AI.TKS1AN WELLS. 423 



and Too to 800 feel to the Laramie, making the bases of the formations 

 respectively 100 feet, 650 to 700 feet, and 1,350 to 1,500 feel beneath 

 the datum level of the Platte River. The vertical and lateral distribution 

 of the materials of this series of strata has already been discussed, bul 

 the distribution of the flows in connection therewith now requires brief 

 consideration. 



Two broad water-bearing zones are clearly defined: A lower, corre- 

 sponding in thickness and position with the lower zone of conglomerates 

 and sandstones of the Arapahoe formation; an upper, between loo and 

 200 feel thick, corresponding with the series of sandy strata in the upper 

 part of the Arapahoe, a zone w hich at mosl points along the outcrop of the 

 formation does not appear so distinctly developed as beneath the central 

 portions of the held. 



Extending In-low these zones into the Laramie formation, there are 

 but lo wells, which vary greatly in depth and are widely distributed in 

 location. Thej indicate little as to the value of the upper Laramie as a 

 water-bearing series, bul from the general succession of beds in the anas 

 of outcrop it is doubtful if the formation becomes of economic importance 

 until its lower, basal member of sandstones is reached. Moreover, the 



waters from the deepest wells in the Laramie of the Denver Basin are 

 considerably mineralized. 



The (lows recorded from within the Denver formation are bul eight in 

 number, only three of which are utilized. 



The irregularities which have been encountered in the vertical and 

 lateral distribution of the several flows are not altogether indicative of 

 equal irregularities in the water-bearing capacity of the strata or of the 

 actual absence of flows in localities in which wells have not been sunk to 

 the lowest horizon. < >n the contrary, it is highly probable that had all the 

 wells been drilled to a uniform depth, as, for instance, to the lower limit of 

 the Arapahoe, the water-bearing zones would have appeared much more 

 unbroken. This is borne OUt both on natural grounds and from an exami- 

 nation of the flows of the upper zone over those portions of the field 



from which the most complete information has Keen obtained. It has not 

 always been possible to obtain data as to minor Hows, these having often 



