Journal of Nuclear Science, Engineering and Technology (JONSAT)
In cooperation with the Iranian Nuclear Society

Mineralogy and geochemistry of thorium mineralization in the Chahgaz iron deposit, Bafq district, Central Iran

Document Type : Research Paper

Authors

S. Ziapour 1
D. Esmaeily 1
K. Khoshnoodi 2
S. Niroomand 1

1 Department of Geology, Faculty of Science, University of Tehran, P.O.BOX: 141556455, Tehran– Iran

2 Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, AEOI, P.O.Box:11365-8486, Tehran-Iran

https://doi.org/10.24200/nst.2022.1386
Abstract
The Chahgaz iron deposit (XIV Anomaly) is located in the Bafq mining district in the Central Iranian geostructural zone in Yazd province. The Chahgaz deposit is hosted by Early Cambrian subvolcanic and volcanic rocks that range compositionally from granite to diorite. The field gamma spectrometry, mineralogical and geochemical studies in this deposit indicate that the thorium mineralization is mainly associated with Na-Ca and Mg- alterations, and in minor amount with the magnetite ore. The mineralogical studies by optical and electron microscope (SEM and EPMA) indicate that the main thorium host mineral in the Chahgaz deposit is thorite associated with minor titanite, allanite and zircon. The average contents of Th and ΣREE in the Th-mineralization zone are 450 and 596 ppm, respectively. Thorite is paragenesis with albite, actinolite, tremolite and augite in the Na-Ca alteration zone, and with talc in the Mg- alteration zone. In the Th-bearing iron ore, thorite is paragenesis with magnetite, calcite and apatite mineral assemblage. The similarity in mantle-normalized REE patterns of host rocks and thorium mineralization zone suggests that Th-mineralization is related to Early Cambrian calc-alkaline magmatism in continental-margin arc setting. The occurrence of paragenetic magnetite with thorite and distinct negative Eu anomaly in the thorium mineralization zone can be inferred probably a reduced condition for thorium mineralizing fluids.

Highlights

1. R. Frietsch, J.A. Perdahl, Rare Earth Elements in Apatite and Magnetite in Kirunatype Iron Ores and Some Other Iron Ore Types, Ore Geol. Rev., 9, 489 (1995).

 

2. M.W. Hitzman, In: Hydrothermal Iron Oxide Copper-Gold and Related Deposits: A Global Perspective, Edited by T.M. Porter (PGC Publishing Adelaide Australia), 9-25 (2000).

 

3. P.J. Williams, P.J. Pollard, Australian Proterozoic Iron Oxide-Cu-Au Deposits: Overview with New Metallogenic and Exploration Data from the Cloncurry District, Northwest Queensland, Explor. Min. Geol, 10, 191 (2001).

 

4. H.G. Stosch, et al., Uranium-Lead Ages of Apatite from Iron Oxide Ores of the Bafq District, East-Central Iran, Miner. Depos., 46, 9 (2011).

 

5. L. Corriveau, P. Williams, H. Mumin, In: Exploring for Iron Oxide Copper–Gold Deposits: Canada and Global Analogues, Edited by L. Corriveau, and H. Mumin, (Geological Association of Canada, Short Course Notes), 87-106 (2010).

 

6. M.D. Barton, In: Treatise of Geochemistry, Edited by H. Holland, and K. Turekian (Elsevier, London), 515-536 (2014).

 

7. K. Khoshnoodi, et al., Alkali Metasomatism and Th-REE-Mineralization in the Choghart Deposit, Bafq District, Central Iran, Geol. Croat., 70, 53 (2017).

 

8. H. Förster, A. Jafarzadeh, The Bafg Mining District in Central Iran: a Highly Mineralized Infracambrian Volcanic Field, Econ. Geol., 89, 1697 (1994).

 

9. M. Jami, The University of New South Wales, Ph.D Thesis, (2005).

 

10. F. Daliran, H.G. Stosch, P. Williams, In: Proceedings of the 10th Biennial SGA Meeting, Edited by Williams et al., (Townsville, Australia), 623-625 (2009).

 

11. S. Ziapour, et al., Mineralogy, Geochemistry, and Genesis of the Chahgaz (XIVA Anomaly) Kiruna-Type Iron Oxide-Apatite (IOA) Deposit, Bafq District, Central Iran, Ore Geol. Rev., 128 (2021).

 

12. F. Moore, S. Modabberi, Origin of Choghart Iron Oxide Deposit, Bafq Mining District, Central Iran: New Isotopic and Geochemical Evidence, J. Sci. 14(3), 259 (2003).

 

13. F. Torab, Clausthal University of Technology, Ph.D Thesis, (2008).

 

14. J. Ramezani, R.D. Tucker, The Saghand Region, Central Iran: U-Pb Geochronology, Petrogenesis and Implications for Gondwana Tectonics, Am. J. Sci., 303, 622 (2003).

 

15. N.A. Titayeva, Nuclear geochemistry, 1st Ed. (CRC Press/ Taylor & Francis, London, 1994).

 

16. A. Kontonikas-Charos, C.L. Ciobanu, N.J. Cook, Albitization and Redistribution of REE and Y in IOCG Systems: Insights from Moonta-Wallaroo, Yorke Peninsula, South Australia, J. Lithos. 208-209, 178 (2014).

 

17. B.E. Leake, et al., Nomenclature of Amphiboles: Report of the Subcommittee on Amphiboles of the International Mineralogical Association, Commission on New Minerals and Mineral Names, Am. Mineral., 82, 1019 (1997).

 

18. N. Morimoto, et al., Nomenclature of Pyroxenes, Mineral. Mag., 14, 198 (1988).

 

19. S.S. Sun, W.F. McDonough, In: Magmatism in the Ocean Basins, Edited by A.D. Saunders, and M.J. Norry (Geological Society of London, Special Publication), 313-345 (1989).

 

20. E. Aldanmaz, et al., Petrogenetic Evolution of Late Cenozoic, Post-collision Volcanism in Western Anatolia, Turkey, J. Volcanology and Geothermal Research. 102, 67 (2000).

 

21. A.W. Hofmann, Chemical Differentiation of the Earth: The Relationship Between Mantle, Continental Crust, and Oceanic Crust. J. Earth and Planetary Science Letters. 90, 297 (1988).

 

22. P. Henderson, Raer earth element geochemistry, 1st Ed. (Elsevier Science, 1984).

 

23. H.R. Rollinson, Using Geochemical Data: Evaluation, Presentation and Interpretation, 1st Ed. (Longman, London, 1993).

Keywords

Chahgaz deposit
Bafq mining district
Thorium mineralization
Na-Ca alteration
Mg- alteration
1. R. Frietsch, J.A. Perdahl, Rare Earth Elements in Apatite and Magnetite in Kirunatype Iron Ores and Some Other Iron Ore Types, Ore Geol. Rev., 9, 489 (1995).
 
2. M.W. Hitzman, In: Hydrothermal Iron Oxide Copper-Gold and Related Deposits: A Global Perspective, Edited by T.M. Porter (PGC Publishing Adelaide Australia), 9-25 (2000).
 
3. P.J. Williams, P.J. Pollard, Australian Proterozoic Iron Oxide-Cu-Au Deposits: Overview with New Metallogenic and Exploration Data from the Cloncurry District, Northwest Queensland, Explor. Min. Geol, 10, 191 (2001).
 
4. H.G. Stosch, et al., Uranium-Lead Ages of Apatite from Iron Oxide Ores of the Bafq District, East-Central Iran, Miner. Depos., 46, 9 (2011).
 
5. L. Corriveau, P. Williams, H. Mumin, In: Exploring for Iron Oxide Copper–Gold Deposits: Canada and Global Analogues, Edited by L. Corriveau, and H. Mumin, (Geological Association of Canada, Short Course Notes), 87-106 (2010).
 
6. M.D. Barton, In: Treatise of Geochemistry, Edited by H. Holland, and K. Turekian (Elsevier, London), 515-536 (2014).
 
7. K. Khoshnoodi, et al., Alkali Metasomatism and Th-REE-Mineralization in the Choghart Deposit, Bafq District, Central Iran, Geol. Croat., 70, 53 (2017).
 
8. H. Förster, A. Jafarzadeh, The Bafg Mining District in Central Iran: a Highly Mineralized Infracambrian Volcanic Field, Econ. Geol., 89, 1697 (1994).
 
9. M. Jami, The University of New South Wales, Ph.D Thesis, (2005).
 
10. F. Daliran, H.G. Stosch, P. Williams, In: Proceedings of the 10th Biennial SGA Meeting, Edited by Williams et al., (Townsville, Australia), 623-625 (2009).
 
11. S. Ziapour, et al., Mineralogy, Geochemistry, and Genesis of the Chahgaz (XIVA Anomaly) Kiruna-Type Iron Oxide-Apatite (IOA) Deposit, Bafq District, Central Iran, Ore Geol. Rev., 128 (2021).
 
12. F. Moore, S. Modabberi, Origin of Choghart Iron Oxide Deposit, Bafq Mining District, Central Iran: New Isotopic and Geochemical Evidence, J. Sci. 14(3), 259 (2003).
 
13. F. Torab, Clausthal University of Technology, Ph.D Thesis, (2008).
 
14. J. Ramezani, R.D. Tucker, The Saghand Region, Central Iran: U-Pb Geochronology, Petrogenesis and Implications for Gondwana Tectonics, Am. J. Sci., 303, 622 (2003).
 
15. N.A. Titayeva, Nuclear geochemistry, 1st Ed. (CRC Press/ Taylor & Francis, London, 1994).
 
16. A. Kontonikas-Charos, C.L. Ciobanu, N.J. Cook, Albitization and Redistribution of REE and Y in IOCG Systems: Insights from Moonta-Wallaroo, Yorke Peninsula, South Australia, J. Lithos. 208-209, 178 (2014).
 
17. B.E. Leake, et al., Nomenclature of Amphiboles: Report of the Subcommittee on Amphiboles of the International Mineralogical Association, Commission on New Minerals and Mineral Names, Am. Mineral., 82, 1019 (1997).
 
18. N. Morimoto, et al., Nomenclature of Pyroxenes, Mineral. Mag., 14, 198 (1988).
 
19. S.S. Sun, W.F. McDonough, In: Magmatism in the Ocean Basins, Edited by A.D. Saunders, and M.J. Norry (Geological Society of London, Special Publication), 313-345 (1989).
 
20. E. Aldanmaz, et al., Petrogenetic Evolution of Late Cenozoic, Post-collision Volcanism in Western Anatolia, Turkey, J. Volcanology and Geothermal Research. 102, 67 (2000).
 
21. A.W. Hofmann, Chemical Differentiation of the Earth: The Relationship Between Mantle, Continental Crust, and Oceanic Crust. J. Earth and Planetary Science Letters. 90, 297 (1988).
 
22. P. Henderson, Raer earth element geochemistry, 1st Ed. (Elsevier Science, 1984).
 
23. H.R. Rollinson, Using Geochemical Data: Evaluation, Presentation and Interpretation, 1st Ed. (Longman, London, 1993).

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