Geochemistry and tectonics of Cenozoic volcanism in the Lesser Caucasus (Azerbaijan) and the peri-Arabian region: collision-induced mantle dynamics and its magmatic fingerprint

Abstract

The Lesser Caucasus occurs in the hinterland of the Arabia–Eurasia collision zone in the broad Alpine–Himalayan orogenic belt and includes Cenozoic plutonic and volcanic sequences that provide important clues for collision-driven continental magmatism and mantle dynamics. Two main magmatic episodes (Eocene and late Miocene–Quaternary) formed the volcanic landscape and the igneous assemblages in the Lesser Caucasus of Azerbaijan. (1) The Eocene sequence consists of trachybasalt and basaltic trachyandesite with subordinate tephrite-basanite, basaltic andesite, and trachyandesite, showing shoshonitic and mildly alkaline compositions. The Miocene–Quaternary magmatic episode is represented by (2a) an early phase of upper Miocene–lower Pliocene andesite, trachyandesite, trachydacite, dacite and rhyolite lavas, and by (2b) a late phase of upper Pliocene–Quaternary trachybasalt, basaltic trachyandesite, basaltic andesite, trachyandesite, trachyte, and rhyolite flows. The rocks of the early phase have high-K calc-...