Sr, C and O isotope ratios of Neogene sediments from DSDP Hole 38-341, Voring Plateau
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| Natura: | Dataset Open Access |
| Lingua: | en |
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PANGAEA
1986
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| _version_ | 1867169498789838848 |
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| author | Smalley, P Craig Nordaa, A Raheim, A |
| author_facet | Smalley, P Craig Nordaa, A Raheim, A |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The Neogene sediments from DSDP site 341 on the Voring Plateau, Norwegian Sea, contain a thin glauconitic pellet-bearing subunit, which separates underlying pelagic clays from overlying glacial-marine sediments. Oxygen isotope measurements of benthic foraminifera show a delta18O shift of + 1 per mil during deposition of this subunit, probably a combined effect of a drop in bottom water temperature and a rise in seawater delta18O. The chronology of this sedimentological and O isotope transition is, however, poorly constrained by fossil evidence. Rb-Sr dating of glauconitic pellets indicates that the lower part of the glauconitic subunit was deposited 11.6 +/- 0.2 Ma ago. Further geochronological evidence, derived from the Sr and C isotopic compositions of foraminifera compared with known seawater-time variations, indicates that the lower pelagic clays are early to middle Miocene, deposited at a mean rate of ~15 m/Ma. The glauconitic subunit contains part of the middle Miocene and probably all of the late Miocene in a condensed sequence with a very low mean depositional rate (~0.2 m/Ma). The overlying glacial marine sediments are probably Pliocene, with a high mean rate of deposition, ~45 m/Ma. This is the first application of C, O and Sr isotopic stratigraphy combined with Rb-Sr dating of glauconitic minerals, and it illustrates the applications of this integrated approach in geochronology. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_714252 |
| institution | PANGAEA |
| language | en |
| publishDate | 1986 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Sr, C and O isotope ratios of Neogene sediments from DSDP Hole 38-341, Voring Plateau Smalley, P Craig Nordaa, A Raheim, A 38-341; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg38; North Atlantic/Norwegian Sea The Neogene sediments from DSDP site 341 on the Voring Plateau, Norwegian Sea, contain a thin glauconitic pellet-bearing subunit, which separates underlying pelagic clays from overlying glacial-marine sediments. Oxygen isotope measurements of benthic foraminifera show a delta18O shift of + 1 per mil during deposition of this subunit, probably a combined effect of a drop in bottom water temperature and a rise in seawater delta18O. The chronology of this sedimentological and O isotope transition is, however, poorly constrained by fossil evidence. Rb-Sr dating of glauconitic pellets indicates that the lower part of the glauconitic subunit was deposited 11.6 +/- 0.2 Ma ago. Further geochronological evidence, derived from the Sr and C isotopic compositions of foraminifera compared with known seawater-time variations, indicates that the lower pelagic clays are early to middle Miocene, deposited at a mean rate of ~15 m/Ma. The glauconitic subunit contains part of the middle Miocene and probably all of the late Miocene in a condensed sequence with a very low mean depositional rate (~0.2 m/Ma). The overlying glacial marine sediments are probably Pliocene, with a high mean rate of deposition, ~45 m/Ma. This is the first application of C, O and Sr isotopic stratigraphy combined with Rb-Sr dating of glauconitic minerals, and it illustrates the applications of this integrated approach in geochronology. |
| title | Sr, C and O isotope ratios of Neogene sediments from DSDP Hole 38-341, Voring Plateau |
| topic | 38-341; Deep Sea Drilling Project; DRILL; Drilling/drill rig; DSDP; Glomar Challenger; Leg38; North Atlantic/Norwegian Sea |
| url | https://doi.org/10.1594/PANGAEA.714252 |