Compositional and isotopic data on core MD84641

The organic carbon isotopic record of the sapropels(S1 and S3-S10) and intercalated marl oozes has been determined in a 12-m piston core from the eastern Mediterranean. The d13C_organic values are systematically lighter (mean=-21.0±0.82 per mil) in all sapropels and heavier (mean=-18.8±1.07 per mil)...

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Main Authors: Fontugne, Michel R, Calvert, Stephen E
Format: Dataset
Language:English
Published: PANGAEA 1992
Subjects:
NOE
PC
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.701585
https://doi.org/10.1594/PANGAEA.701585
id ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.701585
record_format openpolar
spelling ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.701585 2023-05-15T16:39:23+02:00 Compositional and isotopic data on core MD84641 Fontugne, Michel R Calvert, Stephen E LATITUDE: 33.020000 * LONGITUDE: 32.380000 * DATE/TIME START: 1984-01-01T00:00:00 * DATE/TIME END: 1984-01-01T00:00:00 1992-08-19 application/zip, 2 datasets https://doi.pangaea.de/10.1594/PANGAEA.701585 https://doi.org/10.1594/PANGAEA.701585 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.701585 https://doi.org/10.1594/PANGAEA.701585 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Fontugne, Michel R; Calvert, Stephen E (1992): Late Pleistocene variability of the carbon isotopic composition of organic matter in the eastern Mediterranean: monitor of changes in carbon sources and atmospheric CO2 concentrations. Paleoceanography, 7(1), 1-20, https://doi.org/10.1029/91PA02674 Marion Dufresne (1972) MD84-641 Mediterranean Sea NOE PC Piston corer Dataset 1992 ftpangaea https://doi.org/10.1594/PANGAEA.701585 https://doi.org/10.1029/91PA02674 2023-01-20T07:31:13Z The organic carbon isotopic record of the sapropels(S1 and S3-S10) and intercalated marl oozes has been determined in a 12-m piston core from the eastern Mediterranean. The d13C_organic values are systematically lighter (mean=-21.0±0.82 per mil) in all sapropels and heavier (mean=-18.8±1.07 per mil) in the marl oozes. These differences are not due to variable marine and terrestrial organic matter mixtures because all values are heavier than modern plankton in the Mediterranean, there is no relationship between the C_organic/N ratios and the isotopic values, and published information on the abundance and distribution of organic biomarkers shows that terrestrial material constitutes a minor fraction of the total organic matter. Temperature effects on isotope fractionation are also discounted because the change in d13C_organic values between glacial and interglacial horizons is in the opposite sense. Diagenesis, which can produce relatively small changes in the carbon isotopic composition of sedimentary organic matter under certain circumstances, is unlikely to have caused the observed differences because this mechanism would cause an enrichmet in 12C, implying that all values were even heavier originally, and there is no secular trend in the d13C_organic record. The observed differences in d13C_organic between the two lithologies are probably produced by changes in the isotopic composition and the concentration of dissolved CO2. First, freshwater flooding during the formation of the sapropels caused the isotopic composition of the dissolved inorganic carbon in the surface waters of the Mediterranean to become lighter because of the 13C deficiency in fresh waters. Hence photosynthesis would have produced isotopically lighter organic material. Second, changes in atmospheric pCO2 between glacial and interglacial periods, as shown by the Vostok ice core, caused marked changes in the concentration of free dissolved CO2 in the mixed layer; lower values during glacial maxima caused a smaller fractionation of the carbon ... Dataset ice core PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(32.380000,32.380000,33.020000,33.020000)
institution Open Polar
collection PANGAEA - Data Publisher for Earth & Environmental Science
op_collection_id ftpangaea
language English
topic Marion Dufresne (1972)
MD84-641
Mediterranean Sea
NOE
PC
Piston corer
spellingShingle Marion Dufresne (1972)
MD84-641
Mediterranean Sea
NOE
PC
Piston corer
Fontugne, Michel R
Calvert, Stephen E
Compositional and isotopic data on core MD84641
topic_facet Marion Dufresne (1972)
MD84-641
Mediterranean Sea
NOE
PC
Piston corer
description The organic carbon isotopic record of the sapropels(S1 and S3-S10) and intercalated marl oozes has been determined in a 12-m piston core from the eastern Mediterranean. The d13C_organic values are systematically lighter (mean=-21.0±0.82 per mil) in all sapropels and heavier (mean=-18.8±1.07 per mil) in the marl oozes. These differences are not due to variable marine and terrestrial organic matter mixtures because all values are heavier than modern plankton in the Mediterranean, there is no relationship between the C_organic/N ratios and the isotopic values, and published information on the abundance and distribution of organic biomarkers shows that terrestrial material constitutes a minor fraction of the total organic matter. Temperature effects on isotope fractionation are also discounted because the change in d13C_organic values between glacial and interglacial horizons is in the opposite sense. Diagenesis, which can produce relatively small changes in the carbon isotopic composition of sedimentary organic matter under certain circumstances, is unlikely to have caused the observed differences because this mechanism would cause an enrichmet in 12C, implying that all values were even heavier originally, and there is no secular trend in the d13C_organic record. The observed differences in d13C_organic between the two lithologies are probably produced by changes in the isotopic composition and the concentration of dissolved CO2. First, freshwater flooding during the formation of the sapropels caused the isotopic composition of the dissolved inorganic carbon in the surface waters of the Mediterranean to become lighter because of the 13C deficiency in fresh waters. Hence photosynthesis would have produced isotopically lighter organic material. Second, changes in atmospheric pCO2 between glacial and interglacial periods, as shown by the Vostok ice core, caused marked changes in the concentration of free dissolved CO2 in the mixed layer; lower values during glacial maxima caused a smaller fractionation of the carbon ...
format Dataset
author Fontugne, Michel R
Calvert, Stephen E
author_facet Fontugne, Michel R
Calvert, Stephen E
author_sort Fontugne, Michel R
title Compositional and isotopic data on core MD84641
title_short Compositional and isotopic data on core MD84641
title_full Compositional and isotopic data on core MD84641
title_fullStr Compositional and isotopic data on core MD84641
title_full_unstemmed Compositional and isotopic data on core MD84641
title_sort compositional and isotopic data on core md84641
publisher PANGAEA
publishDate 1992
url https://doi.pangaea.de/10.1594/PANGAEA.701585
https://doi.org/10.1594/PANGAEA.701585
op_coverage LATITUDE: 33.020000 * LONGITUDE: 32.380000 * DATE/TIME START: 1984-01-01T00:00:00 * DATE/TIME END: 1984-01-01T00:00:00
long_lat ENVELOPE(32.380000,32.380000,33.020000,33.020000)
genre ice core
genre_facet ice core
op_source Supplement to: Fontugne, Michel R; Calvert, Stephen E (1992): Late Pleistocene variability of the carbon isotopic composition of organic matter in the eastern Mediterranean: monitor of changes in carbon sources and atmospheric CO2 concentrations. Paleoceanography, 7(1), 1-20, https://doi.org/10.1029/91PA02674
op_relation https://doi.pangaea.de/10.1594/PANGAEA.701585
https://doi.org/10.1594/PANGAEA.701585
op_rights CC-BY-3.0: Creative Commons Attribution 3.0 Unported
Access constraints: unrestricted
info:eu-repo/semantics/openAccess
op_rightsnorm CC-BY
op_doi https://doi.org/10.1594/PANGAEA.701585
https://doi.org/10.1029/91PA02674
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