621 



cussed this problem in another work * ; but the 

 materials hitherto collected are too incomplete. 

 It is not easy, when several formations are not 

 yet developed, to pronounce on the age of are- 

 nacious rocks. Even in Germany, the classic 

 soil of geognosy, the most able observers are 

 not agreed on the sandstone of the Black Fo- 

 rest, and of the whole country south-west of 

 Thuringer-Waldgebirge. M. Boussingault, who 

 passed through apart of the steppes of Venezu- 

 ela long after me, is of opinion that the sand- 

 stone of the Llanos of San Carlos, that of the 

 valley of San Antonio of Cucuta, and the table- 

 lands of Barquisimeto, Tocuyo, Merida, and 

 Truxillo, belong to a formation of antient red 

 sandstone, or coal. There is in fact real coal 

 near Carache, south-west of Paramo de las 

 Rosas. 



Before a part of the immense plains of Ame- 

 rica was geognostically examined, it might 

 have been supposed that their uniform and 

 continued horizontality , was owing to alluvial 

 soils, or at least to arenacious tertiary soils. 

 The sands which in the country of the Baltic, 

 and in all the north of Germany cover coarse 

 limestone and chalk, seem to justify these sys- 

 tematic ideas, which have not failed to be ex- 



i * Sur le gisement des roches dans les deux hemispheres, p. 

 230. 



