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| Հիմնական հեղինակ: | |
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| Ձևաչափ: | Dataset Open Access |
| Լեզու: | en |
| Հրապարակվել է: |
PANGAEA
1992
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| Խորագրեր: | |
| Առցանց հասանելիություն: | https://doi.org/10.1594/PANGAEA.771031 |
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Ավելացրեք ցուցիչ
Չկան պիտակներ, Եղեք առաջինը, ով նշում է այս գրառումը!
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| _version_ | 1867170460900261888 |
|---|---|
| author | Koizumi, Itaru |
| author_facet | Koizumi, Itaru |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | A series of excellent upper Miocene through Quaternary diatomaceous sequences recovered at four sites during Leg 127 was examined for diatoms. The diagenetic transition from opal-A to opal-CT is a diachronic horizon from the uppermost part of the Denticulopsis katayamae Zone (8.5 Ma) at Hole 797B to the uppermost part of the Neodenticula kamtschatica Zone (5.73 Ma) at Hole 795A. The diatom zonation of Koizumi (1985) best divides the upper Miocene to Quaternary sequences above the opal-A/opal-CT boundary and also is useful to date carbonate concretions including diatoms below the boundary. Forty diatom datum levels were evaluated biostratigraphically based on the sediment accumulation rate curve, and several isochronous datum levels are newly proposed for the Japan Sea area. A warm-water current did not penetrated into the Japan Sea through the Tsushima strait during the late Miocene and Pliocene time, because subtropical warm-water diatoms are essentially not present in such sediment samples. The occurrences of diatom are cyclic throughout the Quaternary sediments and are affected by eustatic sea level changes. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_771031 |
| institution | PANGAEA |
| language | en |
| publishDate | 1992 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Neogene diatoms of the Japan Sea Koizumi, Itaru 127-794A; 127-795A; 127-796A; 127-797B; DRILL; Drilling/drill rig; Japan Sea; Joides Resolution; Leg127; Ocean Drilling Program; ODP A series of excellent upper Miocene through Quaternary diatomaceous sequences recovered at four sites during Leg 127 was examined for diatoms. The diagenetic transition from opal-A to opal-CT is a diachronic horizon from the uppermost part of the Denticulopsis katayamae Zone (8.5 Ma) at Hole 797B to the uppermost part of the Neodenticula kamtschatica Zone (5.73 Ma) at Hole 795A. The diatom zonation of Koizumi (1985) best divides the upper Miocene to Quaternary sequences above the opal-A/opal-CT boundary and also is useful to date carbonate concretions including diatoms below the boundary. Forty diatom datum levels were evaluated biostratigraphically based on the sediment accumulation rate curve, and several isochronous datum levels are newly proposed for the Japan Sea area. A warm-water current did not penetrated into the Japan Sea through the Tsushima strait during the late Miocene and Pliocene time, because subtropical warm-water diatoms are essentially not present in such sediment samples. The occurrences of diatom are cyclic throughout the Quaternary sediments and are affected by eustatic sea level changes. |
| title | Neogene diatoms of the Japan Sea |
| topic | 127-794A; 127-795A; 127-796A; 127-797B; DRILL; Drilling/drill rig; Japan Sea; Joides Resolution; Leg127; Ocean Drilling Program; ODP |
| url | https://doi.org/10.1594/PANGAEA.771031 |