About the Cover
Pyroclastic Density Currents and the Sedimentation of Ignimbrites
Cover image
Pyroclastie density currents and eruption column at Lascar volcano, Chile, on 19 April 1993. The main current extends 5 km from the vent, having advanced at approximately 55 m S-1. The plume ascended to 23 km. Jacques Et Aicha Guarinos Photos on back cover (top to bottom): (1) Ignimbrite plateau of the Bandelier Tuff, erupted from Valles caldera, Jemez Mountains, New Mexico, U.S.A. The caldera lies behind the hills in the distance. (2) Cross-bedded proximal 1980 ignimbrite of Mount St Helens, Washington, U.S.A. (3) Sampling ignimbrite for fabric studies: Peach Springs Tuff, California, U.S.A. (4) Pumice overpassing at the lower flow-boundary zone of a granular fluid-based pyroclastie density current. (5) Hot, one-day old deposit-derived ignimbrite lies in a canyon eroded into the 1991 ignimbrite of Mount Pinatubo, Philippines.