Landesamt für Denkmalpflege und Archäologie Sachsen-Anhalt
Landesmuseum für Vorgeschichte

Geoarchaeology

Excavation of a grave mound in the Memleben forest, Burgenlandkreis
Excavation of a grave mound of the stone or bronze age in the Memleben forest, Burgenlandkreis
Uncovered soil at the base of the grave mound
Uncovered soil at the base of the grave mound. The high proportion of humus is a sign of an open landscape, possibly used for crops, in the neolithic period. The lighter patches are associated with subsequent forest cover.
Present-day formation of the soil in the Memleben forest
Present-day formation of the soil in the Memleben forest. The forest vegetation initiated a process of increasing soil acidity, which led to the settling of the clay components of the soil down into the lower strata. The result of this is a lighter stratum with little clay, and a darker, clay-enriched stratum.

Geoarchaeology (archaeopedology) is concerned with soil and the phenomena that can be observed in it, in order to learn about the human influences and the interactions between humans and the environment in prehistoric and historic times. Environmental conditions have always been essential in determining the possibilities for human activity. For example, the yield of crop-farming was substantially dependent on the fertility of the soils, and already in prehistoric times the economic prosperity of individual regions was closely tied to the raw materials available in each region.

Through the effects of their actions, humans have significantly altered the landscape. Frequently travelled routes and crop-planting both led to extensive erosion in the soil, which can be identified in the terrain in the form of hollow ways, colluvial deposits at the foot of slopes, and in riverbeds as alluvial loams (Auelehme). The central German loess soils were seriously affected by soil erosion and almost all rivercourses in Europe have thoroughly changed their appearance through the formation of alluvial loams.

Various geological methods are used to investigate these human influences and their consequences. Most of all, pedological (i.e. soil science) field research and laboratory studies are used, for which reason this research discipline is also known as archaepedology, derived from the Greek pedon = earth, soil.

Archaeological supervision of the ribbons of road and supply-line construction, sometimes extending over many kilometres, presents special opportunities for collecting data. In this way, it is possible to document the processes by which colluvial deposits and alluvial loams are formed, processes that have marked the landscape in both large and small scale. By dating the phases of the alluvial loam formation, it is possible to draw conclusions about the intensity of human use of the land.

As well as natural factors, like climatic conditions or biological activities, humans also initiate processes of development in the soil, some of which have affected large regions in the past and continue to do so today.

The use of plaggen cultivation (the burning of clods of earth and other materials on the ground-surface to spread a layer of ash over it) is well known and was used to enrich the agricultural soil with nutrients, creating thick strata of plaggen soils (Esch). The areas from which the minerals were taken, on the other hand, became correspondingly poorer, so that they developed into podzols under heath.

Stages of soil development can be traced very well by comparing excavated soil strata with the present-day soil levels. Here archaeology provides the pedological data, because the excavated soils are often preserved beneath archaeological objects like ramparts or grave mounds, which also establish their date.

In close cooperation with both specialist disciplines (archaeology and soil science), each with their own special methods of investigation, it is possible to establish which factors have been decisive in the development of the soil and in which ways humans have caused changes in it. Beyond this, it is possible to draw conclusions about the former environment and living conditions and to gain hints about how humans have adapted to the conditions in each case.

Profil durch den Siedlungshügel bei Niederröblingen, Kreis Mansfeld-Südharz.
Profil durch den Siedlungshügel bei Niederröblingen, Kreis Mansfeld-Südharz. Im dunklen Basishorizont ist noch der Rest der ehemaligen humosen Oberfläche erhalten. Die gelb-graue Farbe des oberen Abschnittes des Siedlungshügels deutet darauf hin, daß große Mengen an Lehm, wohl für den Hausbau, eingebracht wurden.
Gebranntes Lehmstück mit behandelter Oberfläche aus dem Siedlungshügel
Gebranntes Lehmstück mit behandelter Oberfläche aus dem Siedlungshügel