Vertical movements of ocean island volcanoes: Insights from a stationary plate environment

Marine Geology
By: , and 

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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.

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Publication type Article
Publication Subtype Journal Article
Title Vertical movements of ocean island volcanoes: Insights from a stationary plate environment
Series title Marine Geology
DOI 10.1016/j.margeo.2010.04.009
Volume 275
Issue 1-4
Year Published 2010
Language English
Publisher Elsevier
Contributing office(s) Central Mineral and Environmental Resources Science Center, Geology, Geophysics, and Geochemistry Science Center
Description 12 p.
First page 84
Last page 95
Country Cape Verde
Other Geospatial Cape Verde Archipelago
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