Document Type : Original Research Paper


Assistant Professor, Department of Geology, Faculty of Science, Payame Noor University (PNU), Tehran, Iran


Anarak metamorphic complex located east of Nain city. Based on geological, chronological and paleomagnetical data, the complex consists of different metamorphic units from different varity of source. This metamorphic complex also composed of ophiolitic bodies which crop out in the complex as thrust sheets. This study is concerned with structural investigation of metamorphic rocks around Anarak, specially on a Z shape folding in the chahgorbeh mountains.
Based on field surveys and microscopic investigations there are at least 3 deformationnal phases in the morghab and chahgorbeh units, all of them occurred in ductile conditions possibly related to “Variscan metamorphism” (late carboniferous). In the basic and ultramafic rocks of chahgorbeh unit, the first deformational phase accompanied with HP/LT metamorphic conditions at amphibolite facies. This phase is accompanied with a relatively low grade metamorphism-green schist facies in the metamorphic pelletic rocks of Morghab and Chahgorbeh units and leads to generation of a low grade (S1) foliation. This phase followed by increasing of intensity of deformation and milonitic foliation and sheath folds developed in the rock units through second phase of deformation.
Third phase of deformation continusly affected the pre- deformed rocks in a more low- grade metamorphic and deformational condition than earlier phases.


Main Subjects

Bagheri, S. and Stampfli, G. M., 2008-The Anarak, Jandaq and Posht-e-Badam metamorphic complexes in Central Iran: new geological data, relationships and tectonic implications. Tectonophysics 451, 123–155.
Balini, M., Nicora, A., Berra, F., Garzanti, F., Levera, M., Mattei, M., Muttoni, M., Zanchi, A., Bollati, I., Larghi, C., Zanchetta, S., Salamati, R. and Mossavvari, F., 2009- The Triassic stratigraphic succession of Nakhlak (Central Iran), a record from an active margin. In: Brunet, M.F., Wilmsen, M., Granath, J.W. (Eds.), South Caspian to Central Iran Basins. Geological Society of London Special Publications 312, pp. 287–321.
Berra, F., Zanchi, A. and Nawab, A., 2007- Late Cretaceous transgression on a Cimmerian high (Neka Valley, Eastern Alborz, Iran): a geodynamic event recorded by glauconitic sands. Sed. Geol. 199, 189–204.
Berra,F.,Zanchi,A.,Angiolini,L.,Vachard,D., Vezzoli, G., Zanchetta, S., Bergomi, M., Javadi, H.R., Kouhpeyma,M.2017.The upper Palaeozoic Godar-e-Siah Complex of Jandaq: evidence and significance of a North Palaeotethyan succession in Central. Iran. Journal of Asian Earth Sciences 138, 272–90.
Buchs, D., Baghari, S., Martin, L., Hermann, J. and Arculus, R., 2013- Paleozoic to Triassic ocean opening and closure preserved in Central Iran: Constraints from the geochemistry of meta-igneous rocks of the Anarak area. Lithos. 173, 267- 287.
Fursich, F. T., Wilmsen, M., Seyed-Emami, K. and Majidifard, M. R., 2009- Lithostratigraphy of the Upper Triassic–Middle Jurassic Shemshak Group of northern Iran. In: Brunet, M.F., Wilmsen, M., Granath, J.W. (Eds.), South Caspian to Central Iran Basins. Geological Society of London Special Publications 312, pp. 129–160.
Horton, B. K., Hassanzadeh, J., Stockli, D. F., Axen, G. J., Gillis, R. J., Guest, B., Amini, A., Fakhari, M. D., Zamanzadeh, S. M. and 
Grove, M., 2008- Detrital zircon provenance of Neoproterozoic to Cenozoic deposits in Iran: implications for chronostratigraphy and collisional tectonics. Tectonophysics 451, 97–122.
Javadi, H. R., 2013- Iran Fault Map on Sedimentary- Structural Units. Tectonic Group. Geological Survey of Iran.
Kargaranbafghi, F., Neubauer, F., Genser, J., Faghih, A. and Kusky, T., 2012- Mesozoic to Eocene ductile deformation of western Central Iran: from Cimmerian collisional orogeny to Eocene exhumation. Tectonophysics 564–565, 83–100.
Masoodi, M., Yassaghi, A., Sadat, M. A. A. N., Neubauer, F., Bernroider, M., Friedl, G., Genser, J. and Houshmandzadeh, A., 2013- Cimmerian evolution of the Central Iranian basement: evidence from metamorphic units of the Kashmar-Kerman Tectonic Zone. Tectonophysics 588, 189–208.
Ruttner, A. W., 1993- Southern borderland of Triassic Laurasia in north-east Iran. Geol. Rundsch. 82, 110–120.
Schmidegg, O., 1933 - Neue Ergenbnisse in den südlichen Ötztaler-  Alpen. In Verhandlugen Geol. B.-A., 83-85.
Sharkovski, M., Susov, M. and Krivyakin, B., 1984- Geology of the Anarak area (Central Iran). Explanatory Text of the Anarak Quadrangle Map 1:250000. Geological Survey of Iran, V/O ‘‘Tecnoexport’’ USSR Ministry of Geology Reports, 19.
Sheikholeslami, M. R. and Kouhpeyma, M., 2012- Structural analysis and tectonic evolution of the eastern Binalud Mountains, NE Iran. J. Geodyn. 61, 23–46.
Susov, M., Dvoriankin, A. and Selivanov, E., 1984- 1:100000 series, sheet 6756, Anarak. Geological Survey of Iran, V/O ‘‘Tecnoexport’’ USSR Ministry of Geology.
Wilmsen, M., Fursich, F. T. and Taheri, J., 2009- The Shemshak Group (Lower–Middle Jurassic) of the Binalud Mountains, NE Iran: stratigraphy, depositional environments and geodynamic implications. In: Brunet, M.F., Wilmsen, M., Granath, J.W. (Eds.), South Caspian to Central Iran Basins. Geological Society of London Special Publications 312, pp. 175–188.
Zanchetta, S., Malaspina, N., Zanchi, A. and Benciolini, Martins, S., Javadi, H., Kouhpeyma, M.,  2017- Contrasting subduction–exhumation paths in the blueschists of the Anarak Metamorphic Complex (Central Iran). Geol. Mag.: page 1 of 19 c Cambridge University Press. https;//doi. org/10.1017/S0016756817000218.
Zanchi, A., Nadia, M., Zanchetta, S., Berra, F., Benciolini, L., Bergomi, M., Cavallo, A. and Javadi, H. R., 2015- The Cimmerian accretionary wedge of Anarak, Central Iran. Journal of Asian Earth Sciences 102  pp. 45–72.