Geology, petrography, alteration, mineralization and petrogenesis of intrusive bodies in the Hamech prospect area, Southwest of Birjand

Document Type : Research Article

Authors

Ferdowsi University of Mashhad

Abstract

Introduction
The Hamech prospect area is located in the eastern Iran, 85 kilometers southwest of Birjand. The study area coordinates between 58‌‌˚‌53΄‌00 ˝ to 59˚‌00΄‌00˝ latitude and 32˚‌22΄‌30 ˝ to 32˚‌26΄‌00˝ longitude. Due to the high volume of magmatism and the presence of geo-structure special condition in the Lut Block at a different time, a variety of metal (copper, lead, zinc, gold, etc.) and non-metallic mineralization has been formed (Karimpour et al., 2012). The studied area (Hamech) includes Paleocene-Eocene igneous outcrops which contain a wide range of subvolcanic bodies (diorite to monzonite porphyry) associated with mafic intrusives, volcanic units (andesite), volcaniclastic and sedimentary rocks.

Material and Methods
This study was done in two parts including field and laboratory works. Sampling and structural studies were done during field work. Geological and alteration maps for the study area were also prepared. 200 thin and 60 polished sections for petrographic purpose were studied. The number of 200 thin sections and 60 polished sections were prepared and studied in order to investigate petrography and mineralogy. Major oxides (XRF method- East Amethyst Laboratory in Mashhad), rare earth elements and trace (ICP-MS method-ACME Laboratory in Vancouver, Canada) elements were analyzed for 13 samples that included subvolcanic units and intrusive bodies. Data processing and geological and alteration mapping is done by the GCD.kit and Arcgis software.

Discussion and Results
Based on lab work and XRF analysis, the rocks in the area are composed of intrusive-subvolcanic bodies and volcanic rocks (andesite, trachyandesite and dacite) together with volcano-classic and sedimentary rocks. Also, alteration zones consist of a variety of argillic, silicified, quartz-sericite-pyrite (QSP), propylitic and carbonate. Igneous rock textures are mainly porphyritic for sub-volcanic and granular for intrusive bodies. Phenocrysts mainly consist of plagioclase and hornblende dominated with minor of biotite and pyroxene. XRF studies and output charts show that rocks include monzonite, diorite, gabbro and gabbroic diorite. Intermediate subvolcanic units (monzonite, diorite) and mafic intrusives (gabbro and gabbroic-diorite) are related to high-potassium calc-alkaline (K2O between 2.42 to 4%) and tholeiitic (K2O between 0.15 to 0.27%) series, respectively. Subvolcanic units belong to the I-type granitoid (Chappell and White, 2001).
Mantle normalized , trace-element spider diagrams display enrichment in LREE, such as Rb, Sr, K, and Cs, and depletion in HREE, e.g., Nb, Ti, Zr that indicate magma formed in the subduction zone. Nb depletion (less than 6 ppm, between 0.5 to 5.2 ppm) in subvolcanic bodies represents a volcanic arc granitoids (VAG) tectonic setting that is related to the subduction zone (Pearce et al., 1984). Also, this reduction shows that these rocks are derived of oceanic crust (Wilson, 1989). Enrichment in LREE and depletion of HREE with a low (La/Yb)N ratio in the Hamech subvolcanic rocks (6/85 to 8/13) could represent a low degree of mantle partial melting (Wass and Rogers, 1980). Zr/Nb ratio of more than 10 for Hamech rocks (between 21 and 35 for intermediate subvolcanic and 67 to 72 for mafic bodies) indicates that parental magma has minimal crustal contamination (Karimpour et al., 2012). Sr enrichment (between 646 to 1124) and low negative Eu anomaly (Eu/Eu* ratio between 0.81 to 1/02) show that plagioclase is rare (or is not present) as residue mineral in the source and melt conditions have been in oxidation state (Tepper et al., 1993). Based on Sm/Yb vs. La/Sm (Shaw, 1970) and Ce/Yb vs. Sm/Yb (Wang et al., 2002) diagrams, parent magma is composed of 1 to 5% spinel-garnet lherzolite partial melting (with small amounts of garnet) at a depth between 65 to 67 km (upper mantle) for subvolcanic units and 5 to 20% spinel lherzolite partial melting (depletion mantle-NMORB) with a depth of less than 55 km for mafic bodies.
Suitable tectonic setting, existence of subvolcanic units with intermediate composition, magnetic activity with the nature of calc-alkaline and oxidants, data from major and REE studies, mineralization as disseminated and veinlets with high secondary iron oxides in surface show suitable conditions of porphyry and epithermal mineralization in the Hamech prospect area.

References
Chappell, B.W. and White, A.J.R., 2001. Two
contrasting granite types, 25years later. Australian Journal of Earth Sdiences, 48(4): 489–500.
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)
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.
Shaw, D.M., 1970. Trace element fractionation during anataxis. Geochimica et Cosmochimica Acta, 34(2): 237–243.
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.
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.

Keywords


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.
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