TECTONIC HISTORY OF SHIKOKU MARGINAL BASIN
Studies of marine magnetic anomaly data from the Shikoku basin reveal magnetic lineations which strike northwest almost parallel to the trend of the Palau-Kyushu ridge. The lineation pattern is best developed in the western part of the basin and we can confidently identify a sequence of anomalies 7...
| Main Authors: | , |
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| Format: | Journal article |
| Language: | English |
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1975
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| _version_ | 1826257919587385344 |
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| author | Watts, A Weissel, J |
| author_facet | Watts, A Weissel, J |
| author_sort | Watts, A |
| collection | OXFORD |
| description | Studies of marine magnetic anomaly data from the Shikoku basin reveal magnetic lineations which strike northwest almost parallel to the trend of the Palau-Kyushu ridge. The lineation pattern is best developed in the western part of the basin and we can confidently identify a sequence of anomalies 7 through 5E between the base of the Palau-Kyushu ridge and the center of the basin. In the eastern part of the basin the basement morphology is rough and complex and magnetic anomalies can not be identified unequivocally. We infer that the Palau-Kyushu ridge and the Izu-Bonin island arc began separating about 27 m.y. B.P. An interval of rapid separation (4.2 cm/yr) occurred between 26 and 22.5 m.y. B.P. which approximately coincides with a period of intense volcanic activity in Japan. The observed magnetic lineation pattern and basement morphology can be best explained if the Shikoku basin formed at a two-limb spreading system during the Late Oligocene to Middle Miocene. Subsequently the eastern half of the basin was disrupted by fractures as the Iwo-Jima ridge collided with the Japanese islands. The accretionary process which formed the crust of the Shikoku marginal basin appears similar to that operating at mid-ocean ridges of the world. © 1975. |
| first_indexed | 2024-03-06T18:25:48Z |
| format | Journal article |
| id | oxford-uuid:07ea5998-b8c0-4179-83f1-eacc3abc274b |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T18:25:48Z |
| publishDate | 1975 |
| record_format | dspace |
| spelling | oxford-uuid:07ea5998-b8c0-4179-83f1-eacc3abc274b2022-03-26T09:10:07ZTECTONIC HISTORY OF SHIKOKU MARGINAL BASINJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:07ea5998-b8c0-4179-83f1-eacc3abc274bEnglishSymplectic Elements at Oxford1975Watts, AWeissel, JStudies of marine magnetic anomaly data from the Shikoku basin reveal magnetic lineations which strike northwest almost parallel to the trend of the Palau-Kyushu ridge. The lineation pattern is best developed in the western part of the basin and we can confidently identify a sequence of anomalies 7 through 5E between the base of the Palau-Kyushu ridge and the center of the basin. In the eastern part of the basin the basement morphology is rough and complex and magnetic anomalies can not be identified unequivocally. We infer that the Palau-Kyushu ridge and the Izu-Bonin island arc began separating about 27 m.y. B.P. An interval of rapid separation (4.2 cm/yr) occurred between 26 and 22.5 m.y. B.P. which approximately coincides with a period of intense volcanic activity in Japan. The observed magnetic lineation pattern and basement morphology can be best explained if the Shikoku basin formed at a two-limb spreading system during the Late Oligocene to Middle Miocene. Subsequently the eastern half of the basin was disrupted by fractures as the Iwo-Jima ridge collided with the Japanese islands. The accretionary process which formed the crust of the Shikoku marginal basin appears similar to that operating at mid-ocean ridges of the world. © 1975. |
| spellingShingle | Watts, A Weissel, J TECTONIC HISTORY OF SHIKOKU MARGINAL BASIN |
| title | TECTONIC HISTORY OF SHIKOKU MARGINAL BASIN |
| title_full | TECTONIC HISTORY OF SHIKOKU MARGINAL BASIN |
| title_fullStr | TECTONIC HISTORY OF SHIKOKU MARGINAL BASIN |
| title_full_unstemmed | TECTONIC HISTORY OF SHIKOKU MARGINAL BASIN |
| title_short | TECTONIC HISTORY OF SHIKOKU MARGINAL BASIN |
| title_sort | tectonic history of shikoku marginal basin |
| work_keys_str_mv | AT wattsa tectonichistoryofshikokumarginalbasin AT weisselj tectonichistoryofshikokumarginalbasin |