Upper Holocene Sediments of the Black Sea: Summary of Leg 4 Box Cores (1988 Black Sea Oceanographic Expedition)

摘要: The 1988 R/V Knorr Black Sea Oceanographic Expedition has provided a unique opportunity to study many aspects of the sediments basin. Box cores collected during Leg 4 expedition revealed wide range uppermost Holocene sedimentary facies sampled over broad region southern basin, including from two transects across intersection water- column oxic/anoxic interface with basin-margin substrate. include: 1) muddy gray turbidite layers deep basin ranging in thickness few several tens centimeters and characterized by predominance fine grain sizes [fine silt—clay] strong textural chemical homogeneity, 2) an array closely-spaced sediment types at stations spanning oxycline/substrate which vary highly bioturbated, shell-rich oxic dark-gray black, water-rich, laminated muds anoxic zone 3) coccolith-rich, microlaminated Unit 1 abyssal consisting couplets alternating white [coccolith-dominated] dark-brown black [siliciclastic-dominated] millimeter-scale laminae thought reflect depositional seasonality. These are described detail terms their physical and, lesser degree, properties.