Virtauskivet

Virtauskivet, also known as flowstones, are a type of speleothem found in caves. They are formed by the deposition of mineral matter, typically calcite, from flowing water. Unlike stalactites and stalagmites which grow downwards and upwards respectively, virtauskivet form sheet-like layers on cave walls and floors.

The formation process begins when water containing dissolved minerals seeps through the rock above the cave. As this water emerges and flows over the cave surface, it loses carbon dioxide to the cave atmosphere. This loss of carbon dioxide causes the dissolved minerals, primarily calcium carbonate, to precipitate out of the water. Over long periods, this continuous deposition builds up layers of calcite, creating the smooth, undulating surfaces characteristic of virtauskivet.

Virtauskivet can vary significantly in appearance depending on the rate of water flow and the mineral content. They can be thin and translucent, resembling frozen waterfalls, or thicker and more opaque. Colors can range from white and cream to red and brown, influenced by impurities like iron oxides. Their surfaces are often polished and smooth due to the constant movement of water. These formations are sensitive to changes in the cave environment, and their presence and condition can be indicators of hydrological stability.