زمین شناسی، پتروگرافی، دگرسانی، کانی سازی و پتروژنز توده های نفوذی در محدوده اکتشافی هَمِچ، جنوب‌ غرب بیرجند

نوع مقاله : علمی- پژوهشی

نویسندگان

فردوسی مشهد

چکیده

محدوده اکتشافی هَمِچ در شرق بلوک لوت و در فاصله 85 کیلومتری جنوب‌غرب بیرجند واقع شده است. منطقه شامل برون‌زدهایی از سنگ‌های آذرین پالئوسن- ائوسن است که در برگیرنده طیف گسترده ای از توده های آذرین نیمه عمیق (دیوریت تا مونزونیت پورفیری) به‌همراه واحدهای نفوذی بازی، آتشفشانی حدواسط و سنگ‌های آذرآواری و رسوبی است. انواع دگرسانی آرژیلیک، سیلیسی، کوارتز- سرسیت- پیریت، پروپلیتیک و کربناته در محدوده اکتشافی قابل مشاهده است. کانی سازی در سطح به شکل پیریت پراکنده و رگه‌چه های اکسید‌ آهن و در عمق به‌صورت کانی سازی پراکنده پیریت، کالکوپیریت، گالن و اسفالریت و پیریت رگه‌چه ای دیده می شود. توده های نفوذی حدواسط از نوع کالک‌آلکالن پتاسیم بالا (K2O بین 42/2 تا 4 درصد) و توده های گابرو و گابرودیوریتی مربوط به دسته تولئیتی (K2O بین 15/0 تا 27/0 درصد) است. توده های نفوذی منطقه همه از نوع متاآلومینوس است و در دسته مگنتیت (نوع I) طبقه بندی می‌شوند. نمودارهای عنکبوتی بیانگر غنی شدگی توده های نفوذی حدواسط از عناصر LREE، LILE و تهی شدگی از عناصر HREE به‌همراه مقدار جزئی ناهنجاری منفی Eu (81/0 تا 02/1) و حضور ناهنجاری مثبت Sr است که نشان‌دهنده حضور کم و یا نبود پلاژیوکلاز در سنگ منشأ به‌عنوان کانی باقی‌مانده و وجود شرایط ذوب در حالت اکسیدان است. پایینبودن نسبت N(La/Yb) در سنگ‌های نفوذی محدوده همچ (85/6 تا 72/9) می تواند بیانگر درجه پایین ذوب‌بخشی گوشته اولیه باشد. تهی شدگی Nb به‌همراه نسبت بالای Zr/Nb نشان‌دهنده اشتقاق ماگما از پوسته اقیانوسی با میزان آلودگی پوسته ای کم است. ماگمای مولد توده های نفوذی حدواسط از حدود 1 تا 5 درصد ذوب‌بخشی اسپینل- گارنت لرزولیت (با مقدار کم گارنت) در عمق حدود 65 تا 67 کیلومتری گوشته بالایی و توده های بازی از 5 تا 20 درصد ذوب‌بخشی اسپینل لرزولیت (گوشته تهی‌شده) تشکیل شده‌‌اند. در نمودارهای پتروژنیک و تعیین محیط تکتونوماگمایی، توده‌های نفوذی در جایگاه زمین‌ساختی کمربند آتشفشانی زون فرورانش (VAG1) قرار می گیرند. تنوع واحدهای نیمه عمیق با ماهیت کالک‌آلکالن پتاسیم بالا، گسترش و نوع دگرسانی ها و کانی سازی سولفیدی پراکنده و رگه‌چه ای در محدوده، نشانه هایی از وجود سیستم پورفیری در عمق است.

کلیدواژه‌ها


Abdi, M. and Karimpour, M.H., 2013. Petrochemical characteristics and timing of Middle Eocene granitic magmatism in Kooh-Shah, Lute Block, Eastern Iran. Acta Geological Sinica, 84(4): 1032–1044.
Aghanabati, S.A., 2004. Geology of Iran. Geological Survey of Iran, Tehran, 586 pp. (in Persian)
Alavi, M., 1991. Sedimentary and structural characteristics of the Paleo-Tethys remnants in northeastern Iran. Geological Society of America Bulletin, 103(8): 983–992.
Aldanmaz, E., Pearce, J.A., Thirlwall, M.F. and Mitchell, J.G., 2000. Petrogenetic evolution of late Cenozoic, post-collision volcanism in western Anatolia, Turkey. Journal of Volcanology and Geothermal Research, 102(1): 67–95.
Angeles, C.A., Gingerich, J.C. and Haeri-Ardakani, O., 2004. Status Report on the South Khorasan Joint Study Project, (Birjand area, East Iran). Iranian Mines and Mining Industrls Development and Renovation Organization, Tehran, Report 1, 186 pp. (in Persian)
Asiabanha, A., Bardintzeff, J.M., Kananian, A. and Rahimi G., 2012. Post-Eocene volcanics of the Abazar district, Qazvin, Iran: Mineralogical and geochemical evidence for a complex magmatic evolution. Journal of Asian Earth Sciences, 45: 79–94.
Berberian, M., 1981. Towards a paleogeography and tectonic evaluation of Iran. Canadian Journal of Earth Sciences, 18(2): 210–265.
Berberian, M. and King, G.C.P., 1981. Towards a paleogeography and tectonic evolution of Iran: Reply. Canadian Journal of Earth Sciences, 18(11): 1764–1766.
Boynton, W.V., 1985. Cosmochemistry of the rare earth elements: Meteorite studies, In Rare Earth Element Geochemistry. Elsevier, Amsterdam, 522 pp.
Chappell, B.W. and White, A.J.R., 2001. Two contrasting granite types, 25years later. Australian Journal of Earth Sdiences, 48(4): 489–500.
Cooke, D.R., Hollings, P. and Walshe, J.L., 2005. Giant porphyry deposits: Characteristics, distribution, and tectonic controls. Economic Geology, 100(5) 801–818.
Cotton, J., Le Dez, A., Bau, M., Caroff, M., Maury, R.C., Dulski, P., Fourcade, S., Bohn, M. and Brousse, R., 1995. Origin of anomalous rare-earth element and yttrium enrichments in subaerially exposed basalts, evidence from French Polynesia. Chemical Geology, 119(1–4): 115–138.
Crawford, A.J., Falloon, T.J. and Green, D.H., 1989. Classification, petrogenesis and tectonic setting of boninites. In: A.J. Crawford (Editor), Boninites and Related Rocks, Unwin Hyman, London. pp. 1–49.
Gust, D.A., Arculus, R.A. and Kersting, A.B., 1977. Aspects of magma sources and processes in the Honshu arc. The Canadian Mineralogist, 35(1): 347–365.
Harangi, S., Downes, H., Thirlwall, M. and Gmeling, K., 2007. Geochemistry, petrogenesis and geodynamic relationships of Miocene calc-alkaline volcanic rocks in the western Carpathian arc, eastern Central Europe. Journal of Petrology, 48(12): 2261–2287.
Helvacı, C., Ersoy, E.Y., Sözbilir, H., Erkül, F., Sümer, Ö. and Uzel, B., 2009. Geochemistry and 40Ar/39Ar geochronology of Miocene volcanic rocks from the Karaburun Peninsula: Implications for amphibolebearing lithospheric mantle source, Western Anatolia. Journal of Volcanology and Geothermal Research, 185(3): 181–202.
Ishihara, S., 1981. The granitoid series and mineralization. Resource Geology, 48(4): 219–224.
Kampunzu, A.B., Tombale, A.R., Zhai, M., Bagai, Z., Majaule, T. and Modisi, M.P., 2003. Major and trace element geochemistry of plutonic rocks from Francistown, NEBotswana: evidence for a Neoarchaean continental active margin in the Zimbabwe craton. Lithos, 71(24): 431–460.
Kan Azin Company, 2010. Detailed exploration of minerals in Birjand County (Hamech area). Industries and Mines Organization of South Khorasan province, Tehran, Report 1, 124 pp. (in Persian)
Karimpour, M.H., Malekzadeh Shafaroudi, A., Farmer, L. and Stern, C.R., 2012. Petrogenesis of Granitoids, U-Pb zircon geochronology, Sr-Nd Petrogenesis of granitoids, U-Pb zircon geochronology, Sr-Nd isotopic characteristics, and important occurrence of Tertiary mineralization within the Lut block, eastern Iran. Journal of Economic Geology, 4(1): 1–27. (in Persian with English abstract)
MacDonald, G.D. and Arnold, L.C., 1994, Geological and geochemical zoning of the Grasberg Igneous Complex, Irian Jaya, Indonesia. Journal of Geochemical Exploration, 50(1–3):143−178.
Malekzadeh Shafaroudi, A., 2009. Geology, mineralization, alteration, geochemistry, Microthermometry, radioisotope and Petrogenesis of intrusive rocks copper-gold porphyry Maherabad and Khopik. Ph.D. thesis. Ferdowsi University of Mashhad, Mashhad, Iran, 535 pp. (in Persian with English abstract)
Malekzadeh shafaroudi, A., Karimpour, M.H. and Mazaheri, S.A., 2010. Rb–Sr and Sm–Nd isotopic compositions and Petrogenesis of ore-related intrusive rocks of gold-rich porphyry copper Maherabad prospect area (North of Hanich), east of Iran. Iranian Journal of Crystallography and Mineralogy, 18(2): 15–32. (in Persian with English abstract)
Malekzadeh Shafaroudi, A., Karimpour, M.H. and Stern, C.R., 2015. The Khopik porphyry copper prospect, Lut Block, Eastern Iran: Geology, alteration and mineralization, fluid inclusion, and oxygen isotope studies. Ore Geology Reviews, 65(2): 522–544.
Mandal, A., Ray, A., Debnath, M. and Paul, S.B., 2012. Geochemistry of hornblende gabbro and associated dolerite dyke of Paharpur, Puruliya, West Bengal: Implication for petrogenetic process and tectonic setting. Journal of Earth System Science, 121(3): 793–812.
Martin, H., 1999. Adakitic magmas: modern analogues of Archaean granitoids. Lithos, 46(3): 411–429.
Meinert, L.D., 1987. Skarn zonation and fluid evolution in the Groundhog mine, Central mining district. New Mexico. Economic Geology, 82(3): 523−545.
Meinert, L.D., Dipple, G.M. and Nicolescu, S., 2005. World skarn deposits. Economic Geology, 100(4): 299–336.
Middlemost, E.A.K., 1985. Magmas and Magmatic Rocks: An introduction to igneous petrology. Longman Group, United Kingdom, 390 pp.
Middlemost, E.A.K., 1994. Naming materials in the magma/igneous rock system. Earth-Science Reviews, 37(3): 215–224.
Mitchell, A.H.G. and Garson, M.S., 1972. Relationship of porphyry copper and circum-Pacific tin deposits to palaeo-Benioff zones. Institute of Mining and Metallurgy Transactions, Sect. B Applied Earth Science, 81: B10-B25.
Nicholson, K.N., Black, P.M., Hoskin, P.W.O. and Smith, I.E.M., 2004. Silicic volcanism and back-arc extension related to migration of the Late Cainozoic Australian- Pacific plate boundary. Journal of Volcanology and Geothermal Research, 131(3): 295–306.
Pearce, J.A., 1983. Role of the sub-continental lithosphere in magma genesis at active continental margins. In: C.J. Hawkesworth and M.J. Norry (Editors), Continental basalts and mantle xenoliths. Shiva Publications, Nantwich, United Kingdom, pp. 230–249.
Pearce, J.A., Harris, N.W. and Tindle, A.G., 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology, 25(4): 956–983.
Pearce, J.A. and Parkinson, I.J., 1993. Trace element models for mantle melting: application to volcanic arc petrogenesis. In: H.M. Prichard, T. Alabaster, N.B.W. Harris and C.R. Neary (Editors), Magmatic Processes and Plate Tectonics. Geological Society of London Special Publication, London, pp. 373-403.
Peccerillo, A. and Taylor, S.R., 1976. Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, Northern Turkey. Contributions to Mineralogy and Petrology, 58(1): 63–81.
Perello, J., Carlotto, V., Zarate, A., Ramos, P., Posso, H., Neyra, C., Caballero, A., Fuster, N. and Muhr, R., 2003. Porphyry-style alteration and mineralization of the middle Eocene to early Oligocene Andahuaylas-Yauri belt, Cuzco region, Peru. Economic Geology, 98(8): 1575–1605.
Rollinson, H., 1993. Using geochemical data: evaluation, presentation, interpretation. Longman Singapore Publishers, England, 352 pp.
Samiee, S., Karimpour, M.H., Ghaderi, M., Haidarian Shahri, M.R., Kloetzli, O. and Santos, J.F., 2016. Petrogenesis of subvolcanic rocks from the Khunik prospecting area, south of Birjand, Iran: Geochemical, Sr–Nd isotopic and U–Pb zircon constraints. Journal of Asian Earth Sciences, 115: 170–182.
Seedorff, E., Dilles, J.H., Proffett, J.M., Jr., Einaudi, M.T., Zurcher, L., Stavast, W.J.A., Johnson, D.A. and Barton, M.D., 2005. Porphyry Related Deposits: Characteristics and origin of hypogene features. In: J.W. Hedenquist, J.F.H. Thompson, R.J. Goldfarb and J.P. Richards (Editors), Economic Geology. 100th Anniversary Volume, Littleton, Colorado, pp. 251-298.
Shand, S.J., 1948. Eruptive Rocks. Their Genesis, Composition, Classification, and Their Relation to Ore-Deposits with a Chapter on Meteorite. Journal of Geology, 56: 593–593.
Shaw, D.M., 1970. Trace element fractionation during anataxis. Geochimica et Cosmochimica Acta, 34(2): 237–243.
Siivola, J. and Schmid, R., 2007. List of Mineral Abbreviations: Recommendations by the IUGS Subcommission on the Systematics of Metamorphic Rocks: Web version 01.02.07. (Electronic Source), availeble at: https://www.bgs.ac.uk/scmr/docs/papers/paper_12.pdf
Sillitoe, R.H., 1973. Tops and bottoms of porphyry copper deposits. Economic Geology, 68(6): 799–815.
Sillitoe, R.H., 1988. Epochs of intrusion-related copper mineralization in the Andes. Journal of South American Earth Sciences, 1(1): 89–108.
Sillitoe, R., H., 2010. Porphyry Copper Systems. Economic Geology, 105(1): 3–41.
Sun, S.S. and McDonough, W.F., 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition processes. In: A.D. Saunders, M.J. Norry (Editors), Magmatism in the Ocean Basins, Geological Society of London Publications, Special Publication 42, London, pp. 313-345.
Temizel, I. and Arslan M., 2009. Mineral chemistry and petrochemistry of post-collisional Tertiary mafic to felsic cogenetic volcanics in the Ulubey (Ordu) area, Eastern Pontides, NE Turkey. Turkish Journal of Earth Sciences, 18(1): 29–53.
Tepper, J.H., Nelson, B.K., Bergantz, G.W. and Irving, A.J., 1993. Petrology of the Chilliwack batholith, North Cascades, Washington: generation of calc-alkalinegranitoids by melting of mafic lower crust with variable water fugacity. Contributions to Mineralogy and Petrology, 113(3): 333–351.
Tirrul, R., Bell, I.R., Griffis, R.J. and Camp, V.E., 1983. The Sistan suture zone of eastern Iran. Geological Society of America Bulletin, 94(1): 134–156.
Tosdal, R.M. and Richards, J.P., 2001. Magmatic and structural controls on the development of porphyry Cu ± Mo ± Au deposits. Reviews in Economic Geology, 14: 157−181.
Vahdati-Daneshmand, F. and Eftekhar-Nezhad, J., 1991. Geological map of Birjand, Scale 1:250000. Geological Survey of Iran.
Vassigh, H. and Soheili, M., 1975. Geological map of Sar-E-chah-E-Shur, Scale 1:100000. Geological Survey of Iran.
Wang, K., Plank, T., Walker, J.D. and Smith, E.I., 2002. A mantle melting profile across the Basin and Range, SW USA. Journal of Geophysical Research: Solid Earth, 107(B1): 5–21.
Wass, S.Y. and Rogers, N.W., 1980. Mantle metasomatism- precursor to alkaline continental volcanism. Geochimica et Cosmochimica Acta, 44(11): 1811–1823.
Wilson, M., 1989. Igneous Petrogenesis. Chapman and Hall, London, 466 pp.
Woodhead, J., Eggins S. and Gamble, J., 1993. High field strength and transition element systematic in island arc and back-arc basin basalts: evidence for multi-phase melt extraction and a deoleted mantle wedge. Earth and Planetary Science Letters, 114(4): 491–504.
Wu, F.Y., Jahn, B.M., Wilde, S.A., Lo, C.H., Yui, T.F., Lin, Q., Ge, W.C. and Sun, D.Y., 2003. Highly fractionated I-type granites in China (I): geochronology and petrogenesis. Lithos, 66(3): 241–273.
Zarnab-e-ekteshaf Exploration Consulting Engineers Company, 2009. Report of Geology and alteration maps of Hamech, scale: 125000, (Birjand area, East Iran). Iranian mines and mining industrls development and renovation organization, Tehran, Report 1, 76 pp. (in Persian)
Zulkarnain, I., 2009. Geochemical signature of Mesozoic volcanic and granitic rocks in Madina regency area, North Sumatra, Indonesia and its tectonic implication. Indonesian Journal on Geoscience, 4(2): 117–131.
CAPTCHA Image