Paleostress analysis from brittle failure and minor structures in Dokan Area, Kurdistan Region, NE of Iraq .

Salim. H. Sulaiman Al-Hakari

Department of Geology, University of Sulaimani


The study area is located within the high folded of the northwestern segment of the
Zagros Foreland Fold Thrust Belt in northeast of Iraq. Joints, mesofaults, veins and
stylolites were studied through seven stations in the Kosrat Anticline. The trend of
the fold and the strike of the strata are of NW-SE direction in accordance with the
main trend of Zagros folds.
New geological map and cross section of the study area were constructed. The
exposed rocks of the studied area range in age from Cretaceous up to the Eocene
included the following formations (Qamchuqa, Kometan, Shiranish, Tanjero,
Kolosh and Sinjar) Kometan and Tanjero formations was taken in consideration for
brittle failure analysis . The analyzed structural field data indicate that the
investigated area was subjected throughout its geological history to four stress
phases. First is primary compressive tectonic phase in the directions N-S, NE-SW
and successive phase in the direction ENE-WSW. The second compressive
tectonic stress in the direction NW-SE considered as a secondary phase. Third was
extension tectonic phase in the direction NE-SW which developed during the final
uplift stage of folding is normal to the major folds trend. The fourth is NW-SE
extension face considerate as extension stress related to the primary NE-SW
compressive stress.

Key Words:
analysis, Micro
tectonic analysis,
Brittle frailer


[1] AL-Jumaily, I.S.I. “Tectonic investigation of the brittle failure structures in the Foreland Folds Belt”. Northern Iraq, Unpub. Ph.D thesis, University of Mosul, Iraq, (in Arabic).( 2004). 

[2] Aswad, K.J. “ Arc-Continent Collision in Northeastern Iraq as evidence by the Mawat and Penjwin Ophiolite Complexes”. Raf. Jour. Sci., 10(1), pp. 51-61. (1999). 

[3] Anderson, E, M. “The dynamics of faulting. 1st ed.”, Oliver and Boyed, Edin- burgh, 206p.( 1942). 

[4] Angelier, J. and Mechler, P. “Sur une methode graphique, de recbercbe des contraintes enseismologie: La methode de diedres droits”. Bull. Soc. Geol. France, 7, pp.1309-1318.( 1977). 

[5] Bles, J. L. and Feuga, B. “The fracture of rocks. North Oxford Academic publishers Ltd.”, 131p. (1986). 

[6] Hancock, P.L. “Brittle microtectonics: principles and practices”. J. Struct.Geol., 7, pp. 437-457. (1985). 

[7] Hancock, P.L. and Atiya, M.S. “Tectonic significance of mesofracture systems associated with the Lebanese segment of the Dead Sea fault”. J. Struct. Geol., 1, pp.143-153.( 1979). 

[8] Hancock, P.L. and Alkadhi, A. and Sha'at, N.A. “Regional joint sets in the Arabian platform as imdicators of intraplate processes”. Tectonics, Vol3, pp.27-43.( 1984). 

[9] Haakon Fossen. “Structural geology” Cambridge University Press, New York, USA, 463p. (2010) 

[10] Lisle, R.J. “Principal stress orientation from faults: An additional constraint”. Ann. Tectonics, 1, pp.155-158.( 1987). 

[11] Numan, N. M. S. “ Discussion on "Dextral Transpression in Late Cretaceous Continental Collision, Sanandaj - Sinjar Zone, Western Iran". J. Struct. Geol Vol. 23. ( 2001b) 

[12] Ramsay, J. G and Huber, M. I. “The techniques of modern structural geology” V.2, Folds and Fractures. Academic press, London, 700p. ( 1987). 

[13] Suppe, J., 1985. “Principles of Structural Geology” Prentice-Hall, Inc, New Jersey, 537p. 

[14] Turner, F.J. and Weiss, L.E. “Structural analysis of metamorphic tectonite” McGraw-Hill, New York, 545p.Vol3, pp.27-43. (1963). 

[15] Twiss, R. J. and Moores, E. M. “Structural geology” W.H. Freeman, USA, 717p.( 2007). 

[16] Van der Pluijm, B.A. and Marshak, S. “Earth structure: An introduction to structural geology and tectonics”. WCB/McGraw Hill, USA, 495p. (2004). 

[17] AL-Fadhli, I., Janardan Rao, Y., Oweiss, G. and Khalil, M. “Polyphase deformation in apart of Zagros. Sulaimaniyah district, NE Iraq”. J. Indian Academy of Geoscience. 22, pp.1-31.( 1979). 

[18] AL-Fadhli, I., Janardan Rao, Y., Oweiss, G. and Takla, M.A. ”Superimposed Folding in Sayed-Sadek area, near the Zagros suture zone”, Iraq. Geoviews, VIII, No.111, pp.126-148.( 1980). 

[19] Taha, M.A., Al-Saadi, S.N. and Ibrahim, I.S. “Microtectonic study Dokan area NE Iraq” Iraqi Geol. Soc. Jour., 28 (1), pp.25-35.( 1995).