Bronze Age iron weapon made from a meteorite found in Switzerland
Iron use was relatively rare in prehistoric times, and humanity discovered how to extract iron from natural ores much later.
Surprisingly, iron items appeared in the archaeological record around the Bronze Age.
Archeologists have stumbled upon a 19th-century Bronze Age iron arrowhead made of an unexpected material: meteorite.
This iron arrowhead came to light during a concentrated search for ancient meteoritic artifacts at the Natural History Museum of Bern.
As per a new study, the iron artifact was discovered in Mörigen, Switzerland.
Arrowhead consists of the chemical makeup of meteorites
This ancient arrowhead was found in the museum's collection by geologist Beda Hofmann of the University of Bern in Switzerland.
It was made during the Bronze Age, between 800 and 900 BCE. The arrowhead is 39.3 millimeters (1.5 inches) long and weighs only 2.904 grams (0.102 ounces).
This iron artifact's extraterrestrial origin was determined by its peculiar element makeup.
The researchers investigated the chemical composition using electron microscopy pictures, X-rays, and high-energy radiation analyses.
The findings confirmed the presence of iron and nickel, both known to be present in meteoritic iron. They also discovered the existence of aluminum-26 isotopes, which are only present in extraterrestrial objects.
Back then, iron meteorites were supposed to have crash landed in large numbers on Earth. This is due to the ability of certain meteorites to endure atmospheric entry.
And that’s why archaeologists have long presumed that meteoritic iron was used to make roughly all Bronze Age iron tools and weapons.
The meteorite was traded to Mörigen
The researchers also compared this arrowhead to other iron meteorites discovered in Switzerland's adjacent Twannberg area.
“Mörigen is located just 4–8 km southwest of the large Twannberg iron meteorite strewn field with more than 2000 individual finds totaling ∼150 kg,” mentioned the study.
The findings demonstrated that the metals detected in the arrowhead did not match the meteoritic iron retrieved from the Twannberg region.
Further, a careful examination revealed that the arrowhead was forged from a space rock called IAB meteorite. This IAB meteorite, dubbed Kaalijarv, crashed in Estonia.
This raises the question of how the meteorite reached Mörigen, which is 1,600 kilometers (994 miles) from Estonia.
The authors surmise that some Kaalijarv fragments were most likely collected and traded via the Baltic route (known for amber export).
The study “demonstrates that iron meteorites were used and traded by 800 BCE (or earlier) in Central Europe.”
The results have been published in the Journal of Archaeological Science.
Study abstract:
A search for artefacts made of meteoritic iron has been performed in archaeological collections in the greater area of the Lake of Biel, Switzerland. A single object made of meteoritic iron has been identified, an arrowhead with a mass of 2.9 g found in the 19th Century in the late Bronze Age (900–800 BCE) lake dwelling of Mörigen, Switzerland. The meteoritic origin is definitely proven by combining methods extended and newly applied to an archaeological artefact. Elemental composition (7.10–8.28 wt% Ni, 0.58–0.86 wt% Co, ∼300 ppm Ge), primary mineralogy consisting of the associated Ni-poor and Ni-rich iron phases kamacite (6.7 wt% Ni) and taenite (33.3 wt% Ni), and the presence of cosmogenic 26Al ( dpm/kg). The Ni-rich composition below the oxidized crust and the marked difference to meteorites from the nearby (4–8 km) Twannberg iron meteorite strewn field is confirmed by muon induced X-ray emission spectrometry (8.28 wt% Ni). The Ni-Ge-concentrations are consistent with IAB iron meteorites, but not with the Twannberg meteorite (4.5 wt% Ni, 49 ppm Ge). The measured activity of 26Al indicates derivation from an iron meteorite with a large (2 t minimum) pre-atmospheric mass.