Table 2.

U–Th geochronological analyses from Cava Nera quarry

Sample232Th/238U × 103234U/238U230Th/238U230Th/232Th (ppm)Age uncorrected (ka)Age corrected (ka)d234Uinitial corrected
CN157.06 ± 0.261.2379 ± 0.00850.66520 ± 0.0066811.6686.54 ± 1.4578.97 ± 8.321.2379 ± 0.0085
CN560.93 ± 0.471.2936 ± 0.00990.49392 ± 0.005728.1153.18 ± 0.8645.34 ± 8.471.2936 ± 0.0099
CN862.48 ± 0.271.2229 ± 0.00890.59814 ± 0.004759.5774.74 ± 1.0066.33 ± 9.161.2229 ± 0.0089

Isotope data are expressed as activity ratios. Ages were calculated using the standard U–Th age equation. Decay constants used are 9.195 × 10−6 for 230Th and 2.835 × 10−6 for 234U. All errors are listed at the 2σ confidence level. Ages in the ‘Age corrected’ column were corrected using the initial 230Th/232Th value of 0.155 ± 0.055, the uncertainty on which is propagated into the final age uncertainty. 234U/238Uinitial is calculated using 234U/238U and the corrected age.