gliniaste

Gliniaste is a descriptive term used in regional geological literature to denote a clay-rich sedimentary rock or soil. It refers to rocks with a high proportion of fine clay and silt, often showing low to moderate cementation and a tendency to split into thin layers (fissility) when dry.

Formation and properties: Gliniaste forms by quiet-water deposition of clay- and silt-sized particles in environments such as floodplains, lakes, or shallow-marine settings. Through diagenesis and early lithification, the material becomes a relatively soft, plastic rock that remains cohesive when moist. Color varies with mineralogy and iron content, commonly presenting gray, greenish, or brown hues. The material generally exhibits high plasticity when wet and low permeability.

Classification and usage: The term is not standardized in formal lithostratigraphic schemes and may be used interchangeably with claystone, argillaceous siltstone, or clayey shale in regional catalogs. In engineering and construction contexts, gliniaste soils can be highly sensitive to moisture, potentially swelling and losing strength when wet, which affects stability and compaction considerations.

Occurrence: Regional occurrences are reported in several sedimentary basins and deltaic or paleo-lacustrine settings. The exact mineralogical composition and degree of lithification can vary significantly from one locality to another, reflecting differences in depositional history and diagenetic overprint.

See also: Claystone, Shale, Argillaceous rock, Clay soil, Geotechnical properties.