نشریه علوم زمین خوارزمی

نشریه علوم زمین خوارزمی

بررسی تغییرات هندسی و ریخت‌شناسی کمربند کوهزایی البرز (محدوده قزوین-رشت) با استفاده از مدل‌سازی عددی

نویسندگان
عاطفه لاجوردی 1
اصغر دولتی 1
غلامرضا قرابیگلی 2
کبری حیدرزاده 3
1 دانشگاه خوارزمی
2 شرکت ملی نفت
3 دانشگاه شهید بهشتی
10.22034/KJES.2024.9.2.104672
چکیده
خردقاره‌ها در برخورد با صفحات بزرگ‌تر و مقاوم‌تر راحت‌تر دگرریخت می‌شوند. در این شرایط، دگرریختی در پیشانی برخورد متمرکز بوده و به رفتار مواد و ساختارهای از پیش موجود وابسته است. البرز در حاشیه شمالی خردقاره ایران مرکزی قرار داشته و متحمل دگریختی‌های متعددی از زمان تریاس به بعد (از جمله کوهزایی سیمرین، لارامید و آلپی) گردیده است. بیشترین بالا آمدگی البرز در اواخر سنوزوییک و در ارتباط با کوهزایی آلپی بوده است. جابجایی ناگهانی در پیشانی کوهستان البرز در محدود­ه قزوین- رشت در تصاویر ماهواره‌ای مشهود بوده و شواهد ژئوفیزیکی نیز حاکی از وجود تغییرات پی‌سنگی است. این تغییرات ناگهانی پیشانی کوهستان در قسمت شمالی و جنوبی البرز، به عملکرد یک گسل پنهان در عمق و یا تغییر ناگهانی در پی‌سنگ خزر نسبت داده شده است. به همین منظور پنج مدل‌سازی‌ عددی با فراسنج‌های مختلف، همچون وجود لایه جدایشی قاعده‌ای، میانی و تأثیر تغییر ضخامت این لایه و همچنین تأثیر وجود گسل‌های پی‌سنگی مورد بررسی قرار گرفت. مدل‌سازی‌های انجام شده نشان داد، وجود لایه جدایشی قاعده‌ای موجب انتشار دگرریختی به سمت پیشانی می‌شود. اضافه کردن سطح فراکنشی میانی نیز این فرایند را تشدید می‌کند. در صورتی که ضخامت سطح فراکنشی میانی بیشتر شود، بالاآمدگی و میزان دگرریختی به خصوص در قسمت پیشانی مدل به طرز چشمگیری افزایش می‌یابد. مدل‌های مربوط به تأثیر گسل‌های پی‌سنگی تمرکز دگرریختی در بالای گسل‌های پی‌سنگی را به وضوح نشان می‌دهد و به راحتی می‌تواند باعث انتشار دگریختی به سمت پیشانی مدل گردد. با توجه به برش‌های عرضی ترسیم شده در محل‌های تغییرات جانبی در پیشانی کوهستان، و زمین‌شناسی محدوده مورد مطالعه می‌توان تأثیر ضخامت سازند شیلی ژوراسیک (سازند شمشک) را به عنوان لایه جدایشی در البرز مرکزی مشاهده نمود که باعث بالا آمدگی بیشتر آن و در نتیجه رخنمون وسیع سنگ‌های پالئوزوئیک در البرز مرکزی نسبت به البرز غربی شده است. مدل‌سازی عددی با تغییرات ضخامت در لایه جدایشی میانی (1 و 2 کیلومتر) چنین تغییراتی را در قسمت مرکزی و غربی البرز شبیه‌سازی کرده است. وجود گسلش پی‌سنگی نیز در البرز غربی می‌تواند دلیل حرکت پیشانی کوهستان به سمت جنوب (به سمت پیش‌بوم) باشد.
کلیدواژه‌ها
البرز
مدل‌سازی عددی
تأثیر سطح فراکنش
جابجایی پیشانی کوهستان

عنوان مقاله English

Investigating geometric and morphologic changes in the Alborz orogenic belt (Qazvin-Rasht area), based on 2D numerical modelling

نویسندگان English

Atefeh Lajavardi 1
Asghar Dolati 1
Gholamreza Gharabeigli 2
Kobra Heydarzadeh 3
1 Kharazmi University
2 National Iranian Oil Company
3 Shahid Beheshti University
چکیده English

Deformation of microcontinents occurs during collision with a larger stable continent. Deformation is usually concentrated at the boundaries of the deforming microcontinent and depends on mechanical stratigraphy and pre-existing structures. The Alborz Mountains, located in the northern margin of central Iran underwent various deformations including Cimmerian, Laramide and Alpine compressions since the Triassic and its highest exhumation occurred in Cenozoic, as a result of the Alpine orogeny. Relocation of the Alborz Mountain front is visible in the satellite images in the Qazvin-Rasht area, where the geophysical maps also indicate changes in the basement at the subsurface. The aim of this study is to investigate possible factors responsible for this large displacement of the mountain front, using 2D numerical modeling. We designed and run five 2D models considering different parameters, such as the presence of basal and middle detachments and the effect of their thickness as well as the involvement of basement faults. The experiments show a faster movement of the deformation towards the foreland in the presence of basal detachment compared to the case without basal detachment. The addition of intermediate detachment intensifies this process. Increasing the thickness of the middle detachment increases the exhumation and deformation, especially towards the foreland. The model with a pre-existing basement fault shows very clear localization of deformation on the basement fault which causes developing the deformation towards the foreland. According to the cross sections constructed across the area on both sides of the change in the mountain front, there is an increase in the thickness of the Jurassic shale (Shemshak Formation) as a detachment level in the central Alborz, where higher exhumation and extensive outcrops of Paleozoic rocks is observed compared to the western Alborz. The numerical models with different thickness of intermediate detachments (1 and 2 km) have simulated this difference between the central and western Alborz. Considering the larger displacement of deformation front toward the foreland in the numerical model in the case of a pre-existing fault, the presence of a basement fault in the western Alborz could be assumed to cause the larger southward displacement of the mountain front compared to the central Alborz.

کلیدواژه‌ها English

Alborz
Numerical Modeling
Detachment effect
Mountain front displacement
Alavi, M., 1996. Tectonostratigraphic synthesis and structural style of the alborz mountain system in Northern Iran. Journal of Geodynamics 21, 1 -33.
Allen, M.B., Ghassemi, M.R., Shahrabi, M., Qorashi, M., 2003a. Accommodation of late Cenozoic oblique shortening in the Alborz range, northern Iran. Journal of Structural Geology 25, 659 -672.
Allen, M.B., Vincent, S.J., Alsop, G.I., Ismail - zadeh, A., Flecker, R., 2003b. Late Cenozoic deformation in the South Caspian region: effects of a rigid basement block within a collision zone. Tectonophysics 366, 223 -239.
Annells, R.N., Arthurton, R.A.B., Bazley, R.G., Davies, M.A.R., Hamedi, F.R., 1985. Geological quadrangle map of Iran, Nos. E3 and E4, Qazvin and Rasht, Scale 1:250,000. Geological Survey of Iran (in Persian).
Baharfiruzi, K., Shafaeii, A.R., Azhdari, A., Karimi, H.R., 2003. Geological quadrangle map of Iran, No. 6063, Javaherdeh, Scale 1:100,000. Geological Survey of Iran (in Persian).
Ballato, P., Landgraf, A., Schildgen, T.F., Stockli, D.F., Fox, M., Ghassemi, M.R., Kirby, E., Strecker, M.R., 2015. The growth of a mountain belt forced by base -level fall: Tectonics and surface processes during the evolution of the Alborz Mountains, N Iran. Earth and Planetary Science Letters 425, 204 - 218.
Ballato, P., Uba, C.E., Landgraf, A., Strecker, M.R., Sudo, M., Stockli, D.F., Friedrich, A., Tabatabaei, S.H., 2011. Arabia -Eurasia continental collision: Insights from late Tertiary foreland -basin evolution in the Alborz Mountains, northern Iran. Bulletin 123, 106 - 131.
Berberian, M., 1983. The southern Caspian: A compressional depression floored by a trapped, modified oceanic crust". Canadian Journal of Earth Sciences 20, 163 -183.
Berberian, M., King, G.C.P., 1981. Towards a paleogeography and tectonic evolution of Iran. Canadian Journal of Earth Sciences 18, 210 - 265.
Brunet, M. -F., Granath James, W., Wilmsen, M., 2009. South Caspian to Central Iran basins: introduction. Geological Society, London, Special Publications 312, 1 -6.
Brunet, M. -F., Korotaev, M.V., Ershov, A.V., Nikishin, A.M., 2003. The South Caspian Basin: a review of its evolution from subsidence modelling. Sedimentary Geology 156, 119 -148.
Burke, K., 2011. Plate Tectonics, the Wilson Cycle, and Mantle Plumes: Geodynamics from the Top. Annual Review of Earth and Planetary Sciences 39, 1 -29.
Butler, R.W.H., Tavarnelli, E., Grasso, M., 2006. Structural inheritance in mountain belts: An Alpine –Apennine perspective. Journal of Structural Geology 28, 1893 -1908.
Cherns, L., Wheeley, J.R., 2009. Early Palaeozoic cooling events: peri -Gondwana and beyond. Geological Society, London, Special Publications 325, 257.
Crameri, F., Schmeling, H., Golabek, G.J., Duretz, T., Orendt, R., Buiter, S.J.H., May, D.A., Kaus, B.J.P., Gerya, T.V., Tackley, P.J., 2012. A comparison of numerical surface topography calculations in geodynamic modelling: an evaluation of the ‘sticky air’ method. Geophysical Journal International 189, 38 -54.
Delavari, M., Dolati, A., Mohammadi, A., Rostami, F., 2016. The Permian volcanics of central Alborz: implications for passive continental margin along the southern border of Paleotethys. Ofioliti 41, 59 - 74.
Derakhshi, M., Ghasemi, H., 2015. Soltan Maidan Complex (SMC) in the eastern Alborz structural zone, northern Iran: magmatic evidence for Paleotethys development. Arabian Journal of Geosciences 8, 849 -866.
Djamour, Y., Vernant, P., Bayer, R., Nankali, H.R., Ritz, J. -F., Hinderer, J., Hatam, Y., Luck, B., Le Moigne, N., Sedighi, M., Khorrami, F., 2010. GPS and gravity constraints on continental deformation in the Alborz mountain range, Iran. Geophysical Journal International 183, 1287 -1301.
Domeier, M., Torsvik, T.H., 2014. Plate tectonics in the late Paleozoic. Geoscience Frontiers 5, 303 -350.
Ehteshami -Moinabadi, M., 2016. Possible basement transverse faults in the western Alborz, northern Iran. Journal of Sciences, Islamic Republic of Iran 27, 329 -342.
Eliasi, M., 2001. Fault slip analysis for determination of paleostress tensors and type of deformation in southern part of the Central Alborz. PhD thesis, Tarbiat Modares University (in Persian).
Emami, M.H., 1990a. Geological quadrangle map of Iran, No. 5962, Takestan, Scale 1:100,000. Geological Survey of Iran (in Persian).
Emami, M.H., 1990b. Geological quadrangle map of Iran, No. 6062, Qazvin, Scale 1:100,000. Geological Survey of Iran (in Persian).
Fürsich, F.T., Wilmsen, M., Seyed -Emami, K., Majidifard, M.R., 2009. The Mid -Cimmerian tectonic event (Bajocian) in the Alborz Mountains, Northern Iran: evidence of the break -up unconformity of the South Caspian Basin. Geological Society, London, Special Publications 312, 189 -203.
Gaetani, M., Angiolini, L., Ueno, K., Nicora, A., Stephenson, M.H., Sciunnach, D., Rettori, R., Price, G.D., Sabouri, J., 2009. Pennsylvanian – Early Triassic stratigraphy in the Alborz Mountains (Iran). Geological Society, London, Special Publications 312, 79 -128.
Golonka, J., Gawęda, A., Sharkov, E., 2012. Plate tectonic evolution of the southern margin of Laurussia in the Paleozoic, In: Sharkov, E. (Ed.), Tectonics –Recent advances, InTech, Rijeka, pp. 261 -282.
Guest, B., Axen, G.J., Lam, P.S. and Hassanzadeh, J., 2006. Late Cenozoic shortening in the west - central Alborz Mountains, northern Iran, by combined conjugate strike -slip and thin - skinned deformation. Geosphere, 2(1), 35 -52.
Guest, B., Horton, B.K., Axen, G.J., Hassanzadeh, J., McIntosh, W.C., 2007. Middle to late Cenozoic basin evolution in the western Alborz Mountains: Implications for the onset of collisional deformation in northern Iran. Tectonics 26.
Iranpanah, A., Esfandiari, B., 1979. Structural evolution and correlation of tectonic event in Alborz Montain, the Zagros Range and Central Iran. Bull. Soc. Bege de Geologie 88, 285 -295.
Karami, H., 1997. Determination of Paleostress and Movement Direction of Thrust in North of Tehran (Bectwla Darake Valley and Kan Valley), Master Thesis, . Tarbiat Modares University.
Maadanipour, S., Yasaghi, A., 2009. Structural Geometry of Taleqan Mountains; an evidence for structural evolution of South Central Alborz Range from Inversion to transpression Tectonics. Geosciences Scientific Quarterly Journal 18, 121 -126.
Masson, F., Lehujeur, M., Ziegler, Y., Doubre, C., 2014. Strain rate tensor in Iran from a new GPS velocity field. Geophysical Journal International 197, 10 -21.
Mirzaei Souzani, M., Shahidi, A., Ramezani, R., Alizadeh Sevari, F., 2015. Extension Analysis in Shemshak Sedimentary Basin (Balladeh Valley, Central Alborz). Journal of Geoscience 24, 39 -48 (in Persian).
Moghadam, H.S., Li, X. -H., Griffin, W.L., Stern, R.J., Thomsen, T.B., Meinhold, G., Aharipour, R., O'Reilly, S.Y., 2017. Early Paleozoic tectonic reconstruction of Iran: Tales from detrital zircon geochronology. Lithos 268 -271, 87 -101.
Mohammadi, A., Kaveh -Firouz, A., Cai, F., Dolati, A., Lom, N., Şengör, A.M.C., 2023. Migration of the Palaeozoic magmatic front from Zagros to Alborz mountains with progressive closure of the Palaeo -Tethys Ocean; Insights from Zagros detrital zircon UPb age and Hf isotopic composition. Tectonophysics 849, 229729.
Morley, C.K., Kongwung, B., Julapour, A.A., Abdolghafourian, M., Hajian, M., Waples, D., Warren, J., Otterdoom, H., Srisuriyon, K., Kazemi, H., 2009. Structural development of a major late Cenozoic basin and transpressional belt in central Iran: The Central Basin in the Qom -Saveh area. Geosphere 5, 325 -362.
Nazari, H., 2006. Analyse de la tectonique récente et active dans l'Alborz Central et la région de Téhéran:«Approche morphotectonique et paléoseismologique». Université Montpellier II -Sciences et Techniques du Languedoc.
Nazari, H., Ritz, J., Oghbaee, S., 2007. New insight to paleogeography and structural evolution of the Alborz in Tethyside. Scientific Quarterly Journal of Geosciences 16, 38 -53.
Omidi, P., 2001. DDetailed structural and dynamic analysis of fault zones in the southern margin of East Alborz (Semnan -Damghan Region). Ph.D. thesis, Tarbiat Modares University (in Persian).
Mattei, M., Cifelli, F., Alimohammadian, H., Rashid, H., 2016. Oroclinal bending in the Alborz Mountains (N Iran): New constrains on the age of South Caspian subduction and extrusion tectonics. Gondwana Research 42©.
Ramezani, J., Tucker, R.D., 2003. The Saghand Region, Central Iran: U -Pb geochronology, petrogenesis and implications for Gondwana Tectonics. American Journal of Science 303, 622.
Ranalli, G., Murphy, D.C., 1987. Rheological stratification of the lithosphere. Tectonophysics 132, 281 -295.
Rezaeian, M., Carter, A., Hovius, N., Allen, M.B., 2012. Cenozoic exhumation history of the Alborz Mountains, Iran: New constraints from low -temperature chronometry. Tectonics 31.
Rezaeian, M., Kuijper, C.B., van der Boon, A., Pastor -Galán, D., Cotton, L.J., Langereis, C.G. and Krijgsman, W., 2020. Post -Eocene coupled oroclines in the Talesh (NW Iran): Paleomagnetic constraints. Tectonophysics, 786, 228459.
Rossetti, F., Faccenna, C., Ranalli, G., 2002. The influence of backstop dip and convergence velocity in the growth of viscous doubly - vergent orogenic wedges: insights from thermomechanical laboratory experiments. Journal of Structural Geology 24, 953 -962.
Rossetti, F., Nozaem, R., Lucci, F., Vignaroli, G., Gerdes, A., Nasrabadi, M., Theye, T., 2015. Tectonic setting and geochronology of the Cadomian (Ediacaran -Cambrian) magmatism in Central Iran, Kuh - e -Sarhangi region (NW Lut Block). Journal of Asian Earth Sciences 102, 24 -44.
Ruh, J.B., 2020. Numerical modeling of tectonic underplating in accretionary wedge systems. Geosphere 16, 1385 -1407.
Ruh, J.B., Kaus, B.J.P., Burg, J. -P., 2012. Numerical investigation of deformation mechanics in fold -and -thrust belts: Influence of rheology of single and multiple décollements.
Tectonics 31. Ruh, J.B., Vergés, J., 2018. Effects of reactivated extensional basement faults on structural evolution of fold -and -thrust belts: Insights from numerical modelling applied to the Kopet Dagh Mountains. Tectonophysics 746, 493 -511.
Saidi, A., 2004. Geological quadrangle map of Iran, No. 5964, Rasht, Scale 1:100,000. Geological Survey of Iran (in Persian).
Scotese, C.R., 2021. An Atlas of Phanerozoic Paleogeographic Maps: The Seas Come In and the Seas Go Out. Annual Review of Earth and Planetary Sciences 49, 679 -728.
Sengor, A.C., 1984. The Cimmeride orogenic system and the tectonics of Eurasia. Geological Society of America Special Paper 195, 82.
Shahidi, A., 2008. Evolution Tectonique du Nord de l’Iran (Alborz et Kopet -Dagh). Paris: Universiè Pierre et MarieE Curie.
Shahidi, A., Barrier, E., Brunet, M. -F., Saidi, A., 2011. Tectonic Evolution of the Alborz in Mesozoic and Cenozoic. Journal of Geoscience 21, 201 -216.
Stampfli, G.M., 2000. Tethyan oceans. Geological Society, London, Special Publications 173, 1.
Stampfli, G.M., Borel, G.D., 2002. A plate tectonic model for the Paleozoic and Mesozoic constrained by dynamic plate boundaries and restored synthetic oceanic isochrons. Earth and Planetary Science Letters 196, 17 -33.
Stöcklin, J., 1968. Structural history and tectonics of Iran: a review. AAPG bulletin 52, 1229 - 1258.
Stöcklin, J., 1974a. Northern Iran: Alborz Mountains. Geological Society, London, Special Publications 4, 213.
Stöcklin, J., 1974b. Possible ancient continental margins in Iran, The geology of continental margins. Springer, pp. 873 -887. Takin, M., 1972. Iranian Geology and Continental Drift in the Middle East. Nature 235, 147 -150.
Ter Borgh, M.M., Oldenhuis, R., Biermann, C., Smit, J.H.W., Sokoutis, D., 2011. The effects of basement ramps on deformation of the Prebetics (Spain): A combined field and analogue modelling study. Tectonophysics 502, 62 -74.
Torsvik, T.H., Cocks, L.R.M., 2009. The Lower Palaeozoic palaeogeographical evolution of the northeastern and eastern peri -Gondwanan margin from Turkey to New Zealand. Geological Society, London, Special Publications 325, 3.
Torsvik, T.H., Cocks, L.R.M., 2013. Gondwana from top to base in space and time. Gondwana Research 24, 999 -1030.
van Hinsbergen, D.J.J., Torsvik, T.H., Schmid, S.M., Maţenco, L.C., Maffione, M., Vissers, R.L.M., Gürer, D., Spakman, W., 2020. Orogenic architecture of the Mediterranean region and kinematic reconstruction of its tectonic evolution since the Triassic. Gondwana Research 81, 79 -229.
Wilmsen, M., Fürsich, F.T., Seyed -Emami, K., Majidifard, M.R., Taheri, J., 2009. The Cimmerian Orogeny in northern Iran: tectono - stratigraphic evidence from the foreland. Terra Nova 21, 211 -218.
Yassaghi, A., Madanipour, S., 2008. Influence of a transverse basement fault on along -strike variations in the geometry of an inverted normal fault: Case study of the Mosha Fault, Central Alborz Range, Iran. Journal of Structural Geology 30, 1507 -1519.
Zanchi, A., Berra, F., Mattei, M., R. Ghassemi, M., Sabouri, J., 2006. Inversion tectonics in central Alborz, Iran. Journal of Structural Geology 28, 2023 -2037.
Zanchi, A., Zanchetta, S., Berra, F., Mattei, M., Garzanti, E., Molyneux, S., Nawab, A., Sabouri, J., 2009. The Eo -Cimmerian (Late? Triassic) orogeny in North Iran. Geological Society, London, Special Publications 312, 31 - 55.