Fluvial dynamics of the Žitava River, SW Slovakia, during the last 45 ka BP and their influence on Early Bronze Age human occupation

Abstract

As part of a geoarchaeological project exploring the Early Bronze Age settlement of Fidvár, this geomorphologic study explores the fluvial dynamics of the Žitava River in southwestern Slovakia, casting light for the first time on the regional river's Holocene and late Pleistocene development. In order to reconstruct the Žitava's fluvial evolution, floodplain deposits were investigated by Electrical Resistivity Tomography, selected percussion drillings, and AMS radiocarbon dating. In combination, these methods provided a detailed view into the river's history. As a result of the climatic variations engendered by the last glacial cycle, the fluvial style repeatedly changed between a braided and anastomosing system. However, during long time periods of the Middle and Upper Plenivistulian, the river retained an anastomosing or even meandering style, in contrast to Central European rivers. Therefore, in agreement with other investigations, our results suggest different climatic conditions in the northern Pannonian Basin from 40 to 20 ka BP. During the Early and Middle Holocene, a dense vegetation cover (dry-mesic oak forests) led to stable geomorphological conditions and a meandering channel resulted in lateral erosion of the floodplain fringes. Accumulation of alluvial loamy sediments did not start until the Neolithic and has been related to anthropogenic landscape changes, similar to other naturally favoured areas (Central Europe). Finally, two reconstructed river positions indicate a considerable lateral fluvial erosion of the Early Bronze Age settlement at Fidvár. Consequently, the original settlement area – already thought to be the largest in the region – was once significantly larger.