Episodes of Aleutian Ridge Explosive Volcanism
Earlier workers have overlooked deep-sea bentonite beds when unraveling the Cenozoic volcanic history of an area. In the North Pacific, identification of Miocene and older volcanic episodes is possible only if both altered (bentonite) and unaltered ash beds are recognized. Our study, which includes...
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American Association for the Advancement of Science (AAAS)
1978
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Online Access: | http://dx.doi.org/10.1126/science.199.4325.137 https://www.science.org/doi/pdf/10.1126/science.199.4325.137 |
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craaas:10.1126/science.199.4325.137 2024-09-15T18:16:00+00:00 Episodes of Aleutian Ridge Explosive Volcanism The abundance of deep-sea bentonite beds must be considered in interpreting Cenozoic volcanism. Hein, James R. Scholl, David W. Miller, Jacqueline 1978 http://dx.doi.org/10.1126/science.199.4325.137 https://www.science.org/doi/pdf/10.1126/science.199.4325.137 en eng American Association for the Advancement of Science (AAAS) Science volume 199, issue 4325, page 137-141 ISSN 0036-8075 1095-9203 journal-article 1978 craaas https://doi.org/10.1126/science.199.4325.137 2024-07-25T04:01:26Z Earlier workers have overlooked deep-sea bentonite beds when unraveling the Cenozoic volcanic history of an area. In the North Pacific, identification of Miocene and older volcanic episodes is possible only if both altered (bentonite) and unaltered ash beds are recognized. Our study, which includes bentonite beds, shows that volcanism on the Aleutian Ridge and Kamchatka Peninsula has been cyclic. Volcanic activity seems to have increased every 2.5 × 10 6 years for the past 10 × 10 6 years and every 5.0 × 10 6 years for the time span from 10 to 20 × 10 6 years ago. The middle and late Miocene and the Quaternary were times of greatly increased volcanic activity in the North Pacific and elsewhere around the Pacific Basin. The apparent absence of a volcanic record before the late Miocene at Deep Sea Drilling Project site 192 is the result not of plate motion, as suggested by Stewart and by Ninkovich and Donn, but rather of the diagenesis of ash layers. Major, apparently global volcanic episodes occurred at least twice in the last 20 × 10 6 years. Yet, only one major glacial epoch (the Pleistocene) has occurred. Therefore, even though glaciation coincided with an increase in Quaternary volcanism, the increased volcanism itself may not have been the primary cause of global cooling. Article in Journal/Newspaper Kamchatka Kamchatka Peninsula AAAS Resource Center (American Association for the Advancement of Science) Science 199 4325 137 141 |
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AAAS Resource Center (American Association for the Advancement of Science) |
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language |
English |
description |
Earlier workers have overlooked deep-sea bentonite beds when unraveling the Cenozoic volcanic history of an area. In the North Pacific, identification of Miocene and older volcanic episodes is possible only if both altered (bentonite) and unaltered ash beds are recognized. Our study, which includes bentonite beds, shows that volcanism on the Aleutian Ridge and Kamchatka Peninsula has been cyclic. Volcanic activity seems to have increased every 2.5 × 10 6 years for the past 10 × 10 6 years and every 5.0 × 10 6 years for the time span from 10 to 20 × 10 6 years ago. The middle and late Miocene and the Quaternary were times of greatly increased volcanic activity in the North Pacific and elsewhere around the Pacific Basin. The apparent absence of a volcanic record before the late Miocene at Deep Sea Drilling Project site 192 is the result not of plate motion, as suggested by Stewart and by Ninkovich and Donn, but rather of the diagenesis of ash layers. Major, apparently global volcanic episodes occurred at least twice in the last 20 × 10 6 years. Yet, only one major glacial epoch (the Pleistocene) has occurred. Therefore, even though glaciation coincided with an increase in Quaternary volcanism, the increased volcanism itself may not have been the primary cause of global cooling. |
format |
Article in Journal/Newspaper |
author |
Hein, James R. Scholl, David W. Miller, Jacqueline |
spellingShingle |
Hein, James R. Scholl, David W. Miller, Jacqueline Episodes of Aleutian Ridge Explosive Volcanism |
author_facet |
Hein, James R. Scholl, David W. Miller, Jacqueline |
author_sort |
Hein, James R. |
title |
Episodes of Aleutian Ridge Explosive Volcanism |
title_short |
Episodes of Aleutian Ridge Explosive Volcanism |
title_full |
Episodes of Aleutian Ridge Explosive Volcanism |
title_fullStr |
Episodes of Aleutian Ridge Explosive Volcanism |
title_full_unstemmed |
Episodes of Aleutian Ridge Explosive Volcanism |
title_sort |
episodes of aleutian ridge explosive volcanism |
publisher |
American Association for the Advancement of Science (AAAS) |
publishDate |
1978 |
url |
http://dx.doi.org/10.1126/science.199.4325.137 https://www.science.org/doi/pdf/10.1126/science.199.4325.137 |
genre |
Kamchatka Kamchatka Peninsula |
genre_facet |
Kamchatka Kamchatka Peninsula |
op_source |
Science volume 199, issue 4325, page 137-141 ISSN 0036-8075 1095-9203 |
op_doi |
https://doi.org/10.1126/science.199.4325.137 |
container_title |
Science |
container_volume |
199 |
container_issue |
4325 |
container_start_page |
137 |
op_container_end_page |
141 |
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1810453979327365120 |