The prehistoric fortified settlement Schwarzenbach-Burg

The site Schwarzenbach-Burg is situated south of Vienna and was known since the beginning of the 20th century as a prehistoric fortified settlement. The first archaeological investigations in 1992 to 1993 proved the rampart to date to the Celtic period. Parts of the multiphase rampart are still visible up to seven meters height today and were partly reconstructed in 1994 on the excavation evidence. The fortification on top of the hill Burg once enclosed a 15 ha late Iron Age settlement that could be related to heavy mining activities in the surrounding low lands in the basin of Oberpullendorf. The iron ore mined in this area was the raw material for the high quality Ferrum Noricum perfectly suited for weapon production and much sought after by the Romans. Schwarzenbach-Burg at that time was one of three celtic oppidas in the region controlling the mining and the trade with the iron. The strategic position on the hilltop overlooking the mining area and controlling the shortest way towards the north into the Vienna basin and the Alps was already of importance for the Late Neolithic and Early and Late Bronze Age occupants, traces of their settlements were found by the latest excavations.

A geophysical prospecting project was carried out in 1996 integrating magnetics, resistivity mapping, electro-magnetics and refraction seismic investigating the non-wooded interior. It gave evidence of a densely occupied settlement and helped to locate various activity zones beside the dwellings. The prospection data, later enhanced by ground penetrating radar surveys, formed the basis for the further field research. Various interdisciplinary excavation projects started in 1998, so far focusing on three different areas of the prehistoric site. The project design is based on interdisciplinary studies of the settlement structure from the Neolithic to the Late Iron Age as well as on the economical and social background. Various dwellings from the late Iron Age have been investigated so far, indicating elaborate wooden construction technology and giving evidence on the subsistence of the Celtic occupants. The latest archaeozoological analysis proved the inhabitants to own Roman horses despite of a contemporary ban of horse trade by the Roman Empire. Another important aspect enlightening the elaborate position of the fortified settlement were the finds related to on site minting: coins in silver and gold, raw material as billon, an alloy of copper and silver used for coins and a special mould for melting the portioned metal.

The latest project was established in 2004 to investigate the Iron Age workshops located by prospecting. Large furnaces indicated by heavy magnetic anomalies could be documented probably used for the production of jewellery. The latest campaign showed a variety of specialised tools used in these production processes. The furnaces were built up by large stone blocks many of them molten indicating the high temperatures that could be reached by the Celtic metal and glass production processes.

Beside the economical, social and historical objectives Schwarzenbach evolved into a training ground for the development of digital documentation techniques of stratigraphic excavations, a major research topic of VIAS in close cooperation with the Institute for Pre- and Protohistory of the University of Vienna. The stratigraphic excavation method as primary defined by E.C. Harris is based upon the excavation of single deposits in the reverse order to that in which they were deposited. As deposits are material they can only be documented in a plan by mapping their surfaces. Surfaces and deposits are seen as the immaterial and material aspects of the stratified archaeological record and are known as units of stratification. In addition to the creation of a sequential diagram of the units of stratification known as stratigraphic sequence or Harris Matrix, the three-dimensional recording of the single surfaces as well as the description, sampling and find retrieval from the individual deposits are of crucial importance to the stratigraphic recording process.

To be able to fully reconstruct the part of the site destroyed by excavation, the surfaces of the excavated deposits have to be documented in 3D in a process we call “single surface planning”, an important theoretical and practical extension of the stratigraphical theory. The outstanding importance of 3D single-surface recording for the stratigraphic record demands the use of high resolution 3D laser scanners ( combined with digital imagery. They provide high detail and accuracy for the documentation of single surfaces. The 3D laser scan devices showed a high reliability and efficiency for topographic single surface recording in every day archaeological work. The scanner, as used here, could do the same recording job, done so far by two people using total stations and digital cameras, in only 20 percent of time collecting up to 50 times more data. This would save at a typical 1 month excavation up to 100 working hours. The 3D laser scanner as used at the excavations in Schwarzenbach can be seen as a future standard tool for the high resolution 3D recording of single surfaces on a stratigraphic excavation.

As GIS provides the ability to store, visualise and analyse geographical information in combination with descriptive information, it is a perfect tool for the digital recording of single stratigraphic units. All data recorded on-site during the excavation are processed in a GIS, where the georeferenced data are immediately available for on-site analysis during the excavation process. Data import, terrain modelling, and contouring of the surfaces are automated by a developed software extension. Additional modules make it possible to calculate the volume of any deposit, as well as to draw sections based on the complete 3D data set of the stratification along arbitraryly defined lines. All additional attributable data, such as descriptions of surfaces and deposits and the find and samples database are integrated in the GIS for further analysis of the data. The creation of the stratigraphic matrix is done using ArchEd, so far without interfacing to the GIS. A recent research project together with the Institute for Computer Graphics at the Technical University of Vienna is trying to overcome this shortcoming by integrating the Harris Matrix into the graphical user interface of the GIS.

Over the years the small village Schwarzenbach also became a centre for the education and training of students from Austria and all over the world and got an impressive impact on tourism from the long term research project. The scientific results form an important impact for the archaeological park. From 2002 to 2004 the experimental archaeology from VIAS built up an ensemble of reconstructed Late Iron Age buildings consisting of dwellings as well as workshops based on the excavation results and funded by regional development funds from the European Community. Further reconstructions are planned based on the evidence from the Celtic workshops. At the moment we are developing a new exhibition concept for the museum tower in close cooperation with the community that will be combined with a restaurant on top of the hillfort as additional future attractions.

The unconventional scientific approach of VIAS led towards a close identification of the nowadays 1200 inhabitants of Schwarzenbach with their local heritage and history. Thus research found a close connection to the public and the dissemination of scientific results got a new multiplexed dimension. More than 200 local volunteers have been developing a guiding and experiencing program for pupils based on the research results which can be booked by school classes all around the year and has its peak on the annual day of schools attracting 2000 pupils exploring the prehistoric site and the historical facts of the Celtic period. Enjoying prehistory during interdisciplinary field work and as a touristical concept is forcing archaeological science into the future challenge.