sedimenttisissä
sedimenttisissä is a Finnish adjective meaning "in sedimentary" or "in sediments". It is the inessive plural form of the adjective "sedimenttinen", which translates to "sedimentary". This grammatical form indicates a location within sedimentary material or a state of being related to sedimentary processes.
The term "sedimentary" itself refers to rocks or formations that are created from the accumulation and cementation
Therefore, when something is described as being "sedimenttisissä", it implies it is located within or associated