448 GEOLOGY OF THE 1XENVEB BASIN. 



OTIIEK WELL RECORDS. 



The following records of a few of the wells in Denver and its suburbs 

 are added to afford an idea of individual features. The wells were care- 

 fully canvassed for the last time in December, 1890, since which date the 

 general statement holds that the water supply has still further diminished, 

 and many additional wells have been abandoned. 



I. 1 The Anderson well, near the Colfax Avenue bridge, was sunk at first 

 to a depth of 375 feet, in which distance water-bearing seams were cut at 

 154, 244, 290, 308, and 350 to 375 feet. The well was cased with 3-inch 

 pipe to a depth of 375 feet. The pressure at first was 25 pounds, but this 

 decreased to such an extent that the casing was taken up and the well sunk 

 to a depth of 610 feet to cut the lower flow. After cutting this flow there 

 was for a long time no diminution in the pressure. The original decrease 

 was probably due to bad work in sinking, imperfect casing, and a lack of 

 packing. The well has not been in use since 1888. It is one of the typical 

 wells of the Denver Basin, and the strata passed through are appended below 2 

 as illustrating the principal features of the Arapahoe formation. 



From the surface the bore passed through — 



Feet. 



Gravel and surface wash 12 



Clay 17 



Sandstone 1 



1 1 a nl clay 94 



Hard sandstone 8 



Clay slate 22 



Sandstone (first flow of water) 14 



Hard clay 24 



San (Is tune 2 



Very tough, hard clay 50 



Sandstone (second Bow of water) 16 



Hard clay 30 



Sandstone (third flow of water) 10 



lllne clay 8 



Sandstone (fourth flow of water) 12 



Soft clay 15 



Dark, hard clay 15 



Loose, white sandstone (fifth and greatest flow of water) 25 



Total depth of old well 375 



'The numbers of tlie full series (pp. 132-147) hare here been retained. 

 •Proceedings Colorado Scientific Society, Vol. I, 1883-84, p. 7G. 



