630 GEOLOGY OF CENTRAL WISCONSIN. 



The economic contents of the drift are of considerable importance. 

 In many regions of the state where other limestones are either absent 

 or yield only an inferior lime, the pebbles of the drift are profitahly 

 hurnt. They yield often an excellent white lime, as, for instance, at 

 several points on the Baraboo ranges, and in the sand region of Mar- 

 quette and "Waushara counties. The sand and gravel of the drift are 

 everj'where put to use for the ordinary purposes. The gravel is occa- 

 sionally transported far into the driftless region for railroad balkst- 

 iug. The stratified clays of the drift are everywhere used for brick- 

 making, yielding often, as at Stoughton and Oregon, in Dane county, 

 a cream-colored brick fully equal to the "Milwaukee brick." 



The facts given in the foregoing pages will warrant a few briefly 

 stated theoretical conclusions : 



(1) The drift of Central Wisconsin is true glacier drift; as is 

 well shown by facts similar to those that are appealed to as proof of 

 the same thing in other glaciated regions, viz.: the unstratified nature 

 of the drift materials, except in stream valleys; the frequent moraine- 

 like drift hills and ridges; the absence of fossils, mai-ine or otherwise; 

 the abundance of well rounded, scratched, and polished boAvlders; the 

 existence of a "till" with its striated pebbles; the polished, striated 

 and grooved condition of the underlying rock surface; the linear and 

 parallel erosion outlines; and the entire lack of any evidence of such a 

 submergence of the region as would be necessary for the working of 

 any other distributor of loose materials than a glacier. Moreover, in 

 this special case, there is positive evidence that no such submergence 

 ever did take place. This evidence is found in the sharply defined 

 character and position of the drift limit, which pays no attention what- 

 ever to the topography of the country it traverses, having the higher 

 ground now on one side, now on the other, and crossing the highest 

 ridges and lowest valleys indifferently. Only a glacier could hn.ve 

 ceased its action along such a line. Had the drift materials been 

 spread by floating bergs^ the sea in which these were, borne would 

 never have ceased along such an abrupt line, and, moreover, any sea 

 which was deep enough to have floated icebergs over the higher por- 

 tions of the Baraboo ranges would have carried them westward unin- 

 terruptedly to the Mississippi river. 



(2) The Kettle Raruje of Central Wisconsin is a continuous ter- 

 minal and lateral moraine. The mere fact of the existence of sucli 

 a distinct and continuous belt of unstratified and moraine-like drift, 

 which, in much of its course, lies along the edge of the driftless 

 area, or, in other words, .along the line on which the western foot of 

 a glacier must long have stood, would go far towards proving the 



