Object

Alternative title:

Environmental and cultural conditions of prehistoric sites in the Biebrza and Narew river basns

Abstract:

The use of LIDAR imaging for archaeological surveys in the last few years has enabled the discovery and inventory of 27 structures located in the Biebrza and Narew river basins. These structures are completely invisible in the field, but on scanning images they appear as circular structures consisting of a central area surrounded by rings of embankments and ditches. They have generated a lot of interest, both in the scientific community and among people interested in archaeology, as evidenced by the "Fortresses on the Marshes" exhibition presented in Białystok and Kraków in 2021-2022. The results of previous sporadic or rescue archaeological investigations on individual objects indicate that they were created at the turn of the Late Bronze Age and Early Iron Age. This newly discovered, current and widely interesting topic related to these objects was addressed in a doctoral dissertation. A new approach was taken, treating them as a settlement network in this area. The work focused on the age, environmental and cultural context, and function of these objects, as well as on the interaction between humans and the environment during their creation and operation. The discussion is based on the results of their own interdisciplinary research at three selected sites, as well as a chamber review of the remaining objects in this settlement network. The research area is located in northeastern Poland, in the present-day Podlaskie Voivodeship. The occurrence and functioning of settlement structures from the late Bronze Age and early Iron Age in the northern Podlasie region is a new area of study, which has only been discovered in the last few years. The breakthrough in archaeology brought about by the widespread use of laser scanning has enabled the discovery and inventorying of 27 such structures located in the river valleys of the Biebrza and upper and middle Narew, which show many similarities in terms of location, form, size, and type of construction. They are mainly located in the valleys of the two main rivers of the region - Biebrza and Narew - and their tributaries, as well as in post-glacial depressions. In terms of construction, they have a circular layout with two areas - a protective one consisting of a system of ditches and embankments, and a central one consisting of a flat central square. They can be preliminarily grouped into three types with one, two, and three rings of ditches.
The main aim of the research was to determine the environmental conditions, age, structure, and function of the settlement network in the upper Biebrza and Narew river basins, as well as the interaction between the prehistoric community and the environment during the time period when these sites were in use. The research was carried out in two stages. In the first, archaeological stage, which was combined with geophysical surveys, the focus was on the internal structure and cultural affiliation of the objects. In the second, environmental stage, their natural context was analyzed. The first step was to develop detailed topographic models of the objects and their immediate surroundings within a radius of 5 km. The analysis of LIDAR data in ASCII format, obtained from the Main Geodetic and Cartographic Office, was carried out in SAGA GIS and QGIS software. To identify potential elements of their construction, differences in vegetation cover visible in drone images of the objects were used. The next stage was geophysical surveys. Geomagnetic reconnaissance was carried out on the entirety of the selected objects in a grid with an area of 1 ha, using a Bartington Grad 601 magnetometer. The vertical magnetic field gradient was measured with a resolution of 0.1 nT (nanoTesla) every 0.25 m along 20 parallel traverses. The results obtained were processed in GeoPlot 3.0 software. Based on the geomagnetic data, verification sectors were selected on the sites, each with dimensions of 40x20 m. Ground-penetrating radar (GPR) profiling was conducted within these sectors along axes spaced 0.3 m apart. A two-channel groundpenetrating radar with a pulse repetition frequency of 200 kHz from Mala GeoScience ProEx System (Professional Explorer) was used in the research. The set was equipped with a 500 MHz frequency screened antenna. Excavations were conducted at the Jatwieź Duża and Kościuki sites. The excavations cut radially through all zones of the sites. During the exploration, photographic and graphic documentation was made along with the location of artifact findings. Sedimentological and dating analyses were also carried out on samples taken. At the Filipy site, archaeological exploration was not possible due to the lack of permission from the landowner. Geomorphological and physical-geographical mapping was carried out in areas with a radius of up to 5 km from the sites. The designated areas were grouped into types based on their spatial structure, and their typology was then carried out. Geomorphological maps of types of terrain, and types of stow closest to the object were created.
In order to determine the environmental context of the three sites that were extensively studied, field prospecting and a series of geological boreholes were conducted. These formed cross-sections across the valleys of the Brzozówka (22 boreholes) and Biebła (8 boreholes) rivers, as well as the Narew river (36 boreholes) and the glacial depression in Kościuki (44 boreholes). Samples were taken from the cores for sedimentological and dating analyses. During fieldwork that required survey measurements, an RTK GNSS measurement set was used with a Leica GS15 controller. The data was recorded in ASCII in the Polish Geodetic Coordinate System 2000 (PL-2000) (ETRS89/Poland CS2000) in zone 8. Sedimentological analyses were conducted at the Geomorphological-Hydrological Laboratory of the Department of Geomorphology and Geoarchaeology at the Jan Kochanowski University in Kielce. The grain size distribution of mineral sediments was analyzed using the sieve and laser methods. The organic matter content was determined using the loss on ignition method. The results, together with calculated Folks-Ward grain size parameters (1957); mean grain size (Mz), standard deviation (δl), skewness (Skl), and kurtosis (KG), were presented graphically in the GRANULOM program. A total of 1068 samples from 106 profiles were laboratory tested. To determine the chronology of the objects and environmental events, organic matter and mineral sediment samples were dated using radiocarbon (15 dates) and OSL (2 dates) methods, respectively. Radiocarbon dating was conducted at the Absolute Dating Laboratory in Skała and the Poznań Radiocarbon Laboratory. The radiocarbon dates were calibrated using the OxCal v 4.4.2 program. To determine the settlement of the area within a radius of 5 km around the sites in different periods, data from the Archeological Map of Poland program was used, obtained from the National Heritage Institute. Additionally, a survey analysis of sites that were not extensively examined was conducted. These sites were divided into three types based on the number of rings visible on the LIDAR image and surrounding the inner zone. For each site, LIDAR imaging, a geological map (based on the Detailed Geological Map of Poland 1:50,000 sheets), and a map of physiogeographic geosystems at the terrain type level were created for the area within a radius of 1 km. Based on the geological map, a geological profile was created through the analyzed area, which, in addition to the divisions on the map, proposed in several cases an interpretation in the form of erosion pedestals that may not have been
captured on the map scale. These proposals must be verified in future field studies. The descriptions of three sites also include the results of published or unpublished archaeological, sporadic, or rescue excavations. Research of direct and indirect sources involved querying archival materials, cartographic studies, and literature review. The Starkl chronostratigraphy (1977, 2001, 2013) and the periodization of Kaczanowski and Kozłowski (1998) and Dąbrowski (1997) were used in the work. Radiocarbon dating indicates that the objects were in use in the late Bronze Age/early Iron Age as part of a settlement system within the subgroup of the Suraż culture. However, in order to confirm the temporal homogeneity of the network of objects, absolute dates from subsequent sites must be obtained. The formation of the settlement system was most likely associated with a significant increase in population size ("paleobaby boom"), facilitated by favorable climatic conditions in the period immediately preceding the second Bond event. The increased population density in the area is manifested by a clear increase in the number of sites, which is well visible in the AMP materials. The food needs of this population, engaged in agricultural and livestock farming, led to deforestation of highland slopes and valley slopes. This initiated soil erosion, and the eroded material accumulated in the valley bottoms, causing a clear increase in the ash content of the peat sedentary in this morphological position. The hypothesis that requires verification in the future is the relationship between the number of rings and the age of objects. Previous research results suggest that as time passes, the structure of assumptions becomes more and more complicated. The identified types of objects can be ranked from the oldest single-ringed to the youngest triple-ringed ones. To confirm this hypothesis, dating from single-ringed objects must be obtained. All objects are located in depressions - river valleys and non-drainage glacial depressions. However, Lusatian communities used slightly elevated elevations located in these depressions when building these objects. These were mainly marginal parts of river sandurs, erosion remnants in valley bottoms, or meandering fills within older deposits on the floodplain. Such a location, despite the large number of extreme events during the second Bond event, mainly floods and groundwater rises caused by moistening and cooling of the climate, prevented their flooding or submergence. At the same time, objects were built near non-forested areas such as peatlands. The very high groundwater level prevented shrubs and trees from entering the peat, a phenomenon observed today in the Biebrza Valley after partial reclamation of the area
and its protection in the Biebrza National Park. Therefore, non-forested peatlands, due to the dominant pastoralism in the economy of these communities, were used as pastures. They could serve as kraals or as a place for slaughtering livestock. Earthworks with animal bones found in the central square may suggest that slaughter and meat protection were carried out in one area in storage pits that allowed for its longer storage, especially in cold climate conditions and the mesoclimate of valley bottoms with frequent temperature inversions. In this way, they can be treated as a kind of food storage for a large population, which could prevent hunger during the pre-dawn period, especially in conditions of significant shortening of the vegetation period during cooling. All objects have a standardized structure with a central square surrounded by a ring system of ditches and accompanying embankments. However, their location, small size of the entire design, and the size of the ramparts and ditches rather exclude their defensive or refugial character. However, the standardization of their construction and the significant amount of work required to construct these structures suggest changes in the organization of the population, the emergence of hierarchical social organization based on leadership, which mobilized, managed, planned, and controlled the population. Objects could also play an unknown role as places of socio-economic destination (exchange of goods or assemblies) or cultic (temple sites) separating the sacred area from the profane. The issue of the purpose and method of use of prehistoric sites by communities requires further on-site and off-site research, both at sites that have been thoroughly investigated and at others. The first step should be to verify the location of the sites through fieldwork, conduct paleogeographic studies in smaller valleys surrounding the sites, perform geochemical analyses on the sites and their surroundings, as well as conduct palynological profiles of adjacent peat bogs, which would allow for the verification of the hypothesis about their pastoral use, and also find a clear environmental record of the functioning of prehistoric communities. Archaeological research should be focused on the centers of the sites.

Additional notes:

Zawiera bibliografię ; Zawiera ilustracje kolorowe ; Streszcz. ang.

Identifier:

oai:bibliotekacyfrowa.ujk.edu.pl:10053

Computer catalogue:

click here to follow the link

Language:

pol

Degree name:

doktor

Date obtained:

9.11.2023

Degree grantor:

Uniwersytet Jana Kochanowskiego w Kielcach

Supervisor:

Kalicki, Tomasz (1958- )

Reviewer:

Malik, Ireneusz ; Błaszkiewicz, Mirosław ; Dobrowolski, Radosław

Field:

Dziedzina nauk ścisłych i przyrodniczych

Scientific disciplines:

Nauki o Ziemi i środowisku

Faculty:

Wydział Nauk Ścisłych i Przyrodniczych

Type:

rozprawa doktorska

Access rights:

tylko w Oddziale Informacji Naukowej

Publication status:

niepublikowana