Kerrosttaa

Kerrosttaa is a Finnish verb meaning to layer or to stratify, i.e., to cause something to form or arrange in layers. It is the causative form of kerrostua, which means to become stratified or to form layers, and it derives from kerros, meaning layer or stratum.

In scientific contexts, kerrosttaa describes processes that produce layered arrangements of material. It is used in geology and soil science to refer to the deposition and accumulation that create sedimentary layering, stratified rock, or layered soil horizons. The term can also be applied to other settings where a layered structure develops gradually, such as the buildup of deposits or coatings.

In contrast to kerrostua, which denotes the state of being layered, kerrosttaa highlights the act of forming layers. It is less common in everyday speech and more typical in technical writing related to geology, geomorphology, and related disciplines.