By Eva Leitholdt, Christoph Zielhofer, Stefanie Berg-Hobohm, Katharina Schnabl, Britta Kopecky-Hermanns, Jens Bussmann, Joachim W. Hartling, Klaus Reicherter, and Katrin Unger
Geoarchaeology: An International Journal, Vol. 27 (2012)
Abstract: The Central European watershed passes through the southern Franconian Jura in Bavaria, Germany. This principal watershed divides the Rhine/Main catchment and the Danube catchment. In the early Middle Ages, when ships were an important means of transportation, Charlemagne decided to connect these catchments by the construction of a canal known as the Fossa Carolina. In this paper, we present for the ﬁrst time 14 C data from the Fossa Carolina ﬁll and document a high-resolution stratigraphic record of the Carolingian and post-Carolingian trench inﬁlling. Our results provide clear evidence for peat layers in different levels of the trench inﬁll, suggesting a chain of ponds. However, the majority of these peat layers yield mid-Medieval and younger ages. The period of major peat growth was during the Medieval climatic optimum. Therefore, our preliminary results do not prove the use of the trench during Carolingian times. However, ﬁrst results from the reconstruction of the Carolingian trench bottom support the hypothesis that the Fossa was primarily planned as a navigable chain of ponds and not as a continuous canal. In the eastern part of the trench, a dam is located that was postulated in former studies to be part of a barrage for supplying the Carolingian canal with water. New 14 C data indicate much younger ages and do not support the Carolingian barrage concept.