200 REPORT OP THE 



southern part of the State, has created a very general desire to 

 know to what extent artesian borings would prove successful 

 in other parts of the State. Several unsuccessful borings have 

 been made at points where the work has been directed rather 

 by empiricism than by any adequate knowledge of the exist- 

 ence of such a geological structure as could furnish reasonable 

 grounds for the expectation of success. 



From what has already been stated of the general conforma- 

 tion of the strata underlying the Lower Peninsula, the accumu- 

 lation and retention of vast reservoirs of water in these great 

 peninsular dishes, will appear obvious and necessary. Rains 

 falling upon the surface percolate downwards until the water 

 reaches an impervious stratum along which it flows till it 

 reaches the lowest depression of that stratum, somewhere be- 

 neath the center of the State, and some hundreds of feet from 

 .the surface. The water-bearing strata are, therefore, porous 

 sandstone, immediately underlain and overlain by impervious 

 strata of an argillacious or calcareous character. Each porous 

 sandstone stratum thus underlain and overlain throughout our 

 ■whole series, becomes in this manner surcharged with water 

 admitted at its outcrop. It is obvious, now, that by boring 1 

 down at any point within the circuit of the outcrop of a water- 

 bearing stratum, until that stratum is pierced, the water will 

 rise through the hole to a point on a level with the rim of the 

 basin which holds the water. If the place of boring is lower 

 than that point, the water will rise to the surface and overflow; 

 if higher, it will not. 



In consequence of the general rise of the surface of the penin- 

 sula from the lake shores toward the interior, the outcrops of 

 the strata occur, as a general rule, at lower levels than the 

 points within the basins which they form ; and artesian wells 

 cannot be a thing of general occurrence. In the southern part 

 of Jackson, and the northern part of Hillsdale counties, how 

 ever, the sandstones of the Napoleon and Marshall Groups out- 

 crop at levels considerably higher than the general elevation of 

 -the peninsula, and it is likely that the impediments to a free 



