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author Mollenhauer, Gesine
Kienast, Markus
Lamy, Frank
Meggers, Helge
Schneider, Ralph R
Hayes, John M
Eglinton, Timothy Ian
author_facet Mollenhauer, Gesine
Kienast, Markus
Lamy, Frank
Meggers, Helge
Schneider, Ralph R
Hayes, John M
Eglinton, Timothy Ian
collection Datos científicos de ciencias marinas y ambientales
contents Radiocarbon age relationships between co-occurring planktic foraminifera, alkenones, and total organic carbon in sediments from the continental margins of southern Chile, northwest Africa, and the South China Sea were compared with published results from the Namibian margin. Age relationships between the sediment components are site-specific and relatively constant over time. Similar to the Namibian slope, where alkenones have been reported to be 1000-4500 years older than co-occurring foraminifera, alkenones were significantly (~1000 years) older than co-occurring foraminifera in the Chilean margin sediments. In contrast, alkenones and foraminifera were of similar age (within 2 sigma error or better) in the NW African and South China Sea sediments. Total organic matter and alkenone ages were similar off Namibia (age difference TOC alkenones: 200-700 years), Chile (100-450 years), and NW Africa (360-770 years), suggesting minor contributions of preaged terrigenous material. In the South China Sea, total organic carbon is significantly (2000-3000 years) older owing to greater inputs of preaged terrigenous material. Age offsets between alkenones and planktic foraminifera are attributed to lateral advection of organic matter. Physical characteristics of the depositional setting, such as seafloor morphology, shelf width, and sediment composition, may control the age of co-occurring sediment components. In particular, offsets between alkenones and foraminifera appear to be greatest in deposition centers in morphologic depressions. Aging of organic matter is promoted by transport. Age offsets are correlated with organic richness, suggesting that formation of organic aggregates is a key process.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_837739
institution PANGAEA
language en
publishDate 2005
publisher PANGAEA
record_format pangaea
spellingShingle (Table 2) Radiocarbon contents of TOC and alkenone samples
Mollenhauer, Gesine
Kienast, Markus
Lamy, Frank
Meggers, Helge
Schneider, Ralph R
Hayes, John M
Eglinton, Timothy Ian
Age, 14C AMS; Age, dated; Age, dated, standard deviation; CHIPAL; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Event label; Fraction modern carbon; Fraction modern carbon, error; GeoB3313-1; GeoB5546-2; GIK18287-2; Gravity corer (Kiel type); KL; M42/4b; Mass; Meteor (1986); MUC; MultiCorer; Piston corer (BGR type); SL; SO102/1; SO115; SO115_40; Sonne; South-East Pacific; SUNDAFLUT; Sunda Shelf
Radiocarbon age relationships between co-occurring planktic foraminifera, alkenones, and total organic carbon in sediments from the continental margins of southern Chile, northwest Africa, and the South China Sea were compared with published results from the Namibian margin. Age relationships between the sediment components are site-specific and relatively constant over time. Similar to the Namibian slope, where alkenones have been reported to be 1000-4500 years older than co-occurring foraminifera, alkenones were significantly (~1000 years) older than co-occurring foraminifera in the Chilean margin sediments. In contrast, alkenones and foraminifera were of similar age (within 2 sigma error or better) in the NW African and South China Sea sediments. Total organic matter and alkenone ages were similar off Namibia (age difference TOC alkenones: 200-700 years), Chile (100-450 years), and NW Africa (360-770 years), suggesting minor contributions of preaged terrigenous material. In the South China Sea, total organic carbon is significantly (2000-3000 years) older owing to greater inputs of preaged terrigenous material. Age offsets between alkenones and planktic foraminifera are attributed to lateral advection of organic matter. Physical characteristics of the depositional setting, such as seafloor morphology, shelf width, and sediment composition, may control the age of co-occurring sediment components. In particular, offsets between alkenones and foraminifera appear to be greatest in deposition centers in morphologic depressions. Aging of organic matter is promoted by transport. Age offsets are correlated with organic richness, suggesting that formation of organic aggregates is a key process.
title (Table 2) Radiocarbon contents of TOC and alkenone samples
topic Age, 14C AMS; Age, dated; Age, dated, standard deviation; CHIPAL; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Event label; Fraction modern carbon; Fraction modern carbon, error; GeoB3313-1; GeoB5546-2; GIK18287-2; Gravity corer (Kiel type); KL; M42/4b; Mass; Meteor (1986); MUC; MultiCorer; Piston corer (BGR type); SL; SO102/1; SO115; SO115_40; Sonne; South-East Pacific; SUNDAFLUT; Sunda Shelf
url https://doi.org/10.1594/PANGAEA.837739