Palaeoenvironment and human interaction during the last 4k years in the dried lake sediments (amik lake, southern turkey): evidences of lake level changes

The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman Period when the Antioch city reached its golden age. The basin also sustained a high seismic activity (M≥7) as it is a releasing step-over along the Dead Sea Fault. The study focuses on the sedimentary record of the Amik Lake occupying the central part of the Basin. Our objective is to constrain major paleo-environmental changes in the area over the last 4000 years and to unravel possible human impacts on the sedimentation. A diverse array of complementary methods was applied on the 6 m long record: Inorganic carbon (L.O.I), mineralogy (XRD), geochemistry (XRF), carbon and nitrogen isotopes. The age of the record is constrained combining radionuclide and radiocarbon dating. It is checked using the correlation between the earthquake historical record and rapidly deposited layer identified. Sedimentation rates of 0.12 cm/yr higher than in the central part of the lake are related to the accommodation space created by normal motion along the fault. The sedimentary record shows significant fluctuations of the lake associated with a significant riverine system change of the Afrin River draining into the Amik Lake starting during the Roman Period. In this period the human impact is attested by carbonates saturation of lake water due to the construction of several canals mostly along the Afrin River. This study examines the mechanisms driving long-term carbonate preservation in lacustrine sediments in Amik Lake (southern Turkey) since the last 4000 years. Carbonates precipitate from the alkaline water column, and the sediments preserve dolomite and calcite. Based on X-ray diffraction data, carbonate accumulation has changed significantly and reversals in the abundance of the two carbonate polymorphs have occurred. Chemical composition and carbon and nitrogen isotopes indicate that reversals in carbonate polymorph abundance arise due to physical changes in the lake water as column depth