How small-volume basaltic magmatic systems develop: A case study from the jeju island volcanic field, Korea

Abstract

Jeju is a volcanic field that has erupted from around 1·8 Myr to c. 1 kyr ago. Activity began with dispersed, basaltic, monogenetic, phreatomagmatic eruptions. Continuing monogenetic volcanism was later joined by more voluminous lava effusion events building a central composite shield. Samples from older (>0·7 Ma) and younger (<0·2 Ma) monogenetic centres were analysed for their whole-rock major element, trace element and Sr-Nd-Pb isotopic compositions. Pyroclastic products from the monogenetic centres are dominantly alkali basalt to trachybasalt, whereas the more voluminous lava flows and domes of the central edifice consist of subalkali basalt and alkali basalt to trachyte. Lavas from the ..