S*8 Geoh^ical Delineation «/* South America. 



«f the objects whleli occupy my attention during my tra- 

 vels, to throw any light on the structure of the earth. 

 The laborious journeys which, for eight years, I have made 

 throuEsh Europe, had no other object ; and if I have the 

 good fortune to return to Europe, and to recover my geo- 

 logical luanuscripts which I left behind me in France and 

 Germany, I shall venture to give a sketch of the structure 

 of the earth. What I have long said, that the direction 

 and inclination, the rising and falling of the primitive 

 strata, the angles which they form, with the meridian of 

 the place, and with the axis of the earth, are independent 

 of the direction and depression of the uiountains ; that ih-'v 

 depend on laws, &vA that they observe a general parallelism 

 which can be founded only ui the nrotion and rotation of 

 the earth. AVhat Freieslcbcn, Von Biich and Gruner have 

 proved better than 1 will i)e found confirmed, namely, that 

 the succession of the alluvial strata, which was considered 

 as a peculiaritv of certain provinces, such as Thuringiaand 

 Derbvshirc, takes place generally, and tliat there appears 

 an identity in the order of the strata (see Plate IX.) ; from 

 which there is reason to conclude that the same deposition 

 has been effected at the same time over tlie whole surface of 

 the earth. All thes£ ideas are of the greatest importance, 

 not only to the philosopher, who endeavours to elevate 

 himself to general principles, but also to the miner, who 

 nuist conceive in his mind v. hat he has not before his eyes, 

 and guide himself by analogy deduced from actual ex- 

 perience. 



Before I describe the situation of the mountains which I 

 have observed from tire coast to the province of Venezuela, 

 I shall o-ive a general view of the form of this continent. 

 Unfortunately there are no early observations to serve as a 

 ground for this description. For half a century past many 

 accidental observations respecting this land have been col- 

 lected, but not a single idea relating to its geology has been 

 made known, 'ihe great genius of Condamine, the zeal 

 of Don George Juan de Ulloa, would certainly not have 

 left us in the dark on this subject, had mineralogy been 

 more cultivated at the time when they wrote. All that 

 could then be done was to measure and to take levels. As 

 they were cmplovcd on the high cordillera of tbe Andes, 

 which extends north and south from Zitara, as far as Cape 

 Pilar, and beheld with wonder the immense height of the 

 niountains, they forgot that Soulh America exhibits other 

 Cordilleras, which extend east and west parallel to the 

 equator^ and which^ on account of their height, deserve as 



, much 



