An arrowhead made of meteoritic iron from the late Bronze Age settlement of Mörigen, Switzerland and its possible sourceOPEN ACCESS 

Beda A. Hofmann, Sabine Bolliger Schreyer, Sayani Biswas, Lars Gerchow, Daniel Wiebe, Marc Schumann, Sebastian Lindemann, Diego Ramírez García, Pierre Lanari, Frank Gfeller, Carlos Vigo, Debarchan Das, Fabian Hotz, Katharina von Schoeler, Kazuhiko Ninomiya, Megumi Niikura, Narongrit Ritjoho, Alex Amato

Journal of Archaeological Science
Volume 157, September 2023, 105827

LINK (OPEN ACCESS)

“Highlights

  • Archaeological artefacts made of meteoritic iron were searched for in Switzerland.
  • A Bronze Age arrowhead from Mörigen, made of meteoritic iron, was discovered.
  • Entirely non-destructive analyses prove the meteoritic origin of the arrowhead.
  • The Mörigen arrowhead is not made of iron from the nearby Twannberg strewn field.
  • The Kaalijarv meteorite, Estonia, is proposed as a possible source of the Mörigen iron.”

“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. The flat arrowhead shows a laminated texture most likely representing a deformed Widmanstätten pattern, grinding marks on the surface and remnants of wood-tar. Among just three large European IAB iron meteorites with fitting chemical composition, the Kaalijarv meteorite (Estonia) is the most likely source because this large crater-forming fall event happened at ∼1500 years BC during the Bronze Age and produced many small fragments. The discovery and subsequent transport/trade of such small iron fragments appears much more likely than in case of buried large meteorite masses. Additional artefacts of the same origin may be present in archaeological collections.”

On 30 July 2023 the find was registered in the Meteoritical Bulletin database as MÖRIGEN