Two dimensional finite strain analysis of boudin bearing marble in Khalaj region using Mohr circle, south of Mashhad
Subject Areas :
Mohammad Reza
Sheikholeslami
1
Keywords: Khalaj Boudin Deformation Finite strain Mohr circle. ,
Abstract :
The marbles of the Khalaj area constitute a part of the Mashhad metamorphic complex which was affected by three stages of deformation. Stretches of the boudins, which occurred during the first stage of the regional deformation, are measured in seven stations. The data are used for two dimensional finite strain analyses by Mohr circle. The results indicate the ellipticity of the strain ellipsoids vary between 1.05 to 1.36, and the maximum shear angle is between 4 to 20 degrees. These results are in agreement with field observations indicating dominant pure shear deformation during the first stage. This deformation is marked by generation of continuous folds and chocolate box boudins. These types of boudins were formed due to the stretching in two directions. Results of two dimensional strain analyses also show half to one time positive volume change during first stage of deformation.
الیاسی، م.، 1391. مبانی زمین شناسی ساختمانی، انتشارات دانشگاه تهران، 128
سبزهاي، م.، پورلطيفي، ع.، بهروزي، ا .، جعفري صدر، ع.، 1373. پديده هاي تفريق در ماگماهاي اولترابازيك. گدازههاي اولترامافيك، مافيك و اولاكوژن هاي پالئوزوييك ايران زمين. سيزدهمين گردهمايي علوم زمين، سازمان زمين‌شناسي كشور، صفحه 79-65
شیخ الاسلامی، م.ر.، حقی پور، ن.، نواب پور، پ.، نواب مطلق، ا.، کوه پیما، م.، مافی، آ.، حیدر زاده،. ق.، 1392. بررسیهای زمینشناسی و زمینساختی در پهنه کپهداغ-بینالود. پژوهشکده علوم زمین، نشر رهی، 234 .
Alavi, M., 1991. Sedimentary and structural characteristics of the Paleo-Tethys remnants in northeastern Iran. Geological Society of America Bulletin. 103, 983–992.
Boulin, J., 1988. Hercynian and Eo-cimmerian events in Afghanistan and adjoining regions. Tectonophysics 148, 235–278.
Ghazi, A, M., Hassanipak, A, A., Tucker, P.J., Mobasher, K., and Duncan, R, A., 2001. 40Ar – 39Ar Geochronology and Geochemistry of the Paleo- Tethyan Mashhad ophiolite, NE Iran. Abstract as: Eos (Transactions American Geophysical Union), 82(47), Fall Meeting
Karimpour, M.H., Farmer, L., Ashouri, C., Saadat, S., 2006. Major, Trace and REE geochemistry of Paleo- Tethys Collision- Related Granitoids from Mashhad, Iran. Journal of Sciences, Islamic Republic of Iran, 17(2) 127-145.
Lisle, R. J., and Ragan D. M., 1988. Brevia: Strain from three stretches: a simple Mohr circle solution. Journal of Structural Geology, 10, 905–906.
Madjidi, B.,1983. The geochemistry of ultrabasic and basic lava flows occurences in northern Iran, In Geodynamic project in Iran. Geological Survey of Iran, report No. 51, 436-477.
Nadai, A. 1963. Theory of Flow and Fracture of Solids. Engineering Societies Monographs. McGraw-Hill, New York. 705.
Ragan, D, M., 2009. Structural geology; An Introduction to Geometrical Techniques, fourth edition. Cambridge university Press. 602.
Ramsay, J.G., 1967, Folding and Fracturing of Rocks: McGraw-Hill, New York. 410.
#Ramsay, J.G., and Huber M.I., 1983. The Techniques of Modern Structural Geology: Volume 1:Strain Analysis: Academic Press, London. 307.
Sheikholeslami, M.R., and Kouhpeyma, M., 2012. Structural analysis and tectonic evolution of the eastern Binalud Mountains, NE Iran, Journal of Geodynamics, 61, 23-46.
Taheri, J., and Ghaemi, B., 1996. Geological Map of Mashhad, Scale 1:100,000. Geological Survey of Iran, Tehran.
Treagus, S, H., 1987. Mohr circles for strain, simplified, Geological Journal, 22, 119-132.
Zulauf, G., Gutierrez-Alonso, G., Kraus, R., Petschick, R., and Potel, S., 2011. Formation of chocolate-tablet boudins in a foreland fold and thrust belt: A case study from the external Variscides (Almograve, Portugal), Journal of Structural Geology, 33, 1639-1649.