Samples with a 2 value >5 pass the 2 test at the 95 % confidence level. Central ages (± 1-? error estimates) are reported (GALBRAITH & LASLETT 1993), which are the same as the pooled ages shown on the radial plots for samples which pass the 2 test, but provide a better age estimate for samples which fail the 2test. Ns, Ni, and Nd are the number of spontaneous, induced, and flux dosimeter (CN-5) tracks, respectively. Rhos, Rhoi, and Rhod are the density of spontaneous, induced, and dosimeter tracks (x 106 cm-2 ). A value of 353.5 ±7.1 (CN-5) was used for the zeta factor. For samples marked with an asterisk (*) a 252Cf-irradiated grainmount was used to increase the number of measurable track lengths (analyses by A.M.G.).