The medieval peat layer of the Fossa Carolina - Evidence for bridging the Central European Watershed or climate control?

作者：Leitholdt Eva; Krueger Annett; Zielhofer Christoph^*

来源：Zeitschrift fur Geomorphologie, 2014, 58(1): 189-209.

DOI：10.1127/0372-8854/2012/S-00113

• Fossa Carolina
• limnic facies
• grain size end-members
• Medieval Warm Period
• climatic control
• peat classification

The Central European Watershed passes the Southern Franconian Jura in Bavaria, Germany. This watershed of major geographical importance divides the Rhine-Main catchment and the Danube catchment. In the Early Middle Ages, when ships were important means of transportation, Charlemagne decided to connect both catchments by the construction of a canal that is well known as Fossa Carolina (Karlsgraben). The canal is representing the first attempt to bridge the Central European Watershed and is, therefore, one of the most important early medieval engineering achievements in Europe.
Despite the important geostrategic relevance of the construction it is not clarified if the canal was ever used as a working waterway. In this study we present new C-14 data from the continuous and buried peat layer of the central part of the fosse. The C-14 data document peat growth during Carolingian times and especially during the High Medieval. Both phases of peat growth might support by a more humid climate with an enhanced groundwater table.
Multiple high-resolution stratigraphic records of the central trench fillings derived from grain size distributions and from peat and sapropel classifications indicate for the first time clear evidence for a limnic facies, suggesting the existence of former ponds. However, the majority of these limnic facies reveal High Medieval ages. Our ongoing study does not prove the use of the fosse as a canal during Carolingian times yet.

• 出版日期2014