New constraints on lithospheric thickness of the Iranian plateau using converted waves

Journal of Seismology - Tập 17 - Trang 883-895 - 2013
Najmieh Mohammadi1, Forough Sodoudi2,3, Elham Mohammadi1, Ahmad Sadidkhouy1
1Institute of Geophysics, University of Tehran, Tehran, Iran
2Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Potsdam, Germany
3Freie Universität Berlin, Berlin, Germany

Tóm tắt

The study of mantle lithosphere plays a key role to reveal predominant tectonic setting process of a region. The current geological and tectonic setting of Iran is due to the ongoing continental–continental collision of the Arabian and Eurasian plates. We applied a combined P and S receiver function analysis to the teleseismic data of nine permanent broadband seismic stations of the International Institute of Earthquake Engineering and Seismology located in different tectonic zones of Iranian plateau. More than 4 years of data were used to estimate the thickness of the crust and mantle lithosphere. According to our results, the crust is 50 km thick beneath the Zagros fold and thrust belt (ZFTB). We found the maximum Moho depth of approximately 70 km under the Sanandaj-Sirjan zone (SSZ) indicating the overthrusting of the crust of Central Iran onto the Zagros crust along the main Zagros thrust (MZT). Below the northeasternmost part of the Urumieh–Dokhtar Magmatic Arc (UDMA) and Central Iran, the Moho becomes shallower and lies at 40 km depth. Towards northeast, beneath the Alborz zone, the crust is 55 km thick. Based on S receiver functions, we provided new insights into the thickness of the Arabian and Eurasian lithospheres. The location of the boundary between these plates was estimated to be beneath the SSZ, which is slightly shifted northeastward relative to the surficial expression of the MZT. Furthermore, the Arabian plate is characterized by the relatively thick lithosphere of about 130 km beneath the ZFTB reaching 150 km beneath the SSZ, where the thickest crust was also observed. This may imply that the shortening across the Zagros is accommodated by lithospheric thickening. In contrast, UDMA and Central Iran are recognized by the thin lithosphere of about 80–85 km. This thin lithosphere may be associated with the asthenospheric upwelling caused by either lithospheric delamination or Neo-Tethys slab detachment beneath the Zagros collision zone.

Tài liệu tham khảo

Abt DL, Fischer KM, French SW, Ford HA, Yuan H, Romanowicz B (2010) North American lithospheric discontinuity structure imaged by Ps and Sp receiver functions. J Geophys Res 115:B09301 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 Afsari N, Sodoudi F, Taghizadeh Farahmand F, Ghassemi MR (2011) Crustal structure of Northwest Zagros (Kermanshah) and Central Iran (Yazd and Isfahan) using teleseismic Ps converted phases. J Seismol 15:341–353 Allen MB, Jackson J, Walker R (2004) Late Cenozoic reorganization of the Arabia–Eurasian collision and the comparison of short-term and long-term deformation rates. Tectonics 23:TC2008 Artemieva IM, Mooney WD (2001) Thermal thickness and evolution of Precambrian lithosphere: a global study. J Geophys Res B106:16387–16414 Axen GJ, Lam PS, Grove M, Stockli DF (2001) Exhumation of the West–Central Alborz Mountains, Iran, Caspian subsidence, and collision-related tectonics. Geology 29:559–562 Berberian M, King GCP (1981) Towards a paleogeography and tectonic evolution of Iran. Can J Earth Sci 18:210–265 Berberian M (1983) The southern Caspian: a compression depression floored by a trapped modified oceanic crust. Can J Earth Sci 20(2):163–183 Bird P (1978) Finite element modeling of lithosphere deformation: the Zagros collision orogeny. Tectonophysics 50:307–336 Carminati E, Wortel MJR, Spakman W, Sabadini R (1998) The role of slab detachment processes in the opening of the western–central Mediterranean basins: some geological geophysical evidence. Earth Planet Sci Lett 160:651–665 Davies JH, von Blanckenburg F (1995) Slab breakoff: a model of lithosphere detachment and its test in the magmatism and deformation of collisional orogens. Earth Planet Sci Lett 129:85–102 Debayle E, Leveque JJ, Cara M (2001) Seismic evidence for a deeply rooted low-velocity anomaly in the upper mantle beneath the northeastern Afro-Arabian continent. Earth Planet Sci Lett 193(3–4):423–436 Dehghani GA, Makris J (1984) The gravity field and crustal structure of Iran. Neues Jahrbuch Geol Palaeont Abh 168:215–229 Dewey JF, Hempton MR, Kidd WSF, Saroglu F, Sengor AMC (1986) Shortening of continental lithosphere: the neotectonics of eastern Anatolia—a young collision zone. In: Coward MP, Ries AC (eds) Collision tectonics. Geol Soc, London, pp 3–36 Faber S, Müller G (1980) Sp phases from the transition zone between the upper and lower mantle. Bull Seismol Soc Am 70:487–508 Falcon NL (1974) Southern Iran: Zagros mountains. Spec Pub Geol Soc Lond 4:199–211 Farra V, Vinnik L (2000) Upper mantle stratification by P and S receiver functions. Geophys J Int 141:699–712 Geissler WH, Sodoudi F, Kind R (2010) Thickness of the central and eastern European lithosphere as seen by S receiver functions. Geophys J Int 181(2):604–634. doi:10.1111/j.1365-246X.2010.04548.x Heit B, Sodoudi F, Yuan X, Bianchi M, Kind R (2007) An S-receiver function analysis of the lithospheric structure in South America. Geophys Res Lett 34:L14307 Jackson J, McKenzie D (1984) The active tectonics of the Alpine-Himalayan belt between western Turkey and Pakistan. Geophys J R Astr Soc 77:185–264 Jackson J, Hains J, Holt W (1995) The accommodation of Arabia–Eurasia plate. J Geophys Res 100:15205–15219 Jackson J, Priestley K, Allen M, Berberian M (2002) Active tectonics of the South Caspian Basin. Geophys J Int 148(2):214–245 Kawakatsu H, Kumar P, Takei Y, Shinohara M, Kanazawa T, Araki E, Suyehiro K (2009) Seismic evidence for sharp lithosphere–asthenosphere boundaries of oceanic plates. Science 324:499–502 Kaviani A, Paul A, Bourova E, Hatzfeld D, Pedersen H, Mokhtari M (2007) A strong seismic velocity contrast in the shallow mantle across the Zagros collision zone (Iran). Geophys J Int 171:399–410 Keshvari F, Shomali ZH, Tatar M, Kaviani A (2011) Upper-mantle S-velocity structure across the Zagros collision zone resolved by nonlinear teleseismic tomography. J Seismol 15:329–339 Kennett BLN, Engdahl ER (1991) Travel times for global earthquake location and phase identification. Geophys J Int 105:429–465 Kumar P, Kind R, Hanka W, Wylegalla K, Reigber C, Yuan X, Woelbern I, Chwintzer P, Fleming K, Dahl-Jensen T, Larsen TB, Schweitzer J, Priestley K, Gudmundsson O, Wolf D (2005a) The lithosphere-asthenosphere boundary in the North-West Atlantic region. Earth Planet Sci Lett 236:249–257 Kumar P, Kind R, Kosarev G (2005b) The lithosphere-asthenosphere boundary in the Tien Shan-Karakoram region from S receiver functions: evidence for continental subduction. Geophys Res Lett 32:L07305 Kumar P, Yuan X, Kind R, Ni J (2006) Imaging the colliding Indian and Asian continental lithospheric plates beneath Tibet. J Geophsy Res 111:B06308. doi:10.1029/2005JB003930 Kumar P, Yuan X, Kumar MR, Kind R, Li X, Chadha RK (2007) The rapid drift of the Indian tectonic plate. Nature 449:894–897. doi:10.1038/nature06214 Maggi A, Priestley K (2005) Surface waveform tomography of the Turkish–Iranian plateau. Geophys J Int 160:1068–1080 McKenzie D (1972) Active tectonics of the Mediterranean region. Geophys J R Astr Soc 30:109–185. doi:10.1111/j.1365-246X.1972.tb02351.x McKenzie D, Priestley K (2007) The influence of lithospheric thickness variations on continental evolution. Lithos 102:1–11 Molinaro M, Zeyen H, Laurencin X (2005) Lithospheric structure beneath the south-eastern Zagros Mountains, Iran: recent slab break-off? TerraNova 17:1–6 Oreshin S, Vinnik L, Peregudov D, Roecker S (2002) Lithosphere and asthenosphere of the Tien Shan imaged by S receiver functions. Geophys Res Lett. doi:10.1029/2001GL014441 Paul A, Kaviani A, Hatzfeld D, Vegne J, Mokhtari M (2006) Seismological evidence for crustal-scale thrusting in the Zagros mountain belt (Iran). Geophys J Int 166:227–237 Paul A, Hatzfeld D, Kaviani A, Tatar M, Pequegnat C (2010) Seismic imaging of the lithospheric structure of the Zagros mountain belt (Iran). Geol Soc London Spec Publ 330:5–18 Priestley K, Baker C, Jackson J (1994) Implications of earthquake focal mechanism data for the active tectonics of the south Caspian basin and surrounding regions. Geophys J Int 118:111–141 Radjaee A, Rham D, Mokhtari M, Tatar M, Priestley K, Hatzfeld D (2010) Variation ofMoho depth in the central part of the Alborz Mountains northern Iran. Geophys J Int 181:173–184 Rychert C, Shearer P (2009) A global view of the lithosphereasthenosphere boundary. Science 324:495–498 Sengor AMC, Yilmaz Y (1981) Tethyan evolution of Turkey: a plate tectonic approach. Tectonophysics 75:181–241 Shad Manaman N, Shomali H (2010) Upper mantle S-velocity structure and Moho depth variations across Zagros belt, Arabian–Eurasian plate boundary. Phys Earth Planet Inter 180:92–103 Shad Manaman N, Shomali H, Hemin K (2011) New constraints on upper-mantle S-velocity structure and crustal thickness of the Iranian plateau using partitioned waveform inversion. Geophys J Int 184:247–267 Shapiro NM, Ritzwoller MH (2002) Monte-Carlo inversion for a global shear-velocity model of the crust and upper mantle. Geophys J Int 151:88–105 Sodoudi F, Yuan X, Liu Q, Kind R, Chen J (2006a) Lithospheric thickness beneath the Dabie Shan, central eastern China from S receiver functions. Geophys J Int 166(3):1363–1367 Sodoudi F, Kind R, Priestley W, Hanka W, Wylegalla K, Stavrakakis G, Vafidis A, Harjes HP, Bohnhoff M (2006b) Lithospheric structure of the Aegean obtained from P and S receiver functions. J Geophys Res 111:12307–12330 Sodoudi F, Yuan X, Kind R, Heit B, Sadidkhouy A (2009) Evidence for a missing crustal root and a thin lithosphere beneath the Central Alborz by receiver function studies. Geophys J Int 177(2):733–742 Sodoudi F, Yuan X, Asch G, Kind R (2011) High-resolution image of the geometry and thickness of the subducting Nazca lithosphere beneath northern Chile. J Geophys Res 116:B04302 Shomali ZH, Keshvari F, Hassanzadeh J, Mirzaei N (2011) thospheric structure beneath the Zagros collision zone resolved by non-linear teleseismic tomography. Geophys J Int 187:394–406 Snyder DB, Barazangi M (1986) Deep crustal structure and flexure of the Arabian plate beneath the Zagros collisional mountain belt as inferred from gravity observations. Tectonics 5:361–373 Stern R, Johnson P (2010) Continental lithosphere of the Arabian Plate: a geologic, petrologic, and geophysical synthesis. Earth Sci Rev 101:29–67 Stöcklin J (1968) Structural history and tectonics of Iran: a review. AAPG Bull 52:1229–1258 Taghizadeh-Farahmand F, Sodoudi F, Afsari N, Ghassemi MR (2010) Lithospheric structure of NW Iran from P and S receiver functions. J Seismol 14:823–836 Tatar M, Jackson J, Hatzfeld D, Bergman E (2007) The 2004 May 28 Baladeh earthquake (mw 6,2) in the Alborz Iran: overthrusting the South Caspian Basin margin partitioning of oblique convergence and the seismic hazard of Tehran. Geophys J Int 170:249–261 Vernant P, Nilforoushan F, Hatzfeld D, Abassi MR, Vigny C, Masson F, Nankali H, Martinod J, Ashtiani A, Bayer R, Tavakoli F, Chéry J (2004) Present-day crustal deformation and plate kinematics in the Middle East constrained by GPS measurements in Iran and northern Oman. Geophys J Int 157:381–398 Van de Zedde DMA, Wortel MJR (2001) Shallow slab detachment as a transient source of heat at midlithospheric depths. Tectonics 20(6):868–882 Vinnik LP (1977) Detection of waves converted from P to SV in the mantle. Phys Earth Planet In 15:39–45 Vinnik LP, Farra V, Kind R (2004a) Deep structure of the Afro-Arabian hot spot by S receiver function. Geophys Res Lett 31:L11608 Vinnik LP, Reigber C, Aleshin IM, Kosarev GL, Kaban MK, Oreshin SI, Roecker S (2004b) Receiver function tomography of the Central Tien Shan. Earth Planet Sci Lett 225:131–146 Wong A, Ton SYM, Wortel MJR (1997) Slab detachment in continental collision zones: an analysis of controlling parameters. Geophys Res Lett 24:2095–2098 Wortel MJR, Spakman W (2000) Subduction and slab detachment in the Mediterranean-Carpathian region. Science 290:1910–1917 Yuan X, Kind R, Li X, Wang R (2006) The S receiver functions: synthetics and data example. Geophys J Int 165(2):555–564 Yuan X, Ni J, Kind R, Mechie J, Sandvol E (1997) Lithospheric and upper mantle structure of southern Tibet from a seismological passive source experiment. J Geophys Res 102(27):491–500