Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox Conditions
Non-carbonaceous abyssal fine-grained sediments cover vast parts of the North Pacific’s deep oceanic basins and gain increasing interests as glacial carbon traps. They are, however, difficult to date at an orbital-scale temporal resolution and still rarely used for paleoceanographic reconstructions....
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Frontiers Media S.A.
2021-08-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2021.683177/full |
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| author | Wanzhang Wang Tilo von Dobeneck Thomas Frederichs Yang Zhang Lester Lembke-Jene Ralf Tiedemann Michael Winklhofer Dirk Nürnberg |
| author_facet | Wanzhang Wang Tilo von Dobeneck Thomas Frederichs Yang Zhang Lester Lembke-Jene Ralf Tiedemann Michael Winklhofer Dirk Nürnberg |
| author_sort | Wanzhang Wang |
| collection | DOAJ |
| description | Non-carbonaceous abyssal fine-grained sediments cover vast parts of the North Pacific’s deep oceanic basins and gain increasing interests as glacial carbon traps. They are, however, difficult to date at an orbital-scale temporal resolution and still rarely used for paleoceanographic reconstructions. Here, we show that sedimentary records of past geomagnetic field intensity have high potential to improve reversal-based magnetostratigraphic age models. Five sediment cores from Central North Pacific mid-latitudes (39–47°N) and abyssal water depths ranging from 3,900 to 6,100 m were cube-sampled at 23 mm resolution and analyzed by automated standard paleo- and rock magnetic methods, XRF scanning, and electron microscopy. Relative Paleointensity (RPI) records were determined by comparing natural vs. anhysteretic remanent magnetization losses during alternating field demagnetization using a slope method within optimized coercivity windows. The paleomagnetic record delivered well interpretable geomagnetic reversal sequences back to 3 Ma. This age span covers the climate-induced transition from a biogenic magnetite prevalence in the Late Pliocene and Early Pleistocene to a dust-dominated detrital magnetic mineral assemblage since the Mid-Pleistocene. Volcaniclastic materials from concurrent eruptions and gravitational or contouritic sediment re-deposition along extinct seamount flanks provide a further important source of fine- to coarse-grained magnetic carriers. Surprisingly, higher proportions of biogenic vs. detrital magnetite in the late Pliocene correlate with systematically lowered RPI values, which seems to be a consequence of magnetofossil oxidation rather than reductive depletion. Our abyssal RPI records match the astronomically tuned stack of the mostly bathyal Pacific RPI records. While a stratigraphic correlation of rock magnetic and element ratio logs with standard oxygen isotope records was sporadically possible, the RPI minima allowed to establish further stratigraphic tie points at ∼50 kyr intervals. Thus, this RPI-enhanced magnetostratigraphy appears to be a major step forward to reliably date unaltered abyssal North Pacific sediments close to orbital-scale resolution. |
| first_indexed | 2024-12-22T08:09:17Z |
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| id | doaj.art-bda4f6cc14c047d1b58c69b1c08c4ea3 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-12-22T08:09:17Z |
| publishDate | 2021-08-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Earth Science |
| spelling | doaj.art-bda4f6cc14c047d1b58c69b1c08c4ea32022-12-21T18:33:04ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632021-08-01910.3389/feart.2021.683177683177Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox ConditionsWanzhang Wang0Tilo von Dobeneck1Thomas Frederichs2Yang Zhang3Lester Lembke-Jene4Ralf Tiedemann5Michael Winklhofer6Dirk Nürnberg7MARUM—Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, Bremen, GermanyMARUM—Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, Bremen, GermanyMARUM—Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, Bremen, GermanyMARUM—Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, Bremen, GermanyAWI—Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyAWI—Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, GermanyInstitute for Biology and Environmental Sciences IBU, Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, GermanyGEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, GermanyNon-carbonaceous abyssal fine-grained sediments cover vast parts of the North Pacific’s deep oceanic basins and gain increasing interests as glacial carbon traps. They are, however, difficult to date at an orbital-scale temporal resolution and still rarely used for paleoceanographic reconstructions. Here, we show that sedimentary records of past geomagnetic field intensity have high potential to improve reversal-based magnetostratigraphic age models. Five sediment cores from Central North Pacific mid-latitudes (39–47°N) and abyssal water depths ranging from 3,900 to 6,100 m were cube-sampled at 23 mm resolution and analyzed by automated standard paleo- and rock magnetic methods, XRF scanning, and electron microscopy. Relative Paleointensity (RPI) records were determined by comparing natural vs. anhysteretic remanent magnetization losses during alternating field demagnetization using a slope method within optimized coercivity windows. The paleomagnetic record delivered well interpretable geomagnetic reversal sequences back to 3 Ma. This age span covers the climate-induced transition from a biogenic magnetite prevalence in the Late Pliocene and Early Pleistocene to a dust-dominated detrital magnetic mineral assemblage since the Mid-Pleistocene. Volcaniclastic materials from concurrent eruptions and gravitational or contouritic sediment re-deposition along extinct seamount flanks provide a further important source of fine- to coarse-grained magnetic carriers. Surprisingly, higher proportions of biogenic vs. detrital magnetite in the late Pliocene correlate with systematically lowered RPI values, which seems to be a consequence of magnetofossil oxidation rather than reductive depletion. Our abyssal RPI records match the astronomically tuned stack of the mostly bathyal Pacific RPI records. While a stratigraphic correlation of rock magnetic and element ratio logs with standard oxygen isotope records was sporadically possible, the RPI minima allowed to establish further stratigraphic tie points at ∼50 kyr intervals. Thus, this RPI-enhanced magnetostratigraphy appears to be a major step forward to reliably date unaltered abyssal North Pacific sediments close to orbital-scale resolution.https://www.frontiersin.org/articles/10.3389/feart.2021.683177/fullNorth Pacificabyssal sedimentsrelative paleointensitymagnetic carriersmagnetostratigraphybiogenic magnetite |
| spellingShingle | Wanzhang Wang Tilo von Dobeneck Thomas Frederichs Yang Zhang Lester Lembke-Jene Ralf Tiedemann Michael Winklhofer Dirk Nürnberg Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox Conditions Frontiers in Earth Science North Pacific abyssal sediments relative paleointensity magnetic carriers magnetostratigraphy biogenic magnetite |
| title | Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox Conditions |
| title_full | Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox Conditions |
| title_fullStr | Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox Conditions |
| title_full_unstemmed | Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox Conditions |
| title_short | Dating North Pacific Abyssal Sediments by Geomagnetic Paleointensity: Implications of Magnetization Carriers, Plio-Pleistocene Climate Change, and Benthic Redox Conditions |
| title_sort | dating north pacific abyssal sediments by geomagnetic paleointensity implications of magnetization carriers plio pleistocene climate change and benthic redox conditions |
| topic | North Pacific abyssal sediments relative paleointensity magnetic carriers magnetostratigraphy biogenic magnetite |
| url | https://www.frontiersin.org/articles/10.3389/feart.2021.683177/full |
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