The new technology discovers more subjects and details in the rock painting at Tumlehed. It shows seals, boats with elk heads and a pregnant deer with spreading antlers. In front of the deer is something that looks like a trap.

NASA method discovers new subjects in rock paintings

Svenska 2020-08-25

New technology may lead to earlier research findings being re-evaluated. New subjects are emerging from faded rock paintings on a rock face on Hisingen – thanks to a digital imaging program from NASA. This throws new light on both the interpretation and the dating.

Figures many thousands of years old spread out across a vertical rock face. The colours have faded, but you can make out waves, a deer and perhaps a porpoise. Here at Tumlehed, close to the sea on the island of Hisingen, one of Sweden’s most unusual rock paintings can be found. We have arrived on the top of the hill after climbing steep paths.

Here, Bettina Schulz Paulsson, archaeologist, has been testing methods that she used in her research into Europe’s Megalithic tombs. Her photos from Tumlehed show more subjects than we can see on location, and much greater detail.

“I wanted to come to Sweden to learn new methods, but I also brought with me methods that were not so well-known here.”

She moved to Sweden in 2016 thanks to a position via the EU’s Marie Sklodowska-Curie Research Fellow research programme, and is now working at the Department of Historical Studies at the University of Gothenburg.

Useful method in archaeology

One of the methods she is working with is DStrech, a digital imaging program developed by NASA’s Jet Propulsion Laboratory, and used to research the possible presence of iron on Mars.

The US archaeologist Jon Harman realised that the software could be useful when researching rock paintings, and has since further developed the technique. DStrech is used together with a digital camera, and enhances faded colours so they become visible.

Bettina Schulz Paulsson tells us that DStrech works in slightly different ways with different cameras, and that one of her older models gives the best results. It can also be used for rock carvings, to make indentations clearer.

“The program is incredibly effective, you get quick results. It’s surprising how much emerges.”

Seeing with fresh eyes

The rock painting at Tumlehed was discovered in 1974 by a young ornithologist, who was looking for a rare woodpecker species. The location is well-known to researchers at the department, and they often bring archaeology students there.

Bettina Schulz Paulsson brought along her colleague Christian Isendahl and the student Fredrik Frykman Markurth to see whether it was possible to discover anything further using new methods.

“We arrived with fresh eyes at a place that had already been thoroughly researched, and this gave spectacular results.”

Using the new technology, several new subjects appeared, and more detail than could be seen with the naked eye: seals, boats with elk heads, and spreading antlers on the deer, which is pregnant. In front of the deer is something that looks like a trap.

“It’s incredibly exciting to find elk head boats, I shall continue researching them. They are found in Belarus and Norway, but otherwise not in southern Scandinavia.”

Includes students in articles

They have also worked with PXRF, a portable X-ray fluorescence instrument that can measure the chemical composition of paint, and show things like whether several layers have been painted at different times. This turned out to be the case in Tumlehed.

“Both methods are enormously effective, and they don’t destroy anything.”

The student Fredrik Frykman Markurth carried out PXRF measurements, and was then also included in the scientific article.

“In Germany, students are often included in articles. It’s important that the are included in the academic writing at an early stage, and it’s great to include students.”

Long-distance hunters in the Stone Age

The finds meant that they could re-date the paintings in Tumlehed to Late Stone Age, 4 200–2 500 BCE, not Bronze Age as had been thought before.

“This changes everything in part.”

The subjects show that the paintings were made by long-distance hunters, as similar subjects are found in Alta in northern Norway, for example. The valley below the hill was a sea inlet at the time, and there were plenty of whales, seals, porpoises and dolphins.

The waters were nutritious, as warm currents brought with them plankton. People travelled long distances by boat, to hunt and fish seasonally. Around 4 000 BCE, the climate grew colder again, and supplies declined.

Travelled around with the family

Bettina Schulz Paulsson spent ten years on her gigantic project on megalithic tombs, their origin and distribution, during which she travelled around Europe, often together with her family.

“If space was limited, we sent the children in to take photographs.”

This became her thesis, which was published in the reputable periodical PNAS (Proceedings of the National Academy of Sciences). It also received a lot of media interest.

“It was surprising to be called by a lot of journalists, and the first one to call was from The New York Times. I thought they were joking.”

Continue researching megalithic art

Now she wants to continue researching megalithic art, for example megalithic boats, how seafaring developed, how far they travelled, and what technology they used.

Using a laser scanner – which she also works with – she has found boat engravings in Brittany that were not visible to the naked eye. There are also pictures of whale hunting. This gives an indication that people travelled long distances.

“The finds in Tumlehed make everything fall into place.”

Text: Helena Östlund
Photo: Bettina Schulz Paulsson

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