Health & Environmental Research Online (HERO)


Print Feedback Export to File
478655 
Journal Article 
Geochemistry and petrogenesis of Cretaceous oceanic plateau lavas in eastern Jamaica 
Hastie, AR; Kerr, AC; Mitchell, SF; Millar, IL 
2008 
1 
Lithos
ISSN: 0024-4937 
101 
3-4 
323-343 
English 
Basaltic lavas of Turonian to Coniacian age belonging to the Bath-Dunrobin Formation occur with intercalated island arc tuffs in the south of the Blue Mountain inlier, have been interpreted as being derived from the Caribbean oceanic plateau. This study presents new major and trace element and Sr-Pb-Nd-Hf isotopic data for these igneous rocks. The Jamaican rocks are altered by tropical weathering, hydrothermal and metamorphic processes, which have mobilised many of their elements (e.g. K and Ba). Consequently, the basalts and dacitic tuffs have been classified by using immobile trace elements. The trace element and epsilon(Hf)(i)-epsilon(Nd) (i) geochemistry suggests that the basaltic lavas are derived from a chemically similar source region by variable degrees of partial melting. The Caribbean plateau basalts lie on a mixing line between a depleted plume component and HIMU in Nd-Hf isotopic space. The Pb isotope data also demonstrate that the Jamaican plateau lavas are composed of a larger HIMU component than the other plateau lavas within the Caribbean region. The intercalated island arc tuffs are the first to be found in any oceanic plateau succession in the Caribbean and imply that the Caribbean oceanic plateau at similar to 90 Ma was relatively close to the subduction zone along South America and the Great Arc of the Antilles. (c) 2007 Elsevier B.V. All rights reserved. 
Caribbean; Jamaica; Bath-Dunrobin formation; oceanic plateau; mantle; plume; cretaceous are; flood-basalt province; caribbean plateau; volcanic-rocks; tectonic; evolution; immobile elements; igneous province; south-america; iceland; plume; mantle plume; hf