# Comparison of \({}^{210}\)Pb Age Models of Peat Cores Derived from the Arkhangelsk Region
## 3 Results and Discussion
### Chronology \({}^{210}\)Pb and Rate of Peat Accumulation
#### 3.3.5 Application of the IP-CRS Model
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Layer** & **Depth**, & **Bulk Density** & **imp.s** & \multicolumn{2}{c}{**imp.s**} & \multicolumn{2}{c}{**imp.s**} & \multicolumn{2}{c}{**imp.s**} & \multicolumn{2}{c}{**imp.s**} & \multicolumn{2}{c}{**imp.s**} & \multicolumn{2}{c}{**imp.s**} & \multicolumn{2}{c}{**imp.s**} \\
**cm** & **cm** & **s** cm\({}^{-3}\) & **Original**, **Bulk Reg-1** & **Bulk Reg-2** & **Bulk Reg-3** & **cm**-3** & **Year-1** & **cm**-Year-1** & **Year-1** & **\(f_{i}\)** & **Data from Original** \({}^{129}\)**Pr.s.** & **Data from Corrected** \\
**-** & **cm** & **s** cm\({}^{-3}\) & **Original**, **Bulk Reg-1** & **Bulk Reg-2** & **Bulk Reg-3** & **cm**-3** & **Year-1** & **cm**-Year-1** & **Year-1** & **Year-1** & **Model CBS, Years** & **Year-1** \\ \hline
0-3 & 3 & 0.0448 & 310.75 + 34.18 & 411.0 + 45.12 & 305.6 + 33.06 & 0.100 & 0.288 & 0.100 & 2021 & 2021 \\ \hline
3-5 & 2 & 0.0435 & 211.16 + 30.086 & 222.0 + 54.72 & 330.6 + 37.94 & & 2014 & 2012 & 2012 \\ \hline
5-7 & 2 & 0.0505 & 168.39 + 21.89 & 190.0 + 24.70 & 188.1 + 24.45 & & & 2011 & 2006 \\ \hline
7-9 & 2 & 0.0887 & 155.35 + 35.73 & 158.0 + 36.34 & 203.4 + 46.98 & & & 2008 & 2000 \\ \hline
9-11 & 2 & 0.094 & 168.49 + 21.70 & 132.0 + 15.54 & 111.1 + 13.33 & & & 2005 & 1994 \\ \hline
11-13 & 2 & 0.0400 & 158.02 + 20.35 & 110.0 + 14.30 & 137.5 + 17.87 & & & 2000 & 1988 \\ \hline
13-15 & 2 & 0.0475 & 155.02 + 20.35 & 92.0 + 26.35 & 96.8 + 22.26 & & & 1996 & 1982 \\ \hline
15-17 & 2 & 0.0519 & 131.06 + 20.37 & 76.0 + 29.06 & 73.2 + 11.71 & & & 1900 & 1971 & 1976 \\ \hline
17-19 & 2 & 0.0473 & 180.00 + 23.22 & 64.0 + 11.23 & 67.8 + 11.49 & & & 1000 & 1986 & 1970 \\ \hline
19-21 & 2 & 0.0458 & 240.39 + 73.18 & 540.0 + 21.6 & 58.9 + 17.67 & & & 0.100 & 1978 & 1964 \\ \hline
21-23 & 2 & 0.0400 & 72.20 + 28.88 & 40.4 + 17.6 & 51.1 + 20.44 & & & 0.173 & 1962 & 1958 \\ \hline
23-25 & 2 & 0.0374 & 77.89 + 38.84 & 380.190 & 50.8 + 25.40 & & & 0.162 & 1966 & 1951 \\ \hline
25-27 & 2 & 0.0327 & 44.42 + 26.65 & 30.0 + 18.0 & 45.8 + 27.48 & & & 0.081 & 1949 & 1945 \\ \hline
27-29 & 2 & 0.0344 & 34.34 + 13.74 & 26.0 + 10.4 & 37.7 + 15.08 & & & 0.066 & 1945 & 1938 \\ \hline
29-31 & 2 & 0.0460 & 25.67 + 15.92 & 11.0 + 6.6 & 239.9 + 13.34 & & & 0.086 & 1941 & 1952 \\ \hline
31-33 & 2 & 0.0499 & 28.80 + 11.52 & 18.0 + 10.8 & 23.9 + 13.14 & & & 0.05 & 1937 & 1924 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: IP-CRS modelling and dating results for the ISNO core. Figure 9 shows the calculated values of the linear accumulation rate \(s\) and the mass accumulation rate \(r\) in the peat profile used in this study. The \(s\) values ranged between 0.073 \(\pm\) 0.05 and 0.635 \(\pm\) 0.05 cm\(\cdot\)year\({}^{-1}\) and had a mean value of 0.28 \(\pm\) 0.08 cm\(\cdot\)year\({}^{-1}\), which are slightly lower than the earlier reported values for the subarctic region of European Russia [1] and lower than the values given in [10], where the latter value was 0.38 \(\pm\) 0.07 cm\(\cdot\)year\({}^{-1}\). The accumulation rate of the peat mass \(r\) ranged between 0.0019 \(\pm\) 0.001 and 0.0199 \(\pm\) 0.001 g\(\cdot\)cm\({}^{-2}\cdot\)year\({}^{-1}\). The mean rate was 0.0117 \(\pm\) 0.001 g\(\cdot\)cm\({}^{-2}\cdot\)year\({}^{-1}\). The linear accumulation rate \(s\) uniformly decreased with depth and exhibited a distinct peak at 19-21 cm, which was possibly coincident with the altered climatic conditions for peat in 1964. The pattern of the mass accumulation rate \(r\) was complex, with several peaks at 19-21 cm dating from 1964 and probably associated with the changing climatic conditions for the peat. We noted that the regular has a decreasing \(r\) with depth as the peat deposit compacts with depth.