2005/03/01 by Bramley J. Murton, A. G. Tindle, James A. Milton +1 · 1 citation
Earth and Planetary Sciences · #Geological and Geochemical Analysis #High-pressure geophysics and materials #earthquake and tectonic studies #Geology #Mantle (geology) #Solidus #Lithosphere #Basalt #Geochemistry #Partial melting #Fractional crystallization (geology) #Crystallization #Plagioclase #Petrology #Tectonics #Seismology #Thermodynamics #Materials science #Paleontology
paper · doi:10.1029/2004gc000798
openalex publication_date 2005/03/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/23
Between the Rodrigues Triple Junction and the Marie Celeste fracture zone, basalts from the Central Indian Ridge (CIR) exhibit an enrichment in incompatible elements that increases in intensity northward. In addition, H 2 O/TiO 2 , Al [8] , and Dy/Yb ratios increase, while Na [8] remains unchanged and Fe [8] decreases. Evolution of the enriched magma appears to be affected by elevated water contents, which lower the mantle solidus, thereby increasing the initial depth of melting, as well as delaying plagioclase crystallization. However, the enrichment affecting the northern samples is not a just function of hydrous mantle melting and crystallization. Instead of trending toward a small melt fraction from the mantle, as predicted by hydrous melting models, the CIR samples lie on a mixing line between N‐MORB and a source component that closely resembles present‐day Réunion hot spot lavas. Thus it appears that while hydrous melting and crystallization affect the CIR, the enriched and wet mantle originates from the Réunion hot spot, where it migrates eastward toward the CIR, against the direction of motion of the lithosphere.