Kalsiittijoki

Kalsiittijoki is a small river in northern Finland. The name derives from kalsiitti, the Finnish word for calcite, referring to noticeable calcite-bearing rocks encountered along parts of the river valley. The river is part of the boreal hydrological landscape and flows through sparsely populated forested areas before joining larger watercourses in the region.

Its upper course originates in upland forests and spring-fed hollows, then follows a mostly gentle, meandering path through a valley carved in limestone and till. In its upper reaches the stream features small rapids and clear water, while downstream sections are slower with wider banks and ribbon-like wetlands in places.

Geologically, parts of the watershed expose limestone and other carbonate rocks, which give sections of the river slightly alkaline water. The flow regime is strongly seasonal, with higher discharge during snowmelt and in autumn following rain, and lower flows in winter.

Ecologically, Kalsiittijoki supports cold-water fish such as trout along with a diversity of aquatic invertebrates. Riparian vegetation includes willow and birch, providing habitat for birds and small mammals. The surrounding forest also supports typical boreal fauna.

Human use and conservation: The valley around Kalsiittijoki is sparsely populated and lightly used for forestry and outdoor recreation. The river attracts visitors for fishing, canoeing, and hiking along marked trails. Portions of the watershed are subject to nature protection and are part of regional conservation plans to maintain water quality and biodiversity.