| _version_ | 1867169041346461696 |
|---|---|
| author | Koyama, Masato Cisowski, Stanley M Pezard, Philippe Adrien |
| author_facet | Koyama, Masato Cisowski, Stanley M Pezard, Philippe Adrien |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | A paleomagnetic study was made on the deep-marine sediments and volcanic rocks drilled by Ocean Drilling Program Leg 126 in the Izu-Bonin forearc region (Sites 787, 792, and 793). This study evaluates the sense and amount of the tectonic drift and rotation associated with the evolution of the Philippine Sea Plate and the Izu-Bonin Arc. Alternating-field and thermal demagnetization experiments show that most of the samples have stable remanence and are suitable for paleomagnetic studies. Paleomagnetic declinations were recovered by two methods of core orientation, one of which uses a secondary viscous magnetization vector of each specimen as an orientation standard, and the other of which is based on the data of downhole microresistivity measurement obtained by using a formation microscanner. Oligocene to early Miocene samples show 10° to 14° shallower paleolatitudes than those of the present. Middle Miocene to early Oligocene samples show progressive clockwise deflections (up to ~80°) in declination with time. These results suggest large northward drift and clockwise rotation of the Izu-Bonin forearc region since early Oligocene time. Considering previous paleomagnetic results from the other regions in the Philippine Sea, this motion may reflect large clockwise rotation of the whole Philippine Sea Plate over the past 40 m.y. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_773471 |
| institution | PANGAEA |
| language | en |
| publishDate | 1992 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | (Table 1) Paleomagnetic of ODP Leg 126 sites Koyama, Masato Cisowski, Stanley M Pezard, Philippe Adrien 126-787B; 126-792E; 126-793B; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Event label; Joides Resolution; Leg126; Median demagnetizing field; North Pacific Ocean; NRM, Declination; NRM, Inclination; NRM, Intensity; Ocean Drilling Program; ODP; Sample code/label A paleomagnetic study was made on the deep-marine sediments and volcanic rocks drilled by Ocean Drilling Program Leg 126 in the Izu-Bonin forearc region (Sites 787, 792, and 793). This study evaluates the sense and amount of the tectonic drift and rotation associated with the evolution of the Philippine Sea Plate and the Izu-Bonin Arc. Alternating-field and thermal demagnetization experiments show that most of the samples have stable remanence and are suitable for paleomagnetic studies. Paleomagnetic declinations were recovered by two methods of core orientation, one of which uses a secondary viscous magnetization vector of each specimen as an orientation standard, and the other of which is based on the data of downhole microresistivity measurement obtained by using a formation microscanner. Oligocene to early Miocene samples show 10° to 14° shallower paleolatitudes than those of the present. Middle Miocene to early Oligocene samples show progressive clockwise deflections (up to ~80°) in declination with time. These results suggest large northward drift and clockwise rotation of the Izu-Bonin forearc region since early Oligocene time. Considering previous paleomagnetic results from the other regions in the Philippine Sea, this motion may reflect large clockwise rotation of the whole Philippine Sea Plate over the past 40 m.y. |
| title | (Table 1) Paleomagnetic of ODP Leg 126 sites |
| topic | 126-787B; 126-792E; 126-793B; DRILL; Drilling/drill rig; DSDP/ODP/IODP sample designation; Event label; Joides Resolution; Leg126; Median demagnetizing field; North Pacific Ocean; NRM, Declination; NRM, Inclination; NRM, Intensity; Ocean Drilling Program; ODP; Sample code/label |
| url | https://doi.org/10.1594/PANGAEA.773471 |