Calcareous nannofossils from the Sumisu Rift and Izu-Bonin Forearc Basin
Fuente:
PANGAEA
Guardado en:
| Autores principales: | , |
|---|---|
| Formato: | Dataset Open Access |
| Lenguaje: | en |
| Publicado: |
PANGAEA
1992
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1867170456544477184 |
|---|---|
| author | Firth, John V Isiminger-Kelso, MaLynn |
| author_facet | Firth, John V Isiminger-Kelso, MaLynn |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | During Ocean Drilling Program Leg 126, we recovered three expanded Pleistocene sections from the active backarc rift (Sumisu Rift) and three expanded Oligocene-Miocene sections from the forearc basin of the Izu-Bonin volcanic island arc. Quantitative analysis of the Pleistocene nannofossils revealed five major assemblages between 0 and LO Ma: Assemblage 1 (Holocene-0.085 Ma) contains dominant Emiliania huxleyi; Assemblage 2 (ca. 0.085-0.275 Ma) contains dominant small Gephyrocapsa and common E. huxleyi and Gephyrocapsa oceanica; Assemblage 3 (ca. 0.275-0.6 Ma) contains dominant Gephyrocapsa caribbeanica; Assemblage 4 (ca. 0.6-0.9 Ma) contains a peak abundance of small Gephyrocapsa in the middle part, and dominant occurrences of two types of G. caribbeanica in the lower and upper parts; and Assemblage 5 (ca. 0.9-1.0 Ma) contains dominant small Gephyrocapsa and common G. caribbeanica and Reticulofenestra asanoi. These assemblages are largely synchronous with similar assemblages recognized from tropical and subtropical regions, and can be used for finer subdivision of the Pleistocene than that based on standard Pleistocene nannofossil datums. The Oligocene-Miocene sections contain several hiatuses: up to 3 m.y. may be missing from the uppermost Oligocene (Zone CP19) at Sites 792 and 793; all of Zone CN2 is missing at Sites 792 and 793; part of Zone CN3 and all of Zone CN4 are missing at Site 792. Biochronology of several nannofossil datums at Leg 126 sites indicate that Sphenolithus distentus, Sphenolithus ciperoensis, Cyclicargolithus floridanus, and Discoaster kugleri have diachronous occurrences compared with other sites in the western Pacific Ocean and Philippine Sea. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_729566 |
| institution | PANGAEA |
| language | en |
| publishDate | 1992 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Calcareous nannofossils from the Sumisu Rift and Izu-Bonin Forearc Basin Firth, John V Isiminger-Kelso, MaLynn 126-787; 126-787B; 126-790A; 126-791A; 126-792; 126-792A; 126-792E; 126-793; 126-793B; COMPCORE; Composite Core; DRILL; Drilling/drill rig; Joides Resolution; Leg126; North Pacific Ocean; Ocean Drilling Program; ODP; Philippine Sea During Ocean Drilling Program Leg 126, we recovered three expanded Pleistocene sections from the active backarc rift (Sumisu Rift) and three expanded Oligocene-Miocene sections from the forearc basin of the Izu-Bonin volcanic island arc. Quantitative analysis of the Pleistocene nannofossils revealed five major assemblages between 0 and LO Ma: Assemblage 1 (Holocene-0.085 Ma) contains dominant Emiliania huxleyi; Assemblage 2 (ca. 0.085-0.275 Ma) contains dominant small Gephyrocapsa and common E. huxleyi and Gephyrocapsa oceanica; Assemblage 3 (ca. 0.275-0.6 Ma) contains dominant Gephyrocapsa caribbeanica; Assemblage 4 (ca. 0.6-0.9 Ma) contains a peak abundance of small Gephyrocapsa in the middle part, and dominant occurrences of two types of G. caribbeanica in the lower and upper parts; and Assemblage 5 (ca. 0.9-1.0 Ma) contains dominant small Gephyrocapsa and common G. caribbeanica and Reticulofenestra asanoi. These assemblages are largely synchronous with similar assemblages recognized from tropical and subtropical regions, and can be used for finer subdivision of the Pleistocene than that based on standard Pleistocene nannofossil datums. The Oligocene-Miocene sections contain several hiatuses: up to 3 m.y. may be missing from the uppermost Oligocene (Zone CP19) at Sites 792 and 793; all of Zone CN2 is missing at Sites 792 and 793; part of Zone CN3 and all of Zone CN4 are missing at Site 792. Biochronology of several nannofossil datums at Leg 126 sites indicate that Sphenolithus distentus, Sphenolithus ciperoensis, Cyclicargolithus floridanus, and Discoaster kugleri have diachronous occurrences compared with other sites in the western Pacific Ocean and Philippine Sea. |
| title | Calcareous nannofossils from the Sumisu Rift and Izu-Bonin Forearc Basin |
| topic | 126-787; 126-787B; 126-790A; 126-791A; 126-792; 126-792A; 126-792E; 126-793; 126-793B; COMPCORE; Composite Core; DRILL; Drilling/drill rig; Joides Resolution; Leg126; North Pacific Ocean; Ocean Drilling Program; ODP; Philippine Sea |
| url | https://doi.org/10.1594/PANGAEA.729566 |