Gründelsloch


Useful Information

Location: Kindelbrück. 16 km south of Bad Frankenhausen at the B86, between Erfurt and Sangerhausen.
At the western city limits. Leave B86 towards Kindelbrücker Siedlung, follow "Am Stadtgraben", turn right to "Kalkplatz", turn left. Follow the unpaved road to the end of the allotment gardens.
(51°15'48.39"N, 11°4'36.07"E)
Open: no restrictions [2014]
Fee: free [2014]
Classification: KarstKarst spring, deep spring
Light: n/a
Dimension: D=25 m, VR=9-12 m, Y=10,000 to 20,000 m³/day, T=10-11 °C.
Guided tours:
Photography: allowed
Accessibility: wheelchair accessible
Bibliography: Gerhard Steiner, Ingrid Merbach-Steiner (2006): Die alte handwerkliche Papierherstellung, Projekte-Verlag, 2006, 339 Seiten
Address: Stadt Kindelbrück, Puschkinplatz 17, 99638 Kindelbrück, Tel: +49-36375-510-0, Fax: +49-36375-50455.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then.
Please check rates and details directly with the companies in question if you need more recent info.

History

03-MAR-1611 collapse of underground cavities and creation of the spring.

Description

The Gründelsloch near Kindelbrück is a spring created by the collapse of underground caverns. This event happened in historic times - in the year 1611 - and is thus well documented. Nevertheless the people started to tell legends about the spring, and how it was formed. One of the most popular versions goes like this: Once a carter left Kindelbrück towards Oberbösa with a waggon loaded with quicksilver. Not far from the town a landslip hit the waggon with the carter and the horses and pulled them underground. The quicksilver flowed out of the cracked bottles and dissolved bottomless pits into the rocks where it vanished. The pits were filled with water from below which welled up under high pressure and caused a flood at Kindelbrück. The people were astonished about the flood, because there had been no heavy rain. But finally a hunter came to the town who had seen the accident and told the people what happened. Now it was clear that there was a new spring and the flood wood not vanish after a few hours. The people dug a ditch where the water of the spring flows through the town until today.

Ovbiously this legends mixes fantasy with reality. It is pretty unlikely that there was actually quicksilver on the waggon, because it was expensive and its use was restricted mainly to specific mining operations. But even if it actually was on the waggon, it had no connection with the geologic event. Qucksilver does not react in any way with the rocks of this area. The landslip was caused by the collapse of underground cavern, which already existed. Probably they reached a certains size, the cover became too thin, or the waggon was too heavy and so the rocks collapsed. Much more interesting is the description of the upwelling water. Actually the spring is located on a plain with no other springs nearby. The water must be under pressure as it is welling up, when it reaches the surface it flows downhill again. As this is the only exit for the underground water body, called aquifer, and there must be a water restricting layer on top, hwich is called aquitard. The aquitard got a hole by the collapse of the cavities below, the water was under high pressure and so it started to flow out, taking the debris of the collapse with it. The result was an almost circular spring. Later, when the pressure was partly released the amount of water coming out of spring was reduced. The result is a sort of equilibrium between the wqater pressure and the outflow. This kind of springs, where water is transported for some distance under pressure, are called artesian springs.

The almost circular, deep blue spring Gründelsloch is located in a small wood. It prduces between 10.000m³ and 20.000m³ liter of water per day. This amount of water was a benefit for the town Kindelsbrück. It was used to run a paper mill, but also as drinking water. It was even enough water to run a fish farm for trouts only 50 m from the spring. Today the ponds are used for a salmon hatchery. Below the ponds the water flows through the town and then meets the nearby river Wipper.

The spring water has an extraordinary deep blue colour, which is a result of the high amount of limestone in the water. The water is obviously flowing through limestone rocks for some time. The water originates from the Hainleite, a series of hills to the north, with forests which are used for recreation. The aquifer is limestone, but limestone is not porous the water flows through tectonic cracks which were enarged by solution. There must be a series of water-filled small caves and crevices, as their end has been discovered in the spring. Cave divers found a lot of openings, all of them less tan 20 to 30 cm in diameter. This system of caves is fully waterfilled, so there is actually no such thing as an underground river, its more like a natural pipe system. Rather strange is the fact that the water crosses the nearby river Wipper underground, which is obviously possible because of the covering aquitard.