Sedimentation of Holocene tufa influenced by the Neolithic man: An example from the Sąspowska Valley (southern Poland)

摘要: Abstract A complex of inactive tufas, the thickness which reaches 3.5 m, was studied in lowermost segment Sąspowska Valley Krakow Upland (Ojcow National Park, Poland). Five fluvial tufa barrages were recognized. They are composed moss and stromatolitic accompanied with oncoidal rudstone detrital tufa. Interbarrage ponded areas filled tufa, lutite, subordinately rudstone, limestone gravel peat-like deposit. Radiocarbon dates suggest that formed during Subboreal, Boreal Atlantic time. The main difference between contemporaneous tufas other valleys is higher amount non-carbonate fraction former. Other Lower Middle Holocene mainly or exclusively carbonate fraction. fluviatile resulted from erosion loess cover upper part catchment. related to local activity Neolithic flint miners who cleared forest at a scale, dug shafts exploited flints underlying weathered residuum Jurassic limestone. Consequently, they made copious amounts loose material available for transport down valley subsequent trapping within depositional system.