Racfwld: Major. Trace and Rare Earth Element Geochemistry
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8
6
4
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100
grain-size (/.1m)
0.01
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average shale
213
10
100
Figure 6: Average chemical composition of SPM from the Yana. The x-axis corresponds to the composition of
average shale (Wedepohl. 1971 and 1991). The diagonal represents the straight line of identical values. Al
normalized concentrations based on weight ratios (major elements) and weight ratio· 10 4 (trace elements) are
displayed. The grain-size distribution (volume %) is shown in the upper left corner.
350 ppm) and Cs (up to 90 ppm) (Efremenko, 1976). Consequently, even a small contribution
of material derived from these intrusions results in significant trace element enrichments in the
Yana SPM. The maximum As concentrations (62 ppm) were observed in the Bytaktay (Y6), the
maximum Cs concentrations (more than 8 ppm) in the Bytaktay and the Kyugyurlyur (Y8),
both of which are left bank tributaries of the Yana.
REE patterns of SPM of the Yana and its tributaries are shown in Figure 7. The average Yana
SPM was characterized by a flat REE distribution and a pronounced positive Eu anomaly. The
only tributary that displayed a similar pattern was the Aditcha (Y 4) draining the southeastern
part of the Yana catchment. In agreement with hydrological data (Korotaev, pers. comm.), it
can be concluded that a major fraction of Yana SPM is derived from this tributary. The other
tributaries were characterized by flat REE patterns and a slight enrichment in middle REE which
may be attributed to the occurrence of silt-sized particles containing significant amounts of
heavy minerals. Heavy minerals, such as zircon, garnet, apatite, epidote, and tourmaline, may
have high abundances of REE and exhibit strong variabilities in REE patterns (Taylor and
McLennan, 1985).
In contrast to the trace element enrichment, the REE pattern of Yana SPM, in particular the
positive Eu anomaly, cannot be explained by the influence of granitic intrusions. Volcanic rocks
of Triassic and Jurassic age, which are also present in the Yana catchment, seem to control the
100
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10
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Il...
(f)
ctI
c
ctI 0.1
>0 .01
0.001
0.001
10
8
6
4
2
0 1
10
100
grain-size (/.1m)
0.01
0.1
average shale
213
10
100
Figure 6: Average chemical composition of SPM from the Yana. The x-axis corresponds to the composition of
average shale (Wedepohl. 1971 and 1991). The diagonal represents the straight line of identical values. Al
normalized concentrations based on weight ratios (major elements) and weight ratio· 10 4 (trace elements) are
displayed. The grain-size distribution (volume %) is shown in the upper left corner.
350 ppm) and Cs (up to 90 ppm) (Efremenko, 1976). Consequently, even a small contribution
of material derived from these intrusions results in significant trace element enrichments in the
Yana SPM. The maximum As concentrations (62 ppm) were observed in the Bytaktay (Y6), the
maximum Cs concentrations (more than 8 ppm) in the Bytaktay and the Kyugyurlyur (Y8),
both of which are left bank tributaries of the Yana.
REE patterns of SPM of the Yana and its tributaries are shown in Figure 7. The average Yana
SPM was characterized by a flat REE distribution and a pronounced positive Eu anomaly. The
only tributary that displayed a similar pattern was the Aditcha (Y 4) draining the southeastern
part of the Yana catchment. In agreement with hydrological data (Korotaev, pers. comm.), it
can be concluded that a major fraction of Yana SPM is derived from this tributary. The other
tributaries were characterized by flat REE patterns and a slight enrichment in middle REE which
may be attributed to the occurrence of silt-sized particles containing significant amounts of
heavy minerals. Heavy minerals, such as zircon, garnet, apatite, epidote, and tourmaline, may
have high abundances of REE and exhibit strong variabilities in REE patterns (Taylor and
McLennan, 1985).
In contrast to the trace element enrichment, the REE pattern of Yana SPM, in particular the
positive Eu anomaly, cannot be explained by the influence of granitic intrusions. Volcanic rocks
of Triassic and Jurassic age, which are also present in the Yana catchment, seem to control the