Description of manganese deposits collected by R/V Nothwind during the 1963 expedition in the Laptev sea


Autoria(s): Holmes, ML; Creager, Joe S
Cobertura

MEDIAN LATITUDE: 76.112500 * MEDIAN LONGITUDE: 129.875000 * SOUTH-BOUND LATITUDE: 75.792000 * WEST-BOUND LONGITUDE: 129.867000 * NORTH-BOUND LATITUDE: 76.433000 * EAST-BOUND LONGITUDE: 129.883000 * DATE/TIME START: 1963-09-02T00:00:00 * DATE/TIME END: 1963-09-02T00:00:00 * MINIMUM DEPTH, sediment/rock: 0 m * MAXIMUM DEPTH, sediment/rock: 0 m

Data(s)

18/08/1974

Resumo

The 400-km-wide, low gradient Laptev Sea continental shelf consists of flat terrace-like features at regular depth intervals from 10 to 40 m below present sea level. The five large submarine valleys traversing the shelf do not continuously grade seaward, but contain elongated, closed basins. These terraces and closed basins plus deltaic sediments associated with the submarine valleys quite possibly mark sea level Stillstands, and enable reconstruction of the paleogeography of the Laptev Sea shore line at five periods during post-Wisconsin (Holocene) time. Radiocarbon dates on the silty-clay to clayey-silt sediments from cores of the northeastern Laptev Sea indicate average sedimentation intensity of 2 to 15 mg/cm2/yr. The presence of manganese nodules and crusts in surface samples from less than 55 m depths and a general decrease in total foraminiferal abundances with depth in the cores suggest that the present deposition rate is less than when sea level was lower. The main components of the shelf deposits are near- shore sediments which were spread over the shelf as Holocene sea level fluctuated and marine currents distributed modern fine sediment. Rare silty-sand layers and the coarser nuclei of the manganese crusts and nodules indicate ice rafting. However, this mechanism is probably only locally important as a significant transporting agent.

Formato

text/tab-separated-values, 15 data points

Identificador

https://doi.pangaea.de/10.1594/PANGAEA.859299

doi:10.1594/PANGAEA.859299

Idioma(s)

en

Publicador

PANGAEA

Relação

Grant, J Bruce; Moore, Carla J; Alameddin, George; Chen, Kuiying; Barton, Mark (1992): The NOAA and MMS Marine Minerals Geochemical Database. National Geophysical Data Center, NOAA, doi:10.7289/V52Z13FT

Warnken, Robin R; Virden, William T; Moore, Carla J (1992): The NOAA and MMS Marine Minerals Bibliography. National Geophysical Data Center, NOAA, doi:10.7289/V53X84KN

Direitos

CC-BY: Creative Commons Attribution 3.0 Unported

Access constraints: unrestricted

Fonte

Supplement to: Holmes, ML; Creager, Joe S (1974): Holocene History of the Laptev Sea Continental Shelf (Chapter 9). In: Herman, Y. (Ed.) Marine Geology and Oceanography of the Arctic Seas. Springer Berlin Heidelberg, 211-229, doi:10.1007/978-3-642-87411-6_9

Palavras-Chave #DEPTH, sediment/rock; Description; Event label; GC; Gravity corer; Identification; Laptev Sea; NOAA and MMS Marine Minerals Geochemical Database; NOAA-MMS; Northwind; NW63; NW63-143; NW63-145; Position; Quantity of deposit; Sediment type; Size; Substrate type; Type; Visual description
Tipo

Dataset