Geology, mineralogy and ore fluid characteristics of the Masjed Daghi gold bearing veins system, NW Iran

زمین شناسی اقتصادی

Article 13, Volume 9, Issue 2 - Serial Number 17, November 2017, Pages 561-586   

Document Type: Research Article

DOI: 10.22067/econg.v9i2.51493

Authors

Susan Ebrahimi^{* 1}; Saeed Alirezaei²; Yuanming Pan³; Behzad Mohammadi⁴

¹Shahrood University of Technology

²Shahid Beheshti

³Saskatchewan

⁴Geological Survey of Iran

Abstract

Introduction
The Masjed- Daghi gold deposit lies in an area of widespread Cenozoic volcanic and plutonic rocks at the intersection of the Alborz- Azarbaijan and Urumieh- Dokhtar belts. The area was covered by a detailed exploration program, including geological maps at 1:1,000 scales (~8 km²), several hundred meters of trenches and systematic sampling for Au, Ag, Pb, Zn, Cu, As, Hg analysis, and 16 diamond drill holes at a total of 1200 meters (Mohammadi et al, 2005). The vein type gold deposit in Masjed- Daghi is closely associated with a porphyry type Cu-Au deposit.
Our study focuses on the gold bearing veins system in an attempt to understand the characteristics of ore fluids and mechanisms of ore formation, and to develop exploration criteria for Masjed Daghi and similar occurrences in Alborz and other Cenozoic magmatic assemblages in Iran.

Materials and methods
Various rock types, alteration assemblages and mineral parageneses were characterized by transmitting and reflected light microscopy, X-ray diffraction (XRD) and electron microprobe analysis. Microprobe analyses were performed using a JEOL 8600 Superprobe electron microprobe at Saskatchewan University. Operating conditions were an accelerating voltage of 15 kV and a beam current of 50 nA.
Representative samples from drill holes were selected for fluid inclusion studies. Fluid inclusion data were obtained using a fluid Inc. adapted USGS gas flow heating and freezing system at the Department of Geological Science at the University of Saskatchewan, Canada.
To investigate the source of ore fluids, representative sulfidic samples from drill holes were selected for sulfur isotope studies. Isotopic analyses were performed using a Thermo Finnigan DeltaPlus at the G.G. Hatch Stable Isotope Laboratories, University of Ottawa. The standard error of analyses is less than ±0.1 per mil.

Results
Auriferous quartz veins in Masjed- Daghi are associated with porphyry style mineralization. Various alteration assemblages including argillic, silicic, potassic, phyllic, and propylitic occur in the district (Emamalipour et al., 2010). The auriferous quartz veins are hosted by silicified and kaolinitized volcanic rocks, dominated by trachyandesite. The mean grade of Cu is 0.15% the gold assay varies from

Keywords

Masjed Daghi; Epithermal Gold; Porphyry; Arasbaran; Iran

References

Abdollahi, M.R., Hosseini, M. and Eftekharnejad, J., 1996. Geological map of Julfa, scale 1:100000. Geological Survey of Iran. (in Persian with English abstract)

Adeli, Z., Rasa, I. and Darvishzadeh, A., 2013. Geochemistry and origin of Haftcheshmeh Cu- Porphyry deposit magma, east Azerbaijan, Iran. Scientific Quartery Journal of Geoscience, 23(90): 199-208. (in Persian with English abstract)

Akbarpour, A., Rasa, I., Mehrpartou, M. and Mohammadi, B., 2003. Gold mineralization in Masjeddahji area. Scientific Quartery Journal of Geoscience, 11(62): 2-10. (in Persian with English abstract)

Alavi, M., 1991. Tectonic map of the Middle East, scale 1: 5, 000, 000. Geological Survey of Iran.

Albinson, T., Norman, D.I., Cole, D. and Chomiak, B., 2001. Control on formation of low- sulfidation epithermal deposits in Mexico: Constrain from fluid inclusion and stable isotope data. In: T. Albinson and C.E. Nelson (Editors), New Mines and Discoveries in Mexico and Central America. Society of Economic Geologists, Special Publication 8, Littleton, pp. 1- 32.

Alirezaei. S., Ebrahimi. S. and Pan. Y., 2008. Fluid inclusion characteristics of epithermal precious metal deposits in the Arasbaran metallogenic zone, Northwestern Iran. 2nd Symposium of Asian Current Research on Fluid Inclusions (ACROFI-2), Indian Institue of Technology, Kharagpur, India.

Arribas, Jr. A., 1995. Characteristics of high- sulfidation epithermal deposits, and their relation to magmatic fluid. In: J.F.H. Thompson (Editor), Magmas. Fluids, and Ore Deposits. Mineralogical Association of Canada Short course, Canada , V. 23, pp. 419-454.

Browne, P.R.L., 1978. Hydrothermal alteration in active geothermal field. Annual Review of Earth and Planetary Sciences, 6(2): 229- 250.

Cook, D.R. and Simmons, S.F., 2000. Characteristics and genesis of epithermal gold deposits. In: S.G. Hagemann and P.E. Brown (Editors), Reviews in Economic Geology. Society of Economic Geologists, Special Publication 13, Littleton, pp. 221- 244.

Deen, J.A., 1990. Hydrothermal ore deposition related to high-level igneious activity: A stable isotope study of the Julcani mining district, Peru. Ph.D. Thesis, University of Colorado, Boulder, Colorado, USA, 120 pp.

Ebrahimi., S., Alirezaei, S. and Pan. Y., 2011. Geological setting, alteration, and fluid Inclusion characteristics of Zaglic and Safikhanloo epithermal Gold prospects, NW Iran. Geological Society of London, Special Publication, 350: 133-147.

Emamalipour, A., Abdoli Eslami, H. and Hajalilou, B., 2010. Geochemistry investigation of hydrothermal alteration related to gold epithermal mineralization in the Masjed Daghi area, west Julfa, northwest Iran. Journal of Economic Geology, 3(2): 199-213. (in Persian with English abstract)

Giggenbach, W.F., 1992. Magma degassing and mineral deposition in hydrothermal systems along convergent plate boundries. Economic Geology, 87(8): 1927-1944.

Hassanpour, Sh., Alirezaei, S., Selby, D. and Sergeev, S., 2015. SHRIMP zircon U-Pb and biotite and hornblende Ar-Ar geochronology of Sungun, Haftcheshmeh, Kighal, and Niaz porphyry Cu-Mo systems: evidence for early Miocene porphyry – style mineralization in northwest Iran. International Journal of Earth Sciences, 104(1): 45-59.

Haghighi, E., Alirezaei, S. and Ashrafpour, E., 2013. Mineralization, alteration and ore fluid characteristic in Cheshmeh hafez base and precious metals deposit, Toroud- Chahshirin range, north central Iran. Schientific Quarterly Journal of Geosciences, 22(88): 99-110. (in Persian with English abstract)

Hedenquist, J.W., Arribas, A. and Gozales-Urien, E., 2000. Exploration for epithermal gold deposits. In: S.G. Hagemann and P.E. Brown (Editors), Reviews in Economic Geology. Society of Economic Geologists, Special Publication 13, Littleton, pp. 245- 277.

Heinrich, C.A., 2005. The physical and chemical evolution of low- salinity magmatic fluids at the porphyry to epithermal transition: a thermodynamic study. Mineralium Deposita, 39(8): 864-869.

Hoefs, J., 2004. Stable isotope geochemistry. Springer –Verlog, Berlin,170 pp.

John, D.A., Garside, L.J. and Wallace, A.R., 1999. Magmatic and tectonic setting of late Cenozoic epithermal gold – silver deposits on northern Nevada, with an emphasis on the Pah Rah and Virginia ranges and the northern Nevada rift. In: J.A. Kisiz, (Editor), Low -sulfidation gold deposits in norther Nevada. V.29. Geological Society of Nevada, Special Publication, pp. 65-158.

Karimzadeh Somarin, A., 2004. Geochemical effects of endosakarn formation in the Mazraeh Cu-Fe skarn deposit in northwestern Iran. Geochemistry Exploration Environment Analysis, 4(2): 307-315.

Karimzadeh Somarin, A. and Hosseinzadeh, G., 2002. Mineralogy of the Anjerd skarn deposit, Ahar region, NW Iran. International Mineralogical Association, Edinburgh, Scotland, 271 pp.

Karimzadeh Somarin, A., Moayyed, M. and Hosseinzadeh, G., 2002. Ore mineralization in the Sonajil porphyry copper deposit, Herris region, NW Iran. International Mineralogical Association, Edinburgh, Scotland, 271 pp.

Li, Y.B. and Liu, J.M., 2006. Calculation of sulfur isotope fractionation in sulfides. Geochemica of Casmocemica Acta, 70(6): 1789-1795.

Mandeville, C.W., Webster, J., Tappen, Ch., Taylor, B., Timbal, A., Sasaki, A., Hauri, E. and Bacon, C.R, 2009. Stable isotope and petrologic evidence for open- system degassing during the climactic and pre-climatic eruptions of Mt. Mazama, Crater Lake, Oregon. Geochimica et Cosmochimica Acta, 73(8): 2978-3012.

Mehrpartou, M., 1993. Contribution to the geology, geochemistry, ore genesis and fluid inclusion investigations on Sungun Cu- Mo porphyry deposit (North- West of Iran). Unpublish Ph.D. Thesis, Hamburg University, Hamburg, Germany, 150 pp.

Mohammadi, B., Aliakbari, H., Fard., M. and Samaee, A., 2005. Geology and drilling report of Masjed Daghi area (scale 1:1000). Geological Survey of Iran, Tehran, Report 340, 130 pp. (in Persian)

Mohammadi, B., Bayaz, A. and Mehrpartou, M., 2000. Gold exploration in the Safikhanlou and Youseflou (Zaglic), SE Ahar. Geological Survey of Iran, Tehran, Report 231, 80 pp. (in Persian)

Mokhtari, A.A., Yarmohammadi, A., Abedian, N., Borna, B. and Eshghabadi, M., 2007. Polymetal exploration in the Gharechlar- Anigh area. Geological Survey of Iran, Tehran, Report 382, 181 pp. (in Persian)

Nabavi, M.H., 1976. An Introduction to Geology of Iran. Geological Survey of Iran, Tehan, 109 pp. (in Persian)

NICOCO, 2009. Geology and drilling report of the Masjed Daghi area. National Iranian Copper Company, Report 243, 115 pp. (in Persian)

Ohmoto, H., 1986. Stable isotope geochemistry of ore deposits. Reviews in Mineralogy and Geochemistry, 16(2): 491-559.

Ohmoto, H. and Goldhaber, M.B., 1997. Sulfur and carbon isotopes. In: H.L. Barnes (Editor), Geochemistry of hydrothermal ore deposits. John Wiley and Sons, New York, pp. 509-567.

Pournik, P., 2006. Gold exploration in the Sharafabad area, NW Varzaghan. Geological Survey of Iran, Tehran, Report 320, 170 pp. (in Persian)

Roedder, E., 1984. Fluid inclusions: Reviews in mineralogy. V. 12. Mineralogical Society of America, Virginia, USA, 646 pp.

Rye, R.O., 1993. The evolution of magmatic fluids in the epithermal environment: The stable isotope perspective. Economic Geology, 88(3): 733-753.

Seward, T.M., 1973. Thio complexes and the transport of gold in hydrothermal ore solutions. Geochemica et Cosmochimica Acta, 37(2): 370-399.

Seward, T.M. and Barnes, H.L., 1997. Metal transport by hydrothermal are fluid. In: H.L. Barnes (Editor), Geochemistry of Hydrothermal ore deposits. John Wiley and Sons, New York, pp. 435-486.

Sheikh, S., Calagari, A.A. and Abedini, A., 2010. The mineralogy of alteration systems in Masjeddaghi, east of Jolfa, east Azerbaijan Province. Iranian Journal of Crystalography and Mineralogy, 17(4): 579-590 pp. (in Persian with English abstract)

Sillitoe, R.H., 1989. Gold deposits in the western pacific island arcs: The magmatic connection. Economic Geology, Monograph, 6(2): 274-291.

White, N.C. and Hedenquist, J.W., 1990. Epithermal environmens and styles of mineralization: variations and their causes, and guidelines for exploration. Journal of Geochemical Exploration, 36(3): 445-474.

Whitney, D.L. and Evans, B.W., 2010. Abbreviations for names of roch-forming minerals. American Mineralogist, 95(2): 185-187.

Yaddollahi, R., Kananian, A., Maanijou, M., Sarjoghian, F. and Hassanpour, Sh., 2011. Adakiti magmatism in Masjeddaghi area, Julfa, East Azarbaijan. Iranian Journal of Crystallography and Mineralogy, 20(2): 297-320. (in Persian with English abstract)

Zanoozi, R., 2006. Mineralogy and genesis of the gold mineralization in the Masjed Daghi area. M.Sc. Thesis, Islamic Azad University, Science and Research Branch, Tehran, Iran, 134 pp. (in Persian with English abstract)