From the Soil Micromorphology Slide Collection

Micromorphological description of slide: Microlaminated embedded clay coatings, 100-1 50 um thick with individual laminae about 10 urn thick, highly disrupted, sharp to diffuse extinction, high berefringence; 10YR 6/6 in PPL

Data for the horizon
Horizon sampled: 3ABtb
Physical and chemical data available: Sand = 4%, silt = 54%, clay = 42%
Macromorphological description of horizon: Gray (1OYR 5/1) light silty clay; strong fine and very fine subangular blocky structure; moist friable; many faint discontinuous IOYR 5/6 Fe oxide coatings on ped faces; abundant krotovinas 4-14 cm in diameter
Micromorphological description of horizon: Subangular blocky microstructure; double-spaced porphyric related distribution pattern; porostriated and random striated birefringence fabric; many clay coatings embedded and along pores; 30-35 porosity; common Fe oxide nodules; common ferriginous hypocoatings.

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: Gently sloping backslope
Parent material: Loess, possibly Sangamonian

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

Woida, K. 1991. 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 CT18. Soil Science Society of America, 1993. A Reference Slide Collection for Soil Micromorphology. SSSA, Madison, WI.