Neotectonics of the Pontides: implications for ‘incompatible’ structures along the North Anatolian fault     

A.M Celál Şengör  Si̇lva Büyükaşikoğlu  Nezi̇hi̇ Canitez 《Journal of Structural Geology》1983,5(2):211-216

Data for the post-Serravallian, ‘neotectonic’ evolution of the Pontides in northern Turkey indicate predominant ENE-WSW shortening with complementary NNW-SSE extension. We present a new fault plane solution for the Bartin earthquake (3 September 1968) and compare its mechanism with the movement picture of other neotectonic faults in the Pontides and northern Greece together with that of the Thessaloniki earthquake (20 May 1978). The general strain pattern exhibited by these structures agrees remarkably well with that inferred from early Tortonian-early Pleistocene structures reported from within the North Anatolian fault zone, which have been interpreted as indicating a possible reversal of the sense of movement along the North Anatolian transform fault. Here, we argue that such ‘incompatible’ structures may be related to the overall E-W shortening of Anatolia and the southern parts of the Black Sea resulting from the sideways continental escape from around the African and the Arabian promontories, rather than to hypothetical reversal of motion along the North Anatolian fault, for which there is no evidence other than the above-mentioned ‘incompatible’ structures. This new model also has important implications for seismicity and earthquake risk in regions contained within the southern part of the Black Sea plate.  相似文献   

The focal mechanisms in Iran and their relations to tectonics     

Nezihi Canitez 《Pure and Applied Geophysics》1969,75(1):76-87

Summary Data from focal mechanism solutions obtained by different authors and those of 8 fault-plane solutions found in this study have been used to search for the distribution of the main stress axes in Iran. For this purpose, the area has been divided into three regions as southern, central and northern Iran. The results indicate that the characteristics of the motion at the foci are different in each of the three regions. — By examining the B axes in south Iranian earthquakes, direction of tectonic motion has been obtained as N 66°E. Since the maximum and intermediate stress axes are nearly horizontal, it is concluded that focal movements in this region are of reverse fault type. Thus, there is a similarity between recent crustal movements and those occurring during Alpine orogeny which is in the form of an overthrusting to the southwest. — In central Iran earthquakes however, tension is predominant, and, therefore, in this region faultings are dip-slip normal or strike-slip, and the horizontal components of displacements are dextral. The mean direction of maximum tension axes is nearly perpendicular to the central Iranian complexes. — It is deduced from north Iranian shocks that, in this region, the earthquakes studied are of nearly almost pressural type, and horizontal components of the oblique displacements in foci are sinistral.  相似文献   

Source mechanism and rupture propagation in the Mudurnu Valley,Turkey, earthquake of July 22, 1967     

Nezihi Canitez 《Pure and Applied Geophysics》1972,93(1):116-124

Summary First motions ofP waves and amplitude spectra ofG ₂ andG ₃ waves have been used to determine the source mechanism and rupture propagation. The amplitudes ofG ₃ waves have been corrected for the attenuation using aQ-model obtained from the amplitude spectra ofG ₂ andG ₃ waves. Observed directivities for the strike-direction agreed with a model of a bilateral fault propagated primarily from east to west.  相似文献