TO JUNCTION OF (J HAND AND GREEN RIVERS. 35 



greal basin in which we lia<l bo long been journeying — the valley of the Mississippi — 

 and entered thai of the Rio Grande. At Las Vegas, too, the granite of the Rocky 



Mountains is first seen in place, forming the axis of a subordinate anticlinal, on the 

 eastern Hanks <>l which the Triassic and the Carboniferous formations re appear in suc- 

 cession, thus bringing us to the base of the section which has occupied our attention 

 in the preceding pages. The exposures of these strata are much less full and satisfac- 

 tory here than nearer Santa 1"Y, where they are also less metamorphosed and more 

 fossiliferoUS, and where; the Contrast and coincidences which their exposures present 



with their eastern outcrops may be more accurately determined. 



