Plots of age scenarios. The upper panel shows cumulative growth, and the lower panel differential growth as modelled by the Gompertz equation. The oldest sample is by definition formed in year 0. Establishment is defined as the year in which cumulative radial growth is at least 1 mm, and will be negative compared to the oldest sample from the core in question. Scenario names refer to Table 2. Grey lines (for Jimal a) show scenarios based on 25-year interval dates within 2 sigma ranges for sample VI, i.e. 1800, 1825, 1850, 1875 and 1900. Note the different x-scale on Umm Dihaysi a.