Soil Genesis, Classification, and Mapping
The development of vesicular horizons and porosity in arid environments:
The vesicular horizon is a surface, or near surface, soil horizon comprised of tiny non-connected circular, ovoid, or prolate pores commonly called vesicles. The horizon has been found to form in soils of a variety of parent materials deposited via eolian processes as dust and is often comprised of fine textures. Vesicle pore formation is hypothesized to occur by several different processes with the most widely accepted being entrapped air and soil particle movement following soil wetting (air entrapment due to a wetting front from rain or snowmelt). Field research on hydraulic properties of vesicular horizons has noted significantly lower hydraulic conductivities in vesicular horizons on surfaces of increasing geomorphic age due to greater accumulations of clay. Due to it’s affect on water movement into arid soils, the vesicular horizon may be the most influential soil horizon in arid landscape geomorphology and pedogensis. This project is being undertaken in the Lake Mead National Recreation Area by Maureen Yonovitz, MS Candidate in Geoscience (soil science emphasis), Dept. of Geoscience, Univ. of Nevada, Las Vegas.
