Stress regime change from Miocene to pliocene -Quaternary and its relationship with structures and dykes emplacement in thd Salafchegan area Oroumiyeh -Dokhtar magmatic belt

Document Type : Original Article

Authors

1 Master, Tectonics of Shahid Beheshti University

2 Professor at Shahid Beheshti University

3 Assistant Professor, Shahid Beheshti University

4 Ph.D Tectonic from Shahid Beheshti University

Abstract

Paleostress analysis using fault-slip data and trajectory of dykes in the Salafchegan area, west of Qom Province, has improved our knowledge on tectonic regime changes in the late Cenozoic in this portion of Oroumiyeh-Dokhtar magmatic belt. Stress trajectories drawn on the base of dykes show two direction of maximum principal stress along N-S and NE-SW. although fault-slip data analysis of 150 slickensides by MIM method proved the change of stress regime from Miocene to Pliocene in the study area. Additionally, the faulted and sheared anticline of Kharab-Sarahroud is an asymmetric Z-shape fold that cut by NE-SW left lateral strike slip faults. According to right-lateral transpression is was the active tectonic setting in the Oroumiyeh-Dokhtar belt from Miocene to present. The study area is laid between two main faults including Indes right-lateral strike slip fault to the north and Khorheh-Kahak thrust system to the south. Due to contribution of Oligocene-Miocene rock units, folding of Kharab-Sarahroud anticline has occurred in Miocene and perhaps Pliocene; when the first stress regime was active. Then by clockwise rotation stress axes, the fold was sheared and rotated to find Z-shape geometry. Finally NE-SW left-lateral faults cut the fold in Quaternary.

Keywords

References

امامی، م.، 1379. شرح نقشه زمین­شناسی چهارگوش قم، سازمان زمین­شناسی و اکتشافات معدنی کشور.
امینی، ب.، حاجیان، ج.، امینی جهرق، م.، 1378. نقشه زمین­شناسی تفرش (1:100000)، سازمان زمین­شناسی و اکتشافات معدنی کشور.
جمالی، ف.، حسامی آذر، خ.، قرشی، م.، 1387. گسلهای جنبا و قطعه بندی پهنه گسلی قم-زفره در گستره میان زفره تا شمال کاشان، فصلنامه علوم زمین.
علائی مهابادی، س.، 1379. نقشه زمین شناسی 000 100 : 1 سلفچگان. سازمان زمین­شناسی و اکتشافات معدنی کشور.
منصف، ر.، 1390. ژئوشیمی، پتروژنز و جایگاه تکتونو ماگمایی سنگ­های آتش­فشانی و نیمه آتش فشانی نئوژن غرب سلفچگان تا شمال دلیجان (ایران مرکزی)، رساله دکتری، دانشگاه تربیت مدرس.
 
Alavi, M., 1980.Tectonostratigraphic evolution of the Zagrosides of Iran. Geology 8, 144-149.
Alavi, M., 1994. Tectonics of the Zagros orogenic belt of Iran: new data and interpretations. Tectonophysics 229, 211-238.
Allen, M.B., Kheirkhah, M., Emami, M.H., Jones, SJ., 2011. Right-lateral shear across Iran and kinematic change in theArabia–Eurasia collision zone. Geophysical Journal International 184, 555–574.
Amidi, S.M., 1984. Geological map of the Saveh Quadrangle, scale 1: 250,000, Geol. Surv. Iran, Tehran.
Angelier, J., 1989. From orientation to magnitudes in paleostress determinations using fault slip data. Journal of structural geology 11(1-2), 37-50.
Berberian, F., Muir, I.D., Pankhurst, R.J., Berberian, M., 1982. Late Cretaceous and Early Miocene Andean-type plutonic activity in northern Makran and Central Iran.  Journal of Geological Society of London 139, 605-614.
Dimitrijevic, M.D., 1973. Geology of Kerman region, Geol. Surv. Iran Rep Yu, 52.  
Emami, M.H., 1981. Geologie de la region de Qom-Aran (Iran); Contribution a l, etude dynamique et geochemique du volcanisme tertiaire de l,Iran central, Tnese d,Etat. Univer, Grenoble. France.
Hajian, H., 1977. Geological map of the Tafresh area, scale 1: 100,000. Geol. Surv. Iran, Tehran.
Hessami, K., Pantosi, D., Tabassi, H., Shabanian, E., Abbassi, M., Feghhi, K., Sholaymani, S., 2003. Paleoearthquakes and slip rates of the North Tabriz Fault,NWIran: preliminary results. Annals of Geophysics 46, 903-915.
Knopf, A., 1936. Igneous geology of the Spanish Peaks region, Colorado.  Geological Society of America Bulletin 47(11), 1727-1784.
Morley, C.K., Kongwung, B., Julapour, A.A., Abdolghafourian, M., Hajian, M., Waples, D., Warren, J., Otterdoom, H., Srisuriyon, K., Kazemi, H., 2009. Structural development of a major late Cenozoic basin and transpressional belt in central Iran: The Central Basin in the Qom- Saveh area. Geosphere 5(4), 325-362.
Price, N.J., Cosgrove, J.W., 1990. Analysis of geological structures. Cambridge University Press, 502.
Ramsay, J.G., Lisle, R.J., 2000. Modern structural Geology vol.3, Academic Press.
Sippel, J., Scheck-Wenderoth, M., Reicherter, K., Mazur, S., 2009. Paleostress states at the south-western margin of the Central European Basin System—Application of fault-slip analysis to unravel a polyphase deformation pattern. Tectonophysics 470(1), 129-146.
Yamaji, A., 2000. The multiple inverse method: a new technique to separate stresses from heterogeneous fault-slip data. Journal of Structural Geology 22(4), 441-452.
Yamaji, A., Otsubo, M., Sato, K., 2006. Paleostress analysis using the Hough transform for separating stresses from heterogeneous fault-slip data. Journal of Structural Geology 28(6), 980-990.
Journal of Tectonics
Volume 2, Issue 6
August 2018
Pages 15-25

Files

Share

How to cite

Statistics