TABLE 1a

PRIMORDIAL RADIONUCLIDES OF TERRESTRIAL ORIGINS



Radionuclide


Half-life
(years)


Isotope abundance
(%)
Element abundance
in crustal rock
(ppm)**
Concentration in
crustal rock
(Bq/kg)
Non series decay
40 K
50 V
87 Rb
113 Cd
115 In
123 Te
138 La*
142 Ce*
144 Nd
147 Sm*
152 Gd*
174 Hf
176 Lu*
187 Re
190 Pt
192 Pt
209 Bi

Decay series
232 Th
235 U
238 U
1.26 10 9
6 10 15
4.8 10 10
1.3 10 15
6 10 14
1.2 10 23
1.12 10 11
5 10 16
1.4 10 15
1.05 10 11
1.1 10 14
2 10 15
2.2 10 10
4.3 10 10
6.9 10 11
1 10 15
2 10 18


1.4 10 10
7.1 10 8
4.5 10 9
0.018
0.25
27.85
12.26
95.77
0.87
0.089
11.07
23.87
15.07
0.20
00.163
2.6
62.93
00.0127
00.78
100


100
00.72
99.27
2090
135
90
0.2
0.1
0.002
30
60
28
6
5.4
3
0.5
0.001
0.005
0.005
0.17
603
1 10 -5
70
7 10 -7
2 10 -5
1 10 -7
0.02
1 10 -5
3 10 -6
0.7
7 10 -6
2 10 -7
0.04
1 10 -3
7 10 -8
3 10 -6
1 10 -10
* Denotes a lanthanide or rare earth element
** Elemental abundance in crustal rock is the weight abundance of the element in crustal material multiplied by the per cent abundance of the primordial isotope relative to all isotopes of the element. Data are from Mason (1965).

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