Dating groundwater

We find that the system is controlled by mixing of three distinct water masses: Interglacial or recent meteoric water (δ Kr ages range from 300 ka to 1.3 Ma for interglacial or recent meteoric water and glacial meltwater.For the brine component, ages exceed the dating range of the ATTA-3 instrument of 1.3 Ma.The radiogenic noble gas components seawater that has been modified by later water–rock interaction.Furthermore, as the obtained tracer ages cover several glacial cycles, we discuss the impact of the glacial cycles on flow patterns in the studied aquifer system. Gerber, Christoph, Vaikmae, Rein, Aeschbach, Werner, Babre, Alise, Jiang, Wei, Leuenberger, Markus, Lu, Zheng -Tian, Mokrik, Robert, Muller, Peter, Raidla, Valle, Saks, Tomas, Waber, H. Using 81Kr and noble gases to characterize and date groundwater and brines in the Baltic Artesian Basin on the one-million-year timescale.

Radiocarbon and tritium determinations were carried out in 2 adjacent small aquifers in Israel.

Based on the chemical and noble gas concentrations and the dating results, we conclude that the brine originates from evaporated seawater that has been modified by later water-rock interaction.

As the obtained tracer ages cover several glacial cycles, we discuss the impact of the glacial cycles on flow patterns in the studied aquifer system.

When these individual fractionation factors (0.54 for the Pleistocene and 0.62 for the Judea Group) are used, it is revealed that both aquifers contain young water, in agreement with the Darcy calculation, which was recharged at the beginning of the period of thermonuclear atmospheric testing in the early 1960s.

The 1000-yr difference is an artifact of initial isotopic fractionation differences through the unsaturated zone as established elsewhere for these 2 aquifers.

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