The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde
Abstract Dated paleosea level markers and eustatic sea level changes are necessary but not sufficient information to calculate vertical motion rates on oceanic islands. Therefore, we use a procedure in which we work progressively back in time to incorporate the more recent vertical motion rates impl...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2020-03-01
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| Series: | Geochemistry, Geophysics, Geosystems |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2019GC008754 |
| _version_ | 1797638103291133952 |
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| author | F. O. Marques A. Hildenbrand H. Zeyen C. Cunha S. S. Victória |
| author_facet | F. O. Marques A. Hildenbrand H. Zeyen C. Cunha S. S. Victória |
| author_sort | F. O. Marques |
| collection | DOAJ |
| description | Abstract Dated paleosea level markers and eustatic sea level changes are necessary but not sufficient information to calculate vertical motion rates on oceanic islands. Therefore, we use a procedure in which we work progressively back in time to incorporate the more recent vertical motion rates implied by the youngest paleoshorelines into the vertical motion history of all older shorelines. Specifically, we calculate the time‐averaged vertical motion rates required to explain the present‐day elevations of the dated sequence of paleoshorelines on Santiago volcanic island (Cape Verde). We thus obtain a vertical motion history consisting of time‐averaged vertical motion rates spanning the five intervening periods between paleoshoreline formation and the present day: (1) 5.06 to 3.29 Ma—seamount growth or island subsidence because all the rocks in this period are submarine; (2) fast uplift (approximately 0.96 mm/a) from 3.29 to 2.87 Ma, mostly responsible for putting submarine lavas currently close to 410 m altitude; (3) relatively fast subsidence (approximately −0.11 mm/a) between 2.87 and 2.18 Ma; (4) stagnation from 2.18 to 0.811 Ma; and (5) relatively fast uplift (approximately 0.14 mm/a) between 0.811 and 0 Ma. We numerically tested top‐down (volcanic loading) and bottom‐up (lithosphere thinning, underplating, and mantle plume) mechanisms to explain the inferred vertical movements, and we conclude that volcanic loading and crustal underplating are capable of producing the observed subsidence and uplift, respectively. |
| first_indexed | 2024-03-11T12:58:48Z |
| format | Article |
| id | doaj.art-ac8e3965d30748ea95cadc3892ba5303 |
| institution | Directory Open Access Journal |
| issn | 1525-2027 |
| language | English |
| last_indexed | 2024-03-11T12:58:48Z |
| publishDate | 2020-03-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geochemistry, Geophysics, Geosystems |
| spelling | doaj.art-ac8e3965d30748ea95cadc3892ba53032023-11-03T16:55:58ZengWileyGeochemistry, Geophysics, Geosystems1525-20272020-03-01213n/an/a10.1029/2019GC008754The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape VerdeF. O. Marques0A. Hildenbrand1H. Zeyen2C. Cunha3S. S. Victória4Departamento de Geologia Universidade de Lisboa Lisboa PortugalUniversité Paris‐Saclay, CNRS, GEOPS Orsay FranceUniversité Paris‐Saclay, CNRS, GEOPS Orsay FranceEscola Superior Agrária Instituto Politécnico de Coimbra Coimbra PortugalFaculdade de Ciências e Tecnologia Universidade de Cabo Verde Praia Cape VerdeAbstract Dated paleosea level markers and eustatic sea level changes are necessary but not sufficient information to calculate vertical motion rates on oceanic islands. Therefore, we use a procedure in which we work progressively back in time to incorporate the more recent vertical motion rates implied by the youngest paleoshorelines into the vertical motion history of all older shorelines. Specifically, we calculate the time‐averaged vertical motion rates required to explain the present‐day elevations of the dated sequence of paleoshorelines on Santiago volcanic island (Cape Verde). We thus obtain a vertical motion history consisting of time‐averaged vertical motion rates spanning the five intervening periods between paleoshoreline formation and the present day: (1) 5.06 to 3.29 Ma—seamount growth or island subsidence because all the rocks in this period are submarine; (2) fast uplift (approximately 0.96 mm/a) from 3.29 to 2.87 Ma, mostly responsible for putting submarine lavas currently close to 410 m altitude; (3) relatively fast subsidence (approximately −0.11 mm/a) between 2.87 and 2.18 Ma; (4) stagnation from 2.18 to 0.811 Ma; and (5) relatively fast uplift (approximately 0.14 mm/a) between 0.811 and 0 Ma. We numerically tested top‐down (volcanic loading) and bottom‐up (lithosphere thinning, underplating, and mantle plume) mechanisms to explain the inferred vertical movements, and we conclude that volcanic loading and crustal underplating are capable of producing the observed subsidence and uplift, respectively.https://doi.org/10.1029/2019GC008754uplift and subsidence rates of oceanic islandsvertical displacement in Santiago Island, Cape Verdesea level changespaleoshorelinespassage zonestopography response to isostasy |
| spellingShingle | F. O. Marques A. Hildenbrand H. Zeyen C. Cunha S. S. Victória The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde Geochemistry, Geophysics, Geosystems uplift and subsidence rates of oceanic islands vertical displacement in Santiago Island, Cape Verde sea level changes paleoshorelines passage zones topography response to isostasy |
| title | The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde |
| title_full | The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde |
| title_fullStr | The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde |
| title_full_unstemmed | The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde |
| title_short | The Complex Vertical Motion of Intraplate Oceanic Islands Assessed in Santiago Island, Cape Verde |
| title_sort | complex vertical motion of intraplate oceanic islands assessed in santiago island cape verde |
| topic | uplift and subsidence rates of oceanic islands vertical displacement in Santiago Island, Cape Verde sea level changes paleoshorelines passage zones topography response to isostasy |
| url | https://doi.org/10.1029/2019GC008754 |
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