This peculiar arrowhead was discovered in the 19th century in Lake Biel, in Mörigen (Switzerland). It was found among the remains of a late Bronze Age lake dwelling built between 900 and 800 BC. With its 39.3 millimeters in length and a weight of 2.9 grams, a priori it did not arouse great expectations.
It took more than a century for this artifact, which could be considered relatively common, to become an exceptional piece. This has been thanks to the fact that its composition has been analyzed and it has been discovered that it was made of extraterrestrial material.
Beneath the oxidized crust was iron of meteoritic origin - at a time before the ore was smelted - but which, surprisingly, had a marked difference to fallen space rocks in the nearby area, researchers from the University of Bern explain. in an article published in the Journal of Archaeological Science.
Iron meteorites are the most frequently found, as they are better able to withstand the stress of atmospheric input. They generally consist of iron, with small amounts of nickel and trace amounts of other metals mixed in. Almost all iron tools and weapons of the Bronze Age are believed to have been made from meteoritic iron.
Muon-induced X-ray spectrometry has revealed that the arrow's composition has nothing to do with the nearby (eight kilometers away) Twannberg meteorite, the largest ever found in Switzerland and the only metallic group IIG aerolite ( with little amount of nickel and sulfur) found on the European continent.
As the authors of the study explain, the flat arrowhead presents a laminated texture that most likely represents a deformed Widmanstätten pattern (resulting from the growth of taenite and camazite -two alloys of iron and nickel- produced by very slow cooling over a period of long time), more similar to the specific class IAB.
In all of Europe there are only three large IAB iron meteorites with a suitable chemical composition: Bohumilitz (Czech Republic), Retuerte de Bullaque (Spain) and Kaalijarv (Estonia). And among these, the Estonian meteorite seems the most probable source because during its fall around 1500 B.C. it formed a large crater and produced many small fragments.
But Kaalijarv is about 1,600 kilometers away from Mörigen. This suggests that the material had to travel a long way, perhaps along the same trade routes that Baltic amber used. Experts point out that there are probably other pieces of the same type in European archaeological collections.
“The discovery and subsequent transport of these small iron fragments seems much more likely than the possibility that large masses of buried meteorites exist,” the researchers write. The arrowhead is not only a record of extraterrestrial iron use, but shows the existence of extensive trading networks thousands of years ago.
