LOCATION PYRADY OREstablished Series
TAXONOMIC CLASS: Fine, isotic, frigid Oxyaquic Palehumults
TYPICAL PEDON: Pyrady clay loam - woodland, on a 26 percent southeast-facing slope at 2,860 feet elevation. (When described on June 27, 1989 the soil was dry to 12 inches and moist below this depth. Colors are for moist soil unless otherwise noted.)
Oi--0 to 1 inch; partially decomposed needles, leaves, twigs, and woody materials.
A--1 to 7 inches; dark brown (10YR 3/3) clay loam, yellowish brown (10YR 5/4) dry; moderate medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine, and few medium roots; many very fine and fine tubular pores; 10 percent gravel and 2 percent cobbles; very strongly acid (pH 4.6); clear smooth boundary. (5 to 8 inches thick)
Bt1--7 to 13 inches; dark brown (10YR 4/3) gravelly clay loam, light yellowish brown (10YR 6/4) dry; moderate medium subangular blocky structure; hard, friable, slightly sticky and plastic; common very fine and fine, and few medium roots; many very fine and fine tubular pores; common distinct clay films on ped faces and in pores; 15 percent gravel and 5 percent cobbles; very strongly acid (pH 4.6); clear smooth boundary.
Bt2--13 to 22 inches; olive brown (2.5Y 4/4) gravelly clay loam, light yellowish brown (2.5Y 6/4) dry; moderate medium subangular blocky structure; hard, friable, moderately sticky and moderately plastic; common very fine and fine, and few medium roots; many fine tubular pores; common distinct clay films on ped faces and in pores; 15 percent gravel and 5 percent cobbles; very strongly acid (pH 4.6); clear smooth boundary. (Combined thickness of the Bt horizon ranges from 15 to 22 inches)
2Bt3--22 to 35 inches; olive (5Y 5/3) gravelly silty clay, pale olive (5Y 6/3) dry; strong fine and medium angular blocky structure; hard, firm, moderately sticky and moderately plastic; few fine and medium roots; common fine tubular pores; many distinct clay films on ped faces and in pores; common fine distinct olive yellow (2.5Y 6/6) masses of iron accumulation; 15 percent gravel and 5 percent cobbles; very strongly acid (pH 4.8); clear wavy boundary.
2Btg--35 to 44 inches; dark gray (5Y 4/1) gravelly silty clay, gray (5Y 6/1) dry; strong fine and medium angular blocky structure; hard, firm, very sticky and very plastic; few fine and medium roots; few fine tubular pores; common distinct clay films on ped faces and in pores; many medium prominent olive yellow (2.5Y 6/6) masses of iron accumulation; 15 percent gravel and 5 percent cobbles; very strongly acid (pH 4.8); clear wavy boundary. (Thickness of the 2Bt horizon ranges from 10 to 22 inches)
2C--44 to 67 inches; olive gray (5Y 5/2) gravelly clay, light gray (5Y 7/1) dry; massive; very hard, very firm, very sticky and very plastic; few fine and medium roots; few fine tubular pores; many medium olive brown (2.5Y 4/4) and common coarse prominent olive yellow (2.5Y 6/6) masses of iron accumulation; 15 percent gravel, 5 percent cobbles and 35 percent (2 to 5 mm) manganese concretions; very strongly acid (pH 4.8).
TYPE LOCATION: Curry County, Oregon; about 500 feet north and 330 feet east of the southwest corner of section 36, T. 37 S., R. 12 1/2 W., W. M. (Latitude 42 degrees, 19 minutes, 32 seconds N.; Longitude 124 degrees, 10 minutes, 51 seconds W.)
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 41 to 46 degrees F. The soils are usually moist but are dry in all parts of the moisture control section for less than 45 consecutive days between depths of 4 and 12 inches in the four months following the summer solstice. The particle size control section averages 35 to 50 percent clay, less than 15 percent (by weight) coarser than fine sand, and has 10 to 20 percent rock fragments. Depth to bedrock is greater than 60 inches. Thickness of the solum ranges from 30 to 50 inches. The profile is very strongly acid throughout. Depth to the 2Bt horizon is 20 to 30 inches.
The A horizon has hue of 10YR or 7.5YR, value of 3 or 4 moist, 4 or 5 dry and chroma of 2 or 3 moist and 4 to 6 dry. It has 27 to 35 percent clay, 5 to 10 percent gravel, and 0 to 5 percent cobbles.
The Bt horizon has hue of 10YR or 2.5Y, value of 4 or 5 moist, 5 or 6 dry and chroma of 3 or 4 moist and 4 to 6 dry. It is gravelly clay loam, clay loam, or gravelly clay with 35 to 45 percent clay. It has 10 to 20 percent gravel and 0 to 5 percent cobbles.
The 2Bt horizon has hue of 2.5Y or 5Y, value of 4 to 6 moist, 6 or 7 dry and chroma of 1 through 4 moist and dry. Common fine distinct to many medium prominent redox concentrations occur throughout this horizon. It is gravelly silty clay loam, gravelly silty clay, or gravelly clay with 35 to 50 percent clay. It has 15 to 20 percent gravel and 0 to 5 percent cobbles. The lower portions of this horizon are gleyed.
The 2C horizon has value of 5 through 7 moist, 6 or 7 dry and chroma of 1 or 2 moist and dry. Common coarse to many medium prominent redox concentrations occur throughout the horizon. It is gravelly clay or gravelly silty clay with 45 to 60 percent clay. It has 10 to 15 percent gravel, 0 to 10 percent cobbles, and 30 to 40 percent (2 to 5 mm) manganese concretions.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Pyrady soils are on metastable broad ridgetops of mountains. Slopes are 0 to 30 percent. The soils formed in colluvium and residuum derived dominantly from highly sheared mudstone rocks of the Dothan Formation. Elevations are 2,500 to 3,800 feet. The climate is characterized by cool wet winters and warm moist summers. The mean annual precipitation is 130 to 160 inches. The mean annual temperature is 40 to 45 degrees F. The frost-free period is 60 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bobsgarden, Euchrand, Rilea, Stackyards, Yorel and Zalea soils. Bobsgarden, Rilea, Yorel and Zalea soils occur on broad ridgetops and side slopes of mountains. Bobsgarden soils are loamy-skeletal. Rilea soils are loamy-skeletal and 20 to 40 inches deep to bedrock. Yorel soils are fine-loamy and 20 to 40 inches deep to bedrock. Zalea soils are 20 to 40 inches deep to bedrock. Euchrand soils occur on side slopes of mountains, are loamy-skeletal, and are 10 to 20 inches deep to bedrock. Stackyards soils occur on north-facing side slopes of mountains, are loamy-skeletal, and are 40 to 60 inches deep to bedrock.
DRAINAGE AND PERMEABILITY: Moderately well drained; slow permeability. An apparent high water table fluctuates between depths of 2.0 to 2.5 feet from October to June.
USE AND VEGETATION: The soils are used for timber production, watershed, recreation, and wildlife habitat. The native vegetation is Douglas fir, tanoak, golden chinkapin, Pacific madrone, Port-Orford cedar, canyon live oak, salal, cascade Oregongrape, Pacific rhododendron, western brackenfern, western swordfern, Pacific trillium, Oregon fairybells, whitevein shinleaf, and western rattlesnake plantain.
DISTRIBUTION AND EXTENT: Mountainous areas of southwestern Oregon; MLRA 1. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Douglas County, Oregon, 1994.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Argillic horizon - from a depth of 7 to 44 inches (Bt1, Bt2, 2Bt3, 2Btg horizons).
Palehumults great group - clay distribution in the argillic horizon does not decrease from its maximum amount by more than 20 percent within a depth of 60 inches from the soil surface (Bt1, Bt2, 2Bt3, 2Btg, 2C horizons).
All diagnostic horizons and features are measured from the top of the first mineral horizon.