MINERAL CHEMISTRY AND PETROLOGY OF RUBIO PEAK FORMATION, MOGOLLON DATIL VOLCANIC FIELD, NEW MEXICO
Here, we use petrography combined with whole rock and mineral major and trace element geochemistry to gain insight on the formation from lava flows of the Rubio Peak Formation and compare these data to data from similar age rhyolite tuffs from the region. We also compare 40Ar/39Ar ages from the Rubio Peak to the 40Ar/39Ar and U/Pb ages of Bell Tops 2 and 3. This will help determine if the source of both formations came are linked or if the Rubio Peak was a product of early crustal contamination before fractional crystallization and is not the parental melt of the Bell Top tuffs. Trace element compositions of the Rubio Peak are distinct and do not reflect a parental source from crustal assimilation or by fractional crystallization. Plagioclase compositions of the two formations are unique and core compositions of the Bell Top tuffs do not match any analyzed composition from the Rubio Peak Formation. We suggest that the Bell Top tuffs are the result of partial melting of the upper crust as a result of thermal priming and MASH development during the emplacement of the Rubio Peak and Rubio Peak equivalent andesites and basalts in southern New Mexico.