From the Soil Micromorphology Slide Collection

Micromorphological description of slide: Slickenside zone of anisotropic clay adjacent to a planar pore.

Data for the horizon
Horizon sampled: 3Bgb
Physical and chemical data available: Sand = 5%, silt = 45%, clay = 50%; OC = 0.4 g kg-I ; clay mineralogy: 73% expandable, 7% illite, 20% kaolinite
Macromorphological description of horizon: 2.5 Y 5/2 and 5 Y 5/1 silty clay; moderate medium subangular blocky structure; common medium and fine prominent 7.5 YR 4/6 mottles; common IOYR 5.5/1 clay coatings; common 5 YR 2.5/1 Mn oxide coatings; few 2.5 YR 4/6 Fe oxide coatings; few slickensides; few small pebbles.
Micromorphological description of horizon: Moderate angular blocky structure; 1 5-20% porosity; double-spaced porphyric related distribution pattern (c/f20); porostriated and random striated birefringence fabric; occasional pore and embedded clay coatings.

Data for thin section
Preparation of sample: Air dry
Impregnating medium: Polyester resin
Thickness of section: 30 µm
Orientation of section: Vertical

Physiographic position: Upland
Hill slope position: Level, summit Parent material: Loess
Drainage class: Probably poorly drained when at the land surface

Data for 35-mm slide
Frame length: 7 mm
Light mode: Circularly polarized

Woida, K. 1 991 . The morphology and genesis of soils in a buried Pleistocene toposequence, south-central Iowa. Univ. of Iowa, Iowa City. PhD. Thesis.
Source - K. Woida

Slide CT20. Soil Science Society of America, 1993. A Reference Slide Collection for Soil Micromorphology. SSSA, Madison, WI.