Monitoring tectonic uplift and paleoenvironmental reconstruction for marine terraces near Magaracik and SamandaC, Hatay Province, Turkey


Florentin J. A. , Blackwell B. A. B. , Tuysuz O. , TARI U. , Genç Ş. C. , IMREN C. , ...More

RADIATION PROTECTION DOSIMETRY, vol.159, pp.220-232, 2014 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 159
  • Publication Date: 2014
  • Doi Number: 10.1093/rpd/ncu179
  • Title of Journal : RADIATION PROTECTION DOSIMETRY
  • Page Numbers: pp.220-232

Abstract

Near Hatay, the Antakya-Samandag-Cyprus Fault (ASCF), East Anatolian and Dead Sea Fault Zones, the large faults that form the edges of the African, Anatolian, Cyprus and Arabian Plates, all produce large earthquakes, which have decimated Hatay repeatedly. Near Samandag, Hatay, differential vertical displacement on the ASCF has uplifted the southeastern side relative to northwestern side, producing large fault scarps that parallel the Asi (Orontes) River. Tectonic uplift coupled with Quaternary sealevel fluctuations has produced several stacked marine terraces stranded above current sealevel. This study dated 24 mollusc samples from 10 outcrops on six marine terraces near Samandag electron spin resonance (ESR). Ages were calculated using time-averaged and volumetrically averaged external dose rates, modelled by assuming typical water depths for the individual species and sediment thicknesses estimated from geological criteria. Uplift rates were then calculated for each fault block. At all the MagaracA +/- k terraces, the dates suggest that many shells were likely reworked. On the 30 m terrace at MagaracA +/- k IV (UTM 766588-3999880), Lithophagus burrows with in situ shells cross the unconformity. One such shell dated to 62 +/- 6 ka, setting the minimum possible age for the terrace. For all the MagaracA +/- k terraces at similar to 30 m above mean sealevel (amsl), the youngest ages for the reworked shells, which averaged 60 +/- 3 ka for six separate analyses, sets the maximum possible age for this unit. Thus, the terrace must date to 60-62 +/- 3 ka, at the MIS 3/4 boundary when temperatures and sealevels were fluctuating rapidly. Older units dating to MIS 7, 6, and 5 likely were being eroded to supply some fossils found in this terrace. At MagaracA +/- k Dump (UTM 765391-4001048), similar to 103 m amsl, Ostrea and other shells were found cemented in growth position to the limestone boulders outcropping there < 2.0 m above a wave-eroded notch. If the oysters grew at the same time as the wave-cut notch and the related terrace, the date, 91 +/- 13 ka, for the oysters, this fault block has been uplifted at 1.19 +/- 0.15 m ky(-1), since MIS 5c. At Samandag Kurt Stream at 38 m amsl, molluscs were deposited fine sandy gravel, which was likely formed in a large tidal channel. Four molluscs averaged 116 +/- 5 ka. If these molluscs have not been reworked, this fault block has uplifted at 0.34 +/- 0.05 m ky(-1) since the MIS 5d/5e boundary. The differences in these uplift rates suggests that at least one, and possibly two, hitherto undiscovered faults may separate the MagaracA +/- k Dump site from the other MagaracA +/- k sites and from the Samandag Kurt Stream site.