© Dimitrij Mlekuž, Department of Archaeology, Faculty of Arts, University of Ljubljana
Last update: 27.2.2006

Ljubljansko barje: Archaeological landscape in flux

The Ljubljansko barje project (J6-6013 at the Slovenian Ministry of Higher Education, Science and Technology) focused on landscape and settlement dynamics in early and middle Holocene in Ljubljansko barje microregion. It is a collaborative interdisciplinary effort between the Department of Archaeology at University of Ljubljana (project leader Prof. Mihael Budja, Dr. Dimitrij Mlekuž), Department of Environmental Sciences at Jozef Stefan Institute (Dr. Nives Ogrinc) and Slovenian Forestry Institute (Dr. Tom Levanič).

Ljubljansko barje

Ljubljansko barje (Ljubljana marshes, Ljubljana Moor) is a large wetland in the extreme south of the Ljubljana basin in the central part of Slovenia, located at the interface of the Alps and Dinarides. It is a a tectonic depression filled by thick quaternary sediments. Whole area is characterized by dynamic tectonic activity taking forms from long-term subsidence and uplift to catastrophic earthquakes, last one in 1895. Although featureless on the first sight, Ljubljansko barje is a mosaic of different topographic units and ecosystems and covered by dense drainage network.

Archaeological interest in the region started in the second half of the 19th century when first pile dwellings were discovered. Ljubljansko barje has a long history of archaeological and palaeoenvironmental research being probably one of the most intensively researched regions in Slovenia.

Project aims

Various models and hypotheses on the Holocene dynamic of the Ljubljansko barje landscape have been proposed. The main point of controversy is whether, when and where the basin was covered by permanent or intermittent lake(s), before it was overgrown by peat mosses. It is also not clear whether these presumable changes of the landscape were triggered mainly by climatic fluctuations or human impact on the environment and how they affected the archaeological settlement pattern. This pilot project extends over three years and involves (1) systematic aerial archaeology programme which enables the study of settlement distributions and subtle landforms like former floodplain surfaces and palaeochanels, which record the movement of the river across the valley floor; (2) The riverbed surveying, identification and dendrochronological sampling of subfossil tree trunks; (3) applying Geographical Information Systems (GIS) that can provide not only sophisticated cartographic tool, but a flexible environment within which dynamics of the past landscapes can be modeled and explored; (4) palynological analysis, (5) stable isotope analysis of sediments; (6) Subfossil wood analysis, dendrochronology and C14 dating.

Results

In order to further investigate the dynamics of the landscape, we conducted a LiDAR survey of the Išči ca floodplain. An area 1300 x 600m around the Maharski prekop site was chosen for the LiDAR survey. The LiDAR image of the area around Mahrski prekop shows a comprehensive image of the geomorphology of the project area, particularly highlighting palaeochannels and earlier river courses, which can be seen as linear depressions in the landscape. The palaeochannels are not contemporaneous. Some channels are cut by younger ones, thus establishing a stratigraphic sequence. There are also differences in the shape, width, orientation and relative depth of the palaeochannel depressions. Consequently, at least four distinctive phases of fluvial activity can be discerned based on the relative stratigraphic positions of palaeochannels, their shapes and orientations.

Evidence of fluvial activity which pre- dates those observed in the LiDAR images can be found near Babna gorica Hill, around 2km north- east. In the 1.5m deep section excavated on the edge of the floodplain several episodes of fluvial activity and flooding can be observed in stable isotope sequence. The carbon and nitrogen isotope record, as well as C/N ratios in show some characteristic isotope transitions, indicating the presence of different types of organic material. The sequence demonstrates intensive and complex fluvial and flood activity before 6700 cal BP, with a sequence of ‘wet’ and ‘dry’ episodes.

Maharski prekop LIDAR

Mostišče area on the LiDAR image. Maharski prekop is located just next to the palaeochannel. Note the network of palaeochannels in the area and destruction by the palaeochannel dated to the third phase. J1–J4 – Staško Jesse's test trenches (1954). B1–4 – test trenches by Tatjana Bregant (1975), C – Bregant’s cores (1975), MP1–2 – pollen cores by Gardner (1999) and SM1 – Spodnje Mostišče pile cluster in modern Išica (Čufar et. al 1998).

Thanks to the large area excavated by Tatjana Bregant, it is possible to assess the organisation of space within the Maharski prekop settlement. Bregant interprets it as a single phase ‘pile-dwelling’, with several raised platforms where small houses were located. However, analysis of the distribution of piles and other features of archaeological record reveals the remains of a group of houses with sizes of around 8x4m arranged parallel to each other. Each house is made of three rows of structural timbers, with a central row of centre-posts sup- porting a roof ridge pole; the lateral rows are wall posts. The floors were plastered with clay, and the stone features are probably the remains of thermal structures in the front/back of the house, or possibly paved surfaces. When fire razed the superstructures, only parts of the posts below the occupational surface survived. Thus the heights of the piles indicate the levels of occupational floors at the time when the houses were destroyed. On this basis we can establish a provisional phasing of the piles and houses. Piles under the surface of the cultural layer are therefore older than piles extending above the cultural layer. Thus two phases of the settlement, older and younger, can be identified. Phasing of the occupation of the settlement can be refined through analysis of the stratigraphic sequence and radiocarbon dating. The radiocarbon data available are mostly for wooden piles and are therefore biased towards latter phases of the settlement. Most of the new radiocarbon dates for bones fall within this chronological framework. However, a radiocarbon datum for bone from grid square 34 obviously document earlier settlement of the area. The existence of earlier phase is documented also on the basis of pottery scatters deposited on the pre-settlement surface.

Maharski prekop faze

Maharski prekop. Phasing of piles and houses based on the relative heights of the piles. Purple – older phase, orange – younger phase.

Publications

Mlekuž D., Budja M. and Ogrinc N. 2006. Complex landscape and settlement dynamics of the Iščica floodplain (Ljubljana Marshes, Slovenia). Documenta Praehistorica 33: 253-271.
Abstract | Full text [PDF]

Budja M., Mlekuž D. 2008. Settlements, landscape and palaeoclimate dynamics on the Ižica floodplain of the Ljubljana Marshes. Documenta Praehistorica 35: 45-54.
Abstract | Full text [PDF]

Budja M., Mlekuž D. 2008. The Ižica floodplain and 'pile-dwellings' in prehistory. Arheološki vestnik 59, 459-370.
Full text [PDF]