chap. xiv. Section of the Uspallata Range. 523 



Some of the gray and purplish varieties are thickly 

 speckled with green earth and with white crystalline 

 carbonate of lime; others are largely amy gdaloidal with 

 green earth and calcareous spar. Again, other earthy 

 varieties of greenish, purplish and gray tints, contain 

 much iron, and are almost half-composed of amygdaloidal 

 balls of dark brown bole, of a whitish indurated feld- 

 spathic matter, of bright green earth, of agate, and of 

 black and white crystallised carbonate of lime. All these 

 varieties are easily fusible. Viewed from a distance, 

 the line of junction with the underlying semi-porcel- 

 lanic strata was distinct ; but when examined closely, 

 it was impossible to point out within a foot where the 

 lava ended and where the sedimentary mass began : the 

 rock at the time of junction was in most places hard, of 

 a bright green colour, and abounded with irregular 

 amygdaloidal masses of ferruginous and pure calcareous 

 spar, and of agate. 



Seventhly : strata, eighty feet in thickness, of various 

 indurated tuffs, as before ; many of the varieties have a 

 fine basis including rather coarse extraneous particles ; 

 some of them are compact and semi-porcellanic, and 

 include vegetable impressions. 



Eighthly : a bed, about fifty feet thick, of greenish- 

 gray, compact, feldspathic lava, with numerous small 

 crystals of opaque feldspar, black augite, and oxide of 

 iron. The junction with the bed on which it rested, 

 was ill defined; balls and masses of the feldspathic 

 rock being enclosed in much altered tuff. 



Ninthly : indurated tuffs, as before. 



Tenthly : a conformable layer, less than two feet 

 in thickness, of pitchstone, generally brecciated, and 

 traversed by veins of agate and of carbonate of lime : 

 parts are composed of apparently concretionary frag- 

 ments of a more perfect variety, arranged in horizontal 



