Late Miocene surface uplift of the southern margin of the Central Anatolian Plateau, Central Taurides, Turkey

Abstract

The timing and pattern of surface uplift of Miocene marine sediments capping the southern margin of the Central Anatolian Plateau in southern Turkey provide a fi rst-order constraint on possible mechanisms of regional uplift. Nannofossil, ostracod, and planktic foraminifera biostratigraphy of the Başyayla section (Mut-Ermenek Basin) within the Mut and Köselerli Formations suggests a Tortonian age for marine sediments unconformably capping basement rocks at ~2 km elevation. The identifi cation of biozone MMi 12a (7.81-8.35 Ma) from planktic foraminifera in the upper part of the section provides the tightest constraint on the age, which is further limited to 8.35-8.108 Ma as a result of the reverse polarity of the collected samples (chron 4r.1r or 4r.2r). This provides a limiting age for the onset of surface uplift at the margin of one of the world's major orogenic plateaus, from which an average uplift rate of 0.24-0.25 mm/yr can be calculated.Subhorizontal beds of the uppermost marine sediments exposed throughout the Mut-Ermenek Basin suggest minimal localized deformation, with just minor faulting at the basin margin and broad antiformal deformation across the basin. This implies that the post-8 Ma uplift mechanism must be rooted deep within the crust or in the upper mantle. Published Pn-wave velocity data for the region are compatible with topography compensated by asthenosphere across the southern margin of the plateau, showing a close match to the highest topography when elevations are fi ltered with a 100-km-wide smoothing window. Uplift along the southern margin of the Central Anatolian Plateau is also refl ected by the pattern of Miocene marine sediments capping the margin, which form an asymmetric drape fold over the topography. These observations, together with tomographic evidence for slab steepening and break-off beneath the Eastern Anatolian Plateau, suggest that at least some of the ~2 km of post-8 Ma uplift of the southern Central Anatolian Plateau margin is compensated by low-density asthenospheric mantle that upwelled following slab break-off. their employment. Individual scientists are hereby granted permission, without fees or furtherCopyright not claimed on content prepared wholly by U.S. government employees within scope of Notes

Stable isotope-based reconstruction of Oligo-Miocene paleoenvironment and paleohydrology of Central Anatolian lake basins (Turkey)

“…Parts of the Western Pontides were exhumed along a pre-Miocene ductile shear zone , while the active uplift of the Central Pontides at the northern plateau margin is attributed to stress across the restraining bend of the North Anatolian Fault since the Late Miocene (Yildirim et al 2011). Multiphase post-8 Ma surface uplift of the Central Taurides at the southern margin is associated with slab break-off, which likely also influenced the evolution of the CAP as a whole (Cosentino et al 2012;Schildgen et al 2012aSchildgen et al , 2012b. In the plateau interior of Anatolia OligoMiocene basin development was accompanied by intense Miocene volcanism in the Galatian Province (e.g., Wilson et al 1997).…”

“…Fission-track evidence points to an initial phase of Late Oligocene to Middle Miocene uplift of the Western Pontides in the northwest of the plateau (Zattin et al 2005;Okay et al 2008;Cavazza et al 2012), whereas the still ongoing differential surface uplift of the Central Pontides, which is mainly driven by the North Anatolian Fault Zone, started in the Late Miocene to Early Pliocene (Yildirim et al 2011). Equally important is the multiphased surface uplift history of the Central Taurides that border the CAP from the south, for which Mediterranean slab dynamics appear to have played a fundamental driving role in triggering a rapid phase of surface uplift post-8 Ma (Cosentino et al 2012;Schildgen et al 2012aSchildgen et al , 2012b.…”

Karstic depressions on Bolkar Mountain plateau, Central Taurus (Turkey):distribution characteristics and tectonic effect on orientation

“…Due to uplift in this period along the anticlinal (Şaroğlu et al, 1983;Akay and Uysal, 1988), a central N-S-oriented expansion occurred (Şengör, 1979;Şengör and Yılmaz, 1981;Özgül, 1976;Görür, 1985;Dewey et al, 1986;Dhont et al, 1999;Jaffey and Robertson, 2005). In addition, Cosentino et al (2012) describe the study area as an asymmetric drape fold. Linked to this expansion, E-W oriented extension fracture systems began to form parallel to the fold axes (Figure 8b).…”

A Miocene onset of the modern extensional regime in the Isparta Angle: constraints from the Yalvaç Basin (southwest Turkey)

“…The rather complex geometry of slabs below the study area was recently taken into account by Schildgen et al (2012a) to explain the uplift history of southern Anatolia in latest Miocene and Pliocene time, which recently has received wide attention (e.g. Deynoux et al 2005;Cosentino et al 2012;Schildgen et al 2012aSchildgen et al , b, 2014. These authors inferred that the disconnection between the Aegean, Antalya, and Cyprus slab segments may have led to asthenospheric inflow and resulted dynamic topographic effects.…”

“…1c). Whereas high on the Tauride mountains, relict extensional basins are found with upper Miocene marine sediments (Deynoux et al 2005;Cosentino et al 2012;Schildgen et al 2012a), basins flanking the Tauride mountains to the east are filled by continental sediments and in places volcanics, and formed in an overriding plate setting of the present-day Cyprus subduction zone, as well as above the Antalya slab fragment. These intramontane basins include the Altınapa, Ilgın (or Akşehir) and Yalvaç Basins (Fig.…”