Morpho-tectonic evolution of the Çanakkale Basin (NW Anatolia): evidence for a recent tectonic inversion from transpression to transtension

Abstract

Onshore and offshore seismic and geologicmorphologic evidence from the wider region of the Çanakkale

Morphometric age estimate of the last phase of accelerated uplift in the Kazdag area (Biga Peninsula, NW Turkey)

“…1B). The Late Miocene to Quaternary clastic sediments of the basin lie unconformably on the pre-Miocene to Miocene basement that constitutes the ridge, evidencing differential vertical movement between basin and ridge during this period (Gökaşan et al, 2011), at least until raised marine terraces indicate recent inclusion of the basin in the uplift area, much in the same way as the Bayramiç depression though with more poorly constrained dating (>600 ka?). Available data on the river terrace staircase in the valleys of the Biga Peninsula are still fewer and less conclusive.…”

“…According to dates obtained not only for these onshore deposits but also for sediments that Yaltırak et al (2000) considered as their offshore counterpart in the eastern Marmara Sea (although Gökaşan et al (2008) interpreted the same seismic data in a substantially different way), uplift of the Strait's coasts would be going on since at least 600 ky. Relying on U/Th age data and comparing the present elevation of these marine terraces with sea level stand in the Marmara Sea during sediment deposition, Yaltırak et al (2002) provided uplift rates for the Strait area on the order of 0.4 mm/yr since~225 ka. However, the Çanakkale basin, in which the marine terraces are found, is morphologically clearly distinct from the uplifted NW part of the Biga Peninsula, also called the BozcaadaBiga ridge by Gökaşan et al (2011) (Fig. 1B).…”

“…Therefore, whereas transpression along SW-trending segments of the NAFZ branches (Gökaşan et al, 2011;Okay and Satir, 2000) and/or horst development previously caused localized uplift in the Kazdag massif s.s. and the Bozcaada-Biga ridge, an additional, more regional cause of deformation seems to appear at that time. Such a larger-scale trigger might be found in a temporary increase of compressive stresses within the Anatolian plate, whose westward motion is resisted by the GreeceBalkan domain.…”

Evidence for active faulting in the eastern part of the Gulf of Saros, northern Aegean, from high-resolution seismic data

“…The previous fault maps of the gulf were constructed by interpreting the multi-beam bathymetry maps, and confirmed by the analogue seismic sections (Ç agatay et al 1998;Yaltırak et al 1998;Ustaömer et al 2008;Gökaşan et al 2012). On the other hand, because of the large intervals between the available seismic sections, it was not easy to determine the changes in the fault characters.…”

“…The seismic data covering the Gulf of Saros is limited in order to demonstrate the active faulting within the inner gulf in detail. The available data are mainly distributed on the Aegean Sea exit of the gulf and there are only three seismic profiles (Ç agatay et al 1998;Yaltırak et al 1998;Ustaömer et al 2008;Gökaşan et al 2012) representing the eastern part. Three seismic profiles are not sufficient to understand the tectonic properties at the inner side of the gulf.…”