kihistumine

Kihistumine is the process by which materials organize into distinct, layered units, producing stratified structures. The term is used most often in geology and soil science, but it also applies in limnology and materials engineering. Kihistumine results in successive layers that differ in composition, texture, color, or mineralogy and can be traced through time or space.

Layer formation typically arises from changes in environmental conditions that affect deposition or precipitation. In sediments, fluctuations in energy, sediment supply, or chemistry create alternating beds. In lakes and peatlands, seasonal or episodic changes can produce laminated sequences, such as varves. In soils, horizon formation results from processes like illuviation, eluviation, and varying biological inputs. Diagenetic or weathering processes may alter or preserve these layers.

Common examples include laminated clays and silts, varved lake sediments, peat laminations, and laminated ice in ice cores. In man-made systems, kihistumine describes laminated composites or coatings whose layered microstructure influences mechanical, thermal, and transport properties.

Studying kihistumine helps reconstruct past environments, resource potential, and the mechanical behavior of rocks and soils. It is related to bedding, stratification, and lamination, and is distinguished from deformation-induced foliation in metamorphic rocks. The concept integrates field observations with stratigraphic, sedimentologic, and microstructural analyses.