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Open Access 2019 | OriginalPaper | Buchkapitel

Thermometry of Apatite Saturation (The Kozhym Massif, The Subpolar Urals)

verfasst von : Y. Denisova, A. Vikhot, O. Grakova, N. Uljasheva

Erschienen in: 14th International Congress for Applied Mineralogy (ICAM2019)

Verlag: Springer International Publishing

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Abstract

The results of the study of accessory apatite from the Kozhym massif rocks have been presented in this paper. Apatites of the same morphological type were found in granites. The Kozhym massif granites formation temperatures by apatite were determined by the Watson and Bea saturation thermometry. These temperatures were compared with the previously obtained ones for accessory zircon of the same massif.

1 Introduction

The Kozhym massif is located in the northeastern part of the Subpolar Urals on the left and right banks of the Kozhym River in the Oseu and Ponyu Rivers basins (Fig. 1) among deposits of the Puyvinian Middle Riphean Formation. This massif is the second by area among the geobodies composing the Kozhym intrusion which includes the Kuzpuayu granite massif. The most fully preserved Kozhym massif granites are medium-grained pink greenish-gray rocks. They (the rocks) are characterized by a massive coarse-platy texture with well-defined tectonic gneissiness. The studied massif belongs to the A-type according to B. Chappel classification (Fishman et al. 1968).
The accessory massif apatite is represented by yellow mat elongated crystals of a hexagonal dipyramidal-prismatic habitus. The crystals size is 0.1–0.4 mm, the elongation coefficient is 1.5–3. The mineral shape is represented by a combination of a prism (1010) and a dipyramid (1011). The faces surface is fractured. Characteristic inclusions are quartz, plagioclase, zircon.

2 Methods

Apatite is increasingly used as a geothermometer. The E. Watson saturation thermometry was used to determine the mineral crystallization temperatures. This method allowed determining the apatite and rock formation temperature by the distribution of the phosphorus oxide content between apatite and the rock containing the mineral. The level of phosphorus saturation necessary for the apatite crystallization depends on the silica content in the meta-aluminic rock (A/CNK < 1) and the temperature according to the Harrison and Watson calculations (Harrison et al. 1984):
$$ \begin{aligned} & \text{InDp} = {{\left( {8400 + 26400 \, \left( {\text{SiO}_{2} {-} \, 0,5} \right)} \right)} \mathord{\left/ {\vphantom {{\left( {8400 + 26400 \, \left( {\text{SiO}_{2} {-} \, 0,5} \right)} \right)} {\text{T}{-} \, 3,1 \, {-} \, 12,4 \, \left( {\text{SiO}_{2} {-} \, 0,5} \right),}}} \right. \kern-0pt} {\text{T}{-} \, 3,1 \, {-} \, 12,4 \, \left( {\text{SiO}_{2} {-} \, 0,5} \right),}} \\ & \text{P}_{2} \text{O}_{5} \left( \text{HW} \right) \, = {{42} \mathord{\left/ {\vphantom {{42} {\text{Dp,}}}} \right. \kern-0pt} {\text{Dp,}}} \\ \end{aligned} $$
where Dp is the ratio of P concentration in apatite and melt, P2O5; SiO2 is the weight fraction of the phosphorus oxide, silica in the melt, wt. %, T is the temperature, Kelvin.
Bea (Bea et al. 1992) proposed the following addition to the Watson’s formula for peraluminum rocks (A/CNK > 1):
$$ \text{P}_{2} \text{O}_{5} \left( {\text{Bea}} \right) = \text{P}_{2} \text{O}_{5} \left( {\text{HW}} \right) \, *\text{P}_{2} \text{O}_{5} \left( {\text{HW}} \right) \, *e^{{\frac{{ 6 4 2 9\left( {{\text{A/CNK}} - 1} \right)}}{T - 2 7 3 , 1 5}}}. $$

3 Results and Discussion

The apatite saturation temperatures based on the data of the chemical granites composition of the Kozhym massif (Table 1) were calculated by the author according to Watson and Bea (Table 2).
Table 1.
Chemical granites composition of the Kozhym massif
Component, wt. %
Sample number
К-1
К-2
К-3
К-4
К-5
К-6
К-7
К-8
К-9
К-10
SiO2
77.78
76.89
75.95
75.89
76.49
78.12
77.54
76.26
77.48
76.95
TiO2
0.16
0.22
0.48
0.52
0.48
0.11
0.24
0.42
0.31
0.59
Al2O3
11.88
11.95
12.69
12.52
10.05
11.34
11.78
12.22
11.09
10.92
FeO
1.72
1.29
1.15
1.24
0.56
0.50
0.59
0.62
0.61
1.03
Fe2O3
0.84
1.12
0.52
1.05
0.92
1.21
0.87
1.02
0.89
0.56
MnO
0.02
0.00
0.00
0.01
0.02
0.01
0.02
0.04
0.03
0.03
MgO
0.16
0.25
0.17
0.33
0.38
0.39
0.18
0.29
0.19
0.18
CaO
0.31
0.29
0.22
0.38
0.59
0.28
0.45
0.42
0.37
0.51
Na2O
3.65
3.33
4.22
4.02
3.08
3.15
3.22
4.51
3.01
3.89
K2O
3.88
4.51
4.09
3.89
4.15
5.17
4.99
3.78
4.65
3.28
P2O5
0.01
0.03
0.02
0.02
0.03
0.02
0.01
0.01
0.03
0.02
ппп
0.05
0.29
0.59
0.15
0.75
0.62
0.39
0.98
1.02
1.23
100.46
100.17
100.10
100.02
97.50
100.92
100.28
100.57
99.68
99.19
Note. The chemical composition was obtained using the silicate method in CUC ≪Science≫ of Institute of geology of Komi SC UB RAS (analyst Koksharova O.V.)
Table 2.
Saturation temperatures for the Kozhymmassif apatite
Temperature, ℃
Sample number
К-1
К-2
К-3
К-4
К-5
К-6
К-7
К-8
К-9
К-10
According to Watson
784
860
819
818
856
838
782
770
865
828
According to Bea
722
798
770
764
856
836
768
770
840
826
The Kozhym massif rocks formation temperatures distribution histograms by apatite were compiled on the obtained temperatures for each calculation method (Fig. 2).
The presented histograms show that the studied granites are high-grade rocks. The Kozhym massif formation occurred at temperatures from 770 ℃ to 865 ℃ and averaged 822 ℃ according to Watson. The application of Bea refinements allowed concluding that the massif rocks formation occurred at temperatures from 722 ℃ to 856 ℃ and an average of 795 ℃.

4 Conclusions

The Kozhym massif rocks formation occurred at high temperatures. The similar massif granites formation temperature ranges: 770–865 ℃ according to Watson, 722–856 ℃ according to Bea were obtained using the Watson saturation thermometry by apatite and the Watson formula adjustment for aluminous rocks according to Bea. The data confirmed the temperatures obtained earlier by the author using the Watson saturation thermometry (749–816 ℃) and the classical evolutionary-morphological Pupin analysis (700–900 ℃) for zircon of the same massif (Denisova 2016; 2018a; b). It can be affirmed that the Watson saturation thermometry and the refined Bea formula for apatite provide the same information about regime temperature evolution during the granites formation such as on the Watson saturation thermometry and the Pupin and Tyurko evolutionary-crystallomorphological analysis for zircons.

Acknowledgements

The work was supported by the Basic Research Program of RAS № 18-5-5-19.
Open Access This chapter is licensed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license and indicate if changes were made.
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Literatur
Zurück zum Zitat Bea F, Fershtater GB, Corretgé LG (1992) The geochemistry of phosphorus in granite rocks and the effects of aluminium. Lithos 48:43–56CrossRef Bea F, Fershtater GB, Corretgé LG (1992) The geochemistry of phosphorus in granite rocks and the effects of aluminium. Lithos 48:43–56CrossRef
Zurück zum Zitat Denisova UV (2018a) Apatite of the Nikolaishor granite massif (the Subpolar Urals). Vestnik of Institute of geology of Komi SC UB RAS, Syktyvkar, № 9, pp 24–29 Denisova UV (2018a) Apatite of the Nikolaishor granite massif (the Subpolar Urals). Vestnik of Institute of geology of Komi SC UB RAS, Syktyvkar, № 9, pp 24–29
Zurück zum Zitat Denisova UV (2016) Temperature survey of zircon from the granitoids of the Subpolar Urals. Vestnikof Institute of geology of Komi SC UB RAS, Syktyvkar, №12, pp 37–44CrossRef Denisova UV (2016) Temperature survey of zircon from the granitoids of the Subpolar Urals. Vestnikof Institute of geology of Komi SC UB RAS, Syktyvkar, №12, pp 37–44CrossRef
Zurück zum Zitat Fishman MV, Yushkin NP, Goldin BA, Kalinin EP (1968) Mineralogy, typomorphism and genesis of accessory igneous rocks minerals of the Urals and Timan north. M.-L.: Sci 252 Fishman MV, Yushkin NP, Goldin BA, Kalinin EP (1968) Mineralogy, typomorphism and genesis of accessory igneous rocks minerals of the Urals and Timan north. M.-L.: Sci 252
Zurück zum Zitat Harrison TM, Watson EB (1984) The behavior of apatite during crustal anatexis: equilibrium and kinetic considerations. Geochim Cosmochim Acta 48:1467–1477CrossRef Harrison TM, Watson EB (1984) The behavior of apatite during crustal anatexis: equilibrium and kinetic considerations. Geochim Cosmochim Acta 48:1467–1477CrossRef
Metadaten
Titel
Thermometry of Apatite Saturation (The Kozhym Massif, The Subpolar Urals)
verfasst von
Y. Denisova
A. Vikhot
O. Grakova
N. Uljasheva
Copyright-Jahr
2019
DOI
https://doi.org/10.1007/978-3-030-22974-0_57