TY - JOUR
T1 - Monitoring tectonic uplift and paleoenvironmental reconstruction for marine terraces near maǧaracik and Samandaǧ, Hatay province, Turkey
AU - Florentin, Jonathan A.
AU - Blackwell, Bonnie A.B.
AU - Tüysüz, Okan
AU - Tari, Ufuk
AU - Genç, Ş Can
AU - Imren, Caner
AU - Mo, Shirley
AU - Huang, Yiwen E.W.
AU - Blickstein, Joel I.B.
AU - Skinner, Anne R.
AU - Kim, Maria
PY - 2014/6
Y1 - 2014/6
N2 - Near Hatay, the Antakya-Samandaǧ -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 Samandaǧ, 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 Samandaǧ 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 Maǧaracik terraces, the dates suggest that many shells were likely reworked. On the 30 m terrace at Maǧaracik 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 Maǧaracik terraces at ~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 Maǧaracik Dump (UTM 765391-4001048), ~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 Samandaǧ 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 Maǧaracik Dump site from the other Maǧaracik sites and from the Samandaǧ Kurt Stream site.
AB - Near Hatay, the Antakya-Samandaǧ -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 Samandaǧ, 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 Samandaǧ 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 Maǧaracik terraces, the dates suggest that many shells were likely reworked. On the 30 m terrace at Maǧaracik 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 Maǧaracik terraces at ~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 Maǧaracik Dump (UTM 765391-4001048), ~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 Samandaǧ 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 Maǧaracik Dump site from the other Maǧaracik sites and from the Samandaǧ Kurt Stream site.
UR - http://www.scopus.com/inward/record.url?scp=84903173521&partnerID=8YFLogxK
U2 - 10.1093/rpd/ncu179
DO - 10.1093/rpd/ncu179
M3 - Article
C2 - 24943512
AN - SCOPUS:84903173521
SN - 0144-8420
VL - 159
SP - 220
EP - 232
JO - Radiation Protection Dosimetry
JF - Radiation Protection Dosimetry
IS - 1-4
M1 - ncu179
ER -