What the landscape can tell: An integrative stratigraphic prospection approach for localizing a Black Death mass grave in Erfurt/Central Germany

Michael Hein, Nik Usmar, Annabell Engel, Johannes Rabiger-Völlmer, Johannes Schmidt, Matthias Silbermann, Marco Pohle, Iris Nießen, Martin Offermann, Lukas Werther, Birgit Schneider, Christian Tannhäuser, Alexander Herbig, Jan Nováček, Ulrike Werban, Martin Bauch, Christoph Zielhofer

The Black Death pandemic (1346-53) has caused a 30-50% population decline across Europe. For the city of Erfurt in Thuringia, substantial human losses and corresponding mass graves are well-documented in historical archives. The aim of our study is to localize these mass graves in the deserted village of Neuses in order to validate the written sources and to obtain skeletal remains for future anthropological and archeogenetic analyses. Here we present our integrative approach of historical research and minimally-invasive pedostratigraphical and geophysical prospection. Within the area of interest, narrowed down by historical accounts and GIS implementations, we applied vibracoring and electrical resistivity tomography (ERT). Coupled geophysical and coring sections help elucidate the late Quaternary sedimentary processes as an essential natural background for more detailed geoarcheological prospections. They allow for the designation of two distinct pedogeographical zones with consistent stratigraphical and pedogenic sequences: (1) a Chernozem zone and (2) a Black Floodplain Soil zone. The distribution and extent of these zones co-determined the internal structure of the former village Neuses and the positioning of the presumed associated Black Death mass graves. Our approach enabled a preliminary reconstruction of the medieval subsurface architecture, despite large-scale 20th century ground modifications. We identified a belowground pit structure visible both in the borehole sequences and ERT sections. Recovered bones have been AMS radiocarbon dated to the 14th century. Seeing as confirmed and precisely dated locations of Black Death mass graves are rare in Europe and are commonly found by chance during construction works, our planful discovery may help to advance the research on the origin, spread and evolution of the Yersinia pestis pathogen throughout this pandemic as well as societal coping mechanisms during epidemic outbreaks. Furthermore, our method combination holds the potential to successfully resolve the mapping of similarly demanding sites for archeological and forensic investigations.