Major and trace element geochemistry and Sr–Nd isotopic constraints on mafic volcanic rocks from the Ventura-Espiritu Santo Volcanic Field, San Luis Potosi, Mexico: Petrogenesis and tectonic implications of Cenozoic volcanism in the Basin and Range P

The Ventura Espiritu Santo Volcanic Field (VESVF), located in the central part of the Mesa Central (MC), Mexico, is a monogenetic volcanic field dominated by Late Pleistocene mafic volcanism. It covers an area of approximately 100 km between the localities of Cúcamo and Santa Lucia and is emplaced on a basement composed of metamorphic rocks of the Sierra de Salinas and Triassic marine sequences that are tectonically overlain by the Guerrero Terrane. This study presents new petrographic observations, whole-rock major-and trace-element geochemistry, and Sr-Nd isotopic data for mafic rocks from the Cúcamo, El Rosario, and Santa Lucía areas to constrain the magmatic processes involved in the origin and evolution. Chondrite-normalized REE patterns display moderate enrichment in Light Rare Earth Elements (LREE) accompanied by slight depletion in Heavy Rare Earth Elements (HREE) and absence of an Eu anomaly. Primitive mantle-normalized diagrams show prominent positive anomalies in K, P, and Ti, together with negative anomalies in Pb. The absence of Nb-Ta troughs, together with multidimensional discrimination diagrams, could indicate an affinity to intraplate geochemical signature. Isotopic composition ( 87 Sr/ 86 Sr i = [0.70307–0.70353, εNd = +5.8 to +6.3] suggests derivation from an enriched mantle source. The trace-element behavior, supported by geochemical modeling, further indicates that the mafic rocks were generated by low degree of partial melting of the enriched lherzolite upper lithospheric mantle source, pointing to a tectonic environment dominated by lithospheric extension and asthenospheric upwelling.