Keywords : Paleostress

Fault-slip Analysis and Paleostress Reconstruction at Sara Anticline-Dokan Dam Site Northeastern Iraq

Ibrahim S. Al-jumaily; Saddam I. Al-khatoni

Iraqi National Journal of Earth Sciences, 2013, Volume 13, Issue 1, Pages 75-102

Stress inversion of fault-slip data has been worked by application of improved Right- Dihedral technique, succeeded by rotational optimization (Win-Tensor Software of Delvaux, 2010, version 2.2.3). Attitudes of fault planes, striations and their movement sense, were gathered from quarries and road cut exposures of carbonate rocks at Sara anticline situated in the high fold belt of northeastern Iraq. The obtained paleostress tensors of the current fault-slip analysis are (according to the general trends of δ1 (δHmax.) for strike slip and compressive tensors and δ3 (δHmin.) for extensional tensors): NNE-SSW, NE-SW primary strike slip and compressive tensors; WNW-ESE, NW-SE, NNW-SSE strike slip and compressive subordinate (relaxed) tensors; NW-SE extensional tensor byproduct from the primary tensor sets; and NNE-SSW, NE-SW extensional tensors associated with releasing phase accompanying the final uplift of the main fold. The multitrends of the computed paleostress tensors might be attributed to the oblique convergence and collision of Arabian and Iranian plates along their zigzaged margins.