African laterite dynamics using in situ-produced 10Be

Rates and Timing of Earth Surface Processes From In Situ-Produced Cosmogenic Be-10

“…1-4) were derived considering the behavior of fast neutrons, which dominate the production of 10 Be and 26 Al near the Earth's surface at all latitudes and altitudes. Muons (small, charged particles that are much more weakly attenuated than fast neutrons) also produce 10 Be and 26 Al on and below Earth's surface (Lal 1987;Nishiizumi et al 1989;Brown et al 1995a); however, recent studies suggest that muons produce only 3% or less of total 10 Be nuclide activity in surface samples exposed at sea level and high latitude (Brown et al 1995a;Braucher et al 1998b;Granger and Smith 2000;Stone 2000). At higher altitudes, the muon contribution to total nuclide production in surface samples is even a smaller percentage.…”

Statistical, geochemical, and morphological analyses of stone line formation in Uganda

“…An important exception has been recent work using cosmogenic isotope 10 Be concentrations in quartz gravels to date surface exposures and relate stone line materials to quartz veins. In one study of a stone line exposure in Africa, Braucher et al (1998b) were able to link stone line quartz to a nearby vein. They concluded that the angular quartz had been transported by soil creep, though other processes could have been responsible.…”

Quantifying soil loss with in-situ cosmogenic 10Be and 14C depth-profiles

“…Given the vertical nature of soil processes, most studies involving soils and employing cosmogenic nuclides have used cosmogenic nuclide depth-profiles. For example, Brown et al (1994) and Braucher et al (1998) have used in-situ 10 Be depth-profiles in lateritic tropical soils to explain the formation of certain soil deposits. Phillips et al (1998), using a model of soil burial by colluvium and bioturbation in combination with 21 Ne measurements in depth-profiles, were able to estimate inheritance-corrected exposure ages in stream terraces and an alluvial fan.…”