Badania magnetyczne i elektrooporowe na terenie kopalni krzemienia w Bęble, stan. 4, pow. krakowski / Magnetic survey and electrical resistivity tomography at the flint mine in Bębło, Site 4, Kraków district
by Marcin M. Przybyła 1, Michał Podsiadło 1, Piotr Gruba 2
1 – Firma „Dolmen Marcin Przybyła, Michał Podsiadło s.c.”, pl. Serkowskiego 8/3, 30-512 Kraków; 2 – Uniwersytet Rolniczy im. Hugona Kołłątaja w Krakowie, al. 29 Listopada 46, 31-425 Kraków
In: E. Trela-Kieferling (ed.), Nakopalniane pracownie krzemieniarskie z okresu neolitu w Bęble, stan. 4, woj. małopolskie / Neolithic flint workshops at the mine in Bębło, site 4, Małopolska (Biblioteka Muzeum Archeologicznego w Krakowie 10), Kraków: Muzeum Archeologiczne w Krakowie, Profil-Archeo, 2021, pp. 15-30.
The magnetic and electrical resistivity surveys have led to identifying the geological structure of Site 4 in Bębło, revealing varied limestone karren: karst grooves and clints, at a depth of one metre, under a shallow layer of humus and clayey loess. The bottom of those grooves may have been covered with flint concretions, and it is likely that flint was extracted exactly from there. The clarity of magnetic and geoelectrical anomalies in Bębło indicates that the test results reflect the true character of the mine. The absence of anomalies related to large and deep shafts seems to stem from the lack of those features in Bębło, not from their low susceptibility to geophysical testing. This substantiates the view that flint was extracted in Bębło solely by the method of open-pit mining. The area of intensive extraction may have coincided with the zones of lower resistivity, although this thesis must be verified by excavation. The examined part of the site was subjected to detailed surface survey. Mining items were detected throughout the surveyed area, while workshop items concentrated in the northern part of the site and were almost absent from the lower resistivity zones. This may confirm the opinion that the zones of homogeneously lower resistivity were produced by intensive mining that disturbed the near-surface layers of relatively high resistivity. It is worth noting that the lower resistivity zones do not show any anomalies produced by karst karren that are clearly traceable outside those sections. It is possible, therefore, that the karst features in those places were destroyed by Neolithic miners as well. The geophysical testing, carried out over five hectares, did not cover the entire site, as proven by the scatter pattern of the artefacts on the surface.