Continental Rift Setting for the Central Part of the Mexican Volcanic Belt: A Statistical Approach

I prepared compilations of geochemical data from the central part of the Mexican Volcanic Belt (C-MVB), the Central American Volcanic Arc (CAVA) from Guatemala to northwestern Costa Rica, the continental arc of the Andes in South America, other mostly island arcs, extensional and continental break-up regions, and continental rifts. Using quantitative statistical methods, the origin of the C-MVB is constrained as a continental rift. Specifically, this continental rift setting for the C-MVB is inferred from conventional bivariate discrimination diagrams, new natural logarithmtransformed correct statistics-based discriminant function diagrams, quantitative Nb/Nb* parameter, and 99% confidence limits of the mean for the ratios of slabor continental crust-sensitive and mantle-sensitive parameters. The subductionrelated models based on qualitative interpretations most commonly proposed for the Mexican Volcanic Belt in the literature are not supported from these robust quantitative constraints. All geological, structural, geochemical, isotopic (Sr, Nd, Pb, Os, and Be), and geophysical data are in fact consistent with this statistics-based conclusion of the continental rift setting and exclude involvement of the subducted slab from the genesis of the C-MVB magmas.