6 Historic Climatic Variability and Change: The Importance …
137
Table 1 Isotope data from southeast Botswana, Dendron area, and Johannesburg region, with
calculated mean annual ambient temperature and groundwater mean residence times
Sample
ID
δ 18 O
(‰)
±δ 18 O
(‰)
δ 2 H
(‰)
±δ 2 H
(‰)
14 C
(pMC)
14 C (years) T (°C)
calculated
BH1
−7.66 ±0.11 −36.5 ±0.4 96.5±2.5 300±5
8.5
SE Botswana
BH2
−5.41 ±0.00 −34.0 ±0.0 88.5±2.4 1000±10 11.8
BH3
−5.10 ±0.08 −32.0 ±0.4 81.2±2.4 1700±10 12.2
BH4
−5.38 ±0.00 −34.3 ±0.0 64.9±2.4 3550±10 11.8
BH5
−8.22 ±0.00 −38.8 ±0.0 64±2.4
3700±10 7.7
BH6
−7.65 ±0.00 −35.7 ±0.0 58.1±2.4 4500±10 8.6
Dendron
BH7
−5.23 ±0.00 −33.3 ±0.0 56.5±2.1 4700±10 12.0
BH8
−7.37 ±0.00 −34.8 ±0.0 56.3±2.1 4750±10 9.0
BH9
−3.95 ±0.03 −27.3 ±0.2 47.7±2.1 6100±10 13.9
BH10
−5.11 ±0.00 −30.8 ±0.0 47.2±2.1 6200±10 12.2
BH11
−4.61 ±0.00 −29.9 ±0.0 18±1.7
14200±10 12.9
BH12
−4.56 ±0.00 −28.4 ±0.0 15.7±1.7 15300±10 13.0
BH13
−7.75 ±0.00 −35.7 ±0.0 4.9±1.5 24950±10 8.4
BH14
−8.06 ±0.05 −37.9 ±0.3 1.4±1.5 35300±50 8.0
D1
−4.70 ±0.28 −30.6 ±1.7 85.4±2.5 1300±10 12.8
D2
−4.60 ±0.22 −32.0 ±0.9 93.4±2.6 560±5
12.9
D3
−5.22 ±0.06 −35.8 ±0.3 84.3±2.5 1400±10 12.1
D4
−4.62 ±0.19 −29.1 ±1.1 100±2.6 0±5
12.9
Johannesburg
D5
−3.86 ±0.24 −26.9 ±3.1 100±2.7 0±5
14.0
D6
−4.65 ±0.06 −28.7 ±0.2 92.9±2.6 600±5
12.9
BH1
−1.39 0.13
−6.5 0.6
97.5±2.6 209±5
17.6
BH2
−2.69 0.07
−12.2 0.9
91.3±2.6 752±5
15.7
BH3
−2.87 0.11
−13.0 0.7
98.5±2.6 125±5
15.4
BH4
−2.87 0.04
−12.6 0.8
99.7±2.6 25±5
15.4
BH5
−4.52 0.07
−23.2 1.2
100±2.7 0±5
13.1
BH6
−5.73 0.05
−29.1 0.4
88.2±2.6 1038±10 11.3
BH7
−2.23 0.05
−12.3 0.3
95.7±2.6 363±5
16.4
BH8
−3.55 0.05
−15.8 0.7
62.7±2.3 3859±10 14.5
BH9
−2.62 0.27
−12.5 3.5
84.4±2.5 1402±10 15.8
BH10
−5.08 0.36
−22.5 0.5
99.6±2.6 33±5
12.3
BH11
−4.32 0.05
−21.6 0.4
95.1±2.6 415±5
13.4
BH12
−3.27 0.08
−16.7 0.3
100±2.7 0±5
14.9
BH13
−3.83 0.11
−17.3 1.0
92.9±2.6 609±5
14.1
BH14
−3.83 0.17
−18.2 1.5
98.1±2.6 159±5
14.1
BH15
−5.15 0.03
−25.3 0.4
80.7±2.5 1773±10 12.2
(continued)
137
Table 1 Isotope data from southeast Botswana, Dendron area, and Johannesburg region, with
calculated mean annual ambient temperature and groundwater mean residence times
Sample
ID
δ 18 O
(‰)
±δ 18 O
(‰)
δ 2 H
(‰)
±δ 2 H
(‰)
14 C
(pMC)
14 C (years) T (°C)
calculated
BH1
−7.66 ±0.11 −36.5 ±0.4 96.5±2.5 300±5
8.5
SE Botswana
BH2
−5.41 ±0.00 −34.0 ±0.0 88.5±2.4 1000±10 11.8
BH3
−5.10 ±0.08 −32.0 ±0.4 81.2±2.4 1700±10 12.2
BH4
−5.38 ±0.00 −34.3 ±0.0 64.9±2.4 3550±10 11.8
BH5
−8.22 ±0.00 −38.8 ±0.0 64±2.4
3700±10 7.7
BH6
−7.65 ±0.00 −35.7 ±0.0 58.1±2.4 4500±10 8.6
Dendron
BH7
−5.23 ±0.00 −33.3 ±0.0 56.5±2.1 4700±10 12.0
BH8
−7.37 ±0.00 −34.8 ±0.0 56.3±2.1 4750±10 9.0
BH9
−3.95 ±0.03 −27.3 ±0.2 47.7±2.1 6100±10 13.9
BH10
−5.11 ±0.00 −30.8 ±0.0 47.2±2.1 6200±10 12.2
BH11
−4.61 ±0.00 −29.9 ±0.0 18±1.7
14200±10 12.9
BH12
−4.56 ±0.00 −28.4 ±0.0 15.7±1.7 15300±10 13.0
BH13
−7.75 ±0.00 −35.7 ±0.0 4.9±1.5 24950±10 8.4
BH14
−8.06 ±0.05 −37.9 ±0.3 1.4±1.5 35300±50 8.0
D1
−4.70 ±0.28 −30.6 ±1.7 85.4±2.5 1300±10 12.8
D2
−4.60 ±0.22 −32.0 ±0.9 93.4±2.6 560±5
12.9
D3
−5.22 ±0.06 −35.8 ±0.3 84.3±2.5 1400±10 12.1
D4
−4.62 ±0.19 −29.1 ±1.1 100±2.6 0±5
12.9
Johannesburg
D5
−3.86 ±0.24 −26.9 ±3.1 100±2.7 0±5
14.0
D6
−4.65 ±0.06 −28.7 ±0.2 92.9±2.6 600±5
12.9
BH1
−1.39 0.13
−6.5 0.6
97.5±2.6 209±5
17.6
BH2
−2.69 0.07
−12.2 0.9
91.3±2.6 752±5
15.7
BH3
−2.87 0.11
−13.0 0.7
98.5±2.6 125±5
15.4
BH4
−2.87 0.04
−12.6 0.8
99.7±2.6 25±5
15.4
BH5
−4.52 0.07
−23.2 1.2
100±2.7 0±5
13.1
BH6
−5.73 0.05
−29.1 0.4
88.2±2.6 1038±10 11.3
BH7
−2.23 0.05
−12.3 0.3
95.7±2.6 363±5
16.4
BH8
−3.55 0.05
−15.8 0.7
62.7±2.3 3859±10 14.5
BH9
−2.62 0.27
−12.5 3.5
84.4±2.5 1402±10 15.8
BH10
−5.08 0.36
−22.5 0.5
99.6±2.6 33±5
12.3
BH11
−4.32 0.05
−21.6 0.4
95.1±2.6 415±5
13.4
BH12
−3.27 0.08
−16.7 0.3
100±2.7 0±5
14.9
BH13
−3.83 0.11
−17.3 1.0
92.9±2.6 609±5
14.1
BH14
−3.83 0.17
−18.2 1.5
98.1±2.6 159±5
14.1
BH15
−5.15 0.03
−25.3 0.4
80.7±2.5 1773±10 12.2
(continued)