Evolution, hydrothermal assimilation, and ascent of magma inferred from volatile contents in MORB glasses: An example from thick lava pile at IODP Site 1256

A continuous section through an 811 m-thick lava pile of mid-ocean ridge basalts at Integrated Ocean Drilling Program Site 1256 provides important constraints on the variation with depth of volatile element (H2O, CO2, S and Cl) contents in fresh matrix glasses to understand evolution of magma, condition of magma ascent, and degree of hydrothermal assimilation. The lava pile is divided into two groups based on eruption location: off-axis basalts...