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Chemical Oceanography, 4th Edition
Table 3.13
Outcrop Abundance of Major Rock Types on Land (percentage by area)
Plutonic rocks
11%
Granite
10.40%
Gabbro and peridotite
0.60%
Metamorphic rocks
15%
Gneiss
10.40%
Mica schist
1.50%
Quartzite
0.80%
Marble
0.40%
Amphibolite
1.90%
Volcanic rocks
7.9%
Basalt
4.15%
Andesite
3.00%
Rhyolite
0.75%
Sandstones
15.8%
Quartz sandstone
12.60%
Arkose
0.80%
Graywacke
2.40%
Shales
33.1%
Carbonate sedimentary rocks
15.9%
Detrital carbonate rock
5.90%
Dolomite
3.65%
Limestone
6.35%
Evaporites
1.3%
Gypsum
0.75%
Halite
0.55%
Table 3.14
Origins of Weathering Products by Rock Types (percentage of total amount released)
SiO 2
Ca 2+
Mg 2+
Na +
K +
Cl –
SO 4
2–
HCO 3–
∑+
Granite
10.9
0.60
1.2
5.9
4.9
2.0
1.6
1.6
Gabbro
0.75
0.0
1.1
0
0
0.3
0.3
0.3
Gneiss and micaschists
11.7
1.10
2.8
6.6
8.2
4.6
2.0
2.4
Miscellaneous metamorphic
1.5
4.7
3.2
0.3
1.6
1.7
4.7
3.7
Volcanic rocks
11.1
1.8
4.9
5.4
6.6
0.5
4.2
3.1
Sandstone
16.6
2.1
3.8
5.2
19.6
9.6
2.3
3.2
Shale
35.1
19.9
30.7
22.6
41.0
7.4
30.3
22.5
23.1
Carbonate rocks
11.3
60.4
39.3
3.5
13.1
8.6
59.5
46.7
Gypsum
0.5
7.2
7.2
4.9
1.6
10.0
32.7
1.7
6.8
Rock salt
0.4
2.2
5.8
45.6
3.3
82.6
9.6
1.2
9.1
TOTAL%
100
100
100
100
100
100
100
100
100
10 12 g/ yr
320
504
118
132
24
120
280
1950
Note: ∑+ = sum of cations (milliequivalent/ liter).