Structural relationship between the Sea of Marmara Basin and the North Anatolian Fault Zone

Abstract

The North Anatolian Fault (NAF) zone is 1500 km long, extending almost up to the Greek mainland in the west. It is a seismically active right‐lateral strike‐slip fault that accommodates the relative motion between the Turkish block and Black Sea plate. The Sea of Marmara lies along the western part of the NAF and shows evidence of subsidence. In this area pure strike‐slip motion of the fault zone changes into extensional strike‐slip movement that is responsible for the creation of the Sea of Marmara and the North Aegean basins. The northern half of the Sea of Marmara is interpreted as a large pull‐apart basin. This basin is subdivided into three smaller basins separated by strike‐slip fault segments of uplifted blocks NE‐SW. Basinal areas are covered by horizontally layered sedimentary sequences. Uplifted blocks have undergone compressional stress. All the blocks are subsiding and are undergoing vertical motions and rotations relative to one another. The uplifted blocks exhibit positive Bouguer gravity anomalies. According to gravity interpretation, there is relative crustal thinning under the Sea of Marmara. The northern side of the Sea of Marmara is marked by a distinctive deep‐rooted magnetic anomaly, which is dissected and shifted southward by strike‐slip faulting. The southern shelf areas of the Sea of Marmara are dominated by short‐wavelength magnetic anomalies of shallow origin.

Late Cenozoic tectonics and stratigraphy of northwestern Anatolia: the effects of the North Anatolian Fault to the region

“…5) underlain by (2) calcareous sandstone of Pliocene age, and (3) Pannonian sandstone-mudstone, and tuff/coal-bearing sandstonemudstone. Cretaceous strata were reached at 2,000 m. However, in the borehole North Marmara-1 (NM-1), on the northern shelf of the Sea of Marmara, Paleozoic rocks were reached at 1,100 m (Ergün and Özel 1995). On this basement, only Oligocene units are present.…”

Modelling Seismic Hazard in Earthquake Loss Models with Spatially Distributed Exposure

“…Erdik et al (2004) have used many published findings regarding the fault system below the Sea of Marmara (e.g. Pinar, 1943;Ergun and Ozel, 1995;Le Pichon et al, 1999) to develop a fault segmentation model (Figure 1). The most significant tectonic element in the region is the Main Marmara fault: a through-going dextral strike-slip fault system.…”

Interpretation of ambiguous reflection data by imaging processes: An example profile crossing steep submarine valley at the sea bottom

“…1b) (Okay et al, 1999). Pliocene or younger rocks were not encountered in the wells but the Miocene strata, which are underlined by the Eocene-Oligocene sequence, directly entered at 265 m in Is ßıklar-1 and at 720 m in Doluca-1 wells (Ergün and Özel, 1995;Yazman, 1997).…”