VOLCANOES OF THE UNITED STATES 



447 



Volcanic cones are abundantly scattered over the islands, 

 and comparatively fresh lava flows are not wanting. In 

 recent times small islands have arisen in the group and 

 eruptions have taken place. There are no other islands 



SAN MIGUEL HARBOR IN THE AZORES. 

 Notice the volcanic cones in the distance. 



near them. Their formation is due entirely to volcanic 

 forces. Islands of this kind and coral islands are the only 

 projections rising to the surface from the deep ocean floor. 

 214. Volcanoes of the United States. In the Cordilleran 

 region of the United States, west of the meridian of 

 Denver, there are a score or more of lofty peaks which 

 show conclusive evidence of volcanic origin. Until the 

 summer of 1914 when Mt. Lassen suddenly began to erupt, 

 none of these had been active since white men became 

 familiar with the region. Some of the cones have been so 

 recently formed that the forces of erosion have not had 



