Tectonic and sedimentary evolution of the Cenozoic Hatay Graben, Southern Turkey: a two-phase model for graben formation

Abstract

New structural and sedimentary studies form the basis of a new interpretation for the Neogene Hatay Graben. Fault analysis reveals three contemporaneous trends of fault orientation (000°–180°, 045°–225° and 150°–350°) suggesting that the graben is transtensional in nature. Sedimentary studies show that, following shallow-marine deposition from the Late Cretaceous to the Eocene, a hiatus ensued until Early Miocene fluvial sedimentation. After a Mid-Miocene marine transgression, water depths increased until the Messinian salinity crisis, followed by a regression from the Pliocene to the present day. The basin initially developed as the distal margin of a foreland basin of the Tauride allochthon to the north, developing a classic sedimentary sequence during Mid-Late Miocene. Stresses caused by loading of the crust created a flexural forebulge to the south that supplied sediment mainly northwards. During the Plio-Quaternary, transtensional graben development took place, primarily influenced by the westward tectonic escape of Anatolia along the East Anatolia Fault Zone and left-lateral offset along the northward extension of the Dead Sea Transform Fault. This area is, thus, an excellent example of a foreland basin reactivated in a strike-slip setting. Our new two-phase model: foreland basin, then transtensional basin for the Hatay Graben, is in contrast to previous models, in which it was generally assumed that the Plio-Quaternary Hatay Graben represents a direct extension of the Dead Sea Fault Zone or the East Anatolian Fault Zone.

The kinematics of central-southern Turkey and northwest Syria revisited

“…This fault zone has recently been designated by others (e.g., Boulton et al, 2006Boulton et al, , 2007Boulton and Whittaker, 2009) as the 'Hatay Graben'. However, it is apparent from the published descriptions of the faulting and from the motions of adjoining GPS points (DORT-SENK and ULUC-SENK; Table 1), which suggest rates of left-lateral slip and extension across this zone of ~4-5 mm a -1 and ~3-4 mm a -1 , respectively, that it is not a simple zone of extension as the term 'graben' would imply.…”

“…More recently, others (e.g., Boulton et al, 2006Boulton et al, , 2007Boulton and Whittaker, 2009) have argued that although its NW margin is not an active fault zone, its SE margin is bounded by active oblique normal faults. The evidence of northwest-dipping active faulting along the SE margin of this zone indeed seems compelling (Figs 2, 3), some of these faults having been recognized many years ago, for example by Tolun and Erentöz (1963) or Erol (1963).…”

Palaeozoic-Recent geological development and uplift of the Amanos Mountains (S Turkey) in the critically located northwesternmost corner of the Arabian continent

“…In the northern part of the region, Early Miocene sedimentation was initially non-marine, whereas shallow-marine sediments accumulated directly on Eocene 'basement' in the south and east (Boulton, 2009;Boulton & Robertson, 2007;Boulton, Robertson, & Ünlügenç, 2006). Although an Early Miocene age for the non-marine sediments is assumed, a Late Oligocene age is not precluded, especially for the well-oxidised 2009), again pointing to tectonic instability.…”

“…In addition, the Middle Miocene of the adjacent Hatay area is characterised by peritidal carbonates (Sofular Formation), together with contemporaneous, small patch reefs (Kepez Formation), as exposed near Serinyol and Kırıkhan (Boulton & Robertson, 2007;Boulton et al, 2006). This area was so far from the overthrust Tauride allochthon that it was less influenced by crustal flexure during Early-Middle Miocene time.…”

“…The largest depressed area, the Amik Basin in the south, is variously interpreted as a releasing bend, pull-apart or triple junction (e.g. Boulton et al, 2006;Duman & Emre, 2013). The associated strike-slip/ transtension triggered tilting of the Pliocene sediments and the regional basaltic volcanism around the Amanos Mountains (e.g.…”