Evidence for superposed MORB, oceanic plateau and volcanic arc series in the Lesser Caucasus (Stepanavan, Armenia)

Abstract

New field and petro-geochemical investigations of Jurassic ophiolites from the Lesser Caucasus (Stepanavan area, northwestern Armenia) evidence the occurrence of several superposed magmatic suites, comprising: (1) a plutonic sequence from werhlites to gabbros and plagiogranites cross-cutting a serpentinized mantle, covered by scattered pillow-basalts and radiolarites, representative of a slow-spreading ophiolite type; (2) alkaline rocks possibly representative of a remnant oceanic plateau; (3) arc-type volcanic rocks of probable Upper Cretaceous age.