Crust velocity structure beneath two seismic stations on the southern edge of the Central Alborz (Iran)

Authors

Abstract

Crust velocity structure beneath two broadband seismic stations of Iran National Seismic Network (INSN), DAMV and THKV located in Central Alborz has been investigated by joint inversion of receiver function and Rayleigh wave phase and group velocity dispersion curves. The result suggests that Moho depth beneath the THKV and DAMV stations are 50-51 km and 52-54 km, respectively. Beneath the THKV station, there is a thin layer of very low-velocity materials at the surface and a sedimentary layer having a thickness of 10-12 km above a crystalline crust with a thickness of 34 km. Beneath the DAMV station, there is a thin sedimentary layer of low velocity with a thickness of 3-4 km, and also, a velocity change from 3.2 to 3.6 km/s at the depth of 14-16 km, indicating a discontinuity, which might be attributed to the border between the upper and lower crusts. The average Moho depth on the southern edge of Central Alborz is 52±2 km.

Keywords


Abbassi, A., Nasrabadi, A., Tatar, M., Yaminifard, F., Abbassi, M. R., Hatzfeld, D., Priestley. K., 2010. Crustal Velocity Structure in the southern edge of the Central Alborz (Iran). Journal of Geodynamics, 49, 68-78.
Allen, M., Jackson, J., and Walker, R., 2004, Late Cenozoic reorganization of the Arabia-Eurasia collision and the comparison of short-term and long-term deformation rates. TECTONICS, 23, 10.1029/2003TC001530.
Berberian, M. and King, G. C. P., 1981, Towards a palaeogeography and tectonic evolution of Iran. Can. J. Earth Sci., 18, 210 – 265.
Dehghani, G. A. and Makris J., 1983, The Gravitay Field and Crustal Structure of Iran. Geological Survey of Iran, Report No. 51, 51-68
Herrmann, R.B. and Ammon, C.J., 2003, Computer programs in seismology, Version 3.20, Surface waves, Receiver functions and Crustal structure, Saint Louis University, Penn State Univercity.
Jackson, J. A., Priestley, K., Allen, M. and Berberian, M., 2002, Active tectonics of the South Caspian Basin. Geophys. J. Int., 148, 214–245.
Javan Doloei, G., Roberts, R., 2003, Crust and uppermost mantle structure of Tehran region from analysis of teleseismic P-waveform receiver functions. Tectonophysics, 364, 115-133.
Ligorrı´a, J.P. and Ammon, C.J., 1999, Iterative deconvolution and receiver function estimation. Bull. Seismol. Soc. Am., 89, 1395– 1400.
Paul, A., Hatzfeld, D., Kaviani, A., Tatar, M., & Péquegnat, C. (2010). Seismic imaging of the lithospheric structure of the Zagros mountain belt (Iran). Geological Society, London, Special Publications, 330(1), 5-18
Radjaee, A.H., Rham, D., Mokhtari, M., Tatar, M., Priestley, K., and Hatzfeld, D. 2010, Variation of Moho depth in the Central part of Alborz Mountains, North of Iran. Geophysical Journal International. 181, 173-184.
Rahimi, H., Hamzehloo, H., Vaccari, F., Panza, G.F., 2014, Shear-wave velocity tomography of the lithosphere–asthenosphere system beneath the Iranian Plateau. Bulletin of the Seismological Society of America,104, no. 6, 2782-2798.
Rham D (2009) The crustal structure of the Middle East.Ph.D. thesis, University of Cambridge Library, Cambridge, UK
Ritz, J.F., Nazari, H., Ghassemi, A., Salamati, R., Shafei, A., Solaymani, S., Vernant, P., 2006. Active transtension inside Central Alborz: a new insight into northern Iran–southern Caspian geodynamics. Geology 34, 477–480.
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. Geophysical Journal International, 177, 733-742.
Takeuchi, H., and Saito, M., 1972, Seismic surface waves: in Methods in computational Physics. Academic Press Inc., New York, 11, 217-294.
Tatar, M. R., and Nasrabadi, A., 2013, Crustal thickness variations in the Zagros continental collision zone (Iran) from joint inversion of receiver functions and surface wave dispersion, Journal of Seismology, 17, 1321-1337.