Geochemistry of Neogene Magmatic Rocks in West of Zavarian, Southwest of Salafchegan (Urumieh-Dokhtar Magmatic Belt)

Authors

Department of Geology, Payame Noor University (PNU), Tehran, Iran.

Abstract

Neogene magmatism in the west of Zavarian area has formed the Khastak volcanic mountain through two distinct magmatic phases. The rock units of the earlier phase include a series of basic to intermediate pyroclastics and basaltic andesite to andesite lavas that overlain the equivalent units of the Upper Red Formation. The later phase consists of small subvolcanic bodies with porphyritic gabbro–diorite lithology that cut through the previous units. The andesite – basaltic andesite rocks (earlier phase) and gabbro–diorite rocks (later phase) exhibit similar geochemical characteristics, therefore can be genetically related. In the rare earth element (REE) patterns, the gabbro–diorite group rocks display relatively flat patterns. However, with an increase in silica content and towards the andesite group rocks, the slope of the patterns increases systematically, showing enrichment of LREE compared to HREE. On multi-element diagrams, the LILE elements show slight enrichment compared to the LREE elements. However, as with subduction zone igneous rocks, Nb-Ta depletion can be observed compared to adjacent REEs. Based on the geochemical study of trace elements, these rocks exhibit intermediate characteristics of magmatic rocks associated with active continental margins and island arcs. The intermediate geochemical characteristics of active continental margins and island arcs can be related to magmatism in an extensional continental (ensialic) back-arc basin. The partial melting with relatively high degrees in a shallow lithospheric mantle in the spinel peridotite facies, which has previously undergone metasomatism due to the subduction, can be considered the cause of magmatism in this region.

Keywords

References

[1] Omrani J., Agard P., Whitechurch H., Benoit M., Prouteau G., Jolivet L., “Arcmagmatism and subduction history beneath Zagros: new report of adakites and geodynamic consequences”, Lithos 106 (2008) 380–398.
[2] Stocklin J., “Possible ancient continental margins in Iran”, In: Burk, C.A., Drake, C.L. (Eds.), The Geology of Continental Margins, Springer-Verlag, Berlin (1974) 873–887.
[3] Jung D., Ku¨rsten M., Tarkian M., “Post-Mesozoic volcanism in Iran and its relation to the subduction of the Afro-Arabian under the Eurasian plate. In: Pilger, A., Rosler, A. (Eds.), Afar between continental and oceanic rifting”, Schweizerbartsche Verlagbuchhandlung, Stuttgart (1976) 175-181.
[4] Berberian F., Muir I.D., Pankhurst R.J., Berberian M., “Late Cretaceous and early Miocene Andean type plutonic activity in northern Makran and central Iran”, Journal of Geological Society of London 139 (1982) 605–614.
[5] Shafiei B., Shahabpour J., Haschke M., “Transition from Paleogene normal calc-alkaline to Neogene adakitic-like plutonism and Cu-metallogeny in the Kerman Porphyry Copper Belt: Response to Neogene Crustal Thickening”, Journal of Sciences, Islamic Republic of Iran 19 (2008) 67-84.
[6] Ahmad T., Posht Kuhi M., “Geochemisty and petrogenesis of Urumiah-Dokhtar volcanics around Nain and Rafsanjan areas: a preliminary study.Treatise on the Geology of Iran”, Iranian Ministry of Mines and Metals (1993).
[7] Shahabpour J., “Island-arc affinity of the central Iranian volcanic belt”, Journal of Asian Earth Sciences 30 (2007) 652–65.
[8] Fazlnia A., Alizade A., “Petrology and geochemistry of the Mamakan gabbroic intrusions, Urumieh (Urmia), Iran”, Magmatic development of an intra-oceanic arc. Periodico di Mineralogia 82 (2013) 263-290.
[9] Hosseini B., Ahmadi A., Ghanbari Dolatabadi M., “The origin and tectonomagmatic setting of the dykes in north of Mashhad-Ardeha (in Persian)”, Scientific-Research Quarterly of Earth Sciences, 26 (2017) 187-198.
[10] Amidi S.M., Emami M.H., Michel R., “Alkaline character of Eocene volcanism in the middle part of Iran and its geodynamic situation”, Geologische Rundschau 73 (1984) 917-932.
[11] Hassanzadeh J., “Metallogenic and tectonomagmatic events in the SE sector of the Cenozoic active continental margin of Iran (Shahre Babak area, Kerman Province)”, PhD thesis, University of California, Los Angeles (1993) 204p.
[12] Moradian A., “Geochemistry, geochronology and petrography of feldspathoid bearing rocks in Urumieh-Dokhtar volcanic belt, Iran”, Ph.D thesis, University of Wollongong, Australia (1997).
[13] Alavi M., “Tectonostratigraphic synthesis and structural style of the Alborz Mountain system in northern Iran”, Journal of Geodynamics 21(1996) 1–33.
[14] Ghasemi A., Talbot C.J., “A new scenario for the Sanandaj- Sirjan zone (Iran)”, Journal of Asian Earth Sciences 26 (2006) 683-693.
[15] Emami M.H., “Géologie de la région de Qom-Aran (Iran): Contribution a l'étude dynamique et géochimique du volcanisme Tertiaire de l'Iran Central”, Ph.D thesis, University of Grenoble France (1981) 489 pp.
[16] Sabzehei M., “Les melanges ophiolitiques de la region d'Esfandagheh (Iran Meridional)-etude petrologique et structural”, interpretation dans le cadre Iranian, Thesis, Grenoble (1974) 306 p.
[17] Emami M. H., Monsef  R., Rashid Nejad Omran N., “Geochemistry and Petrogenesis of the Raveh Neogene Volcanic and Sub-Volcanic Rocks in the Urumieh – Dokhtar Magmatic Belt (Central Iran) (in Persian)”, scientific quarterly journal of geosciences 22 (2013) 91-104.
[18] Nazari M., Keshtgar S., Kananian A., Boomeri M., “Geochemistry of Salafchegan quartz diorite pluton (in Persian)”, Iranian Journal of Geology 40 (2016) 107-120.
[19] Zahmatkesh E., Heidar S M., “Geology and mineralization of Zavarian Au-(Cu) deposit (Qom-Salafchegan) (in Persian)”, scientific quarterly journal of geosciences 30 (2020) 39-50.
[20] Alai Mahabadi S., “Geological map of the Salafchegan-Khorhe, Scale 1:100,000”, Geological Survey of Iran, Sheet No. 6958 (2000).
[21] Emami M. H., Hajian J., “Geological map of the Qom, Scale 1:250,000”, Geological Survey of Iran, Sheet No. NI 39-6 (1991).
[22] Emami M. H., “Geologie de la region de Qom-Aran (Iran) contribution a l etude dynamique et geochimique du volcanisme tertiaire de l Iran Central”, These Doctorat Etat Grenoble, (1981) 489 pp.
[23] Chiu H.-Y., Chung S.-L., Zarrinkoub M.H., Mohammadi S.S., Khatib M.M., Iizuka Y., “Zircon U–Pb age constraints from Iran on the magmatic evolution related to Neotethyan subduction and Zagros orogeny”, Lithos 162 (2013) 70–87.
[24] Knaack  C., Cornelius S. B., Hooper P. R., “Trace element analyses of rocks and minerals by ICP-MS, Open File Rep”, Washington State Univ (1994).
[25] Shelly D., “Igneous and Metamorphic Rocks under the Microscope. Classification, Textures, Microstructures and Mineral Preferred Orientations”, London (Chapman and Hall), (1993) 445 p.
[26] Whitney D.L., Evans B.W., “Abbreviations for names of rock-forming minerals”, American mineralogist 95(2010.) 185– 187.
[27] Cox K.G., Bell J.D., Pankhurst R.J., “The Interpretation of Igneous Rocks”, George Allen & Unwin, London, (1979) 450 pp.
[28] Winchester J.A., Floyd P.A., “Geochemical discrimination of different magma series and their differentiation products using immobile elements”, Chemical Geology 20 (1977) 325-343.
[29] Irvine T.N., Baragar W.R.A., “A guide to the chemical classification of the common volcanic rocks”, Canadian Journal of Earth Science 8 (1971) 523–548.
[30] Peccerillo A., Taylor S. R., “Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonou area, northern Turkey”, Contributions to Mineralogy and Petrology 58 (1976) 63-81.
[31] Wilson M., “Igneous petrogenesis: a global tectonic approach”, Chapman & Hall, New York (1989) 496 p.
[32] Ross P. S., Bedard J. H., “Magmatic affinity of modern and ancient subalkaline volcanic rocks determined from trace element discrimination diagram”, Canadian Journal of Earth Sciences 46 (2009) 823–829.
[33] Rollinson H.R., “Using geochemical data: evaluation, presentation, interpretation, Longman”, Harlow, England (1993).
[34] Dai J.G., Wang C.S., Hebert R., Li Y.L., Zhong H.T., Guillaume R., Bezard R., Wei Y.S., “Late Devonian OIB alkaline gabbro in the YarlungZangbo suture zone: Remnants of the paleo-Tethys”, Gondwana Res (2011) 19, 232–243.
[35] Rudnick R., Gao S., “Composition of the continental crust. In Treatise on Geochemistry; Rudnick”, R., Ed.; Elsevier-Pergamon: Oxford, UK (2003) Volume 3, pp. 1–64.
[36] DePaolo D.J., Daley E.E., “Neodymium isotopes in basalts of the southwest basin and range and lithospheric thinning during continental extension”, Chem. Geol. 169 (2000) 157–185.
[37] Abdel-Rahman A., Nassar P., “Cenozoic volcanism in the Middle East: petrogenesis of alkali basalts from northern Lebanon”, Geol. Mag., Volume 141 (2004), pp. 545-563 .
[38] Wang K., Plank T., Walker J D., Smith E I., “A mantle melting profile across the Basin and Range, SW USA”, J. Geophys. Res. Solid Earth 107 (2002.).
[39] Jung C., Jung S., Hoffer E., Berndt J., “Petrogenesis of tertiary mafic alkaline magmas in the Hocheifel”, Germany. J. Petrol 47 (2006) 1637–1671.
[40]  Jahn B M., Wu F Y., Lo C H., “Crust–mantle interaction induced by deep subduction of the continental crust: geochemical and Sr–Nd isotopic evidence from postcollisional mafic–ultramafic intrusions of the northern Dabie Complex, Central China”, Chemical Geology 157 (1999) 119–146.
[41] Wood D.A., “The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary volcanic province”, Earth and Planetary Science Letters 42 (1980) 77-97.
[42] Pearce J. A., Cann J. R., “Tectonic setting of basic volcanic rocks investigated using trace element analyses”, Earth and Planetary Science Letters 19 (1973) 290-300.
[43] Condie K.C., “Geochemical changes in basalts and andesites across the Archean-Proterozoic boundary: Identification and significance”, Lithos 23 (1989) 1-18.
[44] Hollocher K e., “Geochemistry of amphibolite-facies volcanics and gabbros of the Støren Nappe in extensions west and southwest of Trondheim, Western Gneiss Region, Norway: a key to correlations and paleotectonic settings”, American Journal of Science 312.4 (2012) 357-416.
[45] Pearce J A., “Role of the sub-continental lithosphere in magma genesis at active continental margin. In: C.J. Hawkesworth and M.J. Norry (Eds.), Continental basalts and mantle xenoliths”. Shiva, Nantwich (1983) p. 230-249.
[46] Condie K.C., “Geochemistry and tectonic setting of Early Proterozoic supracrustal rocks in the Southwestern United States”, Journal of Geology 94 (1986) 825–864.
[47] Farahat E.S., El Mahalawi M. M., Hoinkes G., Abdel Aal A. Y., “Continental back-arc basin origin of some ophiolites from the Eastern Desert of Egypt”, Mineralogy and Petrology 82 (2004) 81–104.
[48] Shinjo R., Chung S.I., Kato Y., Kimura M., “Geochemical and Sr–Nd isotopic characteristics of volcanic rocks from the Okinawa Trough and Ryuku arc: implications for the evolution of a young intracontinental back arc basin”, Journal of Geophysical Research 104 (1999) 1059–1068.

Files

History

  • Receive Date: 11 September 2024
  • Revise Date: 21 November 2024
  • Accept Date: 04 December 2024

Share

How to cite

Statistics