CHAPTER IV. 

 THE SISKIYOU ISLAND. 



It will be remembered it was stated that 

 when this island was first elevated from the 

 sea bed, the movement was accompanied by 

 so much of violent force and consequent heat 

 that the limestones of the mass were turned 

 to marble, the argillaceous sediments into 

 slates, and between and through these, beds 

 of granite and other eruptive rocks were 

 forced into the positions they now occupy in 

 the mass. 



It will be borne in mind, too, that the up- 

 lifted nucleus of the island was crowded to 

 the surface with so much of heat and pressure 

 as to destroy the outlines of many of the 

 organic forms it contained. 



The island once elevated, the resistance 

 to this crushing force ceased, and a long 

 period of quiet succeeded. 



