Soils as an environmental record of changes between Iron Age and Medieval occupations at Chotebuz-Podobora hillfort

0570933 - ÚJF 2024 RIV NL eng J - Journal Article
Poledník Mohammadi, S. - Horák, J. - Lisá, Lenka - Gryc, J. - Grison, H. - Bajer, A. - Šmejda, L.
Soils as an environmental record of changes between Iron Age and Medieval occupations at Chotebuz-Podobora hillfort.
Geoderma. Roč. 429, JAN (2023), č. článku 116259. ISSN 0016-7061. E-ISSN 1872-6259
R&D Projects: GA MŠMT EF16_019/0000728
Institutional support: RVO:61389005
Keywords : Geoarchaeology * Geochemistry * Magnetic susceptibility * Micromorphology * Pedology
OECD category: Physical chemistry
Impact factor: 6.1, year: 2022
Method of publishing: Limited access
https://doi.org/10.1016/j.geoderma.2022.116259

The geochemical signal of anthropogenic soils reflects past settlement activities. The soils which are a part of an archaeological archive at a multi-phase hillfort Chotebuz-Podobora were formed under the significant influence of Early Iron Age and Medieval occupation and various subsequent factors at different parts of the hillfort. The hillfort layout is divided into three parts distinguished by different geomorphological characteristics, the acropolis, 1st bailey and 2nd bailey. While the original morphology of the 1st and 2nd bailey was relatively flat, the acropolis surface was under the slope.

All these parts were drilled and detected archaeological strata studied in terms of their geochemical composition and magnetic susceptibility, including its frequency dependence. Finally, the soil horizons typical for each of the part of hillfort were studied micromorphologically.

The soil record detected at the site contained high amount of phosphorus, even higher than usually recorded at abandoned medieval villages. Based on areal and stratigraphic distribution were discovered three groups of elements: 1) elements with maxima in 'Archaeology' category (Si, P, Ti, Mn, Sr, Zr), 2) elements with maxima in 'Topsoil' category (Cu, Zn, As, Pb, LE and Fe, Mn partially), 3) elements with maxima in 'C' category (Al, K, Rb and partially Fe). The values of magnetic susceptibility (chi) increased mainly in the topsoil of 2nd bailey. Fre-quency dependent susceptibility (chi FD%) reached the highest values in the archaeological layer with spatial di-versity in 1st and 2nd baileys. The high chi FD% values confirmed that the Hallstatt horizon at acropolis is redeposited soil, not only redeposited dumping.

The oldest human presence is attested by the development of soil reflecting the presence of organic residues. After the first abandonment of the site at the end of Hallstatt period was the organic rich horizon eroded and accumulated at one side of the acropolis. The surface of the acropolis became flatter and levelled. The soil development in the Medieval period was highly influenced by an aggradation of material originally used for different types of building constructions. The presence of anthropogenic elements reflects in that time not only the deposition of organic matter but also the deposition of ash. While the acropolis was heavily occupied, and its geomorphology dramatically changed over time, the 1st bailey served mainly as a production space. The function of the 2nd bailey stays unsolved due to its poor preservation. The most recent human influence in the soil record is visible in the topsoil. First as the result of agricultural practices and second as the contamination by Pb and magnetic particles resulting from the atmospheric pollution.
Permanent Link: https://hdl.handle.net/11104/0342271