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Metamorphic dolomitic marble-hosted talc from the Mulvoj area in the Western Pamir Mountains, Tajikistan

Mohssen Moazzen
Mohssen Moazzen
, 
Intizor Silmonov
Intizor Silmonov
 oraz 
Sangin Elnazarov
Sangin Elnazarov
   | 04 sie 2023
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Article Category: Original Paper
Data publikacji: 04 sie 2023
Zakres stron: 31 - 42
Otrzymano: 24 lut 2023
Przyjęty: 12 cze 2023
DOI: https://doi.org/10.2478/mipo-2023-0004
Słowa kluczowe
© 2023 Mohssen Moazzen et al., published by Sciendo
This work is licensed under the Creative Commons Attribution 4.0 International License.

Figure 1.

Geological Map of the Southwestern Pamirs (modified from Vlasov et al. 1991, Schwab et al. 2004 and Angiolini et al. 2013). The study area is indicated by a box.
Geological Map of the Southwestern Pamirs (modified from Vlasov et al. 1991, Schwab et al. 2004 and Angiolini et al. 2013). The study area is indicated by a box.

Figure 2.

Simplified geological map of the Mulvoj area in the Ishkashim district of Tajikistan (Based on Vlasov et al. 1991).
Simplified geological map of the Mulvoj area in the Ishkashim district of Tajikistan (Based on Vlasov et al. 1991).

Figure 3.

Field photos from the metamorphic rocks in the Mulvoj area. (A) Dolomitic marbles within the gneiss and schist. (B) Large open fold in the metamorphic rocks. (C) Tight folds in gneiss. (D) Tremolite along with carbonate in the dolomitic marble. (E) Rhombohedral pure calcite. (F) Talc in the Mulvoj mine site. (G) and (H) Remaining of old mining metal zip-lines and pillars.
Field photos from the metamorphic rocks in the Mulvoj area. (A) Dolomitic marbles within the gneiss and schist. (B) Large open fold in the metamorphic rocks. (C) Tight folds in gneiss. (D) Tremolite along with carbonate in the dolomitic marble. (E) Rhombohedral pure calcite. (F) Talc in the Mulvoj mine site. (G) and (H) Remaining of old mining metal zip-lines and pillars.

Figure 4.

Microscopic photos from different rock types in the Mulvoj area. (A) Dolomite with minor quartz. (B) dolomite, opaque minerals and idioblastic amphibole (tremolite) in a metamorphic dolostone. (C) Relatively large titanite in textural equilibrium with dolomite. (D) Talc sample with minor calcite.
Microscopic photos from different rock types in the Mulvoj area. (A) Dolomite with minor quartz. (B) dolomite, opaque minerals and idioblastic amphibole (tremolite) in a metamorphic dolostone. (C) Relatively large titanite in textural equilibrium with dolomite. (D) Talc sample with minor calcite.

Figure 5.

(A) XRD pattern for the studied talc sample. The vertical axis shows the intensity of peaks (proportional to the amount of the mineral phase in the studied sample) and the horizontal axis shows the 2Θ angle of the X-ray diffraction, which is indicative of the mineral phase. The sample is composed almost entirely from talc. (b) Classification of Mulvoj talc based on chlorite and carbonate content. Some talc occurrences are shown for comparison (Afghanistan from Tahir et al. 2018; Trimouns, France from Boutin et al. 2016; Montana, USA from Anderson et al., 1990; Austria, from Prochaska, 1989, Finland from GTK. www.gtk.fi).
(A) XRD pattern for the studied talc sample. The vertical axis shows the intensity of peaks (proportional to the amount of the mineral phase in the studied sample) and the horizontal axis shows the 2Θ angle of the X-ray diffraction, which is indicative of the mineral phase. The sample is composed almost entirely from talc. (b) Classification of Mulvoj talc based on chlorite and carbonate content. Some talc occurrences are shown for comparison (Afghanistan from Tahir et al. 2018; Trimouns, France from Boutin et al. 2016; Montana, USA from Anderson et al., 1990; Austria, from Prochaska, 1989, Finland from GTK. www.gtk.fi).

Figure 6.

Al2O3-Fe2O3(T)-MgO diagram classifies the Mulvoj talc as Mg-rich talc with very small Fe and Al content.
Al2O3-Fe2O3(T)-MgO diagram classifies the Mulvoj talc as Mg-rich talc with very small Fe and Al content.

Figure 7.

(A) Selected elements concentration in the Mulvoj talc samples normalized to the chondrite values (McDonough, Sun 1995). (B) Elements concentration patterns normalized to the upper continental crust values (Taylor, McLennan 1985). Peridotite-related samples from Turkey (Yalçin, Bozkaya 2006) and Poland (Gil et al. 2022) are shown for comparison.
(A) Selected elements concentration in the Mulvoj talc samples normalized to the chondrite values (McDonough, Sun 1995). (B) Elements concentration patterns normalized to the upper continental crust values (Taylor, McLennan 1985). Peridotite-related samples from Turkey (Yalçin, Bozkaya 2006) and Poland (Gil et al. 2022) are shown for comparison.

Figure 8.

Phase relations for the studied rock samples in the CMSH-CO2 compatibility diagrams with H2O and CO2 as the excess phases. Tie lines define the mineral reactions. (A): Dol+Qtz assemblage, (B): Tlc+Cal±Qtz assemblage (C): Tr-forming reaction.
Phase relations for the studied rock samples in the CMSH-CO2 compatibility diagrams with H2O and CO2 as the excess phases. Tie lines define the mineral reactions. (A): Dol+Qtz assemblage, (B): Tlc+Cal±Qtz assemblage (C): Tr-forming reaction.

Figure 9.

Temperature-XCO2 diagram for talc formation in the siliceous system with binary H2O-CO2 fluid (Tahir et al. 2018). Stability field for talc + calcite and talc + calcite + tremolite are indicated.
Temperature-XCO2 diagram for talc formation in the siliceous system with binary H2O-CO2 fluid (Tahir et al. 2018). Stability field for talc + calcite and talc + calcite + tremolite are indicated.

Major oxides of the studied samples by XRF (wt%).

Sample No. Detection MVJ1 MVJ2 MVJ3 MVJ4 MVJ5 MVJ6
Rock type Limit (wt %) Talc Talc Talc Talc Talc Marble
SiO2 0.05 60.76 61.07 60.41 59.73 60.12 3.21
TiO2 0.05 0.08 0.08 0.07 0.07 0.08 <0.05
Al2O3 0.05 1.35 1.26 1.14 1.14 1.18 1.28
BaO 0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05
CaO 0.05 0.19 0.12 0.14 0.19 0.18 29.07
Fe2O3* 0.05 0.64 0.71 0.75 0.61 0.59 0.62
K2O 0.05 0.31 0.32 0.30 0.29 0.31 <0.05
MgO 0.05 32.29 33.21 31.98 32.55 32.64 20.76
MnO 0.05 <0.05 <0.05 <0.05 <0.05 <0.05 0.17
Na2O 0.05 0.27 0.22 0.30 0.27 0.29 0.19
P2O5 0.05 <0.05 <0.05 0.06 <0.05 <0.05 0.09
SO3 0.05 <0.05 <0.05 <0.05 <0.05 <0.05 <0.05
Total - 95.89 96.99 95.15 94.85 95.39 55.39

Trace and rare earth element (REE) composition of the analysed talc samples by ICP-MS; all in ppm.

Sample DL* MVJ1 MVJ2 MVJ3 Sample DL MVJ1 MVJ2 MVJ3
Ag 0.5 <0.5 <0.5 <0.5 Pb 1 4 4 4
As 5 1.5 1.5 1.4 Sb 5 0.88 0.79 0.86
Be 1 <1 <1 <1 Sc 0.5 0.8 0.8 0.7
Cd 0.1 0.35 0.34 0.35 Sr 2 6 6 6
Ce 1 1 1 1 Th 5 <5 <5 <5
Co 1 1 <1 1 U 5 <5 <5 <5
Cr 1 <1 <1 <1 V 1 12 12 11
Cu 1 3 2 2 Y 0.5 <0.5 <0.5 <0.5
La 1 1 1 1 Yb 0.2 0.2 0.2 0.2
Li 1 16 17 16 Zn 1 <1 <1 <1
Mo 0.5 0.55 0.53 0.55 Zr 5 <5 <5 <5
Ni 1 11 9 9          
eISSN:
1899-8526
Język:
Angielski
Częstotliwość wydawania:
Volume Open
Dziedziny czasopisma:
Geosciences, Geophysics, other
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