Washington — Catalan Volcanoes and their Rocks. 227 



To the southeast of Olot volcanic cones are more numerous, 

 some twenty being marked by Gelabert. Of these the most 

 important is Cruzcat, the highest of those around Olot, its 

 summit being about 180 meters above the base. This is exten- 

 sively breached on the west side, is not very well preserved, 

 and is covered with a thick forest growth. Like the preced- 

 ing, it is built up largely of loose scoriae and lapilli, though 

 there is also a considerable amount of more or less compact 

 lava, which seems to be uniformly finely vesicular. This vol- 

 cano has ejected an immense quantity of bombs, large numbers 

 of which are to be found on and in the lava- and lapilli-cov- 

 ered plain to the west of it, north of the road from Olot and 

 from 4 to 5 kilometers from the town. These are of very 

 varied shapes, some ovoidal and quite regular, others elongated, 

 flattened and twisted, and they are all composed of more or 

 less vesicular lava. According to Gelabert, who figures many 

 of them, some contain nuclei of feldspar or olivine, but these 

 would seem to be unusual. 



Another interesting cone in this vicinity is Santa Margarita, 

 whose summit is 124 meters above the road between it and 

 Cruzcat, but about 200 above the lowest part of the base, 

 which is to the southeast. This likewise shows a well-formed, 

 circular crater, which is some 300 meters across, and the culti- 

 vated bottom of which lies 66 meters below the highest point 

 of the rim, the northeastern part. This volcano is composed 

 of very loose, fine lapilli, except in the western portion of the 

 rim, where limestone is exposed, and which evidently formed 

 part of the original opening produced by a maar-like explo- 

 sion, the southwest wind which evidently prevailed carrying 

 the bulk of the loose ejectamenta toward the northeast, as 

 pointed out by Sapper. 



Of the other and smaller cones seen in this vicinity it is 

 needless to give any details, as they differ in no essential 

 respects from those already described. 



l)ikes seem to be very rare in the districts about Olot and 

 Gerona, only one having been observed by me. This is 25 

 centimeters wide, cutting tuffs and agglomerates on the road to 

 Santa Pau, about 3 kilometers from Olot. The rock of this 

 does not differ materially from those of the volcanic cones, as 

 will be seen later. Gelabert mentions and figures several 

 dikes which cut the granite of the region around Hostalrich, 

 20 to 30 kilometers to the south of Gerona. 



As will be seen later, the lavas of the flows and of the cones 

 do not differ materially from each other in any respect except 

 in structure, the former being uniformly compact and the latter 

 more usually vesicular, while the chemical and mineralogical 

 features remain much the same. It is clear, therefore, that, 



