Is skarnization the cause of mineralization? a case study, Sanandaj Sirjan zone, west Iran

Subject Areas : Economic Geology

Hossein  Moinevaziri ¹ (Department of Geology, Kharazmi University, Tehran, Iran)
Hossein  Azizi ² (Department of Mining, Faculty of Engineering, University of Kurdistan, Sanandaj, Iran)

Received: 2022-09-29 Accepted : 2022-10-28 Published : 2023-01-01

Keywords: Hydrothermal Fluids, Sanandaj Sirjan zone, Iron ore deposits, magma reaction,

Abstract :

The skarn type mineralization has long been accepted as an interaction of magma and the host carbonate rocks. Most researchers have considered the iron deposits in the northern Sanandaj Sirjan zone (Kurdistan area) as skarn-type mineralization which has been generated during the injection of the granitoid bodies into the host carbonate. The calculation of normative minerals from the mixed composition of granite and host dolomite shows that normal reactions cannot produce a large volume of Fe or Mn mineralization in northwest Iran as skarn deposits. One of the iron deposits which is known as the Saheb skarn deposit, 33 km east of Saqqez, NW Iran was selected for this study. The normative minerals from this deposit were calculated for a mixed composition based on 100 grams of Saheb granite and 50 grams of host dolomite. The results show the iron oxides don’t extend into the last stages of magma crystallization to provide the Fe-Mn mineralization in the host rocks. Occasionally, in the contacts of plutons, various types of mineralization appear, however, they are not the result of a magma and carbonate interaction. They are probably the results of the hydrothermal fluids in the late stages of magma crystallization. The magma fluids and fossil water in the host rocks that were heated during the magma injection, leaching the Fe-Mn from the granitoid bodies and surrounding rocks. As follows, Fe-Mn-rich fluids move towards fractures and caves, finally precipitating as ore deposits into the host rocks. The skarnization phenomenon causes the reduction of volume due to the release of CO2 gas and also the crystallization of relatively dense minerals such as garnet. This process, make a partiality space for the precipitation of Fe-Mn-rich hydrothermal fluids. Our findings show that skarnization only makes space for the precipitation of the Fe from the hydrothermal fluids.

References:

1. Ahmadi-Khalaj A, Esmaeily D, Valizadeh MV, Rahimpour-Bonab H (2007) Petrology and Geochemistry of the Granitoid Complex of Boroujerd, Sanandaj-Sirjan Zone, Western Iran, Journal of Asian Earth Sciences 29: 859-877.


2. Azizi   H, Asaharab Y, Mehrabi B, Chungd SL (2011) Geochronological and geochemical constraints on the petrogenesis of high-K granite from the Suffi abad  Area, Sanandaj-Sirjan Zone, NW Iran, Chemie der Erde 71(4): 363-376.


3. Azizi H, Stern RJ (2019) Jurassic igneous rocks of the central Sanandaj–Sirjan zone (Iran), mark a propagating continental rift, not a magmatic arc, Terra Nova 31(5): 415–423.


4. Babaki A. Aftabi A J (2006) Investigation on the Model of Iron Mineralization at Gol Gohar Iron Deposit, Sirjan-Kerman, Geosciences Scientific Quarterly Journal 61: 40-59 (in Persian).


5. Baghban S, Zandi Z, Lentz D ( 2021) Formation and evolution of the calcic-magnesian Saheb Fe (Cu) skarn deposit from the Sanandaj-Sirjan Belt, NW Iran: Evidence for multistage boiling in episodes of magnetite saturation, Journal of Geochemical exploration  226: 106781.


6. Baharifar AA, Moinevaziri H, BellonH, Piqué A (2004) The crystalline complexes of Hamadan (Sanandaj-Sirjan zone, western Iran): metasedimentary Mesozoic sequences affected by Late Cretaceous tectono-metamorphic and plutonic events, Comptes Rendus Geoscience 336(16): 1443-1452.


7. Berberian F, Berberian M (1981) Tectono-plutonic episodes in Iran, Zagros, Hindu Kush, Himalaya Geodynamic Evolution 3; 5- 32.


8. Berthier F, Billault JP, Halbronn B Maurizot P (1974) Etudestratigraphique, petrologique et structural de la region de Korramabad (Zagros, Iran), Doctoral dissertation, Université de Grenoble 282 p.


9. Braud J, Bellon H (1971) Donnees nouvelles sur le demaine metamorphique du Zagros (zone de Sanandah- Sirjan) au niveau de Kermanshah- Hamadan (Iran): nature age et interpretation des séries métamorphiques et des ihtrusions: evolution structurale, Rapport Universite Paris- Sud: 1-20.


10. Förster H, Knittel U (1979) Petrographic observations on a magnetite deposit at Mishdovan, central Iran, Economic Geology 74(6):1485-9.


11. Ghorbani M (1993) Metallogeny of Iran iron deposits. Unpublished Internal Report, Shahid Beheshti University, Tehran, Iran.


12. Ghorbani M (2013) The economic geology of Iran, Mineral deposits and natural resources, Springer 1-450.


13. Haghipour A (1974) Etude géologique de la région de Biabanak-Bafq (Iran central): Pétrologie et tectonique du socle précambrien et de sa couverture, Doctoral dissertation, Université Scientifique et Médicale de Grenoble.


14. Kazemirad M (2010) Mineralogy, geometry, geochemistry and genesis of Heneshk, Goli and Cheshmeh Esi FeMn deposits in the northeast Safa Shahr (Fars Province), Unpublished M.Sc. thesis, Tarbiat Modares University, Tehran, Iran, 225 p.


15. Massoudi F, Yardley BWD, Cliff RA (2002) Rb-Sr geochronology of pegmatites, plutonic rocks and a hornfels in the region southwest of Arak, Iran. Journal of sciences, Islamic Republicof Iran 13(3): 249-254.


16.  Mohajjel M, Fergusson CL, Sahandi MR (2003) Cretaceous–Tertiary convergence and continental collision, Sanandaj-Sirjan Zone, Western Iran, Journal of Asian Earth Sciences 21: 397- 412.


17. Moinevaziri H (1985) Magmatisme tértiaire et quatérnaire en Iran. Thèse d’ Éta. Université Paris-Sud, Orsay, 260 p.


18. Moinevaziri H (2019) Manganese mine of Tawakalan in Kurdistan - Iran: A rare Mn mineralization process, Iranian Society of Crystallography and Mineralogy 27(2): 411-422.


19. Moinevaziri H, Azizi H, Mehrabi B, Izadi F (2008) Oligocene magmatism in the Zagros Thrust Zone (Sahneh- Marivan area): Evidence for the Neotethyan subduction occurrence in the Paleogene, Journal of sciences, Tehran University 34(1): 113-122 (in persan).


20. Moinevaziri H, Mirza T (2021) Characteritics and origin of iron mineralization in northern Sanandaj- Sirjan zone (Iran- Iraq). Iraqi Bulletin of Geology and Mining 17: 43-58.


21. Motavalli K (2004) Mineralogy, geochemistry and genesis of Khosro Abad and Tekye Bala iron deposits in the northeast Songhor. Unpublished M.Sc thesis, Tarbiat Modares University, Tehran, Iran, 210 p.


22. Nabatian GH, Rastad E, Neubauer F, Honarmand M, Ghaderi M (2015) Iron and Fe- Mn mineralization in Iran: implications for Tethyan metallogeny, Australian Journal of Earth Sciences 62(2): 21-241.


23. Sartipi AH, Haghfarshi E, Sahandi MR (2006) Geological quadrangle map of Sanandaj, 1/100000, Geological Survey and Mineral exploration of Iran.


24. Sepahi AA, Shahbazi H, Siebel W, Ranin, A (2014) Geochronology of plutonic rocks from the Sanandaj- Sirjan zone, Iran, and new zircon and titanite U-Th-Pb ages for granitoid from the Marivan pluton, Geochronolometria 41(3): 207-215.


25. Shabazi S (2010) Mineralogy, geochemistry and genesis of Bashkand iron deposit, southwest of Soltanieh. Unpublished M.Sc. thesis, Tarbiat Modares University, Tehran, Iran, 220 p.


26. Stocklin J (1968) Structural history and tectonics of Iran: a review, AAPG bulletin 52(7):1229-1258.


27. Tavakoli (2003) Mineralogy, geochemistry and source of iron deposits NW of Hamedan. Unpublished M.Sc. thesis, Tarbiat Modares University, Tehran, Iran, 157 p.


28. Valizadeh MV, Cantagrel JM (1975) Premieres donnees radiometriques (K-Ar et Rb-Sr) sur les micas du complexe magmatique du mont Alvand, pres de Hamadan (Iran occidental), 281:1083-1086.


29. Zahedi M, Hajian J (1985) Geological quadrangle map of Sanandaj 1/250000. Geological Survey & Mineral exploration of Iran.


30. Zandi Z, Jafrirad A, Gourabjeripour A, Lotfi M, (2018) Mineralization, Mineralogy, and Geochemistry of Saheb Fe-Cu Deposit of Saqqez (Kurdistan), NW Iran. Open Journal of Geology 31(8): 514-528