The Terceira Rift (TR) is a 550km long ESE trending line
of volcanic reliefs (Graciosa Island, Terceira Island, D. João
de Castro Bank, S. Miguel Island) alternating with deep basins
(e.g.
E of Terceira, Hirondelle) that define the plate boundary
between the European and African plates on the Azores
plateau [1]. Seismic tomography suggests that the Azores
plume is centered NE of Terceira supplying upwelling plume
material SW of Terceira (e.
g. Faial) [2].
Melt inclusions (MI) are small portions of melt trapped
during crystal growth. Their study allows the characterization
of the composition of primary melts, mantle heterogeneity,
magma sources and timescales. This study presents the first
ge
ochemical dataset of olivine
-
hosted unexposed MI sampled
from submarine and subaereal lavas along the TR. Plots of
incompatible trace element ratios (Fig.1) confirm the presence of distinct mantle signatures showing a mixing trend between
two end-members that represent extreme topographic domains: Terceira and Hirondelle Basin. These findings will be discussed considering recent geophysical and geochemical data obtained in the area
