VULCANISM 



381 



From most existing volcanoes both lava-flows and fragmental 

 ejecta are given forth, and the resulting cones are composite in 

 material. The lava breaks through the side of the cone more 



Fig. 298. The eruption cloud of Pelee, December 16, 1902. (Lacroix.) 



frequently than it overflows the summit, and this gives rise to irreg- 

 ularities of form and structure. The cones are also subject to 

 partial destruction both by outbursts of lava and by explosions. 



