3he cosmogenic nuclide age dating
This allows estimates of average erosion rates over timescales of 10^5 -10^7 yr, and constrains spatial patterns of erosion over lengthscales that address questions of paleotopography (e.g., House et al., 1998; 2001; Braun, 2002; Shuster et al., 2005, Ehlers et al., 2006), and possible climate-tectonic feedbacks.
: Alpha decay of U, Th, and intermediate daughter products is highly productive relative to many other extant natural radioisotopic decay systems, and the 4 He daughter is stable.
Here we describe the successful isolation and measurement of in situ10Be concentrations in pyroxene from two mafic sample sets: (i) andesite boulders of the Murimotu Formation debris avalanche on Mt.
Also, many of the same phases that can be dated by He and (U-Th)/He methods also have the potential to provide cosmogenic nuclide exposure ages or erosion rates (Farley et al., 2006).
This indicates that alpha-ejection corrections can be quite accurate and precise if appropriate microscopic measurements are made and assumptions about dated crystals hold up.