Akademik Veri Yönetim Sistemi
OCEANOLOGICA ACTA, cilt.24, sa.1, ss.51-67, 2001 (SCI-Expanded)
Holocene sediments taken from the south-eastern and western Black Sea have been investigated in relation to their geochemical, sedimentological and mineralogical characteristics. Their textures are characterized by their low amount of sand, upward-increasing silt and downward-increasing clay contents. While the terrigenous materials transported from Anatolian volcanic-based sources and European alluvial sediments form the shore deposits, the deep-sea sediments mainly consist of the marine biological production. The highest amount of organic carbon was deposited following the formation of anoxic conditions at the bottom until the beginning of the still continuing carbonate-rich coccolith (Emiliania huxleyi) deposition. The high metal concentrations are associated with fine-grained sediments, some with organic material. The metal concentration is diluted by high organic carbon and carbonate contents within the depositional sequences. While the abundance of illite in the western Black Sea describes the deltaic depositions, the downward decreasing smectite/illite ratio along the core, off the south-eastern shelf, indicates the downward increasing precipitation during the deposition. The variation in the sedimentation pattern and sedimented material is believed to be the response of the biochemical environment in the sea to the changing geological, biological and chemical conditions in and around the Black Sea during the last climatic changes. (C) 2001 Ifremer/CNRS/IRD/Editions scientifiques et medicales Elsevier SAS.