The Jurassic magmatism of the Demerara Plateau (offshore French Guiana) as a remnant of the Sierra Leone hotspot during the Atlantic rifting
Abstract
We report the discovery of 173.4 Ma hotspot-related magmatic rocks in the basement of the Demerara
Plateau, offshore French Guiana and Suriname. According to plate reconstructions, a single hotspot
may be responsible for the magmatic formation of (1) both the Demerara Plateau (between 180 and
170 Ma) and the Guinea Plateau (circa 165 Ma) during the end of the Jurassic rifting of the Central
Atlantic; (2) both Sierra Leone and Ceara Rises (mainly from 76 to 68 Ma) during the upper Cretaceous
oceanic spreading of the Equatorial Atlantic ocean; (3) the Bathymetrists seamount chain since the
upper Cretaceous. The present-day location of the inferred Sierra Leone hotspot should be 100 km west
of the Knipovich Seamount.
Domains
Geochemistry
Origin : Publisher files allowed on an open archive
Loading...