LOCATION CARLIN LA
Established Series
Rev. JDS-CLN
05/2018
CARLIN SERIES
The Carlin series consists of very deep, very poorly drained, rapidly permeable organic soils that formed in herbaceous plant remains over mineral sediments. These soils are in freshwater floating marshes along the Gulf coast. Slopes ranges from 0 to 0.2 percent.
TAXONOMIC CLASS: Clayey, smectitic, euic, hyperthermic Terric Haplosaprists
TYPICAL PEDON: Carlin mucky peat--freshwater floating marsh, wildlife habitat. (Colors are for moist soil unless otherwise stated.)
Oa1--0 to 12 inches; brown (7.5YR 4/4) mucky peat; structureless, massive; 35 percent fiber, unrubbed; 15 percent fiber, rubbed; 50 percent organic matter; moderately alkaline (10 to 24 inches thick).
W--12 to 18 inches; water (6 to 24 inches thick).
Oa2--18 to 36 inches; very dark gray (10YR 3/1) muck; structureless, massive; 10 percent fiber, unrubbed; 5 percent fiber, rubbed; 50 percent organic matter; moderately alkaline (6 to 45 inches thick).
Cg1--36 to 44 inches; gray (5Y 5/1) clay; structureless, massive; moderately alkaline.
Cg2--44 to 56 inches; dark gray (N 4/) clay; structureless, massive; moderately alkaline.
Cg3--56 to 86 inches; dark greenish gray (5GY 4/1) clay; structureless, massive; moderately alkaline.
Cg4--86 to 91 inches; very dark grayish brown (10YR 3/2), mucky clay; structureless, massive; 15 percent organic matter; moderately alkaline.
TYPE LOCATION: St. John the Baptist Parish, Louisiana; located 2800 feet west of Lac des Allemands on Brazan Canal, then 400 feet due south into floating marsh; Latitude 29 degrees, 56 minutes, 52.21 seconds N., Longitude 90 degrees, 38 minutes, 5.57 seconds W., Sec. 16 T. 13 S. R. 18 E. Lower Vacherie, Louisiana USGS 7.5 Minute Quadrangle, NAD-83.
RANGE IN CHARACTERISTICS: The thickness of the surface tier, and the depth to the water layer range from 10 to 24 inches. Depth to mineral layers ranges from 36 to 63 inches.
The O horizons which make up the surface tier typically have a fiber content of more than 1/3 of the organic volume in the unrubbed state. Fiber content in the surface tier is dominantly herbaceous. Colors are in hue of 10YR, value of 2 to 5, and chroma of 3 or less. Bulk density ranges from 0.90 to 1.05 g/cc. Mineral content ranges from 15 to 45 percent. Reaction ranges from moderately acid to moderately alkaline.
The W horizon consists of water that is very low in solids, upon which the surface tier floats. Thickness of the water zone ranges from 6 inches to about 2 feet depending on tide influences and heavy rain events. Organic content ranges from 0 to 17 percent.
Depth to the O horizons which make up the subsurface tier ranges from 18 to 48 inches deep. The fiber content of the subsurface tier, in the rubbed state, ranges from 10 to 40 percent of the organic volume. The materials in the subsurface tier have hue of 7.5YR to 10YR, value 2 to 4, and chroma of 2 or less. Mineral content ranges from 15 to 45 percent. Reaction ranges from moderately acid to moderately alkaline.
Depth to the O horizons which make up the bottom tier ranges from 36 to 60 inches. The materials in the bottom tier have hue of 7.5YR or 10YR, value of 2 to 4, and chroma of 2 or less. They typically have a fiber content of 1/10 to 4/10 after rubbing but some pedons have thin layers with less than 1/10 fiber or more than 4/10. Reaction ranges from moderately acid to moderately alkaline.
The Abg or Cg horizons have hue of 10YR to 5Y, or 5GY, value 3 to 5, and chroma 1 or less. Texture is silty clay loam, sandy clay loam, silty clay, mucky clay, or clay. Reaction ranges from moderately acid to moderately alkaline.
COMPETING SERIES: This is the
Allemands,
Bellpass,
Bessie, and
Clovelly series in the same family. Soils in closely related families include the
Everglades,
Kenner,
Maurepas,
Okeechobee,
Okeelanta,
Pungo, and
Terra Ceia series. None of the competing series have a water layer. Allemands soils have a lower fiber content and do not have a water layer as thick as 6 inches. Bellpass, Bessie, and Clovelly soils have electrical conductivity of more than 3 dS/m in the control section. Kenner soils have lower fiber content, do not have a water layer as thick as 6 inches, and have thin mineral strata below 12 inches. Maurepas, Okeechobee, Pungo, and Terra Ceia soils do not have a mineral layer within a depth of 51 inches, have less fiber in the 12 to 36 inch zone, and do not have a water layer as thick as 6 inches beneath the surface tier.
GEOGRAPHIC SETTING: Carlin soils occur in freshwater floating coastal marshes. The low density surface tier, which floats on the underlying water layer, maintains elevations equal to the surrounding water level, consequently the water table remains at the surface. The water level fluctuates about 18 inches. The climate is subtropical. Mean annual air temperature is 70 degrees F. Mean annual precipitation is about 64 inches at the type location. The soils formed in over 39 inches of the moderately fibrous non-woody organic materials over mineral material. Though the surface layers float, they do not move about horizontally, with the exception of possibly moving during severe storms. The organic layers of these soils, if drained, will initially subside to about 35 percent of their original thickness.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing
Allemands and
Maurepas series, and the
Barbary and
Harris series which are fluid mineral soils.
DRAINAGE AND PERMEABILITY: Very poorly drained. Runoff is neglegible, with no internal drainage. Permeability is rapid, but there is little movement of air and water due to the high water table.
USE AND VEGETATION: The use of these soils is limited to wildlife habitat. Vegetation is primarily aquatic freshwater marsh plants such as Paille fine, water hyacinth, ricefield cutgrass, cattail, plumegrass, water primrose, bulltongue, alligatorweed, smartweed, and pickerelweed.
DISTRIBUTION AND EXTENT: Gulf Coast Marsh (MLRA 151) of south Louisiana. The series is of moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: AUBURN, ALABAMA
SERIES ESTABLISHED: St. John the Baptist Parish, Louisiana; 1971.
REMARKS: Classification changed from Hydric Haplohemists to Terric Haplosaprists after thorough study in 02/2004. The concept of Carlin soils has historically been floating marsh soils that have a total thickness of organic and water layers more than 51 inches, and that have a floating layer of hemic materials that extends into the subsurface tier deeply enough to make up more than half the thickness of the organic layers between depths of 12 to 36 inches. Due to fluctuations in thickness of the water layer, this could vary, but in most cases the floating hemic layer would need to be about 20 inches or more thick in order to fit the Haplohemists classification. In the vast majority of pedons, all of the organic layers below the water layer are actually composed of sapric materials, so pedons that have a floating hemic layer 10 to about 18 inches thick will usually classify as Haplosaprists rather than Haplohemists. Of the helicopter field notes from Terrebonne Parish that were Carlin soils, 73% had a floating layer less than 18 inches thick. Of the transects done on Carlin units in St. John Parish, 100% had a floating layer less than 18 inches thick. These data from the two soil survey areas where Carlin soils have been correlated, all indicate that the series should be classified as a Haplosaprist rather than a Haplohemist. Also, the control section for Histosols can be as thick as 63 inches if the materials in the surface tier have bulk density less than 1.0. Of the helicopter field notes from Terrebonne Parish that were Carlin or Carlin like soils, about 69% had mineral soil materials within a depth of 63 inches. In St. John Parish, 100% of the transect stops in Carlin and Carlin-like soils have mineral materials within a depth of 63 inches. Also the series ranges were adjusted to allow the water layer to be as thin as 6 inches. The type location pedon was moved to a new location in St. John the Baptist Parish in 2004 because the previous type location was no longer floating marsh.
Diagnostic horizons and features recognized in this pedon are:
Histic epipedon--0 to 12 (Oa horizon).
Water layer-- 12 to 18 inches (W horizon).
Mineral substratum - 36 to 91 inches (Cg horizon).
Ecological Site: Freshwater Marsh.
ADDITIONAL DATA: Louisiana State University data from Terrebonne Parish (S94LA-109-019, 022, 026, 028, 029).
TAXONOMIC VERSION: Keys to Soil Taxonomy, Ninth Edition, 2003.
National Cooperative Soil Survey
U.S.A.