(Table 3) Foraminiferal 87Sr/86Sr ratios and ages of ODP Hole 162-986D sediments
Fuente:
PANGAEA
Enregistré dans:
| Auteurs principaux: | , , , , , |
|---|---|
| Format: | Dataset Open Access |
| Langue: | en |
| Publié: |
PANGAEA
1999
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1867171812052303872 |
|---|---|
| author | Forsberg, Carl Fredrik Solheim, Anders Elverhoi, Anders Jansen, Eystein Channell, James E T Andersen, Espen Sletten |
| author_facet | Forsberg, Carl Fredrik Solheim, Anders Elverhoi, Anders Jansen, Eystein Channell, James E T Andersen, Espen Sletten |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Site 986 was drilled to 965 meters below seafloor (mbsf) on the western Svalbard margin to record the onset of glaciations and to date and document the glacial evolution in the Svalbard-Barents Sea region during the Pliocene-Pleistocene. In this paper, results of sedimentological analyses are discussed in light of seismic stratigraphy and new age determinations. The latter were difficult to obtain in the glacial deposits, and datums are sparse. Through combined paleomagnetic data, biostratigraphy, and Sr isotopes, however, an overall chronology for the main evolutionary steps is suggested. The cored sequence at Site 986 is younger than 2.6 Ma, and the lower 60 m of the section contains no evidence of a major glacial influence. An initial glaciation is interpreted to have occurred at ~2.3 Ma, resulting in increased sand deposition from debris flows at Site 986 and forming a prominent seismic reflector, R7. However, glaciers probably did not reach the shelf break until ~1.6-1.7 Ma (Reflector R6), after which the depositional environment was dominated by diamictic debris flows. A gradual change in source area from the Barents Sea to Svalbard is recorded primarily by changes in carbonate and smectite content, ~355 mbsf (Reflector R5), at an interpolated age of 1.4-1.5 Ma. During the last ~1 m.y., Site 986 has undergone more distal deposition as the main depocenters have shifted laterally. This has resulted in less frequent debris flows and more turbidites and hemipelagic deposits, with a slight fining upward of the cored sediments. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_805206 |
| institution | PANGAEA |
| language | en |
| publishDate | 1999 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 3) Foraminiferal 87Sr/86Sr ratios and ages of ODP Hole 162-986D sediments Forsberg, Carl Fredrik Solheim, Anders Elverhoi, Anders Jansen, Eystein Channell, James E T Andersen, Espen Sletten 162-986D; Age, dated; Age, dated material; Age, maximum/old; Age, minimum/young; Age, strontium isotope, LOWESS fit Howarth & McArthur (1997); DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Joides Resolution; Leg162; North Greenland Sea; Ocean Drilling Program; ODP; Sample code/label; Strontium-87/Strontium-86 ratio Site 986 was drilled to 965 meters below seafloor (mbsf) on the western Svalbard margin to record the onset of glaciations and to date and document the glacial evolution in the Svalbard-Barents Sea region during the Pliocene-Pleistocene. In this paper, results of sedimentological analyses are discussed in light of seismic stratigraphy and new age determinations. The latter were difficult to obtain in the glacial deposits, and datums are sparse. Through combined paleomagnetic data, biostratigraphy, and Sr isotopes, however, an overall chronology for the main evolutionary steps is suggested. The cored sequence at Site 986 is younger than 2.6 Ma, and the lower 60 m of the section contains no evidence of a major glacial influence. An initial glaciation is interpreted to have occurred at ~2.3 Ma, resulting in increased sand deposition from debris flows at Site 986 and forming a prominent seismic reflector, R7. However, glaciers probably did not reach the shelf break until ~1.6-1.7 Ma (Reflector R6), after which the depositional environment was dominated by diamictic debris flows. A gradual change in source area from the Barents Sea to Svalbard is recorded primarily by changes in carbonate and smectite content, ~355 mbsf (Reflector R5), at an interpolated age of 1.4-1.5 Ma. During the last ~1 m.y., Site 986 has undergone more distal deposition as the main depocenters have shifted laterally. This has resulted in less frequent debris flows and more turbidites and hemipelagic deposits, with a slight fining upward of the cored sediments. |
| title | (Table 3) Foraminiferal 87Sr/86Sr ratios and ages of ODP Hole 162-986D sediments |
| topic | 162-986D; Age, dated; Age, dated material; Age, maximum/old; Age, minimum/young; Age, strontium isotope, LOWESS fit Howarth & McArthur (1997); DEPTH, sediment/rock; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Joides Resolution; Leg162; North Greenland Sea; Ocean Drilling Program; ODP; Sample code/label; Strontium-87/Strontium-86 ratio |
| url | https://doi.org/10.1594/PANGAEA.805206 |