Bronze age dating of timber from the salt-mine at Hallstatt, Austria

Abstract

The prehistoric salt mine of Hallstatt together with its burial ground is one of the most prominent archaeological sites in Austria, which has also given name for the “Hallstatt period” of human civilisation (800–400 BC). Due to the perfect conservation in rock salt a great number of organic materials have been found, among mostly wooden artefacts. Currently, the major archaeological focus is on the Bronze Age salt mining activities with excavations taking place at the historic Christian von Tusch-Werk, Alter Grubenoffen mine. Chronology building started at the Dachstein plateau, in the vicinity of Hallstatt, where tree-trunks were discovered in an alpine lake (Schwarzer See) and after recovery a spruce-larch chronology was compiled that dates back to 1475 BC. In addition, at the bog Karmoos, very close to the mining place of Hallstatt, preserved trees were intensively sampled resulting in a spruce chronology reaching even 1523 BC. Over 500 samples were taken at the Christian von Tusch-Werk, Alter Grubenoffen. They also included samples from the recently discovered world's oldest wooden staircase. The spectrum of wooden species encompassed Norway spruce, Silver fir, beech, European larch and maple. We were able to synchronize 128 samples, ending in a 282-year long floating chronology. While the staircase dated back to 1344 BC, the end year of the floating chronology dated even to 1245 BC. Tree felling dates showed clusters within the chronology, providing evidence for archaeologists to find construction phases and usage periods. The Dachstein–Hallstatt spruce chronology currently holds 840 synchronized series, and includes samples from the lake at the Dachstein, from the Karmoos bog at Hallstatt, from the prehistoric Hallstatt salt mine, and from historical buildings, as well as living trees. The chronology covers the period between 1523 BC through 2004 AD.