Slickenside (Figure 104).
Slickenside.—A specific type of ped surface feature consisting of a shiny, commonly striated and/or grooved slip face surface caused by the movement of one ped surface past another. The soil movement is a result of soil swelling after wetting and the subsequent stress-induced shear failure. If there are sand grains present in the otherwise clayey matrix, they may create striations as the surfaces slip past one another. Slickensides are a diagnostic feature used as a criterion for the Vertisols order as well as Vertic subgroups in Soil Taxonomy. Soil profile descriptions use the horizon suffix symbol “ss” to indicate the presence of slickensides (e.g., Bss). Slickensides are considered to be pedogenic when associated with soil peds or features, such as wedges or bowls in Vertisols. The term “slickenside” is also used in a geogenic context when associated with tectonic or mass movement features, such as faults or slump blocks.
Figure 104.—Soil profile and lower Bkss horizon of a Houston Black soil (fine, smectitic, thermic Udic Haplustert). The Houston Black series consists of very deep, moderately well drained, very slowly permeable soils with high shrink-swell potential that formed in clayey residuum derived from calcareous mudstone of Cretaceous Age. Depth to slickensides is from 33 to 61 cm. See Linear extensibility.
Slickenside (Figure 104).
Slickenside.—A specific type of ped surface feature consisting of a shiny, commonly striated and/or grooved slip face surface caused by the movement of one ped surface past another. The soil movement is a result of soil swelling after wetting and the subsequent stress-induced shear failure. If there are sand grains present in the otherwise clayey matrix, they may create striations as the surfaces slip past one another. Slickensides are a diagnostic feature used as a criterion for the Vertisols order as well as Vertic subgroups in Soil Taxonomy. Soil profile descriptions use the horizon suffix symbol “ss” to indicate the presence of slickensides (e.g., Bss). Slickensides are considered to be pedogenic when associated with soil peds or features, such as wedges or bowls in Vertisols. The term “slickenside” is also used in a geogenic context when associated with tectonic or mass movement features, such as faults or slump blocks.
Figure 104.—Soil profile and lower Bkss horizon of a Houston Black soil (fine, smectitic, thermic Udic Haplustert). The Houston Black series consists of very deep, moderately well drained, very slowly permeable soils with high shrink-swell potential that formed in clayey residuum derived from calcareous mudstone of Cretaceous Age. Depth to slickensides is from 33 to 61 cm. See Linear extensibility.