Estimation of site amplification, attenuation and source spectra of S-waves in the East-Central Iran

2011 ◽  
Vol 31 (10) ◽  
pp. 1397-1413 ◽  
Author(s):  
B. Hassani ◽  
H. Zafarani ◽  
J. Farjoodi ◽  
A. Ansari
Keyword(s):  
Site Amplification ◽  
Central Iran ◽  
East Central ◽  
S Waves ◽  
Source Spectra

Facies analysis of a large-scale Jurassic shelf-lagoon: the Kamar-e-Mehdi Formation of east-central Iran

Facies ◽  
2009 ◽  
Vol 56 (1) ◽  
pp. 59-87 ◽  
Author(s):  
Markus Wilmsen ◽  
Franz T. Fürsich ◽  
Kazem Seyed-Emami ◽  
Mahmoud R. Majidifard ◽  
Massoud Zamani-Pedram
Keyword(s):  
Large Scale ◽  
Facies Analysis ◽  
Central Iran ◽  
East Central

Ordovician echinoderms from the Tabas and Damghan regions, Iran: palaeobiogeographical implications

2005 ◽  
Vol 176 (3) ◽  
pp. 231-242 ◽  
Author(s):  
Bertrand Lefebvre ◽  
Mansooreh Ghobadipour ◽  
Elise Nardin
Keyword(s):  
South China ◽  
Central Iran ◽  
East Central ◽  
First Report ◽  
Middle Ordovician ◽  
Alborz Range ◽  
First Time

Abstract Two echinoderm assemblages are described in the Middle Ordovician of Iran (Darriwilian). The Simeh Kuh section (Damghan area, eastern Alborz range) has yielded a rich and diverse blastozoan fauna consisting of fistuliporite (Echinosphaerites, Heliocrinites) and dichoporite rhombiferans (cheirocrinids indet., hemicosmitids indet.), as well as aristocystitid (Sinocystis) and sphaeronitid diploporites (Glyptosphaerites, Tholocystis). Heliocrinites, cheirocrinids, hemicosmitids, Glyptosphaerites, and Tholocystis are reported for the first time in the Ordovician of Iran. A less diverse assemblage was collected in the Shirgesht section (Tabas area, Derenjal Mountains), and represents the first report of Ordovician echinoderms in east-central Iran. The Shirgesht fauna includes fistuliporite rhombiferans (Heliocrinites), aristocystitid and sphaeronitid diploporites. The new Iranian material documents some of the earliest known assemblages of diploporites and rhombiferans, and thus, brings important information on the radiation of these two major blastozoan classes. The two Iranian echinoderm faunas show relatively strong affinities with contemporary faunas from Baltica, the northern Gondwanan margin (e.g. Bohemia, Morocco), Sibumasu, and South China terranes. Aristocystitids suggest stronger links between Iran, and regions from the “Province à Amphorides” (northern Gondwanan margin, Sibumasu, South China). These observations support a palaeogeographical position of Iran at intermediate palaeolatitudes during the early Middle Ordovician, in the periphery of the northeastern Gondwanan margin.

Uranium–lead ages of apatite from iron oxide ores of the Bafq District, East-Central Iran

2010 ◽  
Vol 46 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Heinz-Günter Stosch ◽  
Rolf L. Romer ◽  
Farahnaz Daliran ◽  
Dieter Rhede
Keyword(s):  
Iron Oxide ◽  
Central Iran ◽  
East Central

Site response and source spectra of S waves in the Zagros region, Iran

2012 ◽  
Vol 17 (2) ◽  
pp. 645-666 ◽  
Author(s):  
H. Zafarani ◽  
B. Hassani
Keyword(s):  
Site Response ◽  
S Waves ◽  
Source Spectra ◽  
Zagros Region

Conodonts from the Niur Formation (Silurian) of the Derenjal Mountains, Central Iran

2013 ◽  
Vol 150 (4) ◽  
pp. 639-650 ◽  
Author(s):  
P. MÄNNIK ◽  
C. G. MILLER ◽  
V. HAIRAPETIAN
Keyword(s):  
Central Iran ◽  
The Other ◽  
Precise Location ◽  
East Central ◽  
Rheic Ocean ◽  
Lowermost Part

AbstractA Llandovery to Ludlow age for the Niur Formation in the Derenjal Mountains (east-central Iran) is proposed based on new conodont data and previous work on other fossils. The uppermost part of the studied section yielded no diagnostic conodonts but may be Pridoli in age. Some intervals can be dated more precisely: Unit 11 (at least its upper part) is middle Telychian in age and corresponds to thePterospathodus amorphognathoides lennartiZone; the lowermost part of Unit 16 is earliest Ludlow in age and corresponds to theKockelella crassaZone; the uppermost Unit 16 is late Ludlow (Ludfordian) in age and corresponds to theOzarkodina snajdriInterval Zone. The Llandovery–Wenlock boundary lies between units 12 and 13 based on sedimentological evidence. The precise location of the Wenlock–Ludlow boundary in the section is not clear but lies below Unit 16. Present-day Iran was located far away from Baltica and Laurentia, on the other side of the Rheic Ocean. This ocean does not seem to have been a major migration barrier for most organisms including the conodonts.

Seismic anisotropy and mantle deformation in NW Iran through splitting measurements of SKS and direct S phases

2020 ◽  
Author(s):  
Shiva Arvin ◽  
Farhad Sobouti ◽  
Keith Priestley ◽  
Abdolreza Ghods ◽  
Seyed Khalil Motaghi ◽  
...  
Keyword(s):  
Flow Field ◽  
Upper Mantle ◽  
Seismic Anisotropy ◽  
Central Iran ◽  
Plate Motion ◽  
Propagation Path ◽  
Mantle Flow ◽  
South Caspian Basin ◽  
Nw Iran ◽  
S Waves

<p><span>The present tectonics of Iran has resulted from the continental convergence of the Arabian and Eurasian plates. Our study area, in NW Iran comprises a part of this collision zone and consists of an assemblage of distinct lithospheric blocks including the central Iranian Plateau, the South Caspian Basin, and the Talesh western Alborz Mountains. A proper knowledge of mantle flow field is required to bettwer constrain mantle kinematics in relation to the dynamics of continental deformation in NW Iran. To achieve this aim, we examined splitting of teleseismic shear waves (e.g. SKS and S) arriving with steep arrival angles beneath the receiver, which provide excellent lateral resolution in the upper mantle. We used data from 68 temporary broadband stations with varying operation periods (4 to 31 months) along 3 linear profiles. We perfomed splitting analyses on SK(K)S and direct S waves. </span>Resultant splitting parameters obtained from both shear phases exhibit broad similarities. Relatively large time delays observed for direct S-waves, however, are anticipated since these waves travel longer than SKS along a non-vertical propagation path in an anisotropic layer. Overall, the fast polarization directions (FPDs) in the Alborz, Talesh, Tarom Mountain and in NW Iran indicate a strong consistency with NE-SW anisotropic orientations. Besides, we observe a good accordance between S and SKS results. A comparison of splitting parameters with the absolute plate motion (APM) vector and structural trends in Iran and eastern Turkey suggests asthenospheric flow field as the dominant source for observed seismic anisotropy. The lithospheric layer beneath these regions is relatively thin (compared to the adjacent Zagros region), explaining why it appears to only make a partial contribution to the observed anisotropy. The stations located in central Iran just southwest of the Alborz yield angular deviations from the general NE-SW trend as this may be explained by changing style of deformation across the different tectonic blocks. These stations indicate significant misfit between SK(K)S and direct S-waves that could be caused by local heterogeneities developed due to a diffuse boundary from the flow organization in the upper mantle of central Iran. Another possibility for large differences between two types of waves might be reflect the anisotropic structure of a remnant slab segment or a foundered lithospheric root beneath central Iran with a volume small enough to be detected by SKS phases, but not by the direct S waves.</p>

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