VALLEY OF LOS NOGALES. 



67 



inclined to the belief that the whole mass of apparent fresh-water deposit was cemented by this 

 material, which also formed the matrix of the volcanic breccia. The trapitic and amygdaloid 

 rocks (f) appeared everywhere, no matter how great the elevation, slightly blended with carbonate 

 of lime, as if it had been precipitated there by water. This calcareous precipitation was espe- 



f f J l>^ 1^-^^^ ^^ \ 



cially perceptible in the vesicular cavities of every trachytic or basaltic boulder, and also in the 

 fissures of the rocks and in the dells where these latter are imbedded. 



On the east slope, in the valley of "Los Nogales,' (Walnuts,) similar strata line the various 



