AMS 14C Dating of Equipment from the Iceman and of Spruce Logs from the Prehistoric Salt Mines of Hallstatt

Abstract

This paper summarizes radiocarbon measurements of mainly botanical samples from the Iceman ("Otzi") and from his discovery site, an Alpine glacier at the Austrian-Italian border. The results were obtained by accelerator mass spectrometry (AMS) at 3 different laboratories (Vienna, Austria; Uppsala, Sweden; Gif-sur-Yvette, France) between 1992 and 1997. All the dates, except 2, are consistent with the time period 3360-3100 BC, as previously determined from bone and tissue samples from the Iceman himself. The 2 exceptional dates from wooden artifacts suggest that the site of the Iceman was used as a mountain pass for millennia prior to and after the lifetime of "Ötzi". For a 2nd sample complex, we studied logs from the beginning of salt mining in the world's oldest salt mines at Hallstatt in Upper Austria. 14C AMS measurements were performed in Vienna on spruce samples found in the prehistoric mines and from a log-house on the surface. Data evaluation included "wiggle matching" of different sets of tree rings. The results suggest that salt mining in the Hallstatt region took place in the 14th-13th century BC, well before the so-called Hallstatt period. We discuss in some detail the chemical pretreatment of the samples and the data evaluation. We also present a comprehensive survey of 14C dates available in the literature concerning both botanical remains from the vicinity of the Iceman and from the earliest salt mining in Hallstatt.