Bits of information
The “Wieliczka” Salt Mine has for centuries allowed visitors to discover its splendid underground. Decades-long co-operation with Polish and world universities and research institutes, as well as the growing popularity of active tourism led to more underground mine workings being opened to visitors. In spring 2009, a route for specialised groups was opened, with the goal of illustrating various mining methods and presenting in an attractive manner the geological structure of the Wieliczka deposit. The new route leads through the levels I to III in the central and eastern parts of the mine, along excavations of approximately 3,400 m.
The route combines visual, cognitive, and teaching values and will be of interest not only to specialists in earth sciences, but also to the lovers of natural beauties and hobbyists. The newly opened "Mysteries of the Wieliczka Mine" route will allow you to admire unique formations of blocky deposit which fill the syncline formed by the two thrust slices of the layered bed - the southern and central. The formations uncovered are the gangue rock formed as marly claystones and claystone micrites as well as blocks of green salt, both typical (laminated) and stained (rough-crystal). In the layered bed expositions, salts of almost the entire profile are present - bronze, shaft and green layered ones. Noteworthy are also examples of the phenomena of sedimentation and salt tectonics and secondary crystallisation of halite. The route offers an excellent teaching potential.
Secondary crystallization salts
Secondary crystallization salts stand out among the natural values of the route, and are a considerable visual attraction. A number of spots are especially noteworthy due to the variety and beauty of these phenomena. The dripstone decoration has been formed as a result of the migration of brine in the rock mass and it displays a wide range of secondary halite forms.
In many excavations, the secondary dripstone decor is visible in the form of salt stalactites and accumulations covering sidewalls and elements of chamber and gallery casings. Salt stalactites in the area are in the form of long narrow tubes, which the miners call “salt pasta.” Build-ups of salt, on the other hand, bear the name of “salt cauliflower.”
A very interesting form of contemporary secondary crystallization of halite are fibrous salts, commonly called “Kinga's hair.” They are formed from halite contained in the mine air, and expand in the direction from which moist air containing sodium chloride is delivered. These salts are formed on porous rocks, in well-ventilated areas.
The most striking formations of secondary crystallization salts along the described route can be admired in minor shafts. Their casing is often covered by a rich dripstone decor formed mainly in the form of salt stalactite and dripstone coats. When brine flows inside the stalactite, it supplies sodium chloride necessary for the crystallization of halite, causing it to increase in length (with "salt pasta" created in the process); when this process occurs both inside and outside the stalactite, it increases both its length and thickness.