Open AccessCorrelated geophysical, geochemical, and volcanological manifestations of plume‐ridge interaction along the Galápagos Spreading Center
Author(s) -
Detrick R. S.,
Sinton J. M.,
Ito G.,
Canales J. P.,
Behn M.,
Blacic T.,
Cushman B.,
Dixon J. E.,
Graham D. W.,
Mahoney J. J.
Publication year - 2002
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2002gc000350
Subject(s) - geology , lava , basalt , volcanism , magma chamber , volcano , mantle plume , plume , mantle (geology) , magma , ridge , petrology , mid ocean ridge , alkali basalt , bouguer anomaly , rift , gravity anomaly , geochemistry , geophysics , volcanic rock , tectonics , seismology , lithosphere , paleontology , physics , oil field , thermodynamics
As the Galápagos hot spot is approached from the west along the Galápagos Spreading Center there are systematic increases in crustal thickness and in the K/Ti, Nb/Zr, 3 He/ 4 He, H 2 O, and Na 2 O content of lavas recovered from the spreading axis. These increases correlate with progressive transitions from rift valley to axial high morphology along with decreases in average swell depth, residual mantle Bouguer gravity anomaly, magma chamber depth, average lava Mg #, Ca/Al ratio, and the frequency of point‐fed versus fissure‐fed volcanism. Magma chamber depth and axial morphology display a “threshold” effect in which small changes in magma supply result in large changes in these variables. These correlated variations in geophysical, geochemical, and volcanological manifestations of plume‐ridge interaction along the western Galápagos Spreading Center reflect the combined effects of changes in mantle temperature and source composition on melt generation processes, and the consequences of these variations on magma supply, axial thermal structure, basalt chemistry, and styles of volcanism.