Amir Pirooz Kolahi-Azar

Assistant Professor of Geology- Tectonics

  • TEL: +98-23220091, Int: 308
  • Education

    • Ph.D. 2006-2013


      Shiraz University, Shiraz, Iran

    • M.Sc. 2001-2004


      Shiraz University, Shiraz, Iran

    • B.Sc. 1994-1998


      Tabriz University, Tabriz, Iran


    • Global Tectonics
    • Tectonics & Mineralization
    • Geophysics & Tectonics
    • Petrofabrics
    • Physical Geology
    • Surveying
    • Geology of Iran

    Selected Publications

    Kolahi-Azar, A.P., Golriz, S. Multifractal Topography: A Tool to Measure Tectonic Complexity in the Zagros Mountain Range (2018) Mathematical Geosciences, 50 (4), pp. 431-445.

    DOI: 10.1007/s11004-017-9720-z

    In this research, it is tried to measure tectonic complexity from the multifractal attributes of the Earth’s surface topography in the Zagros Mountain range. For this aim the multifractal characteristics of topography have been achieved using the strange attractor formalism. The approach is based on wavelet–fractal calculation of one-dimensional topography cross-sections. Wavelet coefficients have been employed for the multifractal formalism in order to obtain the multifractal Hölder singularity and generalized fractal dimension spectrums. The linked shape parameters of the spectrums are considered to determine the multifractal attributes of topography data sets. Calculations indicate the topography is scale invariant and likely to be chaotic; however, every region has its own multifractal characteristics. The obtained results suggest a relatively heterogeneous topography for the middle parts of the simple-folded belt and a quite homogeneous one for the central portions of the high-Zagros thrust belt. Correspondingly, it is concluded the tectonic processes involved in the central parts of the simple-folded belt are relatively intricate and heterogeneous. While in the central portions of the high-Zagros belt, those processes are fairly homogeneous and act in a simple way. Our findings are in correspondence with the tectonic background of the Zagros fold and thrust belt reported in the literature. This study offers a quantitative measure and provides comparative results to evaluate the topography and superficial tectonic features of the crust in the Zagros Mountain range, using a wavelet based strange attractor formalism. © 2017, International Association for Mathematical Geosciences.

    AUTHOR KEYWORDS: Multifractal formalism; Strange attractor; Tectonic complexity measurement; Topography variation; Wavelet transform
    INDEX KEYWORDS: Fractal dimension; Fractals; Landforms; Tectonics; Topography; Wavelet transforms, Complexity measurement; Multifractal characteristics; Multifractal formalism; Quantitative measures; Strange attractors; Tectonic features; Wavelet coefficients; Zagros fold-and-thrust belts, Surface topography, complexity; fold and thrust belt; mountain region; tectonics; topography; transform, Zagros
    PUBLISHER: Springer Verlag

    Samani, B., Kolahi-Azar, A.P. Stress state and fluid pressure analyses using ultramafic dykes and calcite veins, SW Iran (2017) Arabian Journal of Geosciences, 10 (5), art. no. 96, .

    DOI: 10.1007/s12517-017-2879-2

    In this paper, orientations of ultramafic dykes and calcite veins of the Tange-Hana area (SW Iran) are used to determine the relative stress and fluid pressure (Pf) conditions by constructing a 3D Mohr circle. The pole distributions of ultramafic dykes have a wide range of orientation and mainly show the girdle pattern. The 3D Mohr circle construction for ultramafic dykes suggests a Pf > σ2 condition and shows high value of fluid pressure (Pf = 939.51) near to the maximum principal stress (σ1). Driving pressure ratio (R′) and stress ratio (Ø) were calculated as 0.78 and 0.7, for ultramafic dykes, respectively. Calcite vein polar distribution is so limited and mainly shows a cluster pattern. Limited distribution of calcite vein orientation indicates a Pf < σ2 condition. The 3D Mohr circle construction reveals small amount of fluid pressure (Pf = 288.55) near to the minimum principal stress (σ3). The amounts of driving pressure ratio (R′) and stress ration (Ø) were calculated to be equal to 0.07 and 0.27, for calcite veins, respectively. Our results show the occurrence of ultramafic dykes and that calcite veins are related to different stress phases. Also, according to our results, it revealed that ultramafic and calcite dykes and veins were generated in prolate and oblate stress ellipsoid conditions, respectively. © 2017, Saudi Society for Geosciences. [/accordion]
    AUTHOR KEYWORDS: Driving pressure ratio; Driving stress ratio; Fluid pressure; Mohr circle; Stress ratio
    INDEX KEYWORDS: calcite; dike; fluid pressure; Mohr theory; orientation; pressure; ultramafic rock, Iran
    PUBLISHER: Springer Verlag

    Fereidooni, D., Khanlari, G.R., Heidari, M., Sepahigero, A.A., Kolahi-Azar, A.P. Assessment of inherent anisotropy and confining pressure influences on mechanical behavior of anisotropic foliated rocks under triaxial compression (2016) Rock Mechanics and Rock Engineering, 49 (6), pp. 2155-2163.

    DOI: 10.1007/s00603-015-0814-y
    AUTHOR KEYWORDS: Anisotropy; Confining pressure; Elasticity modulus; Metamorphic rocks; Triaxial compressive strength
    PUBLISHER: Springer-Verlag Wien