Tectonic setting and geochronology of the Cadomian (Ediacaran-Cambrian) magmatism in Central Iran, Kuh-e-Sarhangi region (NW Lut Block)

A Late Cretaceous ophiolite complex in the Baft area, southwest of Kerman, Iran, is characteristic of the Central Iranian Ophiolitic Mélange Belt, which wraps around the Lut Block. Despite the extensive tectonic disruption of the Baft complex, most ophiolitic lithologies are present and many original igneous contacts are preserved. A lack of cumulate gabbros within the sequence suggests that a large and continuous magma chamber did not exist beneath the Baft spreading axis. Geochemical data confirm the presence of two distinct compositional groups in the mafic lavas: (1) tholeiitic basalt and (2) transitional tholeiitic basalt. The tholeiitic lavas are similar to typical mid-ocean-ridge basalt compositions, whereas the transitional tholeiites are similar to intraplate basalts. The available data suggest that the Baft ophiolite complex formed in a small ocean basin, possibly at or near a ridge–transform intersection. Emplacement may have occurred as a result of conversion of the transform fault to a subduction zone during a change in relative plate motion. A ridge–transform setting is compatible with the intraplate character of some of the transitional basalts, which probably represent off-axis (seamount) magmatism, marked by the absence of cumulate gabbros and the presence of a serpentinite mélange cut by basaltic dykes. The ridge–transform model suggests formation of the ophiolite in a narrow ocean basin separating the Sanandaj-Sirjan microcontinent from the Central Iran Block in Late Cretaceous time.

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U–Pb zircon geochronology, Sr–Nd geochemistry, petrogenesis and tectonic setting of Mahoor granitoid rocks (Lut Block, Eastern Iran)

Journal of Asian Earth Sciences ◽

10.1016/j.jseaes.2015.07.028 ◽

2015 ◽

Vol 111 ◽

pp. 192-205 ◽

Cited By ~ 13

Author(s):

Roohollah Miri Beydokhti ◽

Mohammad Hassan Karimpour ◽

Seyed Ahmad Mazaheri ◽

José Francisco Santos ◽

Urs Klötzli

Keyword(s):

Tectonic Setting ◽

Zircon Geochronology ◽

Lut Block ◽

Eastern Iran ◽

Granitoid Rocks

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Geochemistry of Carboniferous Sandstones (Sardar Formation), East-Central Iran: Implication for Provenance and Tectonic Setting

Acta Geologica Sinica - English Edition ◽

10.1111/j.1755-6724.2012.00741.x ◽

2012 ◽

Vol 86 (5) ◽

pp. 1200-1210 ◽

Cited By ~ 13

Author(s):

Mohammad KHANEHBAD ◽

Reza MOUSSAVI-HARAMI ◽

Asadollah MAHBOUBI ◽

Mehdi NADJAFI ◽

Mohammad Hosein MAHMUDY GHARAIE

Keyword(s):

Tectonic Setting ◽

Central Iran ◽

East Central

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Biostratigraphy of Baghamshah Formation based on calcareous nannofossils in the Southwest Tabas, Iran

Revista Brasileira de Paleontologia ◽

10.4072/rbp.2021.3.01 ◽

2021 ◽

Vol 24 (3) ◽

pp. 165-178

Author(s):

Azadeh Bordbar ◽

Fatemeh Hadavi ◽

Abbas Ghaderi ◽

Marziyeh Notghi Moghaddam

Keyword(s):

Central Iran ◽

Calcareous Nannofossils ◽

The West ◽

Lithostratigraphic Unit ◽

Lut Block ◽

Sedimentary Cycle ◽

Taxonomic Studies

The Tabas Block is part of the Central Iran microcontinent, located between the Lut Block in the East and the Yazd Block in the West. The Baghamshah Formation is the second lithostratigraphic unit from the sedimentary cycle of the Magu Group and the Baghamshah Subgroup in the Jurassic of Tabas Block. This formation is conformably underlaid with the grey pisoidal limestones of the Parvadeh Formation and overlaid with the Pectinid limestones of the Kamar-e-Mehdi Formation (Esfandiar Subgroup). In this research, the biostratigraphy of the Baghamshah Formation in the Rizu and Kamar-e-Mehdi sections, based on calcareous nannofossils, is examined. The thickness of the Baghamshah Formation in the Rizu section is 270 m (mostly including marl and green shales with intercalation of limestones and calcareous sandstones), and in the Kamar-e- Mehdi section is 236 m (composed of gypsiferous marly shales, marl, marly shales and alternation of marl-shale with limestones and calcareous sandstones). According to the taxonomic studies in the Rizu section, 52 species belong to 24 genera, and in the Kamar-e-Mehdi section, 45 species belong to 23 genera of calcareous nannofossils. Based on index calcareous nannofossils, the CC1, CC2, CC3, and CC4 biozones established by Sissinghh in both sections were determined. It is mentioned that CC5 biozone only occur in Kamar-e-Mehdi section. According to the identified biozones, the suggested age of the Baghamshah Formation is early Berriasian–early Hauterivian in the Rizu section, and early Berriasian–late Hauterivian in the Kamar-e-Mehdi section. Keywords: biostratigraphy, Baghamshah, calcareous nannofossils,Tabas, Iran.

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The November 14 to December 25, 1979 Ghaenat earthquakes of northeast Iran and their tectonic implications

Bulletin of the Seismological Society of America ◽

10.1785/bssa0700051751 ◽

1980 ◽

Vol 70 (5) ◽

pp. 1751-1757

Author(s):

A. Haghipour ◽

M. Amidi

Keyword(s):

Central Iran ◽

Fault Rupture ◽

Quaternary Deposits ◽

Iranian Plateau ◽

East Central ◽

Lut Block ◽

Shallow Earthquakes ◽

Recent Earthquakes ◽

Seismic Area ◽

Northeast Iran

abstract A series of shallow earthquakes occurred in northeast Iran starting on November 14, 1979. The sequence includes two destructive earthquakes which occurred on November 14 and 27. In both cases, ground rupture developed along capable faults through the bedrock and Quaternary deposits. The November 14 earthquake was associated with a 20-km N-S trending right-lateral faulting. The November 27 earthquake accompanied a 60-km E-W trending left-lateral fault rupture. Also, during the second earthquake, the northern end of the earlier rupture continued northeastward to align with the eastern end of the second rupture. The result of the fault displacements of both earthquakes is relative subsidence with northeastward/eastward motion of the southwestern block. The earthquakes are located in the northeast corner of the Lut Block (an eastern fragment of central Iran) and included in the main structural zone of the Central Domain extended from Iran to Central Asia. The recent earthquakes are located in the highly seismic area of northeast Iran where the rate of seismicity has increased markedly in the past decade. Based on structural considerations of earthquake data, the rupture types their recent migration of locations show that a recent relative eastward motion for east-central Iran blocks resulted from northeast compressional movements and shortening of the Iranian Plateau.

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