Ch. XXXI.] PLIOCENE VOLCANOS. 533 



Volcanic cones and lavas. — There are about fourteen distinct cones 

 ■with craters in this part of Spain, besides several points whence lavas 

 may have issued ; all of them arranged along a narrow line running 

 north and south, as will be seen in the map. The greatest number of 

 perfect cones are in the immediate neighborhood of Olot, some of which 

 (fig. 66V, Nos. 2, 3, and 5) are represented in the above drawing; and 

 the level plain on which that town stands has clearly been produced by 

 the flowing down of many lava-streams from those hills into the bottom 

 of a valley, probably once of considerable depth, like those of the sur- 

 rounding country. 



In the above drawing an attempt is made to represent, by the shading 

 of the landscape, the different geological formations of which the country 

 is composed.* The white line of mountains (No. 1) in the distance is 

 the Pyrenees, which are to the north of the spectator, and consist of hy- 

 pogene and ancient fossiliferous rocks. In front of these are the fossilifer- 

 ous formations (No. 4) which are in shade. Still nearer to us, the hills 

 2, 3, 5 are volcanic cones, and the rest of the ground on which the sun- 

 shine falls is strewed over with volcanic ashes and lava. 



The Fluvia, which flows near the town of Olot, has cut to the depth 

 of only 40 feet through the lavas of the plain before mentioned. The 

 bed of the river is hard basalt ; and at the bridge of Santa Madalena are 

 seen two distinct lava-currents, one above the other, separated by a hori- 

 zontal bed of scoriae 8 feet thick. 



In one place, to the south of Olot, the even surface of the plain is 

 broken by a mound of lava, called the " Bosque de Tosca," the upper 

 part of which is scoriaceous, and covered with enormous heaps of frag- 

 ments of basalt, more or less porous. Between the numerous hummocks 

 thus formed are deep cavities, having the appearance of small craters. 

 The whole precisely resembles some of the modern currents of Etna, or 

 that of Come, near Clermont ; the last of which, like the Bosque de 

 Tosca, supports only a scanty vegetation. 



Most of the Catalonian volcanoes are as entire as those in the neigh- 

 borhood of Naples, or on the flanks of Etna. One of these, called 

 Montsacopa (No. 3, fig. 66V), is of a very regular form, and has a cir- 

 cular depression or crater at the summit. It is chiefly made up of 

 red scoriae, undistinguishable from those of minor cones of Etna. The 

 neighboring hills of Olivet (No. 2) and Garrinada (No. 5) are of simi- 

 lar composition and shape. The largest crater of the whole district 

 occurs farther to the east of Olot, and is called Santa Margarita. It is 

 455 feet deep, and about a mile in circumference. Like Astroni, near 

 Naples, it is richly covered with wood, wherein game of various kinds 

 abounds. 



Although the volcanos of Catalonia have broken out through sand 

 stone, shale, and limestone, as have those of the Eifel, in Germany, to 

 ba described in the sequel, there is a remarkable difference in the nature 



* This view is taken from a sketch which I made on the spot in 1839. 



