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Basement Faults and Their Relationships to Salt Plugs in the Arabian Platform in Southern Iran
Godratollah Farhoudi
Professor in Tectonics,
Department of Earth Sciences,
Shiraz University, Shiraz, Iran.
Email: farhoudi@geology.susc.ac.ir
Reza Derakhshani
Department of Earth Sciences,
College of Sciences,
Shiraz University, Shiraz, Iran.
Email: rezaderakhshani@yahoo.com
Jafar Rahnama-Rad
Department of Geology,
Islamic Azad University of Zahedan,
postal code 98167, Zahedan, Iran.
Email: jrahnama2003@yahoo.com
Abstract
The Arabian Platform containing the Zagros Mountain Ranges (ZMR) is located to the northeast of the Arabian Shield. There are nearly 200 salt domes on the Arabian Platform. The structural analysis of landsat satellite data proves the existence of three groups of structural elements:
- Those resulting from the folding of the ZMR;
- Those resulting from the solution processes within the evaporatic formation, especially in the Hormuz Formation in the deeper underground;
- Those resulting from the regional strike - slip faults of the basement ;
Bending of anticlines in the competent cover rock combined with minor strike-slip faults and horizontal displacements of parts of folding structures, strongly point to the presence of these basement faults. The salt plugs, which have pierced cover rocks of up to 10000m thick, are distributed on the Arabian Platform along regional basement faults. The area of diapir outcrops is bounded by the Oman Line to the east and by the Kazerun Fault to the west. The basement has been broken and thrusted to the southern border of the ZMR. Pieces of the basement have been brought up to the surface on some of the salt domes. The fragments were transported by rotational ascent of the Hormuz Salt Formation to the present and former land surfaces. Sinistral and dextral basement faults are interpreted as antithetic and synthetic Riedel Shears which confine major blocks of the northeastern edge of the Arabian Plate, Oman Spur included. Considering the Oman Line and Zagros thrust situations and mechanisms, fold axes bending, the trend of the salt plugs and also the distribution of epicenters of the last 100 years, numerous new basement faults have been discovered and interpreted by this investigation
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