Geology Reference
In-Depth Information
Table 5.15 Crustal abundance of minerals. Data in percentage volume
Mineral
Wedepohl (1969)
Nesbitt and Young (1984)
Plagioclase
41.0
39.9
Quartz
21.0
23.2
Orthoclase
21.0
12.9
Biotite
4.0
8.7
Muscovite
5.0
Chlorite
2.2
Amphiboles
6.0
2.1
Oxides
2.0
1.6
Pyroxenes
4.0
1.4
Olivines
0.6
0.2
Others
0.5
3.0
5.6.1 Early models of the mineralogical composition of the crust
A great deal of effort has been placed in determining the chemical composition of the
upper continental crust. Any published compositions have been frequently refined
and improved by many authors throughout the last century. And yet in contrast,
the mineralogical composition has been only superficially studied because of its
complexity and heterogeneity. A preliminary average mineralogical composition of
the crust was obtained by Wedepohl (1969, 1971), and Nesbitt and Young (1984)
(Table 5.15). According to these authors, only ten types of minerals constitute the
upper crust.
To the authors' knowledge, the first comprehensive mineralogical study of the
upper crust was carried out by Grigor'ev (2007). It was a desk study based on the
partially quantitative analysis of more than 3,000 rock samples, predominating from
the USSR and US. As a result, Grigor'ev (2007) identified the mass concentration
of the most important 265 minerals as shown in Table 5.16.
Table 5.16: Average mineralogical composition of the upper continental crust
according to Grigor'ev (2007). Results are given in percentage mass
Mineral
Abundance, mass %
Native Elements
Copper
4.10E-07
Silver
1.20E-07
Gold
1.80E-08
Lead
1.80E-07
Polixene
3.00E-10
I-Platinum
3.00E-10
Zinc
4.70E-08
Bismuth
4.90E-08
Tin
4.40E-08
Graphite
1.20E-01
Moissonite
7.00E-07
Sulphur
9.00E-05
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