Please use this identifier to cite or link to this item: http://hdl.handle.net/20.500.12136/586
|Title:||Vertical movements of ocean island volcanoes: Insights from a stationary plate environment|
|Authors:||Ramalho, Ricardo dos Santos|
Cosca, Michael A.
Schmidt, Daniela N.
|Keywords:||Ocean island volcanoes;Uplift;Island freeboard;Cape Verde|
|Citation:||Marine Geology, 2010, 275 (1-4), 84-95|
|Abstract:||Uplift reconstructions based on the Cape Verde's geological record provide a unique opportunity to study the long-term isostatic movements associated with hotspot activity on a stationary plate environment. The archipelago is considered stationary with respect to its melting source so the hotspot-driven isostatic effects affecting the ocean islands are expected to be enhanced. In this study, Ar–Ar and U–Th geochronology techniques were used to date a set of palaeo-markers of sea-level from Santiago's and São Nicolau's edifices, two of the main Cape Verde Islands. A comparison between relative sea-level and eustatic sea-level (from a modern eustatic curve) was established to extract the vertical displacement undergone by the markers, and to reconstruct the uplift/subsidence history of each island. The resulting uplift reconstructions confirm that both Santiago and São Nicolau experienced a general uplift trend over the last 6 Ma, seemingly synchronous with the vigorous volcanic activity that built their exposed edifices. These islands, however, exhibit different uplift histories despite their common uplift trend. Several uplift mechanisms were tested and a local rather than regional mechanism is proposed as the main cause of uplift, generally unrelated with far-field effects of surface loading. This mechanism is probably associated with magmatic additions at crustal level.|
|Appears in Collections:||Geocronología y Geología|
Files in This Item:
|Vertical movements of ocean island volcanoes Insights from a stationary plate environment_Ramalho_et_al_2010.pdf||1,3 MB||Adobe PDF||View/Open|
This item is licensed under a Creative Commons License