LOCATION MILLPOND CA+WA
Established Series
Rev. TAC-ET-MAV
06/2016
MILLPOND SERIES
The Millpond series consists of shallow, well drained soils formed in mixed alluvium. Millpond soils are on fan piedmonts and have slopes of 0 to 9 percent. The mean annual precipitation is about 130 mm and the mean annual temperature is about 15 degrees C.
TAXONOMIC CLASS: Loamy, mixed, superactive, thermic, shallow Xeric Argidurids
TYPICAL PEDON: Millpond gravelly loamy sand on a 2 percent north facing slope at an elevation of 1,345 meters under spiny hopsage. (When described on November 17, 1987, the soil was moist to 18 cm; Colors are for dry soil unless otherwise stated). The soil surface is covered with 20 percent gravel.
A--0 to 5 cm; pale brown (10YR 6/3) gravelly loamy sand, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; slightly hard, friable, nonsticky and nonplastic; many very fine and fine roots; common very fine interstitial pores; 20 percent gravel; neutral (pH 7.0); clear smooth boundary. (5 to 10 cm thick)
Bt1--5 to 13 cm; pale brown (10YR 6/3) sandy loam, dark grayish brown (10YR 4/2) moist; weak fine subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; common very fine interstitial pores; common faint clay films on faces of peds and in pores; 10 percent gravel; neutral (pH 7.3); clear smooth boundary. (8 to 20 cm thick)
Bt2--13 to 38 cm; very pale brown (10YR 7/3) gravelly loam, brown (10YR 5/3) moist; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic; common very fine and fine roots; common very fine interstitial pores; few faint clay films on faces of peds and in pores; 30 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (20 to 25 cm thick)
Bqkm--38 to 58 cm; pale brown(10YR 6/3), and very pale brown (10YR 7/3) indurated duripan, yellowish brown (10YR 5/4), and yellowish brown (10YR 5/6) moist; massive; very hard with laminar cap; few very fine irregular pores; violently effervescent, carbonates segregated as few fine irregularly shaped filaments; few faint clay films in pores; neutral (pH 7.0); clear wavy boundary. (15 to 36 cm thick)
2Bqk--58 to 124 cm; pale brown(10YR 6/3), and very pale brown (10YR 7/3) weakly cemented very gravelly loamy sand, yellowish brown (10YR 5/4), and yellowish brown (10YR 5/6) moist; massive; very hard, very firm, nonsticky and nonplastic; common very fine interstitial pores; violently effervescent, carbonates segregated as common fine irregularly shaped filaments; few thin clay films in pores; 50 percent gravel; moderately alkaline (pH 8.0); abrupt wavy boundary. (51 to 79 cm thick)
3Bq--124 to 152 cm; gray (10YR 6/1), and light brownish gray 10YR 6/2) weakly cemented gravelly sand, dark gray (10YR 4/1), and dark grayish brown (10YR 4/2) moist; massive; hard, firm, nonsticky and nonplastic; common very fine interstitial pores; 20 percent grave;; neutral (pH 7.0).
TYPE LOCATION: Inyo County, California; about 2 miles west of Bishop and 0.5 miles east of McGee Creek north of Highway 395 in Inyo County; 2,500 feet north and 900 feet west of the SE corner of Sec.32, T. 6 S., R. 32 E., M.D.B.M; USGS Bishop 7.5 minute topographic quadrangle; latitude 37 degrees 22 minutes 58 seconds N and longitude 118 degrees 28 minutes 51 seconds W; WGS84 Decimal Degrees 37.3827778 latitude, -118.4808333 longitude.
RANGE IN CHARACTERISTICS: An indurated duripan is at a depth of 36 to 51 cm. The mean annual soil temperature is 15 to 17.2 degrees C. The soil temperature is below 8.3 degrees C. from about November 30 to March 15, and is below 5 degrees C. from about December 15 to March 1. Aridic moisture regime bordering on xeric. The soil between the depths of 5 and 38 cm is dry throughout for 200 to 225 days from about April 15 to November 15. It is moist throughout for 40 to 50 days from about January 15 to March 1 and is moist in some or all parts for 25 to 35 consecutive days from about March 15 to April 15 when the soil is above 8.3 degrees C.
The A horizon color is 10YR 6/2 or 6/3. Moist color is 10YR 4/2 or 4/3. It has 2 to 8 percent clay. It contains 15 to 25 percent gravel.
The Bt horizon color is 10YR 6/2, 6/3, 6/4 or 7/3. Moist color is 10YR 4/2, 4/3, 4/4, 5/3 or 5/4. It is loam, gravelly loam, sandy loam or gravelly sandy loam averaging 18 to 25 percent clay. It contains 10 to 30 percent gravel.
The Bqkm horizon color is 10YR 6/3 or 7/3. Moist color is 10YR 5/4 or 5/6. It has a 1 to 2 mm thick laminar cap.
The 2Bqk horizon color is 10YR 6/3 or 7/3. Moist color is 10YR 5/4 or 5/6. It is very gravelly loamy sand or very gravelly sand.
The 3Bq horizon color is 10YR 6/1 or 6/2. Moist color is 10YR 4/1, 4/2. It is gravelly sand or sand.
COMPETING SERIES: There are no series in this family.
GEOGRAPHIC SETTING: Millpond soils are on fan terraces. Slopes are 0 to 9 percent. The soils formed in alluvium from mixed sources. Elevations are 1,280 to 1,375 meters. The climate is semi-arid with warm dry summers and cool moist winters. The mean annual precipitation is 100 to 150 mm. The mean annual temperature is 13.9 to 16.1 degrees C. Mean July temperature is about 24 degrees C., and mean January temperature is about 2.8 degrees C. The frost-free season is 140 to 175 days.
GEOGRAPHICALLY ASSOCIATED SOILS ARE: These are the Dehy (T), Cartago (T), Goodale (T) and Lucerne soils. Dehy soils do not have a duripan and have a mollic epipedon. Cartago soils do not have a duripan and have a sandy control section. Goodale soils do not have a duripan and have a skeletal control section. Lucerne soils do not have a duripan. These soils are all on alluvial fans of nearby landscapes.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderate permeability above the duripan.
USE AND VEGETATION: Millpond soils are used for rangeland, wildlife and watershed. Vegetation is spiny hopsage, bud sagebrush and spiny horsebrush.
DISTRIBUTION AND EXTENT: East Central California. The series is not extensive in MLRA 29.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES PROPOSED: Benton-Owens Valley Area, Inyo County, California, 1988. The name Millpond comes from a nearby abandoned lumber millpond.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
1. Ochric epipedon -- 0 to 5 cm (A)
2. Argillic horizon -- 5 to 38 cm (Bt1, Bt2)
3. Duripan -- 38 to 58 cm (Bqkm)
4. Thermic temperature regime -- mean annual soil temperature is 15 to 17.2 degrees C. This and other climatic characteristics are from available local climatic data and preliminary Soil Conservation Service data.
5. Minerology -- Assumed to be mixed.
6. Particle size class -- Loamy based on hydrometer and field estimate of the 5 to 38 cm control section.
7. Moisture Regime -- Aridic bordering on Xeric
7.1 The moisture control section is dry throughout from April 15 to November 15. It is moist throughout from January 15 to March 1.
7.2 The soil temperature exceeds 5 degrees C. from March 1 to December 15 (290 days). Within this period the moisture control section is dry from April 15 to November 15 (214 days).
7.3 The soil temperature exceeds 8.3 degrees C. from March 15 to December 1 (260 days). Within this time period, the moisture control section is dry from April 15 to November 15 (214 days).
National Cooperative Soil Survey
U.S.A.