Chemistry Reference
In-Depth Information
Table 8.2
(Continued).
Complexes
Laplandsky
(Baltic shield,
Russia)
Belomorsky
(Baltic shield,
Russia)
Karateginsky
(Tien Shan,
Kyrgyzstan)
Korva-Tundra
(Russia)
[Drugova, Skublov, 2004], ICP-MS
LN-130
28c
633b
900
834b
1005c
Metasomatic
rock
Element
Schist
Schist
Gneisses
La
0,300
1,07
10,4
5,96
0,910
1,11
Ce
0,500
2,22
9,05
10,6
1,48
2,29
Pr
N.d.
N.d.
N.d.
N.d.
N.d.
N.d.
Nd
0,310
0,910
5,75
4,99
0,750
1,90
Sm
0,200
0,510
1,72
2,31
0,360
1,19
Eu
0,079
0,089
0,170
0,170
0,074
0,250
Gd
0,110
0,280
0,690
0,950
0,200
0,600
Tb
0,020
0,055
0,063
0,120
0,038
0,069
Dy
0,110
0,270
0,150
0,390
0,230
0,250
Ho
N.d.
N.d.
N.d.
N.d.
N.d.
N.d.
Er
0,071
0,160
0,058
0,140
0,160
0,086
Tm
N.d.
N.d.
N.d.
N.d.
N.d.
N.d.
Yb
0,120
0,210
0,067
0,130
0,220
0,083
Lu
0,026
0,038
0,015
0,023
0,037
0,018
Total
2,03
5,81
28,1
25,8
4,46
7,85
(La/Yb)
n
1,69
3,44
105
31,0
2,79
9,03
(Eu/Eu*)
n
1,48
0,66
0,40
0,30
0,77
0,81
REE patterns of many biotites from metamorphic rocks, which often show a nega-
tive slope, there are positive Sm anomalies, as well as smooth lows in the Nd area
and in the parts of the patterns between Dy and Er (Figure 8.2). The patterns of
biotites from granites from Laplandsky complex in contrast to the patterns of this
mineral from metamorphic rocks, as well as from rhyolites of Twin Peaks prov-
ince (Figure 8.1, 6), are complicated by a very intense positive Eu anomaly (Fig-
ure 8.2, 3). According to the observations of Drugova & Skublov, the variations of
the REE distribution parameters in biotites from metamorphic rocks are in one way
or another predetermined by the composition of mineral parageneses of the rocks
in which they reside. According to the observations of these researchers, the con-
tent of HREE in biotites decreases with increasing temperature of metamorphism of
those protolite that formed biotite-bearing metamorphic rocks. However, according
to Fleet [1984], who studied the REE composition of biotites from gneiss of several
districts in Norway, high concentrations of La, Ce, Dy and Yb in this mineral are
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