Geochemistry and source characteristics of Dehsard mafic volcanic rocks in the southeast of the Sanandaj–Sirjan zone, Iran: implications for the evolution of the Neo-Tethys Ocean

  The Late Jurassic-Early Cretaceous Dehsard mafic volcanic rocks crop out in the southeastern Sanandaj-Sirjan Zone (SSZ), composed primarily of basalts and basaltic andesite with subordinate dolerite. They are influenced to some degree by hydrothermal alteration under zeolite-greenschist facies. Using fairly immobile trace elements, the mafic volcanic rocks show subalkaline (tholeiitic) affinities. They commonly have similar designs with somewhat strong enrichment in light rare earth elements (LREEs) and large ion lithophile elements (LILEs) and depletion in high field strength elements (HFSEs; e.g., Nb, Ta, Ti) and nearly flat heavy rare earth element (HREE) patterns. The negligible or absence of negative Eu anomalies indicate that plagioclase played an insignificant role during magma evolution. The low La/Nb (1.03-2.31) and Nb/Y (0.12-0.46) ratios, relatively high Zr/Y (4.03-8.18) and Th/Ta (2.25- 9.64) ratios, steady enhanced normalized patterns, and moderate La/Nb ratios hint at an island arc and most likely a back-arc basin environment for the formation of Dehsard mafic volcanic rocks. The arc magma resulted from partial melting of depleted mantle source that experienced assimilation and fractional crystallization and was enhanced by melts of subducted sediments or contribution of slabderived fluids in an intraoceanic subduction environment in the Neo-Tethyan Ocean. Therefore, the presence of an island arc setting (Dehsard island arc) must be investigated in the south of the SSZ prior to the Late Jurassic-Early Cretaceous as the Neo-Tethys oceanic crust was subducting north beneath the southern margin of the Central Iranian Microcontinents. The later collision of the arc with SSZ led to tectonic proximity of the Dehsard mafic volcanic rocks to SSZ components.

___

  • Agard P, Omrani J, Jolivet L, Mouthereau F (2005). Convergence history across Zagros (Iran): Constraints from collisional and earlier deformation. Int J Earth Sci 94: 401–419, doi:10.1007/ s00531-005-0481-4.
  • Ahmad T, Posht Kuhi M (1993). Geochemistry and petrogenesis of Urumiah-Dokhtar volcanic belt around Nain and Rafsanjan areas: a preliminary study. Treatise on the geology of Iran. Iranian Ministry of Mines and Metals, p. 90.
  • Ahmadi Khalaji A, Esmaeily D, Valizadeh MV, Rahimpour-Bonab H (2007). Petrology and geochemistry of the granitoid complex of Boroujerd, Sanandaj–Sirjan Zone, Western Iran. J Asian Earth Sci 29: 859-877.
  • Alavi M (2004). Regional stratigraphy of the Zagros folded-thrust belt of Iran and its proforeland evolution. Am J Sci 304: 1-20.
  • Amiri M, Ahmadi Khalaji A, Tahmasbi Z, Santos JF, Zarei Sahamieh R, Zamanian H (2017). Geochemistry, petrogenesis, and tectonic setting of the Almogholagh batholith in the Sanandaje–Sirjan zone, western Iran. J African Earth Sci 134: 113-133.
  • Arvin M, Pan Y, Dargahi S, Malekizadeh A, Babaei A (2007). Petrochemistry of the Siah–Kuh granitoid stock southwest of Kerman, Iran: implications for initiation of Neotethys subduction. J Asian Earth Sci 30: 474-489.
  • Azizi H, Asahara Y (2013). Juvenile granite in the Sanandaj–Sirjan Zone, NW Iran: late Jurassic–Early Cretaceous arc–continent collision. Int Geol Rev 55: 1523-1540.
  • Bagas L, Bierlein FP, English L, Anderson JAC, Maidmentd D, Hustond DL (2008). An example of a Palaeoproterozoic back-arc basin: petrology and geochemistry of the ca. 1864Ma Stubbins Formation as an aid towards an improved understanding of the Granites–Tanami Orogen, Western Australia. Precamb Res 166: 168-184.
  • Baharifar A, Moinevaziri H, Bellon H, Piqué A (2004). The crystalline complexes of Hamadan (Sanandaj–Sirjan zone, western Iran): metasedimentary Mesozoic sequences affected by Late Cretaceous tectono-metamorphic and plutonic events. Compt Rend Geosci 336: 1443-1452.
  • Beccaluva L, Coltorti M, Giunta G, Siena F (2004). Tethyan vs. Cordilleran ophiolites: a reappraisal of distinctive tectono- magmatic features of supra-subduction complexes in relation to the subduction mode. Tectonophysics 393: 163-374.
  • Berberian F, Berberian M (1981). Tectono-plutonic episodes in Iran. In: Gupta HK, Delany FM, editors. Zagros, Hindu Kush, Himalaya, geodynamic evolution: Geodynamic Series 3, Working Group 6, Am Geophys Union, pp. 5-32.
  • Berberian M, King GC (1981). Towards a paleogeography and tectonics evolution of Iran. Can J Earth Sci 18: 210-265.
  • Berberian F, Muir ID, Pankhurst RJ, Berberian M (1982). Late Cretaceous and early Miocene Andean‐type plutonic activity in northern Makran and central Iran. J Geol Soc London 139: 605-614.
  • Bonin B (2004). Do coeval mafic and felsic magmas in post-collisional to within-plate regimes necessarily imply two contrasting, mantle and crustal, sources? A review. Lithos 78: 1-24.
  • Cameron WE, Nisbet EG, Dietrich VJ (1980). Petrographic dissimilarities between ophiolitic and ocean-floor basalts. In: Panayiotou A, editor. Ophiolites. Proc Internat Ophiolite Symp Geol Surv Dept Cyprus Nicosia, pp. 182-192.
  • Cann JR (1970). Rb, Sr, Y, Zr and Nb in some ocean floor basaltic rocks. Earth Planet Sci Lett 10: 7-11.
  • Caulfield JT, Turner SP, Dosseto A, Pearson NJ, Beier C (2008). Source depletion and extent of melting in the Tongan sub-arc mantle. Earth Planet Sci Lett 273: 279-288.
  • Class C, Miller DM, Goldstein SL, Langmuir CH (2000). Distinguishing melt and fluid subduction components in Umnak Volcanics, Aleutian Arc. Geochem Geophys Geosyst 1, doi.org/10.1029/1999GC000010.
  • Condie KC (1989). Geochemical changes in basalts and andesites across the Archean Proterozoic boundary: identification and significance. Lithos 23: 1-18.
  • Cox KG, Hawkesworth CJ (1985). Geochemical stratigraphy of the Deccan Traps at Mahabaleshwar, Western Ghats, India, with implications for open system magmatic processes. J Petrol 26: 355-377.
  • De Paolo DJ, Daley EE (2000). Neodymium isotopes in basalts of the southwest basin and range and lithospheric thinning during continental extension. Chem Geol 169: 157-185.
  • Esna-Ashari A, Tiepolo M, Valizadeh MV, Hassanzadeh J, Sepahi AA (2012). Geochemistry and zircon U-Pb geochronology of Aligoodarz granitoid complex, Sanandaj-Sirjan zone, Iran. J Asian Earth Sci 43: 11-22.
  • Erturk MA, Beyarslan M, Chung SL, Lin TH (2017). Eocene magmatism (Maden Complex) in the Southeast Anatolian Orogenic Belt: Magma genesis and tectonic implications. Geos Front https://doi.org/10.1016/j.gsf.2017.09.008.
  • Fergusson CL, Nutman AP, Mohajjel M, Bennett VC (2016). The Sanandaj–Sirjan Zone in the Neo-Tethyan suture, western Iran: Zircon U–Pb evidence of late Palaeozoic rifting of northern Gondwana and mid-Jurassic orogenesis. Gondwana Res 40: 43-57.
  • Floyd PA (1989). Geochemical features of intraplate oceanic plateau basalts. In: Saunders A, Norry M, editors. Magmatism in ocean basins. Geol Soc London Spec Publ 42: 215-230.
  • Floyd PA, Kelling G, Gocken SL, Gocken N (1991). Geochemistry and tectonic environment of basaltic rocks from the Miss ophiolitic melange, south Turkey. Chem Geol 89: 263-280.
  • Floyd PA, Winchester JA (1978). Identification and discrimination of altered and metamorphosed volcanic rocks using immobile elements. Chem Geol 21: 291-306.
  • Förster H, Fesefeldt K, Kürsten M (1972). Magmatic and orogenic evolution of the central Iranian volcanic belt. In 24th International Geologic Congress, edited by Armstrong JE Hedberg HD, Int Geol Congr Montreal QC Canada, pp. 198- 210.
  • Genç ŞC, Tüysüz O (2010). Tectonic setting of the Jurassic bimodal magmatism in the Sakarya Zone (Central and Western Pontides), Northern Turkey: a geochemical and isotopic approach. Lithos 118: 95-111.
  • Çolakoğlu AL, Günay K, Göncüoğlu MC, Oyan V, Erdoğan K (2014). Geochemical evaluation of the late Maastrichtian subduction- related volcanism in the southern Neotethys in Van area, and a correlation across the Turkish-Iranian border. Ofioliti 39: 51- 65.
  • Gorton MP, Schandl ES (2000). From continents to island arcs: a geochemical index of tectonic setting for arc-related and within-plate felsic to intermediate volcanic rocks. Can Mineral 38: 1065-1073.
  • Haschke M, Gunther A (2003). Balancing crustal thickening in arcs by tectonic vs magmatic means. Geology 31: 933-936.
  • Hawkesworth CJ, Gallagher K, Hergt JM, McDermott F (1993). Mantle slab contributions in arc magmas. Annu Rev Earth Planet Sci 21: 175-204.
  • Hawkesworth CJ, Turner SP, McDermott F, Peate DW van Calsteren P (1997). U-Th isotopes in arc magmas: implications for element transfer from the subducted crust. Science 276: 551-555.
  • Hickey-Vargas R, Savov I, Bizimis M, Ishii T, Fujioka K (2006). Origin of diverse geochemical signatures in igneous rocks from the West Philippine Basin: implications for tectonic models. In: Christie D, editor. Back-arc spreading systems: geological, biological, chemical and physical interactions. AGU Geophys Monog Ser 166: 287-303.
  • Jung D, Kursten M, Tarakian M (1976). Post-Mesozoic Volcanism in Iran and Its Relation to the Sub-Duction of the Afro-Arabian under the Eurasian Plate. In: Pilger A, Rosler A, editors. Afar between Continental and Oceanic Rifting, Volume II, Stuttgart, Germany: Schweizerbatsche Verlagsbuch-Handlung, pp. 175- 181.
  • Kay SM, Mpodozis C, Ramos VA, Munizaga F (1991). Magma source variations for mid-Tertiary magmatic rocks associated with a shallowing subduction zone and a thickening crust in the Central Andes (288–338S). In Harmon RS, Rapela CW, editors. Andean magmatism and its tectonic setting. Geol Soc Am Spec Publ 265: 113-137.
  • Kay SM, Mpodozis C, Tittler A, Cornejo P (1994). Tertiary magmatic evolution of the Maricunga mineral belt in Chile. Int Geol Rev 36: 1079-1112.
  • Keskin M, Pearce JA, Mitchell JG (1998). Volcano-stratigraphy and geochemistry of collision-related volcanism in the Erzurum- Kars plateau, northeastern Turkey. J Volcanol Geotherm Res 85: 355-404.
  • Leat PT, Livermore RA, Millar IL, Pearce JA (2000). Magma supply in back-arc spreading centre segment E2, East Scotia Ridge. J Petrol 41: 845-866.
  • Leat PT, Pearce JA, Barker PF, Millar IL, Barry TL, Larter RD (2004). Magma genesis and mantle flow at a subducting slab edge: the South Sandwich arc-basin system. Earth Planet Sci Lett 227: 17-35.
  • Liu B, Ma CQ, Zhang JY, Xiong FH, Huang J, Jiang HA (2014). 40 Ar– 39 Ar age and geochemistry of subduction-related mafic dikes in northern Tibet, China: petrogenesis and tectonic implications. Int Geol Rev 56: 57-73.
  • Liu SW, Zhang J, Li QG, Zhang LF, Wang W, Yang PT (2012b). Geochemistry and U– Pb zircon ages of metamorphic volcanic rocks of the Paleoproterozoic Lüliang Complex and constraints on the evolution of the Trans-North China Orogen, North China Craton. Precamb Res 222: 173-190.
  • Ma X, Chen B, Chen JF, Qu WJ (2014). Petrogenesis and geodynamic significance of the late Palaeozoic Dongwanzi Complex, North China Craton: constraints from petrological, geochemical, and Os-Nd-Sr isotopic data. Int Geol Rev 56: 1521-1540.
  • McDonough WF, Sun SS (1995). The composition of the Earth. Chem Geol 120: 223-253.
  • McKenzie D, O’Nions RK (1991). Partial melt distributions of rare earth element concentrations. J Petrol 32: 1021-1091.
  • Mohajjel M, Fergusson CL (2000). Dextral transpression in late Cretaceous continental collision, Sanandaj-Sirjan Zone, Western Iran. J Struct Geol 22: 1125-1139.
  • Mohajjel M, Fergusson CL, Sahandi MR (2003). Cretaceous– Tertiary convergence and continental collision, Sanandaj- Sirjan Zone, western Iran. J Asian Earth Sci 21: 397–412.
  • Nazemzadeh M, Rashidi A (2006). Geological map of the Dehsard (Bezar), Scale 1/100,000. Geological Survey of Iran, Sheet No. 7347.
  • Oyan V, Keskin M, Lebedev VA, Chugaev AV, Sharkov E (2016). Magmatic evolution of the Early Pliocene Etrüsk stratovolcano, eastern Anatolian collision zone, Turkey. Lithos 256-257: 88- 108.
  • Özdamar S (2016). Geochemistry and geochronology of late Mesozoic volcanic rocks in the northern part of the Eastern Pontide Orogenic belt (NE Turkey): implications for the closure of the Neo-Tethyan Ocean. Lithos 248-251: 240-256.
  • Pearce JA (1975). Basalt geochemistry used to investigate past tectonic environments on Cyprus. Tectonophysics 25: 41-68.
  • Pearce JA (1982). Trace element characteristics of lavas from destructive plate boundaries. In: Thorpe RS, editor. Andesites. New York, NY, USA: Wiley, pp. 525-548.
  • Pearce JA (1983). Role of the subcontinental lithosphere in magma genesis at active continental margins. In: Hawkesworth CJ, Norry MJ, editors. Continental Basalts and Mantle Xenoliths. Nantwich, UK: Shiva Press, pp. 230-249.
  • Pearce JA (1996). A user’s guide to basalt discrimination diagrams. In: Wyman DA, editor. Trace Element Geochemistry of Volcanic Rocks; Applications for Massive Sulphide Exploration. Geol Assoc Canada Short Course Notes 12, pp. 79-113.
  • Pearce JA, Baker PE, Havery PK, Luff IW (1995). Geochemical evidence for subduction fluxes, mantle melting and fractional crystallization beneath the South Sandwich island arc. J Petrol 36: 1073-1109.
  • Pearce JA, Cann JR (1973). Tectonic setting of basic volcanic rocks determined using trace element analyses. Earth Planet Sci Lett 12: 339-349.
  • Pearce JA, Lippard SJ, Roberts S (1984). Characteristics and tectonic significance of supra-subduction zone ophiolites. In: Kolelaar BP, Howells MF, editors. Marginal basin geology. Geol Soc London Spec Publ 16: 77-94.
  • Pearce JA, Norry MJ (1979). Petrogenetic implications of Ti, Zr, Y and Nb variations in volcanic rocks. Contrib Mineral Petrol 69: 33-47.
  • Pearce JA, Parkinson IJ (1993). Trace element models for mantle melting: application to volcanic arc petrogenesis. In: Prichard HM, Alabaster T, Harris NBW, Neary CR, editors. Magmatic Processes and Plate Tectonics. Nantwich, UK: Shiva Press, pp. 373-403.
  • Pearce JA, Peate DW (1995). Tectonic implications of the composition of volcanic arc magmas. Annu Rev Earth Planet Sci 23: 251- 286.
  • Pearce JA Stern RJ (2006). Origin of back-arc basin magmas: trace element and isotope perspectives. In: Christie D, editor. Back- arc spreading systems: geological, biological, chemical and physical interactions. AGU Geophy Monog Ser 166: 63-86
  • Pearce JA, Stern JA, Bloomer SH, Fryer P (2005). Geochemical mapping of the Mariana arc-basin system: implications for the nature and distribution of subduction components. Geochem Geophys Geosyst 6, Q07006, doi:10.1029/2004GC000895.
  • Pearce JA, van der Laan SR, Arculus RJ, Murton BJ, Ishii T, Peate DW, Parkinson IJ (1992). Boninite and harzburgite from Leg 125 (Bonin–Mariana forearc): a case study of magma genesis during the initial stages of subduction. Proc Ocean Drill Prog Sci Results pp. 623-659.
  • Pin C, Paquette JL (1997). A mantle-derived bimodal suite in the Hercynian belt: Nd isotope and trace element evidence for a subduction-related rift origin of the late Devonian Brevenne metavolcanics, Massif Central (France). Contrib Mineral Petrol 129: 222-238.
  • Plank T (2005). Constraints from Thorium/Lanthanum on sediment recycling at subduction zones and the evolution of the continents. J Petrol 46: 921-944.
  • Qian X, Wang Y Feng Q, Wei ZiJ, Zhang Y, Chonglakmani C (2016). Petrogenesis and tectonic implication of the Late Triassic post- collisional volcanic rocks in Chiang Khong, NW Thailand. Lithos, 248-251: 418-431.
  • Rajabzadeh MA, Dehkordi TN, Caran S (2013). Mineralogy, geochemistry and geotectonic significance of mantle peridotites with high-Cr chromitites in the Neyriz ophiolite from the outer Zagros ophiolite belts, Iran. J African Earth Sci 78: 1-15.
  • Rapp RP, Watson EB (1995). Dehydration melting of metabasalt at 8-32 kbar: implications for continental growth and crust- mantle recycling. J Petrol 36: 891-931.
  • Sabzehei M (1994). Geological map of the Hajiabad, Scale 1/250,000. Geological Survey of Iran, Quadrangle No. 112.
  • Saunders AD, Tarney J (1979). The geochemistry of basalts from a back-arc spreading centre in the east Scotia Sea. Geochim Cosmochim Acta 43: 555-572.
  • Saunders AD, Tarney J (1984). Geochemical characteristics of basaltic volcanism within back-arc basins. In: Kloeaar BP, Howells MF, editors. Marginal basin geology. Geol Soc London Spec Publ 16: 59-76.
  • Sayit K, Marroni M, Göncüoglu MC, Pandolfi L, Ellero A, Ottria G, Frassi C (2016). Erratum to: Geological setting and geochemical signatures of the mafic volcanic rocks from the Intra-Pontide Suture Zone: implications for the geodynamic reconstruction of the Mesozoic Neotethys. Int J Earth Sci (Geol Rundsch) 105: 39-64.
  • Schandl ES, Gorton MP (2002). Application of high field strength elements to discriminate tectonic settings in VMS environments. Econ Geol 97: 629-642.
  • Schroeder JW (1944). Essai sur la structure de l’Iran. Eclogae Geol Helv 37: 37-81 (in French).
  • Sedighian S, Dargahi S, Arvin M (2017). Petrochemistry of Khunrang intrusive complex, southeast of Kerman, Iran: implications for magmatic evolution of Sanandaj-Sirjan zone in the Mesozoic time. J African Earth Sci 134: 149-165.
  • Şengör AMC, Natal’in BA (1996). Paleotectonics of Asia: fragments of a synthesis. In: Yin A, Harrison TM, editors. The Tectonic Evolution of Asia. Cambridge, UK: Cambridge University Press, pp. 486-640.
  • Shahbazi H, Siebel W, Pourmoafee M, Ghorbani M, Sepahi AA, Shang CK, Abedini MV (2010). Geochemistry and U–Pb zircon geochronology of the Alvand plutonic complex in Sanandaj–Sirjan Zone (Iran): new evidence for Jurassic magmatism. J Asian Earth Sci 39: 668-683.
  • Shaker Ardakani AR (2016). Post-collisional Plio-Pleistocene Anar- Dehaj adakitic subvolcanic domes in the central volcanic belt of Iran: geochemical characteristics and tectonic implications. Period Mineral 85: 185-200.
  • Shaker Ardakani AR, Arvin M, Oberhansli R, Mock B, Moeinzadeh SH (2009). Morphology and petrogenesis of pillow lavas from the Ganj ophiolitic complex, southeastern Kerman, Iran. J. Sci I R Iran 20: 139–151.
  • Shervais JW (1982). Ti-V plots and the petrogenesis of modern and ophiolitic lavas. Earth Planet Sci Lett 59: 101-118
  • Singh J, Johannse W (1996). Dehydration melting of tonalites: part II. Composition of melts and solids. Contri Mineral Petrol 125: 26-44.
  • Slovenec D, Lugovic B, Vlahovic I (2010). Geochemistry, petrology and tectonomagmatic significance of basaltic rocks from the ophiolite mélange at the NW external-internal Dinarides junction (Croatia). Geol Carpathica 61: 273-292.
  • Stocklin J (1968). Structural history and tectonics of Iran: a review. Am Assoc Petrol Geol Bull 52: 1229-1258.
  • Stolz AJ, Jochum KP, Spettel B, Hofmann AW (1996). Fluid- and melt-related enrichment in the subarc mantle: evidence from Nb/Ta variations in island-arc basalts. Geology 24: 587-590.
  • Sun S, McDonough WF (1989). Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. Geol Soc London Spec Publ 42: 313-345.
  • Tatsumi Y, Kosligo T, Nohda S (1995). Formation of a third volcanic chain in Kamchatka; generation of unusual subduction-related magmas. Contrib Mineral Petrol 120: 117-128.
  • Temizel I, Arslan M (2008). Petrology and geochemistry of Tertiary volcanic rocks from the İkizce (Ordu) area, NE Turkey: implications for the evolution of the eastern Pontide paleomagmatic arc. J Asian Earth Sci 31: 439-463.
  • Turner SP, Foden JD, Morrison RS (1992). Derivation of some A-type magmas by fractionation of basaltic magma: an example from the Padthaway Ridge, South Australia. Lithos 28: 151-179.
  • Thompson G (1991). Metamorphic and hydrothermal processes: basalt-sea water interactions. In: Floyd PA, editor. Ocean Basalts. Glasgow, UK: Blackie, pp. 143-73.
  • Wang T, Wang Z, Yana Z, Ma Z, He S, Fua C, Wang D (2016). Geochronological and geochemical evidence of amphibolite from the Hualong Group, northwest China: implication for the early Paleozoic accretionary tectonics of the Central Qilian belt. Lithos 248-251: 12-21.
  • Wilson M (1989). Igneous Petrogenesis: a Global Tectonic Approach. Boston, MA, USA: Unwin Hyman.
  • Winchester JA, Floyd PA (1976). Geochemical magma type discrimination: application to altered and metamorphosed basic igneous rocks. Earth Planet Sci Lett 28: 459-469.
  • Winchester JA, Floyd PA (1977). Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chem Geol 20: 325-343.
  • Wood DA (1980). The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and establishing the nature of crustal contamination of basaltic lavas of the British Tertiary volcanic province. Earth Planet Sci Lett 50: 11-30.
  • Woodhead J, Eggins S, Gamble J (1993). High-field strength and transition element systematics in island arc and back-arc basin basalts: evidence for multiphase melt extraction and a depleted mantle wedge. Earth Planet Sci Lett 114: 491-504.