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| Titel |
Understanding the intraplate deformation of the Anatolian Scholle: Insights from the study of the Ovacik Fault (Eastern Turkey) |
| VerfasserIn |
Cengiz Zabcı, Taylan Sançar, Dmitry Tikhomirov, Susan Ivy-Ochs, Christof Vockenhuber, Müge Yazıcı, Boris A. Natal'in, H. Serdar Akyüz, Naki Akçar |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250110446
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| Publikation (Nr.) |
 EGU/EGU2015-10442.pdf |
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| Zusammenfassung |
| The tectonic evolution of the eastern Mediterranean is mainly defined by the interaction
between three major plates, Eurasia, Africa, Arabia and the smaller Anatolian ‘scholle’. The
Anatolia is being extruded westward along two major tectonic structures, the North Anatolian
(NASZ) and the East Anatolian (EASZ) shear zones, respectively forming its northern and
eastern boundaries. Although there are many geologic and geodetic studies infer that the
deformation is mainly concentrated along the NASZ and the EASZ, it is also well
documented that the central “ova” neotectonic province, which defines a region
between the Aegean extensional regime in the west, the NASZ in the north and the
EASZ in the east, is also deformed internally by a series of NW-striking dextral
and NE-striking sinistral strike-slip faults. These active structures clearly fit to the
passive-Prandtl cell model of an internally deforming body, which is originally
suggested by Sengör (1979) to interpret the neotectonics of the central Anatolia. The
Malatya-Ovacik Fault Zone (MOFZ) and it is northeastern member, the Ovacik Fault
(OF), is one the sinistral faults of the “ova” province, located close to its eastern
boundary.
In the framework of the TUBITAK project no. 114Y227, we started to study the (a) the
geologic slip rate, (b) the palaeoseismology and (c) the cumulative displacement of the OF in
order to understand not only the short and long term spatio-temporal behaviour of this 110
km-long strike slip fault, but also its role in the internal deformation of the Anatolian
‘scholle’. The faulting is clearly observed along the well-preserved scarps and displaced
fluvial landforms at the northern margin of the Ovacik Basin (Tunceli, Turkey), where the
deformation is mainly localised along a single strand. The preliminary cosmogenic 36Cl dates
of two independent terrace risers at a single site yield slip rates about 1.5 and 1.9 mm/yr
(Zabci et al. 2014), which slightly exceed the GPS-based block model velocity of 1.2±0.3
mm/yr. To the west-southwest of the Ovacik Basin the deformation is partitioned along
parallel/sub-parallel branches of the OF, where the MOFZ forms a complex structural setting
in response to the southward bending of the fault zone. Although, the oldest drainage of the
region, Euprates Valley, was measured to have 8 km sinistral displacement, the total
magnitude of slip should be larger when we consider these sub-parallel faults. During the
project studies, we will precisely measure cumulative displacements not only of the
drainage systems, but also across the contacts of the geological formations along
the different branches of the OF. The morphological indices, such as topographic
profiling, hypsometric integral, basin asymmetry and the mountain front sinuosity will
support quantifying the activity of this poorly known fault. Moreover, we are planning
palaeseismological trench studies on potential sites during summer, 2015. The integration of
all these data will also provide information about the seismic hazard assessment of the
region.
Keywords: Geologic slip rate, Ovacik Fault, Anatolia, cosmogenic dating,
palaeoseismology, intraplate deformation
References
Sengör, A. M. C., 1979, The North Anatolian Transform Fault; its age, offset
and tectonic significance, Journal of the Geological Society of London, v. 136, p.
269-282
Zabci, C., Sançar, T., Tikhomirov, D., Vockenhuber, C., Ivy-Ochs, S. & Akçar, N., 2014,
Understanding the intraplate deformation of the Anatolia: Insights from preliminary
slip rates of the Malatya-Ovacik Fault, Eastern Turkey, during the last 16 ka, in
Proceedings 8. International Symposium on Eastern Mediterranean Geology, Muðla. |
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