The Cenozoic sediments in the Holedná game reserve and their significance for archaeology
Article PDFThe Cenozoic sediments in the Holedná game reserve and their significance for archaeology
The Cenozoic sediments partially cover crystalline rocks in the area of Holedná game reserve (Brno town, South Moravia). Holocene to Pleistocene eluvial and/or slope sediments and relics of Ottnangian (Lower Miocene) sediments fill the wide valley to a depth of up to 20 m on the western slope of the Holedná Hill (391 m.a.s.l.). Several landslides were documented in these sediments based on the movement of the fortification wall from the Late Bronze Age. Blocks of limonite-rich sediment situated on the western slope of Holedná Hill (391 m.a.s.l.) were spatially related to the Cenozoic sediments. Sand to silt fraction in the iron oxohydroxides matrix consists of quartz, feldspar and mica. According to the geochemistry, we interpret these sediments as a mixture of the material from at least two sources: products of Neogene lateritic weathering rich in iron oxo-hydroxides (Fe2O3 76.2 wt. %) and continental Ottnangian sediments (sand- and silt-rich layers). In terms of their origin, the Ottnangian sediments in the vicinity of Brno town remain a contro versial problem. These sediments are predominantly continental, with clastic materiál originating from local sources (the transport distance from several kilometres up to tens of kilometres).
David Burianek, Czech Geological Survey, Leitnerova 22, 659 37 Brno, Czech Republic; e-mail: david.burianek@geology.cz
Oldřich Krejčí, Czech Geological Survey, Leitnerova 22, 659 37 Brno, Czech Republic; e-mail: oldrich.krejci@geology.cz
Vladimíra Krejčí, Czech Geological Survey, Leitnerova 22, 659 37 Brno, Czech Republic; e-mail: vladimira.krejci@geology.cz
František Hubatka, KOLEJCONSULT & SERVIS, spol. s r. o., Křenová 131/35, Trnitá, 602 00 Brno; email: hubatka@kcas.cz
Karel Kirchner, Institute of Geonics of the Academy of Sciences, Department of Environmental Geography, Drobného 28, 602 00, Czech Republic; e-mail: Karel.Kirchner@ugn.cas.cz
Aleš Navrátil, Brno City Museum, Špilberk 210/1, 662 24 Brno, Czech Republic; e-mail: navratil@spilberk.cz