Dedicated to the memory of three pioneers, İhsan Ketin, Sırrı Erinç and Melih Tokay, and a recent student, Aykut Barka, who burnt himself out in pursuit of the mysteries of the North Anatolian Fault. ▪ Abstract The North Anatolian Fault (NAF) is a 1200-km-long dextral strike-slip fault zone that formed by progressive strain localization in a generally westerly widening right-lateral keirogen in northern Turkey mostly along an interface juxtaposing subduction-accretion material to its south and older and stiffer continental basements to its north. The NAF formed approximately 13 to 11 Ma ago in the east and propagated westward. It reached the Sea of Marmara no earlier than 200 ka ago, although shear-related deformation in a broad zone there had already commenced in the late Miocene. The fault zone has a very distinct morphological expression and is seismically active. Since the seventeenth century, it has shown cyclical seismic behavior, with century-long cycles beginning in the east and progressing westward. For earlier times, the record is less clear but does indicate a lively seismicity. The twentieth century record has been successfully interpreted in terms of a Coulomb failure model, whereby every earthquake concentrates the shear stress at the western tips of the broken segments leading to westward migration of large earthquakes. The August 17 and November 12, 1999, events have loaded the Marmara segment of the fault, mapped since the 1999 earthquakes, and a major, M ≤ 7.6 event is expected in the next half century with an approximately 50% probability on this segment. Currently, the strain in the Sea of Marmara region is highly asymmetric, with greater strain to the south of the Northern Strand. This is conditioned by the geology, and it is believed that this is generally the case for the entire North Anatolian Fault Zone. What is now needed is a more detailed geological mapping base with detailed paleontology and magnetic stratigraphy in the shear-related basins and more paleomagnetic observations to establish shear-related rotations.
The Tuzg61ti basin complex represents a cluster of epi-sutural depressions nested on the Ankara Knot in central Anatolia, where several sutures converge. The basin complex consists mainly of two sub-basins, the Haymana and the TuzgOlti (s.s.) depressions. During the Late Cretaceous to the Late Palaeocene, the Tuzg61ti and the Haymana sub-basins evolved coevally, but independently, as fore-arc basins along the active margins of the Sakarya Continent and the Klr~ehir block. Turbidites accumulated in the basin interiors, with shallow marine and terrestrial deposition near the basin margins. Late Palaeocene-Early Eocene collision of the Menderes-Taurus block with the Sakarya Continent and the Klr~ehir block along the Inner Tauride Sture, and the coeval collision of the Klrw block with the Rhodope-Pontide Fragment along the Erzincan suture juxtaposed and deformed the two sub-basins. Intra-continental convergence continued during the Early to Middle Eocene with further subsidence and turbidite deposition in both sub-basins. After the Middle Eocene, a single molasse basin was characterized by extensive redbeds and evaporites. Extensive salt deposits in the Tuzg61ti sub-basin probably relate to marine regression in the later Eocene. The present Tuzg61ti basin is part of neotectonic Turkey and constitutes one of the large central Anatolian ovas. 1981, ~eng6r et al. this volume) and some independent palaeomagnetic data (Sanver & Ponat 1981). StratigraphyThe Tuzg61ii basin sensu lato consists of two sub-basins that evolved coevally, but independently, during the Late Cretaceous to Eocene. These are the Haymana sub-basin and the Tuzg61ti (sensu stricto) sub-basin. The Tuzg6lii basin complex refers to the Tuzg61ti basin s.l., including the Tuzg61ti and the Haymana subbasins, whereas the TuzgOlii basin alone designates the Tuzg61ii (s.s.) sub-basin. Because of their separate evolutionary histories, we present the stratigraphic data from the Tuzg61ii and the Haymana sub-basins separately (Fig. 2). 467at University of Otago on January 3, 2015 http://sp.lyellcollection.org/ Downloaded from(~orum Basin ~ol-m 9 9 , , , , 910(
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