Open AccessLithodynamic studies near the Northwest Atlantic Mid-ocean channel
Author(s) -
L. D. Bashirova,
E. V. Dorokhova,
V. V. Sivkov
Publication year - 2019
Publication title -
okeanologiâ
Language(s) - English
Resource type - Journals
ISSN - 0030-1574
DOI - 10.31857/s0030-1574595803-809
Subject(s) - geology , turbidity current , sorting , silt , turbidite , winnowing , quaternary , sedimentary rock , contourite , current (fluid) , sedimentary depositional environment , sediment , seabed , oceanography , channel (broadcasting) , deposition (geology) , grain size , pelagic zone , geomorphology , geochemistry , paleontology , geography , archaeology , computer science , electrical engineering , engineering , structural basin , programming language
In AMK-4474 marine sediment core, recovered from the northern part of the eastern (left) levee of the Northwest Atlantic Mid-Ocean Channel, two stratigraphic units were identified. The lower unit is represented by the Late Quaternary fine-grained sediments of the upper turbidite sequences. The presence of a 1724 m mode in grain-size distributions within the thin silt interlayers in the lower unit may reflect a sorting process of sedimentary material by the spillover of turbidity currents which is similar to the contour currents activity. This allows applying an indicator of the contour current speed sortable silt (SS) content to estimate the intensity of the spill-over current. The upper unit, formed during the last 26 ka, is represented by pelagic sediments. The presence of the fine-grained interlayer in the upper unit of AMK-4474 core is apparently due to a decrease in IRD supply to the study area.