Stress State Study of Siah Cheshmeh-Khoy Fault Zone (NW-Iran) and Using Stress Separation Method in Separation of Neotectonic Stresses from Paleostresses

Zamani Gharechamani, B

doi:10.22071/gsj.2013.53557

Document Type : Original Research Paper

Author

B Zamani Gharechamani

Assistant Professor, Department of Geology, Natural Science Faculty, Tabriz University, Tabriz, Iran

https://doi.org/10.22071/gsj.2013.53557

Abstract

In the present study, the state of stress in SiahCheshme-Khoy fault zone area in the North-West of Iran has been analyzed based on the systematic inversion of focal mechanisms of earthquakes, and fault slip data, to characterise the stress regime controlling of most faults and earthquakes in this area. The calculated average stress regime in this area indicates major NW-SE trending compression which dominates stress regime in strike slip mode with an intermediate stress axis, σ₂, close to vertical. Reconstructed stress has shown that average seismotectonic stress and average stress obtained from fault slip data do not have consistency due to of the multi stress regimes in this fault zone. Nonetheless stress separation analysis results for fault slip data and earthquake data have good consistency and their first and second analyzed stress regimes have the same trend. Also comparison between the results of the stress separation analysis between fault slip data and earthquake data, has shown that the second and third stress regime of this analysis are neotectonic stresses that controlling this fault zone movements. The forth stress regime also is a neostress regime that has been shown in seismotectonic stress separation analysis also, but it seems related to the deep faults. The first stress regime that have resulted from stress separation analysis of both field and earthquake data, it seems a paleostress regime which is not shown in seismic data analysis. Also reconstructed stresses in this study, have good consistency with the latest studies in this area especially with geodetic studies.

Keywords

20.1001.1.10237429.1392.23.89.11.4

References

Angelier, J., 1984 - Tectonic analyses of fault slip data sets. Journal of Geoph. Res, Vol. 89, No. B7, pp. 5835-5848.

Angelier, J., 2002- Inversion of earthquake focal mechanisms to obtain the seismotectonic stress (a new method free of choice among nodal planes) IV. Geophys. J. Int, 150: 588-609.

Angelier, J., 2004- Inversion of earthquake focal mechanisms to reconstruct multiple seismotectonic stress regimees: Refinig and separation processes. Geophy. Research Abst, Vol. 6,03901.

Angelier, J., 2006- Dyngli and Invigli softeware. Pierr and Mari Curri University Paris VI.

Berberian, M. & Arshadi, M., 1976- On the eviderne of the youngest activity of the North Tabriz city. In Geological Survey of Iran, Report No. 39, pp.397-418.

Berberian, M. & Hamdi, B., 1977- First discovery of the Ordovician beds and conodonts in the slightly metamorphosed rocks of the Kun-e-Agh Baba, Maku quadrangle, Azarbaidjan. Geol. Surv. Iran, Internal Report. 7p.

Berberian, M. & Yeats, R., 1999- Patterns of Historical Earthquake Rupture in the Iranian Plateau. Bulletin of the Seismological society of America, 89: 120-139.

Berberian, M., 1997- Seismic sources of the Transcaucasian historical earthquakes. In: Historical and Prehistorical Earthquakes in the Caucasus (D. Giardini and S. Balassanian, eds.), NATO ASI Series, 2. Environment- Vol. 28, 233-311, Kluwer Academic Press, the Netherlands.

Carver, G. & McCalpin, J., 1996- Paleoseismology, 1996, Chapter 5, 587p. Academic press, New York.

CMT, Centroid Moment Tensor Catalogue, Harvard University, 2006- Department of geological Sciences, available online at: http://www.seismology.harvard.edu/CMTsearch.html.

DeMets, C., Gordon, R. G., Argus, D. F. & Stein., S., 1990- Current plate motions. Geophys. J. Int, 101, 425-478.

ISC (International Seismological Centre): available online at: http://www.isc.ac.uk/.

Jackson, J. A. & McKenzie, D., 1984- Active tectonics of the Alpine-Himalayan Belt between western Turkey and Pakistan, Geophys. J. R. Astr. Soc., 77, 185-264.

Jackson, J., 1992- Partitioning of strik- slip and convergent Motion Between Eurasia and Arabia in Eastern Turkey. Journal of Geophysical Research, 97: 12,471-12,479.

Masson, F., Anvari, M., Djamour, Y., Walpersdorf, A., Tavakoli, F., Daigni`eres, M., Nankali, H. & Van Gorp, S., 2007- Large-scale velocity field and strain tensor in Iran inferred from GPS measurements: new insight for the present-day deformation pattern within NE Iran. Geophys. J. Int. 170: 436–440.

Masson, F., Chery, J., Martinod, J., Hatzfeld, D., Vernant, P., Tavakoli, F. & Ghafori-Ashtiani, M., 2005- Seismic versus aseismic deformation in Iran inferred from earthquake and geodetic data, Geophys. J. Int., 160, 217-226.

McClusky, S., Reilinger, R., Mahmoud, S., Ben Sari, D. & Tealeb, A., 2003- GPS constraints on Africa (Nubia) and Arabia plate motions, Geophys. J. Int., 155, 126– 138.

McKenzie, D., 1972- Active tectonics of the Mediterranean Region. Geophys. J. R. Astr. Soc., 30., 109-165.

Mostriouk, A. O. & Petrov, V. A., 1994- Catalogue of focal mechanisms of Earthquakes 1964-1990, Materials of World Data Center B., Moscow, pp. 87, available online at http://www.brk.adm.yar.ru/russian/1-512/1-512-3e.htm.

Nilforoushan, F., Masson, F., Vernant, P., Vigny, C., Martinod, J., Abbassi, M., Nankali, H., Hatzfeld, D., Bayer, R., Tavakoli, F., Ashtiani, A., Doerflinger, E., Daignie` res, M., Collard, P. & Che´ry, J., 2003- GPS network monitors the Arabia-Eurasia collision deformation in Iran. Journal of Geodesy, 77: 411–422.

Ramsay, J., 1986- Modern structural geology, Vol. 2, Press, London.

Rebai, S., Philip, H., Dorbath, L., Borissoff, B., Haessler, H. & Cisternas, A., 1993- Active tectonics in the Lesser Caucasus: coexistence of compressive and extensional structures, Tectonics 12: 1089-1114.

SED, Schweizericher Erdbebendienst, Swiss Seismological Service, 2006- available online at, http// siesmo.ethz.ch/info/mt.htmI.

Vernant, P. & Chery, J., 2006- Low fault friction in Iran implies localized deformation for the Arabia-Eurasia collision zone, EPSL, 246, 197–206.

Vernant, Ph., Nilforoushan, F., Hatzfeld, D., Abbassi, M. R., Vingy, C., Masson, F., Nankali, H., Martinod, J., Ashtiani, A., Bayer, R., Tavakoli, F. & Chery, J., 2004- Present-day crustal deformation and plate kinematics in the Middle East constrained by GPS Measurements in Iran and northern Oman. Geophys. J. Int, 157: 381-398.

ZamaniGharechamani, B., Angelier, J. & Zamani, A., 2008- State of stress induced by plate convergence and stress partitioning in northeastern Iran, as indicated by focal mechanisms of earthquakes. Journal of Geodynamics, 45, 120-132.

ZamaniGharechamani, B., 2011- State of stress in the northern Tabas block, east-central Iran, as inferred from focal mechanisms of the 1978 Tabas earthquake sequence, Central European Journal of Geoscinces, 3(1), 77-89.

Zamani Gharechamani, B. & Masson, F., 2014- Recent tectonic of East (Iranian) Azarbaijan from stress state reconstruction. Tectonophysics, 611, 61-82..

Scientific Quarterly Journal of Geosciences

Stress State Study of Siah Cheshmeh-Khoy Fault Zone (NW-Iran) and Using Stress Separation Method in Separation of Neotectonic Stresses from Paleostresses

References

References

Volume 23, Issue 89 - Serial Number 89
Vol.23, No.89
December 2013
Pages 75-88

Stress State Study of Siah Cheshmeh-Khoy Fault Zone (NW-Iran) and Using Stress Separation Method in Separation of Neotectonic Stresses from Paleostresses

References

References

Volume 23, Issue 89 - Serial Number 89Vol.23, No.89December 2013Pages 75-88

Volume 23, Issue 89 - Serial Number 89
Vol.23, No.89
December 2013
Pages 75-88