Zajkan intermediate-sulfidation epithermal deposit, NW Iran: Mineral paragenesis, fluid inclusion, and oxygen-sulfur isotope

Authors

Hossein Kouhestani¹ , Mir Ali Asghar Mokhtari¹ , Kezhang Qin² , Junxing Zhao²

1. University of Zanjan
2. Institute of Geology and Geophysics, Chinese Academy of Sciences

Conference / event

International Earth Science Colloquium On The Aegean Region, October 2019 (Izmir, Turkey)

Poster summary

Zajkan deposit occurs as quartz-base metal sulfide veins hosted by the Eocene Karaj Formation. Four stages of ore formation are identified at Zajkan. Microthermometric measurements indicate that the veins were formed at temperatures between 217 and 273 °C from fluids with salinities between 1.7 and 6.4 wt.% NaCl equiv. The oxygen isotopic compositions (δ18Owater of +3.7 to +1.1‰) indicate that the ore-forming fluids were mainly derived from magmatic water with the input of meteoric water in the later ore-stages. Sulfur isotopic values of sulfide minerals vary over a narrow range from –5.0 to –0.9‰ (averaging −2.2‰), suggesting that sulfur was derived from a homogeneous magmatic source. The fluid inclusion and stable isotope data indicate that fluid boiling and mixing facilitated hydrothermal alteration and mineralization at Zajkan. Our data suggest that the Zajkan deposit is an intermediate-sulfidation style epithermal mineralization.

Keywords

Fluid inclusion, Stable isotopes, Zajkan

Research areas

Earth Sciences

References

1. Bodnar, R.J., Burnham, C.W., Sterner, S.M., 1985. Synthetic fluid inclusions in natural quartz. III. Determination of phase equilibrium properties in the system H2O–NaCl to 1000 °C and 1500 bars. Geochim. Cosmochim. Acta 49, 1861–1873.
2. Canet, C., Franco, S.I., Prol-Ledesma, R.M., González-Partida, E., Villanueva-Estrada, R.E., 2011. A model of boiling for fluid inclusion studies: Application to the Bolaños Ag–Au–Pb–Zn epithermal deposit, Western Mexico. J. Geochem. Expl. 110, 118–125.
3. Drummond, S.E., Ohmoto, H., 1985. Chemical evolution and mineral deposition in boiling hydrothermal processes in the light of studies in rock-buffered systems; I, iron-copper-zinc-lead sulfide solubility relations. Econ. Geol. 87, 1–22.
4. Fan, H.R., Hu, F.F., Wilde, S.A., Yang, K.F., Jin, C.W., 2011. The Qiyugou gold-bearing breccia pipes, Xiong’ershan region, central China: Fluid-inclusion and stable-isotope evidence for an origin from magmatic fluids. Int. Geol. Rev. 53, 25–45.
5. Goldstein, R.H., 2003. Petrographic analysis of fluid inclusions. In: Samson, I., Anderson, A., Marshall, D. (Eds.), Fluid Inclusions: Analysis and Interpretation. Min. Assoc. of Can. Short Course 32, 9–53.
6. Haas, J.L., 1971. The effect of salinity on the maximum thermal gradient of a hydrothermal system at hydrostatic pressure. Econ. Geol. 66, 940–946.
7. Hedenquist, J.W., Arribas, A.R., Gonzalez-Urien, E., 2000. Exploration for Epithermal Gold Deposits. Rev. Econ. Geol. 13, 245–277.
8. Hoefs, J., 2015. Stable isotope geochemistry. 7th edition. Springer International Publishing, Switzerland.
9. Kouhestani, H., Ghaderi, M., Chang, Z., Zaw, K., 2015. Constraints on the ore fluids in the Chah Zard breccia-hosted epithermal Au-Ag deposit, Iran: Fluid inclusions and stable isotope studies. Ore Geol. Rev. 65, 512–521.
10. Ohmoto, H., Rye, R.O., 1979. Isotope of sulfur and carbon. In: Barnes, H.L. (Ed.), Geochemistry of Hydrothermal ore deposits. John Wiley and Sons, New York, p. 509–567.

Funding

1. Key Laboratory of Mineral Resources, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China (No. KLMR2017-01)
2. Vice Chancellor for Research and Technology, University of Zanjan, Zanjan, Iran

Supplemental files

No data provided

Additional information

Competing interests

No competing interests were disclosed.

Data availability statement

The datasets generated during and / or analyzed during the current study are available from the corresponding author on reasonable request.

Creative Commons license

Copyright © 2024 Kouhestani et al. This is an open access work distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.