The vanished vitrified fort of Schwarzenbach-Burg, Austria - A multi disciplinary study


The multi-period hillfort of Schwarzenbach-Burg, 80 km south of Vienna, Austria, has been in the focus of multi-disciplinary research of the University of Vienna for more than two decades. While the best preserved remains of a large fortification wall (Kelheim-style) and ditch can be dated to the Late Iron Age (LIA), excavations in the inner part of the settlement revealed older traces of preceding ramparts enclosing a smaller part of the hilltop. During three seasons of stratigraphic excavations at one site, evidence was found that this rampart was destroyed by a massive fire impact. In LIA the remains were flattened to provide space for a workshop. For the construction of this older rampart, a timber frame was filled with stone material extracted on the outside of the rampart, synchronously forming an outside ditch. Due to the locally very variable geology, different types of bedrock were extracted and used for the filling, which was recognisable in different forms of vitrification. It ranges from melted orthogneiss to calcite marble processed like calcified limestone. The use of 3D-laserscanners for single surface documentation and in-situ and lab measurements of the susceptibility of the burnt structures in their context, lead to a data set that can contribute significantly to a better understanding of the formation processes of these features. Forthermore, integrating additional results, from topographic studies and geophysical measurements, helps clarify the chronological position and the motifs for vitrification.

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