Hyun, Sangmin and Kim, Seong-Ryul (1999): Geochemical study for provenance and paleoceanography on ODP Site 907 sediments of the North Atlantic Ocean

Leg/Site/Hole:
ODP 151
ODP 162
ODP 151 907
ODP 162 907
Identifier:
2000-034644
georefid

Creator:
Hyun, Sangmin
Korea Ocean Research and Development Institute, Marine Geology and Geophysics Division, Seoul, South Korea
author

Kim, Seong-Ryul
author

Identification:
Geochemical study for provenance and paleoceanography on ODP Site 907 sediments of the North Atlantic Ocean
1999
Geosciences Journal (Seoul)
Hanrimwon Publishing Company for the Geological Society of Korea, Seoul, South Korea
3
2
95-106
A geochemical analysis is conducted on hemipelagic sediments at ODP Leg 162, Site 907, North Atlantic. On the basis of major and minor element concentrations, the sequence is divided into five units. Geochemical data reveal that the sediments originated from two specific source areas, i.e., continental icerafted debris (IRD) and Icelandic basalt. In the upper part (lithological units I and II, 0 to 63.1 meters below sea floor (mbsf)), sediments were derived from continental IRD, whereas in the lower part, sediments (lithological units III, IV, and V, below 63.1 mbsf) comprise mixture of continental IRD and minor supply from the Icelandic basalt. The ratio of TiO (sub 2) /Al (sub 2) O (sub 3) to SiO (sub 2) content and the Th to Ti/Al molar ratio clearly provide a key to discriminate provenances. The change in source area is most likely related to the oceanographic and climatic evolution in the North Atlantic since the middle Miocene. Biogenic fossil-barren intervals (Units II and V) are considered as a consequence of dissolution caused by oceanic circulation. The timing of IRD initiation confers with that of geochemical analysis. Total organic carbon to total nitrogen (C/N) ratio shows a striking variation in the entire core. The C/N ratios exceed 10 below approximately 196 mbsf (lithological unit V) with a gradual downward increase. This suggests that terrigenous organic matters have been supplied from the neighboring continents. The total organic carbon to total sulfur (C/S) ratio also shows such possibility as well as diagenetic changes in Units IV and V. The carbonate-barren intervals presented in Units II and V, and intermittently in Units III and IV are interpreted as a consequence of dissolution effect related with climatic variation and deep-water circulation. Additional low surface productivity was considerable.
English
Serial
Coverage:Geographic coordinates:
North:80.2830
West:-80.0000East: 20.0000
South:0.0000

Geochemistry of rocks, soils, and sediments; Sedimentary petrology; Atlantic Ocean; basalts; carbon; climate change; diagenesis; Europe; geochemistry; hemipelagic environment; Iceland; igneous rocks; Leg 151; Leg 162; marine environment; marine sediments; nitrogen; North Atlantic; Ocean Drilling Program; ODP Site 907; organic carbon; paleo-oceanography; provenance; sampling; sediments; sulfur; volcanic rocks; Western Europe;

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