Holocene Raised Shorelines on the Hatay Coasts (Turkey) - Paleoecological and Tectonic Implications

The marks of two emerged shorelines (superimposed erosional notches, and in-situ bioconstructed rims with the vermetid Dendropoma) on both sides of the Orontes Delta, near the border between Turkey and Syria, are interpreted as representing the occurrence of two rapid uplifts during the late Holocene rather than representing eustatic fluctuations of climatic origin as claimed by previous authors in other areas of the eastern Mediterranean. The upper shoreline, which has an elevation of about +2.0 m south of the delta and which increases from +2.5 m to +3.0 m between 2 and 8 km north of the delta, has been radiocarbon dated (four dates) to between 5170 +/- 190 and 2595 +/- 100 yrs B.P. The lower shoreline, indicating a former relative sea level situated consistently at about +0.7 to +0.8 m, has yielded seven dates between 2910 +/- 95 and 1345 +/- 70 yrs B.P., the latter age being that of fossil oyster shells collected in growth position on a quay of the ancient harbour of Seleucia Pieria. If the possible contamination of some oyster shells is take into account, the two uplift movements may be dated at around 2500 +/- 100 yrs B.P. for the upper shoreline and to historical times for the lower shoreline, probably in July 551 A.D. when devastating earthquake damage was reported from all the Levant regions. The age of the second uplift movement falls within the possible time span of a major tectonic event, the Early Byzantine Tectonic Paroxysm (EBTP), which about 1500 yrs B.P caused sudden relative sea-level changes in various areas of the eastern Mediterranean (Antikythira, western Crete, and Alanya area, the Lebanon, northern Cyprus, etc.). In the Hatay region, the effect of the EBTP has been a reactivation of local fault lines, probably in connection with movements on the East Anatolian Fault system. This has contributed a new jerk to the long-term trend of uplift in this coastal area.