Distribution of Soils in Ohio that are Described with Fractured Substratums in Unconsolidated Materials

Abstract

Soil scientists, who systematically made soil surveys of Ohio, compiled the first comprehensive inventory of fractures in unconsolidated parent materials, or C horizons, of soils. Fractures have been documented in the C horizon of 95 soil series extending across 55 Ohio counties. A variety of terms were used to describe these nearly vertical fractures in otherwise massive materials. By convention, structural units are considered a product of soil-forming processes and the use of structural unit terminology has been limited to the solum consisting of O, A, E, and B master horizons and transitional horizons like AB, BE and BC horizons. Thus, terms used to describe soil structure have not been applied to the C horizon, even though the faces of prismatic structural units in the lower part of the B horizon commonly show continuity with fractures in the C horizon. Fractures have been identified in unconsolidated soil parent materials with textures of loam, silt loam, clay loam, silty clay loam, silty clay and clay. Clay films and carbonate coatings on fracture planes in the C horizon of soils indicate that water moves into and through these fractures. Fractures in the C horizon of soils also affect air movement and plant root extension into C horizons.