Lüneburg Kalkberg in the context of "Boracite"

A salt glacier (or namakier) is a rare flow of salt that is created when a rising diapir in a salt dome breaches the surface of Earth. The name ‘salt glacier’ was given to this phenomenon due to the similarity of movement when compared with ice glaciers. The causes of these formations is primarily due to salt's unique properties and its surrounding geologic environment. A rising body of salt is referred to as a diapir; which rises to the surface and feeds the salt glacier. Salt structures are usually composed of halite, anhydrite, gypsum and clay minerals. Clays may be brought up with the salt, turning it dark. These salt flows are rare on Earth. In a more recent discovery, scientists have found that they also occur on Mars, but are composed of sulfates. A paper published in November 2023 suggests that salt glaciers composed of halite might also be present on Mercury.

The salt glaciers of the Zagros Mountains in Iran are halite whereas the salt glacier of Lüneburg Kalkberg, Germany is composed of gypsum and carbonate minerals.