Periodic Table--Beryllium

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).