Advanced Applied Geology

Advanced Applied Geology

Investigation of deformation temperature and kinematic characteristics of the shear zone in northwest Alvand

Authors
Department of Geology, Faculty of Basic Science, Bu-Ali University, Hemedan, Iran.
Abstract
Reverse shear zones are among the most important deformational structures in orogenic belts, playing a key role in crustal shortening and thickening. The studied shear zone is located in the northwest of the Alvand granite body and is characterized by a northeastward dip and reverse movement toward the southwest. This zone exhibits clear evidence of ductile deformation, including the recrystallization of quartz, feldspar, microcline, and perthite, which indicates temperature conditions of about 500–550 °C and pressures of 3–5 kbar. In this study, the vorticity of the shear zone was determined using two methods: the Porphyroclast Aspect Ratio (PAR) method and the Rigid Grain Net (RGN) method. In both methods, feldspar crystals, which behaved as porphyroclasts within this shear zone, were used. Vorticity analysis based on kinematic indicators yields values of 0.6 to 0.8, indicating an overall flow dominated by simple shear with a significant component of pure shear. These results suggest that the reverse shear zone in northwest Alvand, in addition to shear displacement, has contributed to lateral shortening and ultimately to crustal thickening in the studied area
Keywords
Subjects

Azizi, H., Daneshvar, N., Rafat, Gh., Asahara, Y., Horie, K., Takehara, M., Kon, Y., Minami, M., Anma, R., 2024. O–Hf isotope ratios of Alvand S-type granite, western Iran, reveal crustal melting in an extensional regime. Lithos 464–465, 107437. https://doi.org/10.1016/j.lithos.2023.107437
Barker, A. J., 2013. Introduction to metamorphic textures and microstructures. Routledge. p. 290. ‏ https://doi.org/10.4324/9781315831626
Behyari, M., Kanabi, A., 2019a. Constraining of strain ellipsoid shape from sectional data in the au bearing shear zone west of Iran. Acta Geodyn Geromater 16, 131–143. https://doi.org/10.13168/AGG.2019.0010
Behyari, M., Shahbazi, M., 2019b. Strain and vorticity analysis in the Zagros suture zone (W Iran): implications for Neo-Tethys postcollision events. Journal of Structural Geolology 126, 198–209. https://doi.org/10.1016/j.jsg.2019.06.002
Chiu, H.Y., Chung, S.L., Zarrinkoub, M.H., Mohammadi, S.S., Khatib, M.M., Iizuka, Y., 2013. Zircon U–Pb age constraints from Iran on the magmatic evolution related to Neotethyan subduction and Zagros orogeny. Lithos 162, 70-87.‏ https://doi.org/10.1016/j.lithos.2013.01.006
Das, J.P., Bhattacharyya, K., Mookerjee, M., Ghosh, P., 2016. Kinematic analyses of orogen-parallel L-tectonites from Pelling-Munsiari thrust of Sikkim Himalayan fold thrust belt: Insights from multiple, incremental strain markers. Journal of Structural Geolology 90, 61–75. https://doi.org/10.1016/j.jsg.2016.07.005
Deer, W.A., Howie, R.A., Zussman, J., 2013. An introduction to the rock-forming minerals. Mineralogical Society of Great Britain and Ireland, p. 498. https://doi.org/10.1180/DHZ ‏
Derikvand, S., 2021. Quantitative kinematic analyses of the Darizhun shear zone within the hinterland of the Zagros orogenic belt, Iran. International Journal of Earth Sciences 110(2), 609-626.‏ https://doi.org/10.1007/s00531-020-01976-9.
Dutta, D., Mukherjee, S., 2019. Opposite shear senses: geneses, global occurrences, numerical simulations and a case study from the Indian western Himalaya. Journal of Structural Geology 126, 357–392. https://doi.org/10.1016/j.jsg.2019.05.008
Faghih, A., Dehghan, M., Sobhani, S.S., 2023. Study of deformation pattern and kinematic characteristics in the Gelmandeh metamorphic complex, Saghand region, Central Iran. Advanced Applied Geology 12(4), 617-634. https://doi.org/10.22055/aag.2021.37039.2216
Festa, V., Prosser, G., Caggianelli, A., Grande, A., Langone, A., Mele, D., 2015. Vorticity analysis of the Palmi shear zone mylonites: new insights for the Alpine tectonic evolution of the Calabria-Peloritani terrane (southern Italy). Geological Journal 51, 670–681. https://doi.org/10.1002/gj.2673
Fossen, H., Cavalcante, G.C.G., 2017. Shear zones – a review. Earth Science Review 171, 434–455. https://doi.org/10.1016/j.earscirev.2017.05.002
 Fossen, H., Tikoff, B., 1993.The deformation matrix for simultaneous simple-shearing, pure-shearing and volume change, and its application to transpression–transtension tectonics. Journal of Structural geology 15, 413–422. https://doi.org/10.1016/0191-8141(93)90137-Y
Fossen, H., 2016. Structural geology. Cambridge university press. ‏
Ghosh, S.K., Ramberg, H., 1976. Reorientation of inclusions by combination of pure-shear and simple-shear. Tectonophysics 34, 1–70. https://doi.org/10.1016/0040-1951(76)90176-1
Jessup, M.J., Law, R.D., Frassi, C., 2007. The Shear-Rigid Grain Net (RGN): an alternative method for estimating mean kinematic vorticity number (Wm). Journal of Structural Geology 29, 411–421. https://doi.org/10.1016/j.jsg.2006.11.003
Jones, R.R., Holdsworth, R.E., Clegg, P., McCaffrey, K.J.W., Tavarnelli, E., 2004. Inclined transpression. Journal of Structural Geology 26, 1531–1548. https://doi.org/10.1016/j.jsg.2004.01.004
Lister, G.S., Snoke, A.W., 1984. SC mylonites. Journal of Structural Geology 6, 617–638. https://doi.org/10.1016/0191-8141(84)90001-4
Liu, L., Zhou, D.W., Dong, Y.P., Zhang H.F., Liu, Y.J., Zhang, Z.J., 1995. High pressure metabasites and their retrograde metamorphic P-T–t path from Songshugou area, eastern Qinling Mountain. Acta Petrol Sin 11,127–136.  https://doi.org/10.1111/jmg.12527
Mahmoudi, S., Corfu, F., Masoudi, F., Mehrabi, B., Mohajjel, M., 2011. U–Pb dating and emplacement history of granitoid plutons in the northern Sanandaj–Sirjan Zone, Iran. Journal of Asian Earth Sciences 41(3), 238-249.‏ https://doi.org/10.1016/j.jseaes.2011.03.006
McCaffrey, R., 1992. Oblique plate convergence, slip vectors, and fore arc deformation. Journal of Geophysics Research 97, 8905–8915. https://doi.org/10.1029/92JB00483
Means, W.D., 1994. Rotational quantities in homogeneous flow and the development of small-scale structure. Journal of Structural Geology 16, 437–445. https://doi.org/10.1103/PhysRevFluids.4.024609
Means, W.D., Hobbs, B.E., Lister, G.S., Williams, P.F., 1980. Vorticity and non-coaxially in progressive deformations. Journal of Structural Geology 2, 371–378. https://doi.org/10.1016/0191-814 (80)90024-3
Michibayashi, K., Murakami, M., 2007. Development of a shear band cleavage as a result of strain partitioning. Journal of Structural Geology 29, 1070–1082. https://doi.org/10.1016/j.jsg.2007.02.003
Mohajjel, M., Fergusson, C.L., 2000. Dextral transpression in Late Cretaceous continental collision, Sanandaj-Sirjan zone, western Iran. Journal of Structural Geology 22, 1125–1139. https://doi.org/10.1016/S0191-8141(00)00023-7
Passchier, C.W., Urai, J.L., 1988. Vorticity and strain analysis using Mohr diagrams. Journal of Structural Geology 10:755–763. https://doi.org/10.1016/0191-8141(88)90082-X
Passchier, C.W., 1997. The fabric attractor. Journal of Structural Geology 19, 113–127. https://doi.org/10.1016/S0191-8141(96)00077-6
Passchier, C.W., 1987. Stable positions of rigid objects in non-coaxial flow-a study in vorticity analysis. Journal of Structural Geology 9, 679–690. https://doi.org/10.1016/0191-8141(87)90152-0
Passchier, C.W., Trouw, R.A.J., 2005. 2st edition, Microtectonics. Springer, p. 366.
Philpotts, A.R., Ague, J.J., 2009. Principles of igneous and metamorphic petrology. Cambridge University Press. P.685.
Samani, B., 2017. Deformation flow analysis and symmetry of Goushti shear zone, Sanandaj-Sirjan metamorphic belt, Iran. Geopersia 7(1), 117-130. https://doi.org/10.22059/geope.2017.219333.648281
Samani, B., Saki, A., Taghizadeh, S., 2019. The geometric symmetry analysis of Kamary shear zone using planar and linear Structural elements, Sanandaj-Sirjan metamorphic belt, Iran. Journal of Tectonics 3(11), 49-59.‏ https://doi.org/10.22077/jt.2020.1505
Sarkarinejad, K., Azizi, A., 2008. Slip partitioning and inclined dextral transpression along the Zagros Thrust System, Iran. Journal of Structural Geology 30, 116–136. https://doi.org/10.1016/j.jsg.2007.10.001
Sarkarinejad, K., Keshavarz, S., Faghih, A., Samani, B., 2017. Kinematic analysis of rock flow and deformation temperature of the Sirjan thrust sheet, Zagros Orogeny, Iran. Geological Magazine 154(1), 147-165.‏ https://doi.org/10.1017/S0016756815000941
Sarkarinejad, K., Derikvand, S., 2017 Structural and kinematic analyses of the basement window within the hinterland fold-and-thrust belt of the Zagros orogeny, Iran. Geological Magazine 154, 983–1000. https://doi.org/10.1017/S0016756816000558
Sarkarinejad, K., Goftari, F., 2019. Thick-skinned and thin-skinned tectonics of the Zagros orogeny, Iran: constraints from Structural, microstructural and kinematics analyses. Journal Asian Earth Science 170, 249–273. https://doi.org/10.1016/j.jseaes.2018.10.021
Sarkarinejad, K., Keshavarz, S., Faghih, A., 2015. Kinematics of the Sirjan mylonite nappe, Zagros Orogenic Belt: insights from strain and vorticity analyses. Journal of Geoscience 60,189–202. https://doi.org/10.3190/jgeosci.198
Sepahi, A.A., 2008. Typology and petrogenesis of granitic rocks in the Sanandaj-Sirjan metamorphic belt, Iran: with emphasis on the Alvand plutonic complex. Neues Jahrbuch für Geologie und Paläontologie-Abhandlungen 247(3), 295-312.‏ https://doi.org/10.1127/0077-7749/2008/0247-0295
Shahbazi, H., Siebel, W., Pourmoafee, M., Ghorbani, M., Sepahi, A.A., Shang, C.K., Abedini, M.V., 2010. Geochemistry and U–Pb zircon geochronology of the Alvand plutonic complex in Sanandaj–Sirjan zone (Iran): new evidence for Jurassic magmatism. Journal of Asian Earth Sciences 39 (6), 668–683. https://doi.org/10.1016/j.jseaes.2010.04.014
Sheikholeslami, M.R., Ghassemi, M.R., Hassanzadeh, J., 2019. Tectonic evolution of the hinterland of the Zagros Orogen revealed from the deformation of the Golpaygan Metamorphic Complex, Iran. Journal of Asian Earth Sciences 182, 103929. https://doi.org/10.1016/j.jseaes.2019.103929
Simpson, C., De Paor, D.G., 1993. Strain and kinematic analysis in general shear zones. Journal of Structural geology 15, 1–20. https://doi.org/10.1016/0191-8141(93)90075-L
Simpson, C., De Paor, D.G., 1997. Practical analysis of general shear zones using the porphyroclast hyperbolic distribution method: an example from Scandinavian Caledonides. In: Sengupta S (ed) Evolution of geological structures in micro to macro scales. Springer, Netherlands, 169–184.
Stahr, D.W III., Law, R.D., 2011. Effect of finite strain on clast-based vorticity gauges. Journal of Structural geology 33, 1178–1192. https://doi.org/10.1016/j.jsg.2011.05.002
Stipp, M., Stünitz, H., Heilbronner, R., Schmid, S.M., 2002. The eastern Tonale fault zone: a ‘natural laboratory’ for crystal plastic deformation of quartz over a temperature range from 250 to 700 °C. Journal of Structural geology 24(12), 1861–1884. https://doi.org/10.1016/S0191-8141(02)00035-4
Teyssier, C., Tikoff, B., Markley, M., 1995. Oblique plate motion and continental tectonics. Geology 23, 447–450. https://doi.org/10.1130/0091-7613(1995)023<0447: OPMACT>2.3.CO;2
Truesdell, C., 1953. Two measures of vorticity. Journal of Rational Mechanics and Analysis 2,173–217.
Tullis, J., Yund, R.A., 1985. Dynamic recrystallization of feldspar: A mechanism for ductile shear zone formation. Geology 13(4), 238–241. https://doi.org/10.1130/0091-613(1985)13<238:DROFAM>2.0.CO;2
Vernon, R.H., Johnson, S.E., Melis, E.A., 2004. Emplacement-related microstructures in the margin of a deformed pluton: The San José tonalite, Baja California, México. Journal of Structural Geology 26(10), 1867-1884.‏ https://doi.org/10.1016/j.jsg.2004.02.007
Vernant, P., Nilforoushan, F., Hatzfeld, D., Abassi, M., Vigny, C., Masson, F., Nankali, H., Martinod, J., Ashtiani, A., Bayer, R., Tavakoli, F., Chery, J. 2004. Contemporary crustal deformation and plate kinematics in Middle East contrained by GPS measurements in Iran and northern Oman, Geophysical Journal International 157, 381–398.https://doi.org/10.1111/j.1365-246X.2004.02222.x
Vollmer, F.W., 2015. EllipseFit 3.2. https://www.frederickvollmer.com/ellipsefit/
Wallis, S.R., Platt, J.P., Knott, S.D., 1993. Recognition of syn-convergence extension in accretionary wedges with examples from the Calabrian Arc and the Eastern Alps. American Journal of Science 293, 463–494. https://doi.org/10.2475/ajs.293.5.463https://doi.org/10.2475/ajs.293.5.463
Whitney, D.L., and Evans, B.W, 2010. Abbreviations for names of rock-forming minerals. American mineralogist 95(1), 185-187.‏ https://doi.org/10.2138/am.2010.3371
Wallis, S.R., 1992. Vorticity analysis in a metachert from the Sanbagawa Belt, SW Japan. Journal of Structural Geology 14, 271–280. https://doi.org/10.1016/0191-8141(92)90085-B
Xypolias, P., 2010. Vorticity analysis in shear zones: a review of methods and applications. Journal of Structural Geology 32, 2072–2092. https://doi.org/10.1016/j.jsg.2010.08.009
Zhang, Q., Teyssier, C., 2013. Flow vorticity in Zhangbaling transpressional attachment zone, SE China. Journal of Structural Geology 48, 72–84. https://doi.org/ 10.1016/j.jsg.2012.12.006
Zhang, Q., Fossen, H., 2020. The dilemma of asymmetric porphyroclast systems and sense of shear. Journal of Structural Geology 130, 103893. https://doi.org/10.1016/j.jsg.2019.103893
Zhang, Z., Xiao, W., Ji, W., Majidifard, M.R., Rezaeian, M., Talebian, M., Xiang, D., Chen, L., Wan, B., Ao, S., Esmaeili, R., 2018. Geochemistry, zircon U-Pb and Hf isotope for granitoids, NW Sanandaj-Sirjan zone, Iran: Implications for Mesozoic-Cenozoic episodic magmatism during Neo-Tethyan lithospheric subduction. Gondwana Research 62, 227-245. ‏https://doi.org/10.1016/ j.gr.2018.04.002.