Geoscience Reference
In-Depth Information
Table 23.1
Estimates of 'fertile mantle' compositions derived by mixing components (continental crust (CC), ultramafic rocks (UMR),
MORB, OIB, kimberlite (Q)) in various proportions in order to match chondritic ratios of refractory elements. BSE is bulk silicate Earth
(CC, upper mantle, and lower mantle). Several estimates are given for some components
%
BSE
BSE
CC
NMORB
EMORB
OIB
KIMB
UMR
UMR
Fertile Mantle
%
SiO
2
48
48
59
50
50
49
35
44
45
44
45
45
SiO
2
MgO
34
34
4
8
8
8
28
41
39
39
37
37
MgO
CaO
3.6
3.1
6.4
11.4
10.7
10
19
2.2
3.2
2.8
3.6
3.7
CaO
Al
2
O
3
4.5
3.8
15.8
15.7
16.4
14
1.3
2.3
4.0
3.2
4.6
4.7
Al
2
O
3
K
2
O
0.03
0.02
1.9
0.1
0.6
0.38
1
0.05
0.01
0.07
0.02
0.02
K
2
O
Na
2
O
0.4
0.3
3.2
3.1
3.3
2.1
0.8
0.2
0.13
0.44
0.29
0.33
Na
2
O
TiO
2
0.2
0.2
0.2
1.5
1.7
2.5
0.5
0.1
0.13
0.19
0.21
0.22
TiO
2
ppm
ppm
Ba
6.99
5.22
390
6.8
100
350
2000
33.0
0.563
35.3
5.43
6.08
Ba
Rb
0.64
0.39
58
0.7
12
31
200
1.9
0.05
2.3
0.61
0.71
Rb
U
0.02
0.02
1.42
0.05
0.3
1.0
20
0.1
0.003
0.1
0.02
0.04
U
Th
0.09
0.08
5.60
0.14
1.1
4.0
92
0.7
0.01
0.7
0.07
0.18
Th
Ta
0.04
0.04
1.1
0.1
0.2
2.7
40
0.4
0.01
0.4
0.04
0.08
Ta
Nb
0.71
0.97
12
2
16
48
400
4.8
0.15
5.0
0.65
0.95
Nb
Zr
11
13
123
109
139
280
400
21.0
5.08
28.4
12.31
12.54
Zr
La
0.7
0.6
18
3.5
10
37
200
2.6
0.19
2.9
0.70
0.79
La
Sm
0.4
0.3
3.9
3.6
4
10
30
0.5
0.24
0.7
0.48
0.51
Sm
Yb
0.5
0.3
2
3.4
3
2
1
0.3
0.37
0.5
0.52
0.56
Yb
