142 Dr Bou^ on the Elevation of Mountain Chains^ 



posed to have happened between the deposition of the greensand 

 and chloritose chalk, and that of the marly and white chalk. 



As 1 have already given examples of a direction from N.N. W. 

 to S.S-E., as in the Riesengebirge, one would thus have speci- 

 mens of the errors to which we are led by the theory of the 

 parallelism of elevations in the same epoch, unless M. de Beau- 

 mont can include such cases under his Mont Viso system. 



The Pyrenees are the type of his niiith system of elevation, 

 which appeared between the chalk period and the commence- 

 ment of the tertiary deposits. All geographers have recognised 

 a uniform type of structure in the range of hills extending from 

 Cape Ortegal in Gallicia, to Cape Creuss in Catalonia. On 

 the great scale, it is to be regarded as a congeries of parallel 

 ranges running W. 18^ N. to E. 18° S., and in an oblique direc- 

 tion in relation to the line which joins the two extremities. 



Pareto (See Bull, de la Soc. Geol. de France, vol. i. p. 64), and 

 I (T. de Geol. vol. iii. p. 353, andResume pour 1832, p. cxviii.) 

 maintain the union of the Apennines with the system of the Pyre- 

 nees, while M. de Beaumont persists in his first opinion on the 

 subject. We tell him, that in Italy the direction of the uphea- 

 ving, and also that of the igneous dikes and veins, is from S.W. 

 to N.E. ; while he finds, upon geolog^^al or geographical maps, 

 indications of fracture, which those who have been on the spot 

 have not been able to discover. On the other hand, if M* de 

 Beaumont would admit that his ninth system of elevation has, 

 like some of the other systems, taken place in different directions, 

 we should very nearly agree as to the respective position of the 

 tertiary rocks, M. de Beaumont lays much weight upon his 

 preconceived line of the igneous rocks, but their position does 

 not prove much, for, from their fluid or pasty state, they have 

 naturally filled up rents produced during elevations, and yet 

 these rents would be transverse to the axis of the principal move- 

 ment. Besides, M. de Beaumont himself acknowledges that the 

 ophites are in that particular case, and " qu''ils ont suivi les 

 directions de toutes les anciennes fractures et do tous les clevages 

 plus ou moins obliteres du sol,'' (p. Q5^). 



The other examples given by M. de Beaumont, are the steep 

 wall of the Southern Alps; the Julian Alps; a part of Croatia, 

 Dalmatia, and Bosnia ; the Achaic system in Greece ; the 



