Two-stage subduction history under North America inferred from multiple-frequency tomography
Eastward subduction of oceanic tectonic plates has shaped the geologic history of western North America over the past 150 million years. The mountain-building and volcanism that brought forth the spectacular landscapes of the West are credited to the vast ancient Farallon plate, which interacted mec...
| Main Authors: | , , |
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| Format: | Journal article |
| Language: | English |
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Nature Publishing Group
2008
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| _version_ | 1826272775313031168 |
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| author | Sigloch, K McQuarrie, N Nolet, G |
| author_facet | Sigloch, K McQuarrie, N Nolet, G |
| author_sort | Sigloch, K |
| collection | OXFORD |
| description | Eastward subduction of oceanic tectonic plates has shaped the geologic history of western North America over the past 150 million years. The mountain-building and volcanism that brought forth the spectacular landscapes of the West are credited to the vast ancient Farallon plate, which interacted mechanically and chemically with the overlying continent as it plunged back into the mantle. Here, we use finite-frequency travel-time and amplitude measurements of teleseismic P-waves in seven frequency bands to obtain a high-resolution tomographic image to 1,800 km depth. We discover several large, previously unknown pieces of the plate which show that two distinct stages of whole-mantle subduction are present under North America. The currently active one descends from the Pacific northwest coast to 1,500 km depth beneath the Great Plains, whereas its stalled predecessor occupies the transition zone and lower mantle beneath the eastern half of the continent. We argue that the separation between them is linked to the Laramide era 70-50 Myr ago, a time of unusual volcanism and mountain-building far inland generally explained by an episode of extremely flat subduction. © 2008 Macmillan Publishers Limited. |
| first_indexed | 2024-03-06T22:17:54Z |
| format | Journal article |
| id | oxford-uuid:54082d51-bbfc-4406-884a-b81a0e3e6fe2 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:17:54Z |
| publishDate | 2008 |
| publisher | Nature Publishing Group |
| record_format | dspace |
| spelling | oxford-uuid:54082d51-bbfc-4406-884a-b81a0e3e6fe22022-03-26T16:35:19ZTwo-stage subduction history under North America inferred from multiple-frequency tomographyJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:54082d51-bbfc-4406-884a-b81a0e3e6fe2EnglishSymplectic Elements at OxfordNature Publishing Group2008Sigloch, KMcQuarrie, NNolet, GEastward subduction of oceanic tectonic plates has shaped the geologic history of western North America over the past 150 million years. The mountain-building and volcanism that brought forth the spectacular landscapes of the West are credited to the vast ancient Farallon plate, which interacted mechanically and chemically with the overlying continent as it plunged back into the mantle. Here, we use finite-frequency travel-time and amplitude measurements of teleseismic P-waves in seven frequency bands to obtain a high-resolution tomographic image to 1,800 km depth. We discover several large, previously unknown pieces of the plate which show that two distinct stages of whole-mantle subduction are present under North America. The currently active one descends from the Pacific northwest coast to 1,500 km depth beneath the Great Plains, whereas its stalled predecessor occupies the transition zone and lower mantle beneath the eastern half of the continent. We argue that the separation between them is linked to the Laramide era 70-50 Myr ago, a time of unusual volcanism and mountain-building far inland generally explained by an episode of extremely flat subduction. © 2008 Macmillan Publishers Limited. |
| spellingShingle | Sigloch, K McQuarrie, N Nolet, G Two-stage subduction history under North America inferred from multiple-frequency tomography |
| title | Two-stage subduction history under North America inferred from multiple-frequency tomography |
| title_full | Two-stage subduction history under North America inferred from multiple-frequency tomography |
| title_fullStr | Two-stage subduction history under North America inferred from multiple-frequency tomography |
| title_full_unstemmed | Two-stage subduction history under North America inferred from multiple-frequency tomography |
| title_short | Two-stage subduction history under North America inferred from multiple-frequency tomography |
| title_sort | two stage subduction history under north america inferred from multiple frequency tomography |
| work_keys_str_mv | AT siglochk twostagesubductionhistoryundernorthamericainferredfrommultiplefrequencytomography AT mcquarrien twostagesubductionhistoryundernorthamericainferredfrommultiplefrequencytomography AT noletg twostagesubductionhistoryundernorthamericainferredfrommultiplefrequencytomography |