Geochemical Investigations of mineralizing fluid, and economic evaluation based on Fluid Inclusion Studies in the Chah-Firuzeh Porphyry Copper Deposit, North of Shahre Babak, Kerman Province

Authors

Department of Mining and Metallugical Engineering, Amirkabir University of Technology, Tehran, Iran

Abstract

The Chah-Firuzeh porphyry copper deposit is located 35 km north of Shahre Babak (Kerman province). It is associated with granodioriteic pluton of Miocene age, which intruded Eocene volcano sedimentary rocks.  Copper mineralization was accompanied by both potassic and phyllic alterations.  Field observations and petrographic studies demonstrate that the emplacement of Chah-Firuzeh pluton took place in several intrusive pulses, each with associated hydrothermal ore fluid formation that was also associated with hydrostatic pressure increasing related to that of lithostatic pressure (and fracturing development-relative boiling) by circulated fluid. Copper is concentrated as a very early hydrothermal mineralized phase in the evolution of the hydrothermal system. Early hydrothermal alteration produced a potassic assemblage (orthoclase‑biotite) in the central deep part of the stock.  Alteration of ore fluids could be classified into two groups: A) liquid-reach, containing solid phases, with high temperature (320 to 500 oC) and high salinity (more than 60 wt% NaCl equiv.). B) gas-rich, with high temperature (310 to 570 oC), no solid phase and low salinities. These magmatic fluids illustrate sever boiling processes that are responsible for both potassic alterations, quartz group I and II veins and chalcopyrite deposition. Propylitic alteration is caused by the liquid-rich, low temperature (220 to 360 oC) and Ca-rich fluid with meteoric origin. Continuous decreasing temperature lets the meteoric water diffuse into the system, mix with magmatic fluids and descending the salinities down to the 1 wt% NaCl equiv. and leaching Cu from vein groups II and III by sever thermodynamic anarchies from potassic to the phyllic alteration zones. Phyllic alteration and copper leaching were resulted from the inflow of oxidized and acidic meteoric waters with decreasing temperature of the system followed by the incursion of this fluid into and its convection in top of the system. A late episode of boiling occurred in the upper part of the phyllic zone, and was associated with significant copper deposition. Based on the field observation on sharp alteration and related mineralization, it is possible to say that all these procedures have been controlled by local faults that could be active even before the pluton injection. These faults and the new form ones (which have been formed after injection), could crash the host rocks, and act as physical dams to restrict and limit the mineralization in special strikes and zones.
 
 

Keywords

References

 
 
Ahmad, S. N., and Rose, A. W., 1980, Fluid inclusion in porphyry and skarn ore at Santa Rita, New Mexico: Economic Geology, v. 75, p. 229‑250.
Bodnar, R. J., 1992, Experimental determination of the liquidus and isochores of a 40 wt % NaCl‑H2O solution using synthetic fluid inclusions [abs]: Pan‑American Conf. Research Fluid Inclusions (PACROFI IV), Lake Arrowhead, CA, May 22‑25, 1992 Program abstracts, V. 4, P. 14.
Chou, I. M., 1987, Phase relations in the system NaCl-KCl-H2O. III: solubilities of halite in vapor-saturated liquids above 445 oC and redetermination of phase equilibrium properties in the system NaCl-H2O to 1000 oC and 1500 bars, Geochimica et Cosmochimica Acta. V. 51, P. 1965-1975.
Eastoe, C. G., 1978, A fluid inclusion study of the Panguna porphyry copper deposit, Bougainville, Papua New Guinea: Economic Geology, v. 73, p. 721‑748.
Ford, J. H., 1978, A chemical study of alteration at the Panguna porphyry copper deposit, Bougainville, Papua New Guinea: Economic Geology, v. 73, p. 703‑720.
Haynes, F. M., 1984, Vein densities in drill core, Sierrita porphyry copper deposit, Pima County, Arizona: Economic Geology, v. 79, p. 755‑758.
 
Hezarkhani, A., 1997, Physicochemical controls on alteration and copper mineralization in the Sungun porphyry copper system, Iran. Unpublished Ph.D thesis, Canada, University of McGill, 281 p.
 
 
   
Hezarkhani, A., and Williams-Jones, A. E., (1998), Controls of alteration and mineralization in the Sungun Porphyry Copper Deposit, Iran: Evidence from fluid inclusions and stable isotopes.  Association of American Economic Geologist. USA.  V. 93, P. 651-670.
Hezarkhani, A., (2006)a, Fluid Inclusion Investigations of the Raigan Porphyry Copper System Kerman-Bam, Iran: Journal of IGR, California, USA. V. 48, P. 255-270.
Hezarkhani, A., (2006)b, Hydrothermal Evolutions at the Sar-Cheshmeh Porphyry Cu-Mo Deposit, Iran: Evidence from Fluid Inclusions. Journal of Asian Earth Sciences,  England. V. 28,. P. 408-422.
Hezarkhani, A., (2006)c, Alteration/Mineralization and Controls of Chalcopyrite Dissolution/Deposition in the Raigan Porphyry System, Bam-Kerman, Iran, Journal of IGR, California. USA . V. 48, P. 561-572.  
Hezarkhani, A., (2006)d, Petrology of Intrusive rocks within the Sungun Porphyry Copper Deposit, Azarbaijan, Iran. Journal of Asian Earth Sciences. England. V. 73, P. 326-340.
 
Hezarkhani, A, (2007), Hydrothermal Evolution in Miduk Porphyry Copper System (Kerman, Iran): Based on the Fluid Inclusion Investigation. Journal of IGR, California. USA . (in press).
Quan, R. A., Cloke, P. L., and Kesler, S. E., 1987, Chemical analyses of halite trend inclusions from the Granisle porphyry copper deposit, British Columbia: Economic Geology, v. 82, p. 1912‑1930.
Roedder, E., 1984, Fluid inclusions. In: Ribbe, P. H. (ed.) Reviews in Mineralogy 12, 644p.
Sourirajan, S„ and Kennedy, G.C., 1962, The system HnO-NaCI at elevated temperatures tod pressures: American Journal of Science, v. 260, p. 115-141.
Sterner, S. M., Hall, D. L., and Bodnar, R. J., 1988, Synthetic fluid inclusions. V. Solubility of the system NaCl-KCl-H2O under vapor-saturated conditions. Geochimica et Cosmochimica Acta, V. 52, P. 989-1005.
Titley, S.R„ and Beane, R.E„ 1981, Porphyry copper deposits, Pt, 1. Geologic settings, petrology, and tectonogenesis. Pt. 2. Hydrottiermal alteration and mineralization: Economic Geology 75th Anniversary Volume, p.214-269.
Advanced Applied Geology
Volume 1, Issue 2 - Serial Number 2
January 2012
Pages 43-53

Files

Share

How to cite

Statistics