ENULicH.] BASIC VOCCANIC ERUPTIVES ISOLATED BASALT. 251 



Near CaSon City* two small basaltic hills occur. Farther south, to- 

 ward Pueblo, another may be noticed. Along the Huerfano Eivert a 

 number of them may be noticed, occurring together with some dikes 

 composed of the same material. It is a noticeablefact that all of these 

 last-mentioned eruptions have broken through and are exposed in Cre- 

 taceous or lignitic beds. Some form low, prominent hills, others merely 

 act as protecting covers to the penetrated strata. An interesting case 

 of this kind is the blulf upon which a station was located near Badito. 

 Eising rather abruptly from the surrounding country, the bluff reaches 

 an elevation of 6,952 feet above sea-level. Three prominent cones of 

 basalt, standing in a line on the summit of the bluff, denote the original 

 points of outflow. Sharply defined, they are distinguishable from a long 

 distance, and before being visited their appearance awakened the hope of 

 seeing small, well-defined craters. Although the basaltic eruptions have 

 been productive of forms resembling crater-cones more closely than any 

 of the other eruptives, not one occurrence has been observed in Colo- 

 rado that could directly be compared to the cone and crater of an active 

 or typical volcano. This fact has been recognized some time since, and 

 no exception to this rule has been discovered as yet. Instances do 

 occur which a lively imagination could transform into a crater-cone, but 

 upon examination they prove not to be such. 



* Eep. U. S. Geol. Surv., 1873, p. 331. tEep. U. S. Geol. Surv., 1875, p. 131- 



