Kiesig

Kiesig is an adjective used in geology and soil science to describe materials that contain a substantial fraction of gravel-sized particles. The term is common in German- and Dutch-language geomorphology and sedimentology, where kies denotes gravel and the suffix -ig yields “gravelly” or “gravel-containing.” In many English-language sources kiesig is rendered as gravelly or gravel-rich.

As a texture descriptor, kiesig indicates that gravel particles, typically defined as 2 millimeters in diameter or larger, are a meaningful component of the material, often dominating over finer fractions. It is not a formal soil taxonomy category, but a qualitative descriptor used in conjunction with other texture terms, such as kiesig sand, kiesig loam, or kiesig gravel.

Occurrence and contexts commonly include fluvial and glacial sediments, such as alluvial gravels, outwash deposits, and other unconsolidated, coarse-textured materials. Such deposits are usually well to moderately sorted and exhibit high porosity and drainage compared with finer-textured soils.

Engineering and hydrological implications of kiesig materials include higher permeability and lower cohesion relative to soils with finer textures, which affects bearing capacity, erosion susceptibility, drainage design, and frost heave potential. Root penetration can be restricted in highly gravelly layers, depending on packing and size distribution.

Assessment typically relies on field description and particle-size analysis to estimate the gravel fraction, though no universal threshold defines kiesig; the descriptor is applied relative to surrounding textures and the material’s context. See also gravel, soil texture, and sedimentology.