Prognosis of of gold mineralization phases by multifractal modeling in the Zehabad epithermal deposit, NW Iran

Subject Areas : Mineralogy

سمیه  شهبازی ¹ (گروه زمین‌شناسی اقتصادی، دانشگاه تربیت مدرس، تهران، ایران)
مجید  قادری ² (گروه زمین‌شناسی اقتصادی، دانشگاه تربیت مدرس، تهران، ایران)
Peyman  Afzal ³ (Department of Petroleum and Mining Engineering, South Tehran Branch, Islamic Azad University, Tehran, Iran)

Received: 2018-12-17 Accepted : 2020-10-08 Published : 2021-01-01

Keywords: Zehabad, Gold mineralization phases, Epithermal, Concentration-Number (C–N) fractal method,

Abstract :

Concentration–Number (C–N) fractal method has been used for determining and separating mineralization phases based on surface lithogeochemical Au, Ag, Cu, Pb, Zn, As and Sb data in the Zehabad epithermal deposit, NW Iran. Five mineralization phases are demonstrated by multifractal modeling for the mentioned elements correlating with geological studies. The extreme phase of Au mineralization is higher than 7.9 ppm, which is correlated with hematite deposition in silicic veins and veinlets, whereas Ag (˃79.43 ppm), Cu (˃15.85%), Pb (˃63.1%), Zn (˃11.2%) extreme phases are associated with the main stage sulfidation phases. The results show that Au, Cu, Pb, Zn and Ag have two different mineralization trends based on the multifractal nature in this area. These trends are presented based on oxidic and sulfidic mineralization. According to mineralogical studies, the main stages of mineralization include: 1) formation of chalcopyrite ± sphalerite in silicic veins in sulfidic trend; 2) deposition of native gold and specular hematite in silicic veins in response to boilling, in oxidic trend; 3) next phase of fluid penetration and replacing chalcopyrite by galena, sphalerite and tetrahedrite-tennantite in the sulfide veins, in sulfic trend. Neighbouring copper and silver are due to the formation of tetrahedrite-tennantite solid solution. The obtained results show a positive correlation between mineralization phases and the faults present at the deposit. Moreover, mineralization phases of these elements demonstrate a good correlation with silicification and silicic veins and veinlets.

References:

1. Afzal P, Dadashzadeh Ahari H, Omran NR, Aliyari F (2013) Delineation of gold mineralized zones using concentration–volume fractal model in Qolqoleh gold deposit, NW Iran, Ore Geology Reviews 55: 125–133.


2. Afzal P, Khakzad A, Moarefvand P, Rashidnejad Omran N, Fadakar Alghalandis Y (2011) Delineation of mineralization zones in porphyry Cu deposits by fractal concentration–volume modeling, Geochemical Exploration 108: 220–232.


3. Aghazadeh M, Castro A, Badrzadeh Z, Vogt K, (2011) Post-collisional polycyclic plutonism from the Zagros hinterland. The Shaivar-Dagh plutonic complex Alborz belt, Iran. Geol. Mag. 148, 980–1008.


4. Agterberg FP, Cheng Q, Brown A, Good D (1996) Multifractal modeling of fractures in the Lac du Bonnet batholith, Manitoba, Comput. Geosci 22(5): 497–507.


5. Amin Khorramdasht Exploration Company (2006) Final Report of Technical Services in Zehabad Pb-Zn Deposit. Internal Report. Tehran, Iran: Amin Khorramdasht Exploration Company (in Persian).


6. Asiabanha A, Foden F (2012) Post-collisional transition from an extensional volcano-sedimentary basin to a continental arc in the Alborz ranges, N-Iran. Lithos 148: 98-111.


7. Castro A, Aghazadeh M, Badrzadeh Z, Chichorro M (2013) Late Eocene–Oligocene post-collisional monzonitic intrusions from the Alborz magmatic belt, NW Iran. An example of monzonite magma generation from a metasomatized mantle source, Lithos 180-181: 109–127.


8. Cheng Q, Agterberg FP, Ballantyne SB (1994) The separartion of geochemical anomalies from background by fractal methods, Geochemical Exploration 51: 109–130.


9. Esmaeli M, Lotfi M, Nezafati N (2015) Fluid inclusion and stable isotope study of the Khalyfehlou copper deposit, southeast Zanjan, Iran, Arabian Journal of Geoscience 8 (11): 9625–9633.


10. Hassanpour S, Afzal P (2013) Application of concentration–number (C–N) multifractal modeling for geochemical anomaly separation in Haftcheshmeh porphyry system, NW Iran, Arabian Journal of Geosciences 6(3): 957–970.


11. Khalili H, Afzal P (2018) Application of spectrum-volume fractal modeling for detection of mineralized zones, Journal of Mining & Environment 9(2): 371–378.


12. Kouhestani H, Mokhtari MAA, Chang Z, Johnson CA (2018) Intermediate sulfidation type base metal mineralization at Aliabad-Khanchy, Tarom-Hashtjin metallogenic belt, NW Iran, Ore Geology Reviews 93: 512–521.


13. Li C, Ma T, Shi J (2003) Application of a fractal method relating concentrations and distances for separation of geochemical anomalies from background, Geochemical Exploration 77: 167–175.


14. Mandelbrot BB (1983) The fractal geometry of nature. Freeman, San Francisco.


15. Mehrabi B, Ghasemi M, Goldfarb R, Azizi H, Ganerod M, Marsh E (2016) Mineral assemblages, fluid evolution and genesis of polymetallic epithermal veins, Glojeh district, NW Iran, Ore Geology Reviews 78: 41–57.


16. Mokhtari MAA, Kouhestani H, Pang KN, Chung SL (2018) Age and geochemical constraints on granitoid petrogenesis in the Khorram Darag-Khakriz region (36.5˚N, 48.5˚E), Urumieh-Dokhtar magmatic arc, NW Iran, Geochemistry Symposium, Antalya, Turkey.


17. Nabatian G, Ghaderi M (2014) Mineralogy and geochemistry of rare earth elements in iron oxide - apatite deposits of the Zanjan region, Scientific Quarterly Journal of Geosciences 24(93): 157–170.


18. Nabatian G, Ghaderi M, Corfu F, Honarmand M (2014) Geology, alteration, age, and origin of iron oxide–apatite deposits in Upper Eocene quartz monzonite, Zanjan district, NW Iran, Mineralium Deposita 49(2): 217–234.


19. Nabatian G, Wan B, Honarmand M (2017) Whole rock geochemistry, molybdenite Re-Os geochronology, stable isotope and fluid inclusion investigations of the Siah-Kamar deposit, western Alborz-Azarbayjan: New constrains on the porphyry Mo deposit in Iran, Ore Geology Reviews 91:638-659.


20. Nabavi MH (1976) Introduction to Geology of Iran. Tehran, Iran, Geological Survey of Iran.


21. Rezaeian M, Carter A, Hovius N, Allen M B (2012) Cenozoic exhumation history of the Alborz Mountains, Iran: New constraints from low-temperature chronometry, Tectonics, 31, TC2004.


22. Sim BL, Agterberg FP, Beaudry C (1999) Determining the cutoff between background and relative base metal contamination levels using multifractal methods, Comput. Geosci 25: 1023–1041.


23. Shahbazi S (2020) Geochemistry and genesis of Zehabad Pb-Zn-Au-Ag-Cu polymetallic deposit in NW Iran, P.hd thesis, Tarbiat Modares university, Iran.


24. Shahbazi S, Ghaderi M (2014) Zehabad gold mineralization: an example of epithermal deposits related to high-potassium magmatism in post-subduction extension environment, 18th Symposium of the Geological Society of Iran: 4.


25. Shahbazi S, Ghaderi M, Alfonso P (2019) Mineralogy, alteration, and sulfur isotope geochemistry of the Zehabad intermediate-sulfidation epithermal deposit, NW Iran, Turkish Journal of Earth Sciences 28(6): 882-901.


26. Shahbazi S, Ghaderi, M, Madanipour S (2018) The role of Zanjan-Manjil semi-brittle zone in controlling the Zehabad Pb, Zn, Au, Ag (Cu) mineralization, NW Qazvin, The 36th National and the 3rd National Geosciences Congress, Tehran, Iran.


27. Yasami N, Ghaderi, M, Alfonso P (2018) Sulfur isotope geochemistry of the Chodarchay Cu-Au deposit, Tarom, NW Iran, Neues Jahrbuch für Mineralogie - Abhandlungen 195(2): 101–113.