Magmatism in the southern Grenville Province records a collisional and postcollisional history during the period 1.20-1.15 Ga in the Adirondack Lowlands (New York State, USA) and the Frontenac terrane (Ontario, Canada). These orogenic magmatic episodes are related to the latest manifestations of the continental arc in Sonora the adakitic affinity could be related to a particular configuration of the slab in the final stage of the microplate subduction. Geochemically, rocks of both units are calc-alkaline, are enriched in light rare earth elements, and display a pronounced fractionation of the heavy rare earth elements, low Y and Yb concentrations, and high Sr content, which is more prominent in the younger unit. Field, petrographic and geochemical characteristics differentiate two sequences: 1) Cerro Prieto volcanic member, composed of vitreous, porphyric, two pyroxenes and olivine andesitic lavas, and 2) Las Agujas Volcanic Complex, consisting of hypabyssal rocks, domes and dacitic lavas with two pyroxenes and amphibole. Both rock sequences occur as lavas, domes and volcanic necks, which were affected by a Miocene extensional tectonic regime. The orogenic magmatism in the region of Rayon is covered by anorogenic pyroclastic deposits related to the proto-Gulf of California and is divided into two stages: early Miocene volcanism (16.51 +/- 0.64 Ma) followed by a middle Miocene event (14.88 +/- 0.47 Ma). In Sonora, this magmatism is commonly intercalated with clastic units, and presents calc-alkaline, high-potassium calc-alkaline and shoshonitic affinity. Neogene magmatism associated to the subduction of the Farallon plate is widely distributed in a NW-SE belt in northwestern Mexico.
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