L. Ebadi; S. A. Alavi; M. R. Ghassemi
Abstract
In this paper a part of the Shahr-e-Babak area in NW-Kerman is studied, which is geologically located in Central Iran and Urumiyeh- Dokhtar Belt. The basin was strongly affected by compression in Miocene times, in which deformation is characterized by development of NW-SE trending fold and thrust belt. ...
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In this paper a part of the Shahr-e-Babak area in NW-Kerman is studied, which is geologically located in Central Iran and Urumiyeh- Dokhtar Belt. The basin was strongly affected by compression in Miocene times, in which deformation is characterized by development of NW-SE trending fold and thrust belt. In this paper, we aim atdeciphering polyphase deformation and paleostress history of part of the Central Iran in the Shahr-e-Babak area, and that how various geological aspects may be related to a stress field that has been reoriented through time. Also, we indicate how the brittle deformation studies and paleostress analyses may contribute in the interpretations of the post-collisional tectonic evolution of this area. In this paper, by using systematic brittle tectonic analyses, including stress tensor inversion form fault-slip data, we decipher the succession of deformational events that resulted in present-day structures. Therefore, a statistical view of the brittle tectonic reconstructions taken as a whole leads one to better understand the relationships between the different stress fields and folding events that governed the history of compression in this area .The systematic reconstruction of brittle tectonic regimes led us to characterize an anticlockwise change in the main direction of compression through time. Thus, it can be seen that the late Cretaceous to late Miocene pre-folding N055° and N084° compression was followed by syn-folding N040° compression in the Miocene. The Miocene compression then continued into the Pliocene post-folding N029° direction, and changed afterward to the Pleistocene-Recent post-folding N003° direction. Although this general anticlockwise rotation of compression has probably been progressive through time, our data suggest three distinct stress regimes that (1) predate, (2) are contemporaneous with, and (3) post-date the more consistent compressional stress regime of the folding and thrusting process. According to this reconstruction, it is confirmed that many local right-lateral strike–slip faults were reactivated from NW-SE reverse faults in the Sahahr-e-Babak area of SW Central Iran .These results could properly support the hypothesis of a significant anticlockwise change in the movement direction of the Arabian plate with respect to the Eurasian plate and block rotation in Central Iran.
L. Ebadi; S.A. Alavi; Sh. Shafiei
Abstract
Hydrothermal vein and porphyry copper deposits are notable within Eocene volcanic rocks of Shahr-e-Babak area. In this paper, the structural patterns within Shahr-e-Babak area as well as the relationship between structural elements and the emplacement of dikes and hydrothermal vein and porphyry copper ...
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Hydrothermal vein and porphyry copper deposits are notable within Eocene volcanic rocks of Shahr-e-Babak area. In this paper, the structural patterns within Shahr-e-Babak area as well as the relationship between structural elements and the emplacement of dikes and hydrothermal vein and porphyry copper deposits have been discussed. Three fault trends of WNW-ESE and N-S are recognized in northeastern Shahr-e-Babak according to satellite images and field observations. The WNW-ESE and N-S trending faults are normal faults, while the NE-SW trending faults are sinistral faults with normal component. Two trends are recognized for the dikes in Shahr-e-Babak area namely, WNW-ESE(T2) and N-S (T1) following the trends of preexisting fractures in the area. The existence of an extensional system is recognized by the pattern of tension gashes and Pennant and the presence of extensional joints in the area. The shift in s1 direction from NE-SW to N-S, confirm the presence of some rotation in the area. The rotation in a transpressional regime caused the development of extensional structures in the Shahr-e-Babak area; the extensional structures provided the space for the passage of ore fluids and the emplacement of polymetallic vein and porphyry copper deposits in northeastern Shahr-e-Babak
