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Groundwater dating

A number of general reviews of the use of atmospherically produced radionuclides for dating groundwater have been written [12-16]. Most of these reviews center on the use of 3H and 14C. [Pg.195]

K. 0. Mtinnich [18] published the first description of the use of 14C to date groundwater. Since this pioneer paper, countless studies have been made utilizing 14C in conjunction with conventional hydrogeologic investigations in almost all parts of the world [4,13,19-22]. One of the most extensive of these studies was by Pearson who sampled the Carrizo aquifer in Texas and was able to show a reasonable relationship between hydrodynamic and 14C ages of water over a wide region [23]. [Pg.195]

A number of decay products may be of interest ultimately as a basis of dating groundwater. At present, however, the accumulation of inert gases appears to offer the most significant possibilities for dating [19,36,58-60]. Some candidate gases are given in Table 3. Of those listed, 4He will probably be the most useful because of its relatively rapid rate of production. As already mentioned, because it is the decay product of tritium, the other... [Pg.204]

Table 3. Noble Gases of Possible Use for Dating Groundwater. Table 3. Noble Gases of Possible Use for Dating Groundwater.
Three primary problem areas exist in dating groundwater. These are (1) Formulation of realistic geochemical-hydrodynamic models needed to interpret data which are generated by field and laboratory measurements, (2) development of sensitive and accurate analytical methods needed to measure trace amounts of various stable and unstable nuclides, and (3) theoretical and field oriented studies to determine with greater accuracy the extent and distribution of the subsurface production of radionuclides which are commonly assumed to originate only in the atmosphere. [Pg.218]

When the anthropogenic tritium was noticed, hopes arose that the specific tritium pulses, contributed by the individual tests, would provide a way to accurately date groundwater. However, it turned out that the input values in precipitation varied considerably from one location to another and from one season and year to the next. In addition, complicated mixing takes place in each aquifer, and the mode and extent of mixing of each year s recharge... [Pg.216]

In order to date groundwaters, they have to be studied for possible mixing of waters of different ages. Helium concentrations should be applied for the calculation of meaningful ages only for nonmixed water or for reconstructed end members. [Pg.326]

Davis, S.N. and Bentley, H.W. (1982) Dating groundwater, a short review. In Nuclear and Chemical Dating Techniques Interpreting the Environmental Record, Currie L.A. (ed.), American Chemical Society Symp. Series 176, 187-222. [Pg.440]

He, and " He have been used to date groundwater at the aquifer scale. Notable examples include the Ojo Alamo aquifer in the San Juan Basin, New Mexico (Phillips et al., 1989 Stute et ai, 1995), the Stampriet and Uitenhage aquifers in Southern Africa (Heaton et al., 1983 Vogel et al., 1982),... [Pg.2730]

Mook W. G. (1976) The dissolution-exchange model for dating groundwater with carbon-14. In Interpretation of Environmental Isotope and Hydrochemical Data in Groundwater Hydrology, IAEA, Vienna, pp. 213-225. [Pg.2746]

Investigations into these possible applications of helium surveys have been conducted in North America, the former USSR, Australia and northern Europe over the last three decades. Initial results were commonly quite encouraging, but further studies have demonstrated that their potential in mineral exploration is limited and there has been little research and few publications since about 1987. Nevertheless, applications in hydrocarbon exploration and earthquake prediction remain possible. Total He analysis is ineffective for dating groundwaters but He isotope ratios are routinely applied to distinguishing mantle-derived gases. In this chapter, the occurrence and properties of helium are briefly outlined, followed by a description of appropriate sampling and analytical techniques and reviews and assessments of the possible uses of helium surveys. [Pg.304]

Purposes Used to define net masses of minerals (or gases) dissolved and/or precipitated along a flow path between two wells. Also considers ion exchange and other user-definable mass transfer processes. Can account for the mixing of two waters to produce a third, final water. NETPATH can also be used to age-date groundwaters (using C) and can solve isotope evolution problems. [Pg.558]

Country or region Discovery date Groundwater level [/ig As L ] Population at risk... [Pg.1333]


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