Holocene terraces in the Middle Euphrates Valley, between Halfeti and Karkemish (Gaziantep, Turkey) [ Terrasses holocènes dans la moyenne vallée de l'Euphrate entre Halfeti et Karkemish (Gaziantep, Turquie).]

摘要

The Holocene fluvial and archaeological records in the valleys draining the south-eastern piedmont of the Taurus range present several contrasted phases, interrupted by transition and/or rupture periods. The low terrace records identified in the Middle Euphrates valley between Halfeti and Karke- mish give the following results 1 ) a pre-Holocene incised topography is dated Upper or Late Pleistocene, 2) Late Pleistocene/Early Holocene alluviation deposited sands and silts forming a "high terrace" (+8-10 m) fossilising the previous incision, 3) at mid-Holocene the valley was forested and the landscape stable, 4) at the end of the 5th mill. BC, erosion and incision preceded the instalment of new settlements on the valley floor, 5) high floods followed this incision, 6) during the 2nd mill. BC or only in its second half, the river deposited a +4 m terrace, which was followed by incision during the first centuries of the 1st mill. BC. The comparison with previous works realised within the Turkish and Syrian Middle Euphrates basin shows similarities and differences in the chronology of events and in the interpretation of the possible climatic significance of the changes observed Discussion then tries to take into account 1) the records of global and regional climatic changes, 2) the sizes and geographic characters of the watersheds studied, 3) their position in the whole Euphrates basin, 4) the specific history of man's occupation of the land.