222 Washington — Catalan Volcanoes and their Rocks. 



many well-formed cinder cones, of which Gelabert enumerates 

 thirty-four. The greater number of these are in the neighbor- 

 hood of Olot, where they occur very close together, while 

 others are met with, but more widely separated, to the east, 

 near the town of G-erona, but mostly to the west of this. As 

 far as my observations permitted me to judge, it would seem 

 that none of these cones are based immediately upon the 

 Eocene limestone, but that they rest either upon Quaternary 



Castellfullit from the north. 



deposits or upon the earlier lava flows, in most cases the latter 

 being true. Furthermore, it would appear that the place of 

 origin of these cones, as well as of the lava flows, is never near 

 the upper edge of a fault block, but always in or near the 

 fault valley, and" sometimes close to the face of the fault scarp. 

 A similar emplacement was observed in the case of some of 

 the smaller and most recent cinder cones in Sardinia, and such 

 a situation above or near a well-marked fault is readily con- 

 ceivable as most favorable to the formation of a volcano. 

 These small volcanoes are invariably typical cinder cones, 



