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تاریخ::
رادیوکربن
In one claim to have dated rock art by proximity, Lorblanchet (1992) constructed an entire 18,500-year petroglyph sequence at Gum Tree Valley near Dampier, Australia, after securing a single radiocarbon date from a shell, a surface find from near the petroglyphs, which is over twice as old as all other dates from the area.
Radiocarbon analysis of mineral accretions
Radiocarbon occurs in such deposits because about one half of its carbon derives from atmospheric carbon dioxide (Bo¨ gli, 1960; Franke, 1951, 1967; Franke & Geyh, 1970; Franke, Mu¨ nnich & Vogel, 1958; Geyh, 1970; Hendy, 1969).
The approximate age of reprecipitated calcite is therefore measurable by determination of its remnant content of radiocarbon, at least in theory (Wendt et al.
Carbonate speleothems (Moore, 1952) may experience ''radiocarbon rejuvenation'', for example where porosity is available for the deposition of younger carbonate, as well as through isotope exchange in the presence of moisture.
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