بررسی میانبارهای سیال کانسار پورفیری طلا-مس ساری نو (کوه ناب) (شمال مرند- شمالغرب ایران)

نوع مقاله : مقاله پژوهشی

نویسندگان

گروه علوم زمین، دانشکده علوم طبیعی، دانشگاه تبریز، تبریز، ایران

چکیده

توده پورفیری ساری‌نو بخشی از پهنه کانه‌دار ارسباران در کمربند ساختاری البرز غربی–آذربایجان است. نفوذ توده کوارتزمونزونیت تا کوارتزمونزودیوریت با سن الیگوسن-میوسن در سنگ‌های آتشفشانی (تراکی‌آندزیت تا آندزیت) و رسوبی کرتاسه پسین، دگرسانی‌های پتاسیمی، فیلیک، آرژیلیک و پروپیلیتی و کانه‌زایی طلا، مس و مولیبدن را در پی داشته است. کانه‌های فلزی شامل پیریت، کالکوپیریت، اسفالریت و مولیبدنیت و کانی‌های باطله بیشتر کوارتز و کلسیت هستند. بافت غالب کانه‌زایی، انتشاری و رگه-رگچه‌ای است. بررسی­های ریزدماسنجی نشان می‌دهد که دمای همگن‌شدگی میانبارهای سیال در رگه‌های کالکوپیریت-کوارتز (پهنه پتاسیمی) و پیریت-کوارتز (پهنه فیلیک) به‌ترتیب بالای ۵۵۰ و حدود ۴0۰ درجه سانتی‌گراد است. شوری سیال های در پهنه پتاسیمی عمدتا بین ۵۰ تا بیش از ۶۰ درصد وزنی NaCl و در پهنه فیلیک از ۳ تا 5/14 درصد وزنی متغیر است. این نتایج هم‌زمانی کانه‌زایی طلا-مس با دگرسانی‌های پتاسیمی و فیلیک را نشان می‌دهد که ناشی از رسوب سیال های گرمابی طی جوشش اولیه و ثانویه است. در مرحله اول، جوشش باعث تشکیل میانبارهای فوق‌اشباع و بخار در کوارتزهای پهنه پتاسیمی و هم‌زمان با نهشت کالکوپیریت شده است. در مرحله دوم، جوشش دوباره میانبارهای مایع-بخار را در کوارتزهای همراه با پیریت در پهنه فیلیک به‌وجود آورده و طلا به‌صورت میانبارهای ریز در پیریت ته‌نشین شده است. فشار برآمده از میانبارهای با نمک فوق‌اشباع در پهنه پتاسیمی حدود ۸۰۰ بار (عمق حدود ۳ کیلومتر، سنگ ایستایی) و در پهنه فیلیک حدود ۳۰۰ بار (عمق حدود ۳ کیلومتر، ایستابی) برآورد شده است.

کلیدواژه‌ها


عنوان مقاله [English]

Fluid inclusion investigation of the Sari-Nou (Kuh-e-Nab) Porphyry gold-copper deposit, northern Marand, NW Iran

نویسندگان [English]

  • Hassan Shokoei
  • Nasir Amel
  • Mohsen moayyed
Department of Earth Sciences, Faculty of Natural Sciences, University of Tabriz, Iran
چکیده [English]

The Sari-Nou porphyry body is a part of the Arasbaran mineralization zone within the Western Alborz–Azerbaijan structural belt. The intrusion of quartz monzonite to quartz monzodiorite (Oligocene–Miocene age) into the Upper Cretaceous volcanic (trachyandesite to andesite) and sedimentary (shale and sandstone) rocks has led to potassic, phyllic, argillic, and propylitic alterations, along with gold, copper, and molybdenum mineralization. The ore minerals include pyrite, chalcopyrite, sphalerite, and molybdenite, while the main gangue minerals are quartz and calcite. Disseminated and vein-veinlet textures are predominant. Microthermometric studies show that homogenization temperatures of fluid inclusions in chalcopyrite–quartz (potassic zone) and pyrite–quartz (phyllic zone) veins are mostly >550 °C and ~400 °C, respectively. Fluid salinity ranges from 50 to over 60 wt% NaCl equiv. in the potassic zone and 3 to 14.5 wt% in the phyllic zone. These data indicate that gold-copper mineralization occurred concurrently with potassic and phyllic alterations, driven by hydrothermal fluid during initial and secondary boiling phases. At the first stage, boiling produced supersaturated and vapor-rich inclusions in quartz, synchronous with chalcopyrite precipitation in the potassic zone. At the second stage, renewed boiling formed liquid–vapor inclusions in quartz associated with pyrite in the phyllic zone, where gold mainly occurs as fine inclusions within pyrite. Pressure estimates based on halite-saturated inclusions, suggest potassic alteration occurred at ~800 bar (≈3 km depth, lithostatic), while less-altered inclusions in the phyllic zone indicate ~300 bar (≈3 km depth, hydrostatic) conditions.

کلیدواژه‌ها [English]

  • Fluid inclusion
  • investigation
  • Sari-Nou (Kuh-e-Nab)
  • gold-copper deposit
  • NW Iran
[1] Calagari A.A., “Fluid inclusion studies in quartz veinlets in the porphyry copper deposit at Sungun, East-Azarbaidjan, Iran” J. Asian Earth Sci. 23 (2) (2004) 179–189.
[2] Simmonds V., “Characteristics and timing of the Cu–Mo mineralization in the Kighal porphyry stock, NW Iran: Implications for the timing of por­phyry Cu-related magmatism in Iran and southern Armenia” Ore Geology Reviews 113 (2019) 103108.
[3] Mikaeili K., Leybourne M., Sharifiyan S., “Evolution of the Magmatic-Hydrothermal System of the Anjerd Porphyry Cu(-Mo) Deposit, East-Azarbaijan, NW Iran”, Economic Geology 120 1 (2025) 119–135.
[4] Castro A., Aghazadeh M., Badrzadeh, Z., Chichorro M. “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 (2013) 109-127.
[5] Bakker R.J., “AqSo-NaCl: Computer program to calculate P-T-V-X properties in the H2O-NaCl fluid inclusion research and pore fluid modelling”, Computers and Geoscience (2018) P.xx-xx.
[6] Bodnar R.J. “Revised equation and table for determining the freezing point depression of H2O-NaCl solutions”, Geochimica et Cosmochimica Acta 57 (1993) 683-684.
[7] Hall D.L., Sterner S.M., Bodnar R.J., “Freezing point depression of NaCl-KCl-H2O solutions”, Economic Geology 8 (1988) 197-202.
[8] Bakker R.J., “Package FLUIDS. Part4: Thermodynamic modelling and purely empirical equations for H2O-NaCl-KCl solutions”, Mineralogy and Petrology 105 (2012) 1-29.
[9] Nabavi M.H., “An introduction to the geology of Iran”, Geological Survey of Iran. (1976) 109 (in Persian).
[10] Adamia S.A., Chkhotua T., Kekelia M., Lordkipanidze M., Shavishvili I., Zakariadze G., “Tectonics of the Caucasus and adjoining regions: Implications for the evolution of the Tethys Ocean”, Journal of Structural Geology 3(4) (1981) 437–447.
[11] Aghazadeh M., Castro A., Badrzadeh Z., Vogt K., “Post-collisional polycyclic plutonism from the Zagros hinterland: the Shaivar Dagh plutonic complex, Alborz belt, Iran”, Geological Magazine Cambridge University Press (2011) 1–29.
[12] Roedder E., “Fluid inclusions. Mineralogical Society of America”, Reviews in Mineralogy 12 Vancover 644 (1984).
[13] Goldstein R. H., Samson I., Anderson A.,  Marshall D., “Petrographic analysis of fluid inclusions. Fluid inclusions: Analysis and interpretation”, 32 (2003) 9-53.
[14] Bodnar R.J., Lecumberri-Sanchez P., Moncada D., Steele-MacInnis M., “Fluid inclusions in hydrothermal ore deposits”, in Elsevier ed., Treatise on geochemistry (2014) 119–142.
[15] Audétat A., “A Plea for More Skepticism Toward Fluid Inclusions: Part II. Homogenization via Halite Dissolution in Brine Inclusions from Magmatic-Hydrothermal Systems Is Commonly the Result of Postentrapment Modifications” Economic Geology 118 1 (2023) 43–55.
[16] Zhang, D., Audétat, A., “A Plea for More Skepticism Toward Fluid Inclusions: Part I. Postentrapment Changes in Fluid Density and Fluid Salinity Are Very Common” Economic Geology, 118 1 (2023) 15–41.
[17] Audétat A, Günther D., “Mobilization and H2O-loss from fluid inclusions in natural quartz crystals”, Contrib Mineral Petrol 137 (1999) 1–14.
[18] Becker S. P., Fall A., Bodnar R. J. “Synthetic fluid inclusions. XVII. 1 PVTX properties of high salinity H2O-NaCl solutions (> 30 wt% NaCl): Application to fluid inclusions that homogenize by halite disappearance from porphyry copper and other hydrothermal ore deposits”, Economic Geology 103(3), (2008) 539-554.
[19] Burnham C.W., “Magmas and hydrothermal fluids. In: Geochemistry of Hydrothermal Ore Deposits”, John Wiley and Sons, NY, (1979) 71–136.
[20] Ramboz C., Pichavant M., Weisbrod A., “Fluid immiscibility in natural processes: use and misuse of fluid inclusion data”, II. Interpretation of fluid inclusion data in terms of immiscibility. Chem. Geol. 37, (1982) 29–48.
[21] Ronacher E., Richards J.P., Johnston M.D., “Evidence for fluid phase separation in high-grade ore zones at the Porgera gold deposit, Papua New Guinea” Miner. Dep. 35 (2000) 683–688.
[22] Rusk B.G., Reed M.H., Dilles J.H., “Fluid inclusion evidence for magmatic-hydrothermal fluid evolution in the porphyry copper-molybdenum deposit at Butte, Montana”, Econ. Geol. 103 (2008) 307–334.
[23] Roedder E., Bodnar R.J., “Geologic pressure determinations from fluid inclusion studies”, Annu. Rev. Earth Planet. Sci. 8 (1980) 263–301.
[24] Sillitoe R.H., “Porphyry copper systems”, Econ. Geol. 105 (2010) 3–41.
[25] Canet C., Franco S.I., Prol-Ledesma R.M., González-Partida E., Villanueva-Estrada R.E., “A model of boiling for fluid inclusion studies: Application to the Bolaños” (2011).
[26] Ahmad S.N., Rose A.W., “Fluid inclusions in porphyry and skarn ore at Santa Rita, New Mexico”, Econ. Geol. 75 (1980) 229–250.
[27] Simmonds V., Moazzen M., “Fluid inclusion studies on Cu-Mo-Au bearing quartz-sulphide veins and veinlets in Qarachilar area, Qaradagh pluton (NW Iran)”, Periodico di Mineralogia 85, (2016) 261-276.
[28] Ulrich T., Günther D., Heinrich C.A., “The Evolution of a Porphyry Cu-Au Deposit, Based on LA-ICP-MS Analysis of Fluid Inclusions: Bajo de la Alumbrera, Argentina”, Economic Geology 97 8 (2002) 1889–1920.
[29] Klemm L.M., Pettke T., Heinrich C.A., Campos E., “Hydrothermal Evolution of the El Teniente Deposit, Chile: Porphyry Cu-Mo Ore Deposition from Low-Salinity Magmatic Fluids”, Economic Geology 102 6 (2007) 1021–1045.
[30] Tsuruoka S., Monecke T., Reynolds T.J., “Evolution of the mag­matic-hydrothermal system at the Santa Rita porphyry Cu deposit, New Mexico, USA” Importance of intermediate-density fluids in ore formation: Economic Geology 116 6 (2021) 1267–1284.
[31] Fournier R., “Conceptual models of brine evolution in magmatic-hydrothermal systems”, U.S. Geological Survey Professional Paper, 1350, (1987) 1487–1505.
[32] Fournier R.O., “The transition from hydrostatic to greater than hydrostatic fluid pressure in presently active continental hydrothermal systems in crystalline rock” Geophysical Research Letters 18 5 (1991) 955–958.
[33] Campbell A.R., Lundberg S.A.W., Dunbar N.W., “Solid inclusions of halite in quartz: evidence for the halite trend” Chemical Geology, 173, 1–3 (2001) 179–191.
[34] Mernagh T.P., Leys C., Henley R.W., “Fluid inclusion systematics in porphyry copper deposits: The super-giant Grasberg deposit, Indonesia, as a case study” Ore Geology Reviews 123 (2020) 103570.
[35] Ouyang H., Wu, X., Mao J.W., Su H., Santosh M., Zhou Z., Li C., “The nature and timing of ore formation in the Budunhua copper deposit, southern Great Xing’an Range: evidence from geology, fluid inclusions, and U-Pb and Re–Os geochronology”, Ore Geol. Rev. 63 (2014) 238–251.
[36] Driesner T., Heinrich C. A., “The system H2O–NaCl. Part I: Correlation formulae for phase relations in temperature–pressure–composition space from 0 to 1000 C, 0 to 5000 bar, and 0 to 1 XNaCl”, Geochimica et Cosmochimica Acta 71(20) (2007) 4880-4901.
[37] Hedenquist J.W., Arribas A., Reynolds T.J., “Evolution of an intrusion-centered hydrothermal system; Far Southeast-Lepanto porphyry and epithermal Cu-Au deposits”, Philippines: Economic Geology 93 4 (1998) 373–404.