IS MAGMATIC ADDITION A SIGNIFICANT CRUSTAL GROWTH MECHANISM IN CORDILLERAN SYSTEMS?
The contribution of magmatic addition as a significant mechanism for high plateau formation remains a lingering question because of the inherent difficulty in quantifying P:V ratios and MAR. Although estimates of P:V ratios and MAR still have uncertainties associated with them, the general agreement between larger P:V ratios and MAR measured from recent independent approaches is a provocative topic for research. It is our contention that integrating advances in crustal-scale seismic imaging with increased geological and geochemical sampling of volcanic deposits can further elucidate the enigmatic plutonic to volcanic relationship. The focus of our work presented here tries to address the following question: Are the recent P:V ratios and MAR a function of the non-uniform sampling imposed by our ability to measure them in only a few select regions of the American Cordillera or can they be generalized to represent type behavior in cordilleran systems? While not yet being able to answer this question definitively, we present both geophysical and geological evidence that show promise in resolving this interesting problem of plateau growth in cordilleran systems.