158 



VOLCANIC COUNTRY IN CATALONtA. 



Volcanic 

 country in 

 C^taluuia. 



Extensive. 



(jianitic soil 

 intersected by 

 limestone. 



Montferrat si- 

 milar to olher 

 he ghts in tlie 

 "Hicinity. 



XIIL 

 Eifrart of a Lrtter from Mr.W . Maclure, Member of the 

 Phc/oj'jp/iical Sociffi/ of Pliilndclphia, to J: C. Delame- 

 TKt.RiE, on the Volcanoes of Allot in Catalonia*. 



Jl Shall communicate to you some mineralogical observa- 

 tions made by Mr. Fondi and me. 



After having- crossed the Py ranees on oiir way to Barce- 

 lona, we round lava and scorite in the bed of the Fluviai 

 We ascended toward the source of the river; we crossed ten 

 miles of a volcanic country round Allot, and there observed 

 several streams of lava, volcanic ashes, or puzzolana, era* 

 tors not yet obliternted, &c. We had observed that this 

 volcanic country extended fifteen or twenty miles to the 

 south, beyond Amira, where in 14!i8 there was an erup* 

 tion, that destroyed Allot, leaving but a single house stand- 

 ing. We found a great deal of lava in the bed of the river 

 Ter; and near Massanit crossed an ancient stream of lava 

 between two and three miles broad, in a state of decompo- 

 sition, and covered with alluvial soil. From Massanit to 

 Allot is near forty miles, so that the theatre of the volcanic 

 action in this country is much more extensive than that of 

 Vesuvius. 



Proceeding along the seashore from this place to Barce- 

 lona we crossed a granite country near fifty miles long. In 

 two places it is intersected by a limestone soil. 



On the road to Cafdona, by Montferr'at, we found alter- 

 nate stratifications of sandstone and puddingstone with clay, 

 marie, and limestone, inter})osed occasionally for near fifty 

 miles, similar to the stratification of Rigi, in the canton of 

 Schwitz, which is higher than IVIontfeirat : so that this ce- 

 lebrated mountain, which is said to be insolated, is but a 

 portion of a bed of puddingstone and sandstone, which ex- 

 tends through a square of about fifty miles, and forms all 

 the neighbouring mountains. These puddingstones are 

 composed of four fifths limcotone and pebbles : the cement 

 is also calcareous, with some sandstones, a little quartz, and 

 lapis Lydius. The latter has been improperly considered as 



a lava. 



* Journal tie Thysiq ue, vc!. LX Vi, p. 220. 



XIV. 



