LOCATION ORCADIA TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Oxyaquic Glossudalfs
TYPICAL PEDON: Orcadia silt loam--pasture.
(Colors are for moist soil unless otherwise stated.)
A--0 to 5 inches; dark grayish brown (10YR 4/2) silt loam; weak medium prismatic structure parting to weak fine subangular blocky; slightly hard, firm; many fine and few medium roots; common fine tubular pores; many medium distinct grayish brown (10YR 5/2) iron depletions; few fine prominent brown (7.5YR 4/4) iron accumulations along root channels; very strongly acid; abrupt smooth boundary. (3 to 8 inches thick)
E--5 to 10 inches; grayish brown (10YR 5/2) silt loam; weak medium subangular blocky structure; slightly hard, firm; common fine and medium roots; common fine tubular pores; many medium distinct dark grayish brown (10YR 4/2) depletions and common fine distinct yellowish brown (10YR 5/4) iron accumulations; few fine prominent strong brown (7.5YR 4/6) iron accumulations along root channels; very strongly acid; clear smooth boundary. (3 to 8 inches thick)
Bt/E--10 to 15 inches; dark grayish brown (10YR 4/2) silty clay loam (Bt); moderate medium prismatic structure parting to weak medium subangular blocky; hard, firm; common fine and medium roots along surface of prisms; common fine tubular pores; few patchy yellowish brown (10YR 5/6) stains with clear boundaries on surface of peds; few fine prominent strong brown (7.5YR 4/6) iron accumulations along root channels; 30 percent light brownish gray (10YR 6/2) albic material (E) on surface of prisms; very strongly acid; clear smooth boundary. (3 to 8 inches thick)
Bt--15 to 29 inches; dark gray (10YR 4/1) clay; weak medium prismatic structure parting to strong fine angular blocky; extremely hard, extremely firm; few fine roots along surface of peds; few fine tubular pores; common fine and medium dark red (2.5YR 3/6) and few fine red (10R 4/6) iron accumulations with sharp boundaries inside peds; few pressure faces; very strongly acid; gradual smooth boundary. (0 to 20 inches thick)
Btg--29 to 45 inches; gray (10YR 5/1) clay; weak medium prismatic structure parting to strong fine angular blocky; extremely hard, extremely firm; few fine roots along surface of peds; few fine tubular pores; common fine and medium dark red (2.5YR 3/6) and few fine red (10R 4/6) iron accumulations with sharp boundaries inside peds; common pressure faces; very strongly acid; gradual smooth boundary. (10 to 30 inches thick)
Btssg--45 to 59 inches; gray (10YR 5/1) clay; weak medium prismatic structure parting to strong fine angular blocky; extremely hard, extremely firm; few fine roots along surface of peds; few fine tubular pores; many fine and medium dark red (2.5YR 3/6) and few fine brownish yellow (10YR 6/6) iron accumulations with sharp boundaries inside peds; common pressure faces; common prominent slickensides; strongly acid; gradual smooth boundary. (10 to 20 inches thick)
B'tg1--59 to 70 inches; light brownish gray (10YR 6/2) clay; weak medium prismatic structure parting to strong fine angular blocky; extremely hard, extremely firm; few fine roots along ped faces; few fine tubular pores; common fine and medium dark red (2.5YR 3/6) and common fine brownish yellow (10YR 6/8) iron accumulations with sharp boundaries inside peds; 5 percent light gray (10YR 7/1) iron depletions between prism faces; few pressure faces; strongly acid; gradual smooth boundary.
B'tg2--70 to 80 inches; light brownish gray (10YR 6/2) clay; weak medium prismatic structure parting to moderate fine angular blocky; extremely hard, extremely firm; few fine roots along surface of peds; few fine tubular pores; common fine and medium yellowish brown (10YR 5/8) and common fine reddish brown (2.5YR 4/4) iron accumulations with sharp boundaries inside peds; 5 percent light gray (10YR 7/1) iron depletions between prism surfaces; few pressure faces; very strongly acid. (combined thickness of the B'tg horizon is 15 to 40 inches.)
TYPE LOCATION: Orange County, Texas; from the intersection of Texas Highway 73 and 87 and Farm Road 1442 in Bridge City; 2.2 miles east on Farm Road 1442; 1.0 mile south on private road; 400 feet east of road in pasture. (Latitude 30N, 01, 14; Longitude 93W, 47, 32)
RANGE IN CHARACTERISTICS: Solum thickness is greater than 80 inches. Weighted average clay content of the particle-size control section is 35 to 50 percent. The surface layer is saturated 30 to 40 days mainly during late winter and early spring. Redox features are considered both contemporary and relict. This soil does not have aquic conditions in most years. Depth to the glossic horizon ranges from 8 to 15 inches.
The A or Ap horizon has color with hue of 10YR, value of 4 and chroma of 1 or 2. Iron accumulations range from few to common in shades of brown or yellow. Reaction ranges from extremely acid to strongly acid.
The E horizon has color with hue of 10YR, value of 5 or 6 and chroma of 1 or 2. Iron accumulations range from few to many in shades of brown or yellow. Reaction ranges from extremely acid to strongly acid.
The glossic horizon, or Bt/E, ranges from 3 to 8 inches thick. The Bt part has color with hue of 10YR, value of 4 or 5, and chroma of 2. Texture is silty clay loam, silty clay, or clay. The E part, or albic material, has color with hue of 10YR, value of 5 to 7, and chroma of 1 or 2. Iron accumulations are in shades of red, brown, or yellow. Reaction ranges from extremely acid to strongly acid.
The Bt, Btg, and Btssg horizons have color in hue of 10YR, value of 4 to 6, and chroma of 1 or 2. Texture is silty clay or clay. Iron accumulations range from few to many in shades of red, brown, and yellow. Pressure faces range from few in the Bt and Btg horizon to common or many in the Btssg horizon. Slickensides range from few to common in the Btssg horizon. Reaction ranges from extremely acid to strongly acid.
The B'tg horizon has color in hue of 10YR or 2.5Y, value of 6 or 7 and chroma of 1 or 2. Texture is silty clay or clay. Iron accumulations range from common to many in shades of red, brown, and yellow. Reaction ranges from extremely acid to strongly acid.
A BC horizon is in some pedons below a depth of 70 inches. Color is in hue of 10YR or 2.5Y, value of 6 or 7 and chroma of 2 or 3. Texture is sandy clay loam or clay loam. Iron accumulations range from common to many in shades of red and brown. Reaction is extremely acid or very strongly acid.
COMPETING SERIES: There are no competing series. Similar soils are Acadia, Anahuac, Aldine, Bissonnet, Gist, Vidrine, and Texla. Acadia soils do not have a glossic horizon. Anahuac and Bissonnet soils have A and E horizons more than 18 inches thick and, in addition, Anahuac soils have albic materials in the lower part of the solum. Aldine soils have a fine-silty over clayey particle-size control section. Gist soils have a coarse-silty particle-size control section. Bissonnet and Texla soils have a fine-silty particle-size control section. Vidrine soils have a coarse-silty over clay particle-size control section and typically have carbonates in the lower part of the solum.
GEOGRAPHIC SETTING: Orcadia soils are on plane to slightly convex, nearly level uplands. Slopes are 0 to 2 percent. These soils are on the Coast Prairie east of the Trinity River. The soils formed in clayey and loamy sediments of the Beaumont Formation of Pleistocene age. Mean annual precipitation is 50 to 60 inches. The mean annual temperature is 70 to 72 degrees F. Frost free days range from 250 to 270. Elevation ranges from 8 to 40 feet. The Thornthwaite P-E index is 68 to 80.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Anahuac and Aris, and Labelle and Leton soils. Anahuac soils are on slightly higher better drained positions in the landscape. Aris and Leton soils have aquic conditions and are on lower positions in the landscape. Labelle soils are on similar position in the landscape and have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Orcadia soils are somewhat poorly drained. Runoff is low to medium. Permeability is very slow. These soils are saturated from 8 to 15 inches below the soil surface for a period of 30 days or more in most years. In some years, these soils have aquic conditions in the E and Bt/E horizons.
USE AND VEGETATION: Mainly used for pasture and rangeland. Some areas are used for woodland where pine and hardwoods have encroached. Pastures are bahiagrass or bermudagrass. Native vegetation is tall prairie grasses, mainly andropogons, panicum, and paspalums.
DISTRIBUTION AND EXTENT: The Gulf Coast Prairie (MLRA 150A) of southeast Texas and possibly Louisiana. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Orange County, Texas; 1996.
REMARKS: The Orcadia soils were formerly included with the Acadia and Aldine series.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 5 inches (A horizon).
Albic horizon - 5 to 10 inches (E horizon).
Glossic horizon - 10 to 15 inches (Bt/E horizon).
Argillic horizon - 10 to 80 inches (Bt/E, 2Bt, 2Btg, 2Btssg, and 2B'tg horizons).
Oxyaquic feature - They are saturated in the subsurface layer for 30 or more days in most years. In some years these soils have aquic conditions.
ADDITIONAL DATA: TAMU data (S94TX-361-001) from type location in Orange County.
SOIL INTERPRETATION RECORD NUMBER: TX1293.