The Pliocene-Quaternary Buffalo Valley volcanic field, Nevada: Post-extension, intraplate magmatism in the north-central Great Basin, USA

摘要: Abstract The Buffalo Valley volcanic field consists of Pliocene through Quaternary lava flows and spatter cones located south Battle Mountain adjacent to the Fish Creek Mountains, north-central Nevada. rocks are split into two groups by age geochemistry. sequence (4.02 2.75 Ma) olivine- plagioclase-bearing alkali basaltic with minor pyroclastic deposits, found primarily along flank also at north end Mountains within caldera. series (1.99 1.14 Ma) includes nearly a dozen trachybasaltic short erupted northwest Mountains. Normalized rare earth element incompatible plots for both light Nb–Ta enriched, resembling basalts from ocean islands, but lavas more element-enriched cross basalt patterns Eu. Radiogenic stable isotope ratios consistent an asthenospheric mantle source, indicate shift melting in spinel garnet peridotite time. Basaltic other intraplate fields Great Basin, including Lunar Crater Cima fields, only include that originated depth field. is margin proposed lithospheric drip (delamination) zone thinning extends across northern Nevada, which may control where asthenosphere occur. proximity edge Precambrian–Phanerozoic lithosphere boundary be factor melt generation.