The Quartzites of Sauk and Columbia Counties. 129" 



SOME EVIDENCES BEARING UPON THE METHOD 

 OF THE UPHEAVAL OF THE QUARTZITES OF 

 SAUK AND COLUMBIA COUNTIES.* 



BY T. C. CHAMBERLIN, M. A., 

 ProfesBor of Natural History, Beloit College. 



Next to the age of these quartzites, perhaps no question in 

 WisconsiQ geology has been more prolific in speculation and 

 discussion, if not in investigation, than the method of their up- 

 heaval. The former question has been discussed with much 

 success by Prof. Irving. Evidence bearing upon the latter 

 question cannot then fail to be interesting in itself, while it 

 must also strengthen or otherwise the conclusions that have 

 been reached concerning the former. The evidence which will 

 be adduced in this paper rests chiefly on the peculiarities of 

 certain bands of talco-silicious schist interstralified between 

 heavy beds of quartzite. The best observed exposure of thia 

 is to be found on the east side of Devil's lake, and is repre- 

 sented in the accompanying figure. 



The dip of the quartzite beds, as well as of the included 

 stratum of schist is 15° to the northward. The determination 

 of this does not rest alone upon the inclination of the beds, 

 but is rendered certain by that of the laminie and layers of 

 pebbles included in the quartzite, as well as by ripple-marked 

 surfaces. Another similar band, but less conveniently ex- 

 posed, occurs in the north range near Ableman, standing^ 

 nearly vertically, corresponding to the higher dip of that 

 range. 



The material of these bands is not sufficiently defined by 



*It is proper here to state that the observations on which this and the following paper 

 are based, were made in connection with a party organized at Whitewater for the pur- 

 pose of studying this region, and some credit at least is due to the remaining members 

 though I hare made use of my own observations exclusively. The party consisted of 

 T. a. Vincent, S. R. Aldeu, A. L. Arey, P, 11. King, L. C. Wooster, L. W. Winslow and 

 H. D. Bell. 



