Chemistry Reference
In-Depth Information
0.50
0.50
0.50
1
2
3
0.40
0.40
0.40
0.30
0.30
0.30
0.20
0.20
0.20
0.10
0.10
0.10
0.00
0.00
0.00
0.0 0
0. 10
0 .20
0.3 0
0 .40
0.5 0
0.00
0.10
0.20
0.30
0.40
0.50
0.00
0.10
0.20
0.30
0.40
0.50
Pd, ppm
Ru, ppm
Os, ppm
0.50
0.50
0.50
4
5
6
0.40
0.40
0.40
0.30
0.30
0.30
0.20
0.20
0.20
0.10
0.10
0.10
0.00
0.00
0.00
0.0 0
0. 10
0 .20
0.3 0
0 .40
0.5 0
0.00
0.10
0.20
0.30
0.40
0.50
0.00
0.10
0.20
0.30
0.40
0.50
Pd, ppm
Ru, ppm
Os, ppm
0.50
0.50
0.50
7
8
9
0.40
0.40
0.40
0.30
0.30
0.30
0.20
0.20
0.20
0.10
0.10
0.10
0.00
0.00
0.00
0.0 0
0. 10
0 .20
0.3 0
0 .40
0.5 0
0.10
0.20
0.30
0.40
0.50
0.10
0.20
0.30
0.40
0.50
Pd, ppm
Pt, ppm
Ru, ppm
Figure 10.34
Relationship between some REE compositions and some PGE compositions for dunites
from Galmoenan massif (Koryak highland, Kamchatka, Russia) (data Table 10.15).
at different magmatic processes: 1) partial melting of mantle sources, 2) crystalliza-
tion fractionation of magmatic melts, and 3) reallocation at late-magmatic and post-
magmatic transformations of rocks. These researchers believed that PGE can not be
in the form of isomorphous impurity in the structure of minerals such as olivine and
chromite. A similar point of view was later expressed by Borisov [2005], who believed
that all PGE are incompatible with the structure of major silicate phases composing
the upper mantle - olivine, orthopyroxene, clinopyroxene and garnet. According to
Borisov, the values of K
d
(silicate mineral/melt) for all PGE are less than 1. He also
suggested that, when the degree of partial melting of mantle sources is 20%, an almost
full transition into melt of all those phases that originally contained PGE occurs.
Calculations made by McDonough & Sun [1995] showed that the average PGE
contents in non-depleted upper mantle are (ppb): Os - 3.4; Ir - 3.2; Ru - 5; Pt - 7.1;
Pd - 3.9. Similar estimates for primitive mantle were previously given by Rollinson
[1993] (ppb): Os - 3.3; Ir - 3.6; Ru - 4.3; Pt - 7. McDonough & Sun noted that in
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