نظریه جدید در خصوص زمان و گرادیان حرارتی پوسته اقیانوسی فرورانده شده با تأکید بر سنگ میزبان دولومیت و شیل در تشکیل کانسارهای سرب و روی کمربند ایرانکوه- آهنگران

نوع مقاله : علمی- پژوهشی

نویسندگان

1 فردوسی مشهد

2 اصفهان

3 کلرادو

چکیده

کمربند ایرانکوه- آهنگران یکی از مهم‌ترین زو‌ن‌های کانی­‌سازی سرب و روی ایران است که با روند شمال‌غربی- جنوب‌شرقی در مرکز زون ساختاری سنندج- سیرجان واقع‌شده است. سه منطقه ایرانکوه، آهنگران و حسین­‌آباد به‌عنوان مثال موردی در این مقاله بررسی شده­‌اند. بر پایه شواهد زمین‌شناسی، ساختاری، شکل و نوع کانی­‌سازی، شیمی محلول هیدروترمالی، آلتراسیون و پاراژنز مینرالی و مقایسه با انواع ذخایر سرب و روی، کلیه کانسارهای سرب و روی کمربند ایرانکوه- آهنگران از نوع MVT هستند. این کانسارها با گسل­‌های تراستی مرتبط بوده و در زون ساختاری جلوی کمانی مربوط به پوسته اقیانوسی فرورونده جوان و داغ تشکیل شده­‌اند. در چنین پوسته­‌هایی قبل از رسیدن به اعماق 40 کیلومتری، بیش از 90 درصد آب اقیانوسی آزاد و سیلیکات‌های غنی از منیزیوم شکسته می­‌شوند. فلزات بخشی از پوسته اقیانوسی و بخشی از پوسته قاره‌­ای تأمین شده است. از آنجایی‌که گسل­‌های تراستی سنگ­‌های ژوراسیک تا کرتاسه بالایی را قطع کرده­‌اند و با توجه به تعیین سن دقیق انجام‌شده در ایرانکوه، کانی‌سازی­‌های این کمربند در دامنه سنی بین 66 تا 56 میلیون سال پیش اغلب در پالئوسن شکل گرفته­‌اند.
شیمی محلول کانه‌دار ذخایر MVT فقیر از Si و غنی از Mg و Fe است. چنین سیالی همراه با فلزات از طریق گسل‌های تراست بالا آمده­ است و در سنگ میزبان دولستون (ایرانکوه و آهنگران) یا شیل- سیلتستون (حسین­ آباد و بخشی از ایرانکوه و آهنگران) کانی‌­سازی انجام‌شده است. تفاوت‌های فاحشی در نوع پاراژنزها، آلتراسیون، شکل، ابعاد، میزان ذخیره و عیار در کانسارهای این کمربند دیده می­‌شود که توسط نوع سنگ میزبان کنترل‌شده است.
با استناد به تمام شواهد سنگ‌شناسی، آلتراسیون، شکل و حالت کانی‌­سازی، وجود گسل­‌های تراست، پاراژنز مینرالی و موقعیت خاص زمین‌­شناسی و جغرافیایی ارائه‌شده، می‌توان برای اکتشاف ذخایر MVT پنهان در این کمربند اقدام کرد.

کلیدواژه‌ها


Agard, P., Omrani, J., Jolivet, L. and Mouthereau, F., 2005. Convergence history across Zagros, Iran: Constraints from collisional and earlier deformation. International Journal of Earth Sciences, 94(3): 401–419.
Akbari, Z., 2017. Model for the genesis of Ahangaran Fe-Pb deposit (SE of Malayer), based on ore types, Geochemistry and stable isotopic studies. Ph.D. Thesis, Shahid Beheshti University, Tehran, Iran, 264 pp.
Appold, M.S. and Garven, G., 1999. The hydrology of ore formation in the Southeast Missouri District: numerical models of topography-driven fluid flow during the Ouachita Orogeny. Economic Geology, 94(6): 913–936.
Ayati, F., Dehghani, H., Mokhtari, A.R. and Mojtahedzadeh, H., 2013. Geochemistry and mineralogy studies of Gushfil Pb-Zn deposit, Irankuh, Isfahan. Journal of Analytical and Numerical Methods in Mining Engineering, 3(6): 83–91 (in Persian).
Barrie, C.T. and Hannington, M.D., 1999. Introduction: Classification of VMS deposits based on host rock composition. In C.T. Barrie and M.D. Hannington (Editors), Volcanic-Associated Massive Sulfide Deposits: Processes and Examples in Modern and Ancient Settings. Society of Economic Geologists, Reviews in Economic Geology 8, pp. 2–10.
Bradley, D.C., 1993. Role of lithospheric flexure and plate convergence in the genesis of some Appalachian zinc deposits. U.S. Geological Survey Bulletin, 2039: 35–43.
Bradley, D.C. and Leach, D.L., 2003. Tectonic controls of Mississippi Valley-type lead–zinc mineralization in orogenic forelands. Mineralium Deposita, 38(6): 652–667.
Boveiri Konari, M. and Rastad, E., 2017. Nature and origin of dolomitization associated with sulphide mineralization: new insights from the Tappehsorkh Zn-Pb (-Ag-Ba) deposit, Irankuh Mining District, Iran. Geological Journal, 53(1): 1–211
Boveiri Konari, M., Rastad, E., Mohajjel, M., Nakini, A. and Haghdoost, M., 2016. Structure, Texture, Mineralogy and Genesis of Sulphide Ore Facies in Tappehsorkh Detrital-Carbonate-Hosted Zn-Pb-(Ag) Deposit, South of Esfahan. Scientific Quarterly Journal, Geosciences, 25‌(97): 221–236. (in Persian with English abstract).
Duane, M.J. and de Wit, M.J., 1988. Pb-Zn ore deposits of the northern Caledonides; products of continental-scale fluid mixing and tectonic expulsion during continental collision. Geology, 16(11): 999–1002.
Ehya, F., Lotfi, M. and Rasa, I., 2010. Emarat carbonate-hosted Zn–Pb deposit, Markazi Province, Iran: A geological, mineralogical and isotopic (S, Pb) study. Journal of Asian Earth Sciences, 37(2): 186–194.
Garven, G., 1985. The role of regional fluid flow in the genesis of the Pine Point deposit, Western Canada Sedimentary Basin. Economic Geology, 80(2): 307–324.
Ge, S. and Garven, G., 1992. Hydromechanical modeling of tectonically driven groundwater flow with application to the Arkoma Foreland Basin. Journal of Geophysical Research, 97(B6): 9119–9144.
Ghasemi, A., 1995. Facies analysis and geochemistry of Kolah-Darvazaeh, Goud-Zendan, and Khaneh-Gorgi Pb-Zn deposits from south of Irankuh. M.Sc. Thesis, Tarbiat Modares University, Tehran, Iran, 158 pp. (in Persian)
Ghasemi, A. and Talbot, C.J., 2006. A new tectonic scenario for the Sanandaj-Sirjan Zone (Iran). Journal of Asian Earth Sciences, 26(6): 683–693.
Ghazban, F., McNutt, R.H. and Schwarcz, H.P., 1994. Genesis of sediment-hosted Zn-Pb-Ba deposits in the Irankuh district, Esfahan area, west-central Iran. Economic Geology, 89(6): 1262–1278.
Hosseini-Dinani, H. and Aftabi, A., 2016. Vertical lithogeochemical halos and zoning vectors at Goushfil Zn–Pb deposit, Irankuh district, southwestern Isfahan, Iran: Implications for concealed ore exploration and genetic models. Ore Geology Reviews, 72(1): 1004–1021.
Hosseini-Dinani, H., Aftabi, A., Esmaeili, A. and Rabbani, M., 2015. Composite soil-geochemical halos delineating carbonate-hosted zinc–lead–barium mineralization in the Irankuh district, Isfahan, west-central Iran. Journal of Geochemical Exploration, 156: 114–130.
Hosseinkhani, A. and Molasalehi, F., 2013. Lead and silver mineralogical studies and lead isotope investigations in Ahangaran mine, Malayer, Iran. Scientific Quarterly Journal, Geosciences, 24(94): 359–368. (in Persian with English abstract)
Houshmandzadeh, A.R., Ohanian, T., Sahandi, M.R., Taraz, H., Aganabati, A., Soheili, M., Azarm, F. and Hamdi, B., 1975. Geological map of Eglid, scale 1:250000. Geological Survey of Iran, Tehran, Iran.
Kaiser, C.J. and Ohmoto, H., 1988. Ore-controlling structures of Mississippi Valley-type mineralization on the North American midcontinent as products of late Paleozoic convergent plate tectonism. In: G. Kisvarsanyi and S.K. Grant (Editors), North American Conference on the Tectonic Control of Ore Deposits and the Vertical and Horizontal Extent of Ore Systems, Proceedings Volume: Rolla. University of Missouri-Rolla, Missouri, pp. 424–430.
Karimpour, M.H., Malekzadeh Shafaroudi, A., Esmaeili Sevieri, A. and Shabani, S., 2018a. Mineralogy and geochemical varations of altered host rock in Irankuh Pb-Zn mining district, SW Isfahan. Journal of Advanced Applied Geology, in press. (in Persian)
Karimpour, M.H., Malekzadeh Shafaroudi, A., Esmaeili Sevieri, A., Shabani, S., Allaz, J.M. and Stern, C.R., 2018b. Geology, mineralization, mineral chemistry, and ore-fluid conditions of Irankuh Pb-Zn mining district, south of Isfahan. Journal of Economic Geology, 9(2): 267–294. (in Persian with English abstract)
Karimpour, M.H. and Sadeghi, M., 2018. Dehydration of hot oceanic slab at depth 30–50 km: KEY to formation of Irankuh-Emarat Pb-Zn MVT belt, Central Iran. Journal of Geochemical Exploration, 194: 88–103.
Kesler, S.E. and Carrigan, C.W., 2002. Discussion on “Mississippi Valley-type lead–zinc deposits through geological time: implications from recent age-dating research” by DL Leach, D.L., Bradley, D., Lewchuk, M.T., Symons, D.T.A., de Marsily, G. and Brannon, J. (2001) Mineralium Deposita, 36: 711–740. Mineralium Deposita, 37(8): 800–802.
Kesler, S.E. and van der Pluijm, B.A., 1990. Timing of Mississippi Valley-type mineralization: relation to Appalachian orogenic events. Geology, 18(11): 1115–1118.
Khosrobeygi, M., 2019. Mineralization, geochemistry and microthermometry studies in the Hossein-Abad deposit (southwest Arak). M.Sc. Thesis, University of Isfahan, Isfahan, Iran, In Press.
Leach, D.L., Bradley, D.C., Lewchuk, M., Symons, D.T.A., Brannon, J. and de Marsily, G., 2001. Mississippi Valley-type lead-zinc deposits through geological time: implications from recent age-dating research. Mineralium Deposita, 36(8): 711–740.
Leach, D.L. and Sangster, D., 1993. Mississippi Valley-type lead-zinc deposits. Geological Association of Canadian. Specific Paper, 40: 289–314.
Leach, D.L., Sangster, D.F., Kelley, K.D., Ross, R.L., Garven, G. and Allen, C.R., 2005. Sediment-hosted Pb-Zn deposits: a global perspective. Economic Geology, 100th Anniversary, 1905–2005: 561–608.
Leach, D.L, Taylor, R.D., Fey, D.L., Diehl, S.F. and Saltus, R.W., 2010. A Deposit Model for Mississippi Valley-Type Lead-Zinc Ores, Chapter A of Mineral Deposit Models for Resource Assessment. U.S. Geological Survey, Reston, Virginia, Scientific Investigations Report 2010–5070–A., 64 pp.
Liu, Y., Song, Y., Fard, M., Zhou, L., Hou, Z. and Kendricke, M.A., 2019. Pyrite Re-Os age constraints on the Irankuh Zn-Pb deposit, Iran, and regional implications. Ore Geology Reviews, 104: 148–159.
Maanijou, M., Vafaei Zad, M. and Aliani, F., 2015. Fluid inclusion and sulfur stable isotope evidence for the origin of the Ahangran Pb-Ag deposit. Journal of Economic Geology, 7(2): 343–367. (in Persian with English abstract)
Mahmoodi, P., Rastad, P., Rajabi, A. and Peter, J.M., 2018. Ore facies, mineral chemical and fluid inclusion characteristics of the Hossein-Abad and Western Haft-Savaran sediment-hosted Zn-Pb deposits, Arak Mining District, Iran. Ore Geology Reviews, 95: 342–365.
Mohajjel, M., Fergusson, C.L. and Sahandi, M.R., 2003. Cretaceous–Tertiary convergence and continental collision, Sanandaj–Sirjan zone, western Iran. Journal of Asian Earth Sciences,
21(4): 397–412.
Momenzadeh, M., Shafighi, S., Rastad, E. and Amstutz, G.C., 1979. The Ahangaran lead-silver Deposits, SE-Malayer, west central Iran. Mineralium Deposita, 14(3): 323–341.
Rajabi, A., Rastad, E. and Canet, C., 2012. Metallogeny of Cretaceous carbonate-hosted Zn–Pb deposits of Iran: geotectonic setting and data integration for future mineral exploration. International Geology Review, 54(14): 1649–1672.
Ranjbaran, M., 1991. Sedimentary environment and diagenesis of carbonate rocks containing lead and zinc in Ahangaran mine, Malayer. M.Sc. Thesis, Tehran University, Tehran, Iran, 137 pp.
Rastad, E., 1981. Geological, mineralogical and ore facies investigations on the Lower Cretaceous stratabound Zn – Pb – Ba – Cu deposits of the Irankuh mountain range, Isfahan, west central Iran. Ph.D. Thesis, Heidelberg University, Heidelberg, Germany, 334 pp.
Reichert, J., 2007. A metallogenetic model for carbonate-hosted non-sulphide zinc deposits based on observations of Mehdi Abad and Irankuh, Central and Southwestern Iran. Ph.D. Thesis, Martin Luther University Halle Wittenberg, Halle, Germany, 152 pp.
Timoori-Asl, F., 2010. Sedimentology and petrology of Jurassic deposits and Basinal brines studies in formation of Irankuh deposit. M.Sc. Thesis, Isfahan University, Isfahan, Iran, 120 pp. (in Persian)
Timoori-Asl, F., Pakzad, H.R. and Bagheri, H., 2011. Source of metals and ore-bearing fluids in Irankuh Pb-Zn deposit. Sedimentology and Stratigraphy Research, 27(44): 83–102. (in Persian)
Zahedi, M., 1976. Geological map of Esfahan, scale 1:250,000. Geological Survey of Iran.
Zamanian, H., 1993. Mineralogy, paragenesis and genesis of lead and silver of Ahangaran, Malayer. M.Sc. Thesis, Tarbiat Moalem University, Tehran, Iran, 280 pp.
CAPTCHA Image