoff; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: Used for timber production, wildlife habitat and watershed. Native vegetation is Douglas-fir, tanoak, Pacific madrone, Cascade barberry, bracken fern and modesty.
DISTRIBUTION AND EXTENT: Siskiyou-Trinity Area, MLRA 5. The name is taken from Moon Creek. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Humboldt Del Norte area, California, 2007.
REMARKS: Diagnostic horizons and features include:
1. Ochric epipedon - The zone from 0 to 8 centimeters (Oi and A horizons).
2. Argillic horizon - The zone from 8 to 200 centimeters (ABt, Bt1, Bt2, Bt3, and Bt4, horizons).
3. Particle size control section - The zone from 8 to 58 centimeters, averaging 31 percent clay and 20 percent rock fragment.
4.Palehumult great group - does not have a clay decrease of 20 percent or more from the maximum: 33 percent clay maximum decreases to only 30 percent clay.
ADDITIONAL DATA: NASIS User Pedon ID: 05CA023605001
Soil classified using Keys to Soil Taxonomy, 12th edition.
NSSL pedon number: 05N0639 (type location) and 04N0746 (supporting note)
The classification of the series was changed in 2008 from Typic Palexerults to Xeric Palehumults after review of the lab data supports the Palehumults Great Group. ET
National Cooperative Soil Survey
U.S.A.