Dome growth at the Soufriere Hills volcano (1996 to 1998) was frequently accompanied by repetitive cycles of earthquakes, ground deformation, degassing, and explosive eruptions. The cycles reflected unsteady conduit flow of volatile-charged magma resulting from gas exsolution, rheological stiffening, and pressurization. The cycles, over hours to days, initiated when degassed stiff magma retarde...

Microcrystalline inclusions within microlite-poor matrix are surprisingly common in low intensity eruptions around the world, yet their origin is poorly understood. Inclusions are commonly interpreted as evidence of crystallization along conduit margins. Alternatively, these clasts may be recycled from low level eruptions where they recrystallize by heating within the vent. We conducted a serie...

The historic Penouta mine in northwest Spain is the focus of efforts to extract tantalum from tin mining waste. This paper describes the characterisation of the tantalum mineralogy of waste material from the deposit. Characterisation was realised using quantitative mineralogy and geochemistry. This paper further identifies other phases of interest and investigates the potential for extraction u...

Previous studies of Vulcanian eruptive products have shown that the respective volcanic conduits were filled for most part with low-porosity magma (i.e., < 10 vol%) prior to eruption. Comparison theoretical porosity distribution expected from closed-system degassing suggests gas loss must taken place at depth within magmatic column (between 3 and 5 km). At such high pressures 70 110 MPa), howev...

Basaltic pyroclastic volcanism takes place over a range of scales and styles, from weak discrete Strombolian explosions (!10–10 kg s) to Plinian eruptions of moderate intensity (10–10 kg s). Recent well-documented historical eruptions from Etna, Kı̄lauea and Stromboli typify this diversity. Etna is Europe’s largest and most voluminously productive volcano with an extraordinary level and diversit...