Table 2 Sample ID, origin and age of reference samples⁴⁴ and new sample sets.

rec

Rohr im Gebirge, Austria

recent

61

A

Eisenerz, Austria

about 1800 CE

35

B

Eisenerz, Austria

13th–early 15th cent. CE

32

C

Eisenerz, Austria

15th–13th cent. BCE

26

Additional sample sets

Rio

Rio de Janeiro, Brazil

18th–19th cent. CE

30

WI

Wittnau, Germany

15th–20th cent. CE

38

IZ

Iznang, Germany

3270–3250 BCE

76

BO

Bodnegg, Germany

3950–650 BCE

125

OL

Olzreute, Germany

2900–2820 BCE

97

SP

Speckhau, Germany

400–300 BCE

40