El Tigre volcano is located within the Fonseca Gulf, Honduras, where there is a break in the strike of the Central America Volcanic Front (Walker et al., 2000; Carr et al., 2003; Bolge et al., 2009). The origin of this gulf arise from the intersection of three first-order tectonic structures, and such a complex tectonic setting is the result of the oblique subduction on the Central American trench (Carr et al., 2003; Burkart & Self, 1985). For these reasons, the knowledge of El Tigre is of paramount importance for unravelling the magmatological and volcanological evolution of this area. Lavas from El Tigre consist of basalts and basaltic andesites with calc-alkaline affinity. The fundamental mineralogical assemblage is typical of relatively primitive subalkaline rocks, and is made of plagioclase, olivine, clinopyroxene, orthopyroxene and opaques. Lavas show a significant LILE enrichment and Nb depletion, a strong slab signature and incompatible element contents similar to those in the main front of the adjacent volcanoes from El Salvador and Nicaragua (e.g. Ba/La up to 80). However, a small group of basalts from El Tigre, with higher MgO content (> 5 wt%) and lower Ba/La, Ba/Nb and Zr/Nb ratios (34-39, 35-49 and 5-7, respectively), emphasizes that mantle-derived magmas were not produced by the same source or process throughout the span-time activity of the volcano. El Tigre lavas are characterized by higher 87Sr/86Sr (0.7038) and lower 143Nd/144Nd (0.51301) with respect to arc volcanoes of El Salvador and Nicaragua, whereas 208Pb/204Pb and 206Pb/204Pb isotope ratios are very similar (38.2 and 18.5, respectively).
Petrography, major-trace elements and isotopic compositions of the lavas from El Tigre volcano (Fonseca Gulf, Honduras): increasing data on the Central America Volcanic Front
MATTIOLI, MICHELE;RENZULLI, ALBERTO;
2014
Abstract
El Tigre volcano is located within the Fonseca Gulf, Honduras, where there is a break in the strike of the Central America Volcanic Front (Walker et al., 2000; Carr et al., 2003; Bolge et al., 2009). The origin of this gulf arise from the intersection of three first-order tectonic structures, and such a complex tectonic setting is the result of the oblique subduction on the Central American trench (Carr et al., 2003; Burkart & Self, 1985). For these reasons, the knowledge of El Tigre is of paramount importance for unravelling the magmatological and volcanological evolution of this area. Lavas from El Tigre consist of basalts and basaltic andesites with calc-alkaline affinity. The fundamental mineralogical assemblage is typical of relatively primitive subalkaline rocks, and is made of plagioclase, olivine, clinopyroxene, orthopyroxene and opaques. Lavas show a significant LILE enrichment and Nb depletion, a strong slab signature and incompatible element contents similar to those in the main front of the adjacent volcanoes from El Salvador and Nicaragua (e.g. Ba/La up to 80). However, a small group of basalts from El Tigre, with higher MgO content (> 5 wt%) and lower Ba/La, Ba/Nb and Zr/Nb ratios (34-39, 35-49 and 5-7, respectively), emphasizes that mantle-derived magmas were not produced by the same source or process throughout the span-time activity of the volcano. El Tigre lavas are characterized by higher 87Sr/86Sr (0.7038) and lower 143Nd/144Nd (0.51301) with respect to arc volcanoes of El Salvador and Nicaragua, whereas 208Pb/204Pb and 206Pb/204Pb isotope ratios are very similar (38.2 and 18.5, respectively).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
