DEGAZMAG : The october 2011 submarine eruption of El Hierro, Canary Islands

The october 2011 submarine eruption of El Hierro, Canary Islands

	Microphotograph of a white pumice from October 2011 submarine volcanic eruption in El Hierro (Canary Islands, Spain). This microphotograph shows a large bubble containing a small xenocryst of quartz covered by a discontinuous shell of glass and connected by glass threads to the bubble walls (microphotograph taken by D. Laporte using a scanning electron microscope in secondary electron imaging mode). See Sigmarsson et al. (2013, Contrib. Mineral. Petrol., 165-3: 601-622) for more explanation.
	Shape of a quartz xenocryst extracted from El Hierro 2011 white pumice by hydrofluorosilicic acid treatment. The xenocryst has a very contorted shape, with deep embayments and holes, and its surface is covered by etch pits. As quartz is not attacked by hydrofluorosilicic acid at room temperature, these etch pits are presumably inherited from the magmatic stage and could represent the sites where a multitude of tiny gas bubbles nucleated on the quartz surface (microphotograph taken by D. Laporte using a scanning electron microscope in secondary electron imaging mode). See Sigmarsson et al. (2013, Contrib. Mineral. Petrol., 165-3: 601-622) for more explanation.

Microphotograph of a white pumice from October 2011 submarine volcanic eruption in El Hierro (Canary Islands, Spain). This microphotograph shows a large bubble containing a small xenocryst of quartz covered by a discontinuous shell of glass and connected by glass threads to the bubble walls (microphotograph taken by D. Laporte using a scanning electron microscope in secondary electron imaging mode).
See Sigmarsson et al. (2013, Contrib. Mineral. Petrol., 165-3: 601-622) for more explanation.

Shape of a quartz xenocryst extracted from El Hierro 2011 white pumice by hydrofluorosilicic acid treatment. The xenocryst has a very contorted shape, with deep embayments and holes, and its surface is covered by etch pits. As quartz is not attacked by hydrofluorosilicic acid at room temperature, these etch pits are presumably inherited from the magmatic stage and could represent the sites where a multitude of tiny gas bubbles nucleated on the quartz surface (microphotograph taken by D. Laporte using a scanning electron microscope in secondary electron imaging mode).
See Sigmarsson et al. (2013, Contrib. Mineral. Petrol., 165-3: 601-622) for more explanation.