Document Type : Original Research Paper

Authors

1 Ph.D. Student, Department of Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran

2 Assistant Professor, Department of Geology, Shiraz Branch, Islamic Azad University, Shiraz, Iran

3 Associate Professor, Department of Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran

Abstract

Dehkooye salt dome is located 30 km northeast of Lar in Fars province, Iran. The salt dome occurred in Zagros folded zone where infracambrian thick evaporate strata (Hormoz series) intruded Cenozoic sedimentary rocks. Core of the dome mainly made up of salt and gypsum and overlain by marl, gypsum, limestone, and dolomitic formations. Besides primary stratiform mineralization, epigenetic iron and copper mineralization occurred mostly within dolomitic lime stone members in the cap rock of the salt dome in Hormoz Formation. Ore mineralogy is simple and includes hematite, minor goethite, and sparse occurrence of magnetite. Chalcopyrite is evident as minor phase. Samples for fluid inclusion studies were collected from sulfide-bearing quartz veins and veinlets. According to homogenization temperature (Th: 172-374 ° C with average 374° C), which in fact represents the boiling point of the irrigation solution, indicate the epithermal to the beginning of hypothermal conditions and the mean of the beginning of the mesothermal. The depth formation of deposit was between 50 to 1500 meters and an average of about 200 meters. The hydrothermal solutions forming the ore deposit, due to their high salinity, have the origin of magmatic brine that have been displaced because of low density and tectonic pressures. This solutions have climbed upwards along faults and fractures and after being mixed with meteoric waters, epigenetic mineralization is created.

Keywords

Main Subjects

References
Ahmadzadeh Heravi, M., Houshmandzadeh, A. and Nabavi, M. H., 1990- New Concepts of Hormuz Formation Stratigraphy and The Problem of Salt Diapirism in South Iran, Symposium in Southern Iran, A. A. P. G. Bull., Vol..58, No. 9, Pp. 1758- 1770.
Ala, M. A., 1974- Salt Diapirism in Southern Iran. AA PG Bull. Vol. 58, PP. 1758-1770.
Arian, M. and Noroozpour, H., 2015- Tectonic Geomorphology of Iran’s Salt Structures, Open Journal of Geology, 5, 61-72.
Bakker, R. J., 1997- Clathrates: Computer programs to calculate fluid inclusion V-X properties using clathrate melting temperatures. Computers and Geosciences, V. 23, 1- 18.
Bakker, R. J., 2003- Computer programs for analysis of fluid inclusion data and for modelling bulk fluid properties: Chemical Geology 194 , 3- 23.
Best, M. G., 1982- Igneous and metamorphic petrology,New York: W. H. Freemanand company, 630p.
Bodnar, R., 1983- A metod of calculating fluid inclusion volumes based on vapor bubble diameters and PV-T-X properties of inclusion fluid. Economic Geology 78: 535-542.
Brown, P. E, 1989- FLINCOR: A microcomputer program for the reduction and investigation of fluid-inclusion data, American Mineralogist, V. 74, p. 1390-1393.
Clynne, M. A. and Potter, R. W., 1977- Freezing point de-pression of synthetic brines.Geol. Soc. Am., Abstr. Pro-grams 9, 30.
Darvishzadeh, A., 1990- Geological features Infracambrian Persian Gulf salts. Proceedings of the Symposium diapirism with special regard to Iran.
Harrison J. V., 1930- The geology of some salt plugs in Laritsan, South Persia, Geol. Soc. London, Quart, Jour., 86, 465-522.
Hass, J. L., 1971- The effect of salinity on the maximum thermal gradient of a hydrothermal system at hydrostatic pressure, Economic Geology, V. 66, p. 940- 946.
Henley, R. W. and McNabb, A., 1978- Magmatic vapor plumes and ground-water interactions in porphyry copper emplacement: Economic Geology, v. 73, p. 1-20.
Kesler, S. E., 2005- Ore-forming fluids: Elements, v. 1, p. 13-18, doi: 10.2113/gselements.1.1.13.
Moore, J. N., Nomian, D. I., Kennedy, B. M. and Adams, M. C., 1997- Origin and chemical evoiution of The Geysers, california. hyrothermal fluids: Implications from fluid inclusion gas compositions. Geotherm. Resources Clouncil Trans. 21, 635-64 1.
Oberin, C. A., 1957- Salt diapirism in South Persia", Geologie eu mijnbouw, 1 , 212- 238.
Pirajno, F., 2009- Hydrothermal processes and mineral systems: Springer, New York, 1273p.
Player, R. A.,1969- The Hormuz Salt Plugs of southern Iran. MS, PhD. Thesis, 300 pp. Reading Univ. Reading.
Roedder, E., 1979- Fluid inclusions as samples of ore fluids: In H. L. Barnes (Ed), Geochemistry of Hydrothermal Ore deposits: John Wiley and Sons, p. 684- 737.
Roedder, E., 1984- Fluid inclusion. review in mineralogy. Mineralogical Society of America, Book Crafters, Inc., Chelsea, Michigan,644 P.
Roedder, E., 1958- Technique for the extraction and partial chemical analysis of fluid filled inclusion from minerals.econ.geol.53,235-269.
Shepherd, T., Rankin, A. H. and Alderton, D. H. M., 1985- A practical guide to fluid inclusion studies: Blackie, USA Champan and Hall, New York, 239p.
Sterner, S. M. and Bonder, R. J.,1984- Synthetic fluid inclusions in natural quartz. I.Compositional types synthesized and applications to experimental geochemistry, Geochim et Cosmochim.Acta,V.48, p. 2659-2668.
Stocklin J., 1972- Iran Central, septentrional et Oriental. Lexique stratigraphique International", Ш, Fasicule, Centre National de rechercher Scientifique, Paris 9b, Iran , 1-283.
Sun, T., Zhang D. B. and Wentzcovitctch, R. M., 2013- Dynamical stabilization of cubic CaSiO3 perovskite at high temperatures and pressures, Abstract in International Conference on 3-D Wave Propagation and Imaging through the Earth’s Interior ,Wuhan, China.
Talbot C., 2009- potash in salt mushroom at Hormoz strait, Iran, Journal of ore geology review 35, 317-332.
Talbot, C. J. and Alavi, M., 1996- The Past of Future Syntax is Across The Zagros. ‘‘In: Salt Tectonics. (Edited by Aesop, G. I. Blundell, D. J. and Davison, I.), Geol. Soc. Spec. Pub. No. 10. 10, 89-109.
Walshe, J. L. and Hobbs, B. E., 1999- Hydrothermal systems, giant ore deposits and a new paradigm for predictive mineral exploration. CSIRO Exploration and Mining Research Reviews 30-31.
Waltham, T., 2008- Salt terrains of Iran, Geology today, vol. 24 ,No. 5, 188-194.
Wilkinson, J. J., 2001, Fluid inclusions in hydrothermal ore deposits: Lithos, V.25, p. 229- 272.
Yoo, B. C., Brown, P. E. and White, N. C., 2011- Hydrothermal fluid characteristics and genesis of Cu quartz veins in the Hwanggangri metallogenic district, Republic of Korea: mineralogy, fluid inclusion and stable isotope studies. Journal of Geochemical Exploration 110 (3), 245- 259.
Zhang, Y. G. and Frantz, J. D., 1987- Determination of the homogenization temperatures and densities of supercritical fluids in the system NaCl- KCl-CaCl2-H2O using synthetic fluid inclusions. Chem. Geol., 64, 335-350.