Human interactions with the geosphere in historic and prehistoric mining areas
|Location||International Geological Congress,oslo 2008|
|Author||Raab, Thomas۱; Vِlkel, Jِrg۲|
|Holding Date||08 October 2008|
Properties and characteristics of many apparently near-natural ecosystems are consequences of indirect or direct human interactions with the geosphere during historic or prehistoric periods. Beside the socio-economic upheavals of the Neolithic times, starting in Central Europe some 7500 years ago, the adjacent development of metal working is the most important cultural change in the early history. The basis for all metal-using cultures till the modern cultures was and is a mining system which guarantees the surveying, the mining, the processing and the trading of ore-containing raw materials. Due to the persistence of cultures relying on mining economy over thousands of years mining system (in addition to clearing and agriculture) must be considered as a main factor of landscape change in the Late Holocene.
This investigation characterises and evaluates sustainable impacts of former mining on the landscape and presents case studies from East Bavaria.
Interdisciplinary methods and techniques are applied to detect the mining-caused or mining-induced landscape change. Essential part of the study is the characterisation of landforms, soils and sediments by field and laboratory analyses in selected study areas which were intensively mined during different (pre)historic cultural epochs. The aim is to differentiate anthropogenic from geogenic environmental changes and to classify these changes chronologically as far as possible. It is of specific interest, if and to what extent anthropogenic changes are of relevance for landscape ecology until today.
The former mining area of Amberg-Sulzbach (East Bavaria, Germany) was one of the most important sites of pre-modern iron industry in Central Europe, especially during the late Middle Ages. In several case studies environmental impacts of historic mining are elucidated by a combined approach of geomorphology, soil science, historical cartography in combination with GIS analysis and dating methods (IRSL, 14C). The results prove major man-induced geomorphic changes of almost all landscape elements. Most prominently affected are river floodplains, dry valleys and adjoining slopes. On the river floodplains metal processing sites influenced the fluvial dynamics and river channel architecture since the 14th century at least. On the slopes, soil erosion was induced because of the large need for charcoal as energy source for smelting. The eroded soil material was deposited on the dry valley bottoms, but also partially transported on the river floodplains forming intersecting colluvial-alluvial fans and subsequently alluvial sediments. At least two phases of soil erosion can be differentiated. The first one most probably dates back to the Iron Age period and refers to known prehistoric land-use of the area. During a second phase in the Middle Ages gullies were formed as a consequence of linear erosion induced by carts supplying the iron works with wood and ore.