618 



stone of the Llanos, of which the relative anti- 

 quity has appeared to me to be less verified. 



VI. FORMATION OF THE SANDSTONE OF THE LLANOS 

 OF CALABOZO. 



I place the formations in the successive order 

 which I thought I perceived from my first im- 

 pressions on the spot. The carburated slate or 

 thonschiefer of the peninsula of Araya connect 

 the primitive rocks of gneiss-granite, and mica- 

 slate gneiss, with the transition soil (blue and 

 green slate, diorite, and serpentine mixed with 

 amphibol, granular greenish-grey limestone) of 

 Molpasso,Tucutunemo, and San J uan . Towards 

 the south, the sandstone of the Llanos rests on this 

 transition-soil; it is destitute of shells, and com- 

 posed (savannahs of Galabozo) of rounded frag- 

 ments of quartz*, kieselschiefer and lydian, 



Mexico a very singular agglomerated feldspathic formation, 

 superposed upon, perhaps inclosed in, red sandstone, near 

 Guanaxuato. See my Political Essay, Vol. ii, p. 179, 180 - } 

 and my work on the position of rocks, p. 2 8. 



* In Germany, sandstones which belong indubitably to 

 red sandstone, contain also (near Weiderstadt, in Thuringia) 

 galets, and rounded fragments (Friesleben, Vol. iv, p. 77). 

 They have on that account been designated by the name of 

 nageljluhe (Meinicke, in the Naturforscher , St. 17, p. 48). I 

 shall not cite the pudding-stones subordinate to the red sand- 

 stone of the Pyrenees, because the age of that sand- 

 stone, destitute of coal, may be contested (Charpentier, p. 



