Beryllium has only one isotope, 9Be, on earth. Cosmogenic
Be is produced in the atmosphere by cosmic ray spallation of oxygen and
nitrogen (Arnold and Al-Salih, 1955; Peters, 1955, 1959). Because beryllium
tends to exist in solution at pH levels less than about 5.5 (and most rainwater
has a pH less than 5), it will enter into solution and be transported to
the Earth's surface bia rainwater. As the precipitation quickly becomes
more alkaline, Be drops out of solution. Cosmogenic 10Be thereby
accumulates at the soil surface, where its logn half-life (1.6 Ma) permits
a long residence time before decaying to 10Be. 10Be
and its daughter products have been used to examine soil erosion (Pavich
et al., 1985; Brown et al., 1995), regolith soil formation (Barg et al.,
1992), the development of lateritic soils (Bernat et al., 1992).
Concentrations of 7Be and 10Be have been measured
in precipitation (Domink et al., 1987; Brown et al., 1989; Brown et al.,
1992; Knies et al., 1994), atmospheric aerosols (Dibb et al., 1994), and
river waters and associated sediments (Brown et al., 1992, 1995). The atmospheric
flux of cosmogenic 7Be (half-life = 53 days) has been measured
to determine erosion rates and fluvial transport mechanisms (Dominik et
al., 1987), as well as to determine direct contribution of rainfall to
terrestrial waters (e.g. streamwater; Cooper et al., 1991). To our knowledge,
no studies have reported beryllium isotopes in ground-water samples. While
beryllium isotopes may prove analytically difficult becasue of its low
concentrations in catchment waters, and because interpretations would require
close consideration of sorption versus solution behavior, the substatial
differences in nuclide contents between important catchment compartments
may make Be istopes worth examining (Nimz, 1998).
Source of text: This review was assembled by Eric Caldwell
and Dan Snyder, drawing mostly from Nimz (1998).
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by cosmic rays". Science, 121: 451-453.
||Barg, E., Lai, D., Jull, A. J. T., Southon, J., Caffee, M. W., Finkel,
R. C., and Pavich, M. (1992). "Applications of cosmogenic nuclear
methods for studying soil erosion and formation rates." In: Y. K.
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of the 7th International Symposium on Water-Rock Interaction.
Balkema Publishers, Rotterdam, p. 541.
||Bernat, M., Bokilo, J. E., Yiou, F., Raisbeck, G. M., and Muller, J-P.
(1990). "10Be and natural isotopes of U and Th in a laterlite
cover from Camaroon." Chem. Geol., 84: 347.
||Brown, L., Stensland, G. J., Klein, J. and Middleton, R. (1989). "Atmospheric
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||Brown, E. T, Edmond, J. M., Raisbeck, G. M., Bourles, D. L., Yiou, F.
and Measures, C. I. (1992). "Beryllium isotope geochemistry in tropical
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||Brown, E. T., Stallard, R. F., Laren, M. C., Raisbeck, G. M., and Yiou,
F. (1995). "Denudation rates determined from the accumulation of in-situ
produced 10Be in the Luquillo experimental forest, Puerto Rico."
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||Cooper, L. W., Olsen, C. R., Solomon, D. K., Larsen, I. L., Cook, R.
B., and Grebmeier, J. M. (1991). "Stable Isotopes of Oxygen and Natural
Fallout Radionuclides Used for Tracing Runoff During Snowmelt in an Arctic
Watershed". Water Resour. Res., 27, 9: 2171- 2179.
||Dibb, J. E., Meeker, L. D., Finkel, R. C., Southon, J. R., Caffee, M.
W., and Barrie, L. A. (1994). "Estimation of stratospheric input to
the Arctic troposphere: 7Be and 10Be in aerosols
at Alert." Canada J. Geophys. Res., 99: 12855.
||Domink, J., Burrus, D. and Vernet, J-P. (1987). "Transport of environmental
radionuclides in an alpine watershed." Earth Planet. Sci. Lett.,
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||Knies, D. L., Elmore, D., Sharma, P., Vogt, S., Li, R., Lipshutz, M.
E., Petty, G., Ferrel, J., Monagham, M. C., Fritz, S., and Agee, E. (1994).
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Hydrology." In: C. Kendall and J. J. McDonnell (Eds.), Isotope
Tracers in Catchment Hydrology. Elsevier, pp. 247-290.
||Pavich, M. J., Brown, L., Valette-Silver, J. N., Klein, J. and Middleton,
R. (1985). "10Be analysis of a Quaternary weathering profile
in the Virginia Peidmont." Geology, 13: 39.
||Peters, B. (1955). "Radioactive beryllium in the atmosphere and
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