From the Soil Micromorphology Slide Collection

Description of biological feature: Silty intercalations were formed by packing and disintegration of earthworm pellets. Fecal pellets were about 1 mm in diameter. Intercalations are about 1 00 pm thick. The intercalations are elongate. They appear to contain more organic matter than the material that they bound. Calcite hypocoatings are associated with pores at the bottom of the slide.

Data for the horizon
Horizon sampled: BCkt
Depth sampled: 94-1 10 cm
Physical and chemical data available: Sand = 22%, silt = 58%, clay = 20%; pH = 8.2, caC03 200 g kg-I ; OC = 2 g kg -I .
Macromorphological description of horizon: 10 YR 5/6 silt loam; massive structure; 10 YR 4/4 clay coatings; common, fine, prominent 1 0 YR 8/2 secondary carbonates.
Micromorpho!ogical description of horizon: Single-spaced porphyric related distribution pattern. Crystallitic birefringence fabric. Channel microstructure.
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.: Typic Hapludalf

Physiographic position: Upland
Topography and hill slope position: 0-2% summit
Parent material: Late Weichselian loess
Soil climatic data and/or soil water balance: Mean annual temperature: 10.5 degrees C, mean annual precipitation: 634 mm
Vegetation: Deciduous forest

Data for 35-mm slide
Frame length: 7000 um
Light mode: Plane polarized

Thompson M.L., N. Fedoroff and B. Fournier. 1 990. Morphological features related to agriculture and faunal activity in three loess-derived soils in France. Geoderma 46: 329-349.
Source - M. L. Thompson


Slide BF18. Soil Science Society of America, 1993. A Reference Slide Collection for Soil Micromorphology. SSSA, Madison, WI.