Balanced Cross Sections and Determine of Shortening in North Makran Ophiolite Mélange, Southeastern Iran
Subject Areas :
Azizollah Tajvar
1
,
Mohammad Mahdi Khatib
2
,
Mohamad Hossian Zarinkoub
3
1 - Assistant Professor, Department of Oceanography, Chabahar Maritime and Marine Sciences University, Chabahar, Iran
2 -
3 -
Keywords: North Makran ophiolite mélange, Balance cross section, Shortening, Thrust faults,
Abstract :
The geometrical and kinematic characteristics of structural elements of north Makran have been measured and analyzed in five structural sections. Then, by using of balance cross sections and restoring the structures to their original state, the amount of shortening has been determined in different parts of the area. The Bashagard, Dranar, Abenma, Koh Bahark and Vernach thrust faults with a WNW-ESE trend and 20 to 35 degrees dip towards the NNE are the main deformation controllers in this region and are the main cause of shortening. The excellent fit between N209/09 principal stress axis calculated based on the geometry of thrust faults and compression axis that formed folds, indicates that these structures were formed as a result of the same tectonic regime. The difference in the amount of shortening in different parts of the north Makran ophiolite mélange of is also directly related to the thrust faults. So that, in western part of north Makran, thrust faults caused shortening amount 22.66, 22.85 and 14.32% in structural sections A-A', B-B' and C-C' respectively,. In the eastern parts, due to the lack of thrust faults and the presence of more strike-slip faults, the amount of shortening has decreased to 4.52% and 6.67%, respectively, in the sections D-D' and E-E'. Balanced cross sections and restoring the structures to the pre-deformation stages represent the narrow width of the early oceanic basin in the north of Makran.
تاج‌ور، ع.ا. 1399. ارزیابی تکوین زمین‌جنبشی باریکه‌های اقیانوسی درون قاره‌ای به کمک تحلیل هندسی - جنبشی قطعات سنگ‌کره‌ی اقیانوسی فرارانده شده، مطالعه موردی: افیولیت ملانژهای شمال مکران، جنوب شرق ایران. رساله دکتری، دانشگاه بیرجند، 394.
- تاج‌ور، ع.ا.، خطیب، م.م. و زرین‌کوب، م.م.، 1399. جایگاه تکتونوماگمایی دیابازها و جریان‌های بازالتی افیولیت شمال مکران، جنوب شرقی ایران. فصلنامه زمین‌شناسی ایران، 55، 79-67.
- تاج‌ور، ع.ا.، خطیب، م.م. و زرین‌کوب، م.م.، 1401. تحلیل تنش دیرین در آمیزه افیولیتی شمال مکران، جنوب خاوری ایران. فصلنامه علوم زمین، (1)32، 14-1.
- قاسمی، م. ر.، 1387. پایه‌های زمین‌شناسی ساختمانی. انتشارات سازمان زمین‌شناسی و اکتشافات معدنی ایران. 230.
- Aghanabati, A., Mahdavi, M. A. and Arshadi, S., 1987. Geological map of Espakeh, scale 1:100000. Geological Survey of Iran.
- Almalki, K.A., Betts, P.G. and Ailleres, L., 2016. Incipient seafloor spreading segments: Insights from the Red Sea. Geophysical research letters, 43, 2709–2715.
- Arshadi. S., Mahdavi, M.A. and Eftekhar-Nezhad, J., 1987. Geological map of Fannuj, scale 1:100000. Geological Survey of Iran.
- Berberian, M. and King, G.C.P., 1981. Towards a paleo-geography and tectonic evolution of Iran – Reply: Canadian Journal of Earth Sciences, 18, 1764-1766.
- Burg, J.-P., Dolati, A., Bernoulli, D. and Smit, J., 2013. Structural Style of the Makran Tertiary accretionary comples in SE-Iran. In: Al Hosani, K., F. Roure, R. Ellison and S. Lokier (eds.) Frontiers in Earth Sciences, 239 - 259.
- Burg, J.-P., 2019. Geology of the onshore Makran accretionary wedge: Synthesis and tectonic interpretation. Earth-Science Reviews, 185, 1210-1231.
- Cunningham, W. D. and Mann, P., 2007. Tectonics of strike-slip restraining and releasing bends. Geological Society, London, Special Publications 290 (1), 1-12.
- Dahlstrom, C.D.A., 1969. Balanced cross-sections. Canadian Journal of Earth Sciences 6, 743–757.
- DeMets, C., Gordon, R.G. and Argus, D.F., 2010. Geologically current plate motions. Geophysical Journal International, 181(1), 1-80.
- Dilek, Y. and Furnes, H., 2014. Ophiolites and their origins. Elements, 10, 93–100.
- Dolati, A., 2010. Stratigraphy, structural geology and low-temperature thermochronolgy across the Makran accretionary wedge in Iran: [Ph.D. thesis]. Swiss Institute of Technology, 370.
- Dolati, A. and Burg, J. P., 2013. Preliminary fault analysis and paleo stress evolution in the Makran Fold-and-Thrust Belt in Iran. In Lithosphere dynamics and sedimentary basins: The Arabian Plate and analogues (261-277). Springer, Berlin, Heidelberg.
- Farhoudi, G. and Karig, D.E., 1977. Makran of Iran and Pakistan as an active arc system. Geology, 5, 664-668.
- Fossen, H., 2010. Structural Geology, 1st Edition, Cambridge University Press, 463.
- Haghipour, N., Burg, J.P., Kober, F., Zeilinger, G., Ivy-Ochs, S., Kubik, P.W. and Faridi, M., 2012. Rate of crustal shortening and non-Coulomb behavior of an active accretionary wedge: The folded fluvial terraces in Makran (SE, Iran). Earth and Planetary Science Letters, 355, 187-198.
- Hunziker, D., Burg, J.P., Bouilhol, P. and von Quadt, A., 2015. Jurassic rifting at the Eurasian Tethys margin: Geochemical and geochronological constraints from granitoids of North Makran, southeastern Iran. Tectonics, 34, 571–593.
- Hunziker, D., Burg, J.P., Moulas, E., Reusser, E. and Omrani, J., 2017. Formation and preservation of fresh lawsonite: Geothermobarometry of the North Makran Blueschists, southeast Iran. Metamorphic Geology, 7, 1–25.
- McCall, G.J.H., Eftekhar-Nezhad, J., Samimi-Namin, M. and Arshadi, S., 1985. Explanatory text of the Fannuj quadrangle map 1:250,000. In: McCall, G.J.H. (Ed.). Ministry of Mines and Metals, Geological Survey of Iran.
- Mc Quarrie, N., 2004. Crustal scale geometry of the Zagros fold-thrust belt, Iran. Journal of Structural Geology, 26, 519–535.
- Midland Valley, 2017. Move, 2D software, Midland Valley Exploration Ltd, Glasgow, UK.
- Molinaro, M., Leturmy, P., Guezou, J. C. and Frizon de Lamotte, D., 2005. Th e structure and kinematics of the southeastern Zagros fold -thrust belt, Iran: from thin-skinned to thick-skinned tectonics. Tectonics, 24, TC3007.
- Moghadam, H.S. and Stern, R.J., 2011. Late Cretaceous fore-arc ophiolites of Iran. Island Arc, 20, 1-4.
- Moghadam, H. S. and Stern, R. J., 2015. Ophiolites of Iran: Keys to understanding the tectonic evolution of SW Asia (II): Mesozoic ophiolites. Journal of Asian Earth Sciences, 100, 31-59.
- Monsef, I., Rahgoshay, M., Pirouz, M., Chiaradia, M., Michel, G. and Georges, C., 2018. The Eastern Makran Ophiolite (SE Iran): Evidence for a Late Cretaceous fore-arc oceanic crust. International Geology Review, 61(11), 1313-1339.
- Morgan, K.H., McCall, G.J.H. and Huber, H., 1987a. Geological map of Ramak, scale 1:100000. Geological Survey of Iran.
- Morgan, K.H., McCall, G.J.H. and Huber, H., 1987b. Geological map of Remeshk, scale 1:100000. Geological Survey of Iran.
- Shahabpour, J., 2010. Tectonic implications of the geochemical data from the Makran igneous rocks in Iran. Island Arc, 19, 676-689.
- Sherkati, S., Letouzey, J. and Frizon de Lamotte, D., 2006. The Central Zagros fold-thrust belt (Iran): New insights from seismic data, field observation and sandbox modeling. Tectonics, 25, TC4007.
- Vernant, P., Nilforoushan, F., Hatzfeld, D., Abbassi, M., Vigny, C., Masson, F., Nankali, H., Martinod, J., Ashtiani, M., Bayer, R., Tavakoli, F. and Chéry, J., 2004. Contemporary crustal deformation and plate kinematics in Middle East constrained by GPS measurements in Iran and Northern Oman. Geophysical Journal International, 157, 381-398.
- Yamato, P., Kaus, B., Mouthereau, F. and Castelltort, S., 2011. Dynamic constraints on the crustal-scale rheology of the Zagros fold belt, Iran. The Geological Society of America, 39 (9), 815–818.
