Kihtkihilise

Kihtkihilise (from Estonian kiht 'layer' and kihiline 'layered') is a term used in Estonian geology to describe stratified rocks characterized by well-developed bedding planes and rhythmic or repeated layering. It denotes rocks whose visible layering is a defining feature, often readily observable in field sections.

In practice, kihtkihilise refers to sedimentary rocks where lithologies and grain sizes change between successive layers, creating a conspicuous stratification that may be planar, wavy, or cross-laminated.

These rocks form by sequential deposition in sedimentary environments such as shallow seas, deltas, or rivers. Lithologies commonly include sandstone, siltstone, mudstone, limestone, or conglomerate, with layering achieved by changes in sediment supply, energy regime, or diagenetic processes. The term emphasizes the visible bedding rather than specific mineralogy; the rocks can be calcareous, siliceous, or siliciclastic.

Kihtkihilise occurs in several sedimentary sequences across Estonia and in other parts of the Baltic region, where it helps delineate depositional environments and chronological sequences within stratigraphic columns. For geologists, recognizing kihtkihilise aids interpretation of paleoenvironments, changes in sediment supply, and tectonic histories. The concept is used mainly in descriptive stratigraphy and regional geology rather than as a strict lithostratigraphic unit.

Related topics include stratigraphy, bedding, sedimentary rocks, and lithostratigraphy. Further reading includes standard texts on sedimentary rocks and regional Estonian geology.