|
AVERAGE COMPOSITION OF THE EARTH
|
ELEMENT |
CONTINENTAL
CRUST |
OCEANIC
CRUST |
UPPER
MANTLE |
|
Oxygen (O) |
46.6 % |
44.9 % |
42.7 % |
|
Silicon (Si) |
27.7 % |
24.1 % |
19.8 % |
|
Aluminum (Al) |
8.1 % |
7.7 % |
1.2 % |
|
Iron (Fe) |
5.1 % |
8.2 % |
9.7 % |
|
Calcium (Ca) |
3.6 % |
7.8 % |
1.6 % |
|
Sodium (Na) |
2.8 %
|
1.6 % |
0.5 % |
|
Potassium (K) |
2.6 %
|
0.5 % |
< 0.1 % |
|
Magnesium (Mg) |
2.1 % |
4.0 % |
23.2 % |
|
All Others |
1.3 % |
1.2 % |
1.3 % |
Note: all percentages are given in a weight per weight basis
|