Giant’s kettle and sorrounding potholes on Öjberget

On the southern slope of Öjberget, next to the 3 km ski trail,
you can find a deep giant’s kettle with surrounding kettle niches. The site is just a stone’s throw away from where the 3km trail branches off from the 5km trail. This is checkpoint no. 6 on the Öjberget nature trail.

The smoothly polished rocks and hollows at this site were formed by swirling gravel and stones in an Ice Age river/stream, and were later further shaped by the force of sea waves on the raised shorelines.

During the last ice age, probably during deglaciation over 10 000 years ago, a strong current or stream beneath the ice caused stones to swirl at this spot. The swirling stones gradually scooped out a deep pit in the rock = a giant’s kettle. At some stage, one wall on the giant’s kettle was pushed out by water or ice. The kettle's shape, has been highlighted whith yellow in the picture.

A typical giant’s kettle is almost cylindrical in shape, with a rounded, smooth-walled base. Their size can vary from small cavities to pits several metres wide and over 10 metres deep. In the past it was believed that giants had carved these kettles out of the rock to cook food in.

Another possibility is that they are beach potholes and pothole niches formed when the sea’s powerful waves crashed against these coastal rocks around 4 000 years ago. At that time, there was no protective archipelago, so the waves gained considerable force. Stones and gravel acted as ‘abrasives’ in the same manner as when giant’s kettles are formed. However, if this ‘wave force’ did create these cavities, the entire slope at the same altitude on Öjberget should be shaped the same way. Since only a limited section has been smoothed out, it is more likely that the pothole was a formed by a fast-flowing meltwater stream as the ice sheet retreated. It is possible that the pothole could have been further eroded when the sea level was at this height. 

Matts Andersén discovered the giant's kettle on Öjberget in 1984.