U. 8. GEOLOGICAL SURVEY 



BULLETIN eU PLATE XV 



A, TABLE ROCK, AT ENTRANCE TO ROGUE RIVER VALLEY, OREG. 

 A lava flov/ Irom the Cascade Range caps the softer beds and protects them from erosion 



B. OREGON CAVES, SOUTHWEST OF GRANTS PASS, OREG. 



Stalactites, like icicles, hang from the roof of the cave; stalagmites point upward from the floor. When they 

 meet they form a column. These forms are composed of carbonate of lime deposited from solution in water. 



Photograph copyrighted by V^eister Co., Portland 



