LOCATION BLACKLOCK OR+CAEstablished Series
TAXONOMIC CLASS: Sandy, mixed, isomesic, ortstein, shallow Typic Duraquods
TYPICAL PEDON: Blacklock fine sandy loam, 0 to 1 percent slopes. (Colors are for moist soil unless otherwise stated.)
Oi--1 inch to 0; litter of leaves, twigs, root mat and moss; abrupt smooth boundary. (0 to 4 inches thick)
A1--0 to 3 inches; black (10YR 2/1) fine sandy loam, dark gray (10 YR 4/1) dry; massive; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; common very fine and fine tubular pores; very strongly acid; abrupt smooth boundary, (2 to 4 inches thick)
A2--3 to 9 inches; very dark gray (10YR 3/1) loamy fine sand, gray (10YR 6/1) dry; massive; hard, friable, nonsticky and nonplastic; many very fine, fine and medium roots; few very fine and fine tubular pores; very strongly acid; abrupt wavy boundary. (2 to 7 inches thick)
E--9 to 13 inches; gray (10YR 6/1) loamy fine sand, white (N 8/0) dry; dark grayish brown (10YR 4/2) exped staining, gray (10YR 6/1) dry; massive; hard, friable, nonsticky and nonplastic; many very fine, fine and medium roots; few very fine and fine tubular pores; very strongly acid; abrupt wavy boundary. (3 to 10 inches thick)
Bh--13 to 15 inches; black (5YR 2/1) mucky loam, dark reddish gray (5YR 4/2) dry; massive; slightly hard, friable, nonsticky and nonplastic; many very fine, fine, medium and coarse roots; common very fine and fine tubular pores; very strongly acid; abrupt wavy boundary. (0 to 3 inches thick)
Bsm1--15 to 21 inches; strong brown (7.5YR 5/6) strongly cemented sands, yellowish brown (10YR 5/6) dry; massive; extremely hard, extremely firm, nonsticky and nonplastic; very few very fine flattened roots; very few very fine tubular pores; medium acid; clear wavy boundary. (4 to 10 inches thick)
Bsm2--21 to 33 inches; yellowish brown (10YR 5/4) strongly cemented sands, yellowish brown (10YR 5/6) dry; reddish brown (5YR 4/4) and dark red (2.5YR 3/6) stains and seams in the hardpan, brown (7.5YR 4/4) and yellowish red (5YR 5/6) dry; massive; extremely hard, extremely firm, nonsticky and nonplastic; very few very fine roots in horizontal root mats; very few very fine tubular pores; medium acid; clear wavy boundary. (5 to 15 inches thick)
Bsm3--33 to 52 inches; yellowish brown (10YR 5/6) strongly cemented sands, very pale brown (10YR 7/4) dry, strong brown (7.5YR 5/6) streaks; massive; very hard, very firm, nonsticky and nonplastic; very few very fine roots in horizontal root mats; very few very fine tubular pores; medium acid; clear wavy boundary. (0 to 20 inches thick)
C--52 to 75 inches; light olive brown (2.5Y 5/6) sand with red (2.5YR 4/6) and brown (7.5YR 4/4) stains; massive; friable, nonsticky and nonplastic; medium acid.
TYPE LOCATION: Coos County, Oregon; on the west side of Seven Devils Road; 100 feet north, 1,750 feet east of the southwest corner, sec. 33, T. 27 S., R. 14 W.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 30 to 60 inches. Depth to bedrock is greater than 60 inches. Depth to the ortstein layer and effective rooting depth range from 12 to 20 inches. The mean annual soil temperature is about 54 degrees F. The solum is medium to extremely acid and acidity commonly decreases with increasing depth. The substratum is slightly acid to strongly acid. The difference between mean summer and mean winter soil temperature varies from 5 to 9 degrees F. The surface when mixed to a depth of 10 inches has value of 2 or 3 moist, 5 dry and chroma of 1 or 2 moist and dry.
The A horizon has value of 2 or 3 moist and chroma of 1 or 2 moist and dry. It is fine sandy loam, loamy sand or loamy fine sand high in organic matter and contains many roots. The E horizon has hue of 10YR or is neutral, value of 5 to 7 moist and 6 to 8 dry, and chroma of 0 to 2.
The Bh horizon has hue of 10YR or 5YR and chroma of 1 or 2 moist and dry. It is loam or fine sandy loam high in organic matter and contains many fibrous roots. A decomposed root mat is at the base of the Bh horizon in moist pedons. The Bsm horizon has hue of 5YR to 10YR, values of 3 to 5 moist and chroma of 4 to 6. Mottles have chroma of 0 to 6. It is loamy sand or sand. Cementation is weak to strong. The ratio of free iron to carbon ranges from 0.2 to 2.0. BC horizons when present have the same color range as Bsm horizons but are loamy sand or loamy fine sand and have weak or no cementation.
The C horizon is variegated loamy fine sand, loamy sand or sand with lenses cemented by iron or aluminum at a depth of 10 or 12 feet or more.
COMPETING SERIES: There are no other series in this subgroup. The Joeney series is similar and it is in the loamy family.
GEOGRAPHIC SETTING: The Blacklock soils are on marine terraces. They are usually in depressions or flats between low ridges or hummocks but are also in poorly drained areas of gently sloping old sand dunes. They formed in unconsolidated sandy marine sediments and eolian deposits. Elevations range from 25 to 650 feet. Slopes range from 0 to 7 percent. The climate is humid, temperate and marine with a dry season during the summer. Average annual precipitation ranges from 50 to 80 inches, mean annual temperature ranges from 51 to 53 degrees F, and the frost-free period is 200 to 330 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bandon, Bullards, Ferrelo, Knappa, and Netarts soils. All of these soils are well drained. In addition, the Bandon soils are coarse-loamy. Bullards and Netarts soils lack ortstein. The Ferrelo and Knappa soils lack a spodic horizon.
DRAINAGE AND PERMEABILITY: Very poorly or poorly drained; slow to medium runoff; moderate permeability in the upper part of the solum, very slow in the cemented pan and moderately rapid in the underlying material.
USE AND VEGETATION: Most areas of this soil are in native shrubs and trees and are used for wildlife habitat. This soil has limited use for timber production. Intensive uses are for cranberry bogs, pasture, occasional homesites and recreation such as campgrounds and hunting. The native vegetation is shorepine, Sitka spruce, Port-Orford-cedar, western hemlock, evergreen huckleberry, rhododendron, salal, madrone, swordfern, azalea, spirea, sedges, rushes, and water-tolerant grasses. Gorse has invaded some cleared areas in southern Oregon.
DISTRIBUTION AND EXTENT: Coastal marine terraces of southern Oregon and northern California. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Marshfield Area, Coos County, Oregon, 1909.
REMARKS: Diagnostic horizons and features in this pedon:
Albic horizon - from 9 to 13 inches (E horizon).
Spodic horizon - from 13 to 52 inches (Bh, Bsm1, Bsm2, Bsm3 horizons).
Ortstein layer - from 15 to 52 inches (Bh, Bsm1, Bsm2, Bsm3 horizons).
This draft reflects a change in classification from sandy, mixed, mesic, ortstein Typic Tropaquods to sandy, mixed, isomesic, ortstein, and shallow Sideric Tropaquods. This classification is based on the addition of the Sideric subgroup to Tropaquads.
ADDITIONAL DATA: NSSL pedon S80CA-045-019 sampled as Blacklock taxadjunct, Mendocino County, CA.