aerial view of the exposed Hundborg rock
A view from above : Photo Shanti LFE

A rock solid discovery in Hundborg, Denmark

Something big is hidden close to the small village of Hundborg, located in the Northern part of Denmark. In a field a little outside the village, which counts approximately 600 inhabitants, lies what might very well be Denmark’s sixth biggest rock weighing a whopping 170 tons.

16. Aug 2019

As a souvenir from the mountainsides of the Larvik area in the southern part of Norway, sculped and molded during the last ice age, an enormous boulder was left behind in Hundborg by the retreating ice. This piece of ancient rock has been living a quiet life in the Danish rural soil until 1938, when it was discovered for the first time by the former owner of the land, while he was ploughing to prepare for sowing crops.

Rare found

The boulder was in the way of the farmer's activities and needed to be removed. While the farmer started digging, he soon discovered that the rock was bigger than he ever could imagine. Estimates at the time judged the boulder to weigh about 170 tons. This lists this Hundborg Boulder, as it was named, in the top six of biggest rocks ever found in Denmark. Even though the stone was described as “an outstanding geological discovery” by the local media, it was soon covered in soil again.

Søren Bent Torp, employed by NIRAS as geologist, first heard about the boulder in 1988, while he was studying geology. The stone immediately appealed to Søren and he attempted to start an excavation process several times. Despite his efforts, the stone was never freed from its earthy jacket. But Søren never quite stopped thinking about the boulder, slumbering quietly in the earth.
In the beginning of 2019, Søren decided to give it another go and he contacted the local civic association. This time, his timing was perfect and both the association and Thisted municipality, which is the local authority governing Hundborg, agreed on freeing up means to uncover the Hundborg Boulder.

Tourist magnet

And so the boulder will again be touched by sunlight. This time advanced equipment was used to ease the excavation process. The stone was also 3D-scanned to determine the rock’s exact size. Computers are still calculating the rock’s actual weight as we speak.

The municipality’s plans with the stone are just as big as the natural phenomenon it is digging up. If calculations give the green light, the rock will be relocated 50 meters downhill where it will be on display for tourists and geologists to visit, touch and study. The 3D-scanning will also be used to create memorabilia, such as miniatures of the stone, which can be sold at the site. A bigger exemplar will be displayed in the village’s center.

Stepping stone for geological training

What started as a personal interest, which Søren Bent Torp pursued in his spare time, has now turned into an actual project for NIRAS, that plays an advisory role when the boulder is moved. Søren is, amongst others, to determine how much weight the soil in the new designated location can carry, so the stone can be placed securely. The municipality has also expressed the wish that the stone be placed in the exact same position as it was when buried, just above the ground now. This requires some sort of construction, which is yet to be designed by Søren’s colleagues in NIRAS Building West. 3D calculations, that are currently being performed, will help to determine the boulder’s optimal position in its new location.

Søren hopes that the Hundborg Boulder can serve as an inspirational site for geologists and others with an interest in the boulder.

In other parts of Denmark, geological phenomena, such as slopes, serve as a meeting point for those with an interest in geology. It would be wonderful if the Hundborg Boulder can perform the same role.

Søren Bent Torp, NIRAS

 Søren Bent Torp on top of the stone. Photo: Henrik Granat, GEUS

 The stone has been lying in the same place since the ice age.