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During the Late Middle Ages, the Vils River Valley in East Bavaria (Germany) was one of the leading regions for the iron industry in Central Europe. Two hundred ironworks used 378,000 m3 of wood per annum allowing the production of 9,000 tons of iron during the golden age of mining in the 15th century. The intensive historic mining activities in the Vils River catchment should have affected the river structure, the fluvial dynamic and the floodplain sedimentation. The nature and extent of these changes have not been investigated to date, although several studies have examined the environmental impact of this mining. We present the analysis of 288 boreholes from the Vils River floodplain, which can provide an unparalleled insight into the stratigraphy and chronology of the fluvial sediments, and allow the reconstruction of the Late Pleistocene/Holocene floodplain evolution in the valley.
The generalised sequence of the Vils River floodplain is built up by five units representing facies of different genesis (rock/saprolite, gravel, sand, loam, peat) which is identified by physical, chemical and mineralogical parameters (mainly grain size, clast shape and content, TOC, bulk mineralogy). Along the 87 km length of the valley, different units/facies are found at the Upper Vils River (UVR 1 - 5) and at the Lower Vils River (LVR 1 - 4b). In both river sections fine grained material (flood loam) builds the major part (up to 4 m) of the alluvial sequence. 29 age determinations (24 14C, 4 IRSL, 1 tree-ring analysis) show increasing accumulation of flood loam in the last millennium. These data correlate with the beginning of mining at the Vils River and hence suggest the direct causal connection of mining activities in the catchment - both on the slopes and on the floodplain - with the intense deposition of flood loams.
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