From the Soil Micromorphology Slide Collection

Data for the horizon Horizon sampled: 3Ab1
Depth sampled: 174-181 cm below the modern land surface; interpreted to be the surface horizon of the buried paleosol
Physical and chemical data available: Sand = 5%, silt = 66%, clay = 29%; QC = 1.8 g kg- 1 ; pH
= 7.7
Macromorphological description of horizon: 1OYR 4/3 silt loam; moderate fine subangular blocky structure; common, thin, discontinuous 1OYR 7/2 silt coatings; common fecal pellets
Micromorphological description of horizon: Dominantly granular microstructure; single-spaced embedded-grain related distribution pattern; stipple-speckled pattern; porosity dominated by irregularly shaped, compound packing pores of varying size and by channels 150-800 µm in diameter; silt coatings (3-4% of section) and microlaminated clay coatings appear to have been derived from overlying loess; few nodules of micritic calcite; fecal pellets (2-5%, probably earthworm) range from 275 µm to about 1 mm in diameter; moderately to strongly impregnative Fe oxide nodules (2-3%). rounded and irregularly shaped, ranging from 10 to about 900 µm in diameter.

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

Soil Classification
U.S.: Paleosol was probably an Argiudoll when at the land surface

Legal description: E 1/2, SE 1/4, NE 1/4, S20,T76N, R40W Physiographic position: Upland
Topography and hill slope position: Summit of a 9% hillslope Parent material: Loess
Soil climatic data and/or soil water balance: Well-drained position on modern land surface; likely to be similar on paleosurface
Vegetation: Probably tallgrass prairie when paleosol was at the land surface

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

Thompson M. L., and T. A. Soukup. 1990. Morphological characterization of a suite of buried paleosols in Pottawattamie County, Iowa. p. ln E. A. Bettis (ed.) Midwest Friends of the Pleistocene 37th Field Conference, May 12-13, 1990. Iowa Geol. Surv. Bur.
Source - M. L. Thompson

Slide CT48. Soil Science Society of America, 1993. A Reference Slide Collection for Soil Micromorphology. SSSA, Madison, WI.