FAULT FINDING: ESR DATING MOLLUSCS FROM MARINE TERRACES IN HATAY PROVINCE, TURKEY

Hatay Province, Turkey, straddles the Anatolian, Arabian, African, and Cyprean Plates, which are split by the strike-slip East Anatolian, Cyprean-Antakya, and Dead Sea Fault Zones. Repeatedly, large earthquakes located on all three fault zones have destroyed Antioch (now Antakya) and all Hatay. Near Samandağ, south of Antakya, three subparallel faults (= the Cyprean-Antakya Fault Zone) rim a hemi-graben and has had large vertical displacements have uplifted the southeastern side of the fault zone by > 150 m more than the northwestern side in the Quaternary. Coupled with Quaternary cyclic sealevel fluctuations that reworked glacial sediment, stranding several marine terraces high above the current sealevel. Northwest of Çevlik and Mağaracık, at least four Quaternary terraces can be recognized, while near Meydan and Tekebaşı at least three terraces are clearly visible. Since ESR can date molluscs between 0.5 ka and 2 Ma, > 50 mollusc samples from 26 locations on these marine terraces were independently dated by standard electron spin resonance (ESR) in order to date the marine terraces and match the terraces across the graben to measure uplift rates. ESR ages were calculated using time-averaged and volumetrically averaged external dose rates. Time-averaged cosmic and sedimentary dose rates were modelled assuming typical water depths for individual species and sedimentation rates estimated from geological criteria. All the terraces have incorporated older reworked molluscs into their sediment, including molluscs > 1.8-2.0 Ma. Near Mağaracık, the 30-35 m terraces date to 67 ± 2 ka, while the 45 m terrace correlates with MIS 5e, and the 105 m terrace dates at 88 ± 9 ka (MIS 5b). On the 8 m terrace at Meydan Dump, the slump dated at 14 ± 1 ka. Near Tekebaşı, the 170 m terrace correlated with OIS 9-11, while the 57 m terrace dated at 82 ± 8 ka. Therefore, tectonic uplift likely has averaged ~ 0.2-0.5 m/ky, across the area since MIS 5.