BOWLDER TRAINS FROM THE OUTCROPS OF THE 
WATERLOO QUARTZITE AREA. 
IRA M. BUELL. 
INTRODUCTION. 
The study of the crystalline knobs and attendant bowlder 
trains of southeastern Wisconsin was undertaken by the author 
in the summer of 1884, under the direction of Dr. Chamberlin, 
geologist in charge of the glacial division of the U. S. Geol. 
Survey. It was finally completed in 1894, and the preliminary 
report, of which this article is but a resume of one of its most 
important features, passed from the hands of the author in the 
summer of that year. The work itself and the elaboration of 
its material for publication has been done under the immediate 
supervision of Prof. Chamberlin, to whom the credit is due for 
its plan and general scope. The details of the latter, however, 
and the general conclu&.ons derived therefrom are the author’s, 
no one else sharing responsibility for their utterance. Dr. 
Chamberlin has, however, kindly given his permission for 
their publication in this form. 
GENERAL FEATURES. 
The geology of this interesting region has frequently been 
described. The earliest mention of its ledge areas was made by 
Dr. Owen in his report to congress upon the geology of Wis¬ 
consin, Minnesota and Iowa in 1848. 1 Percival afterwards de¬ 
scribes them; 2 also Irving, 3 Chamberlin, 4 and the author. 5 
1 Senate Documents, 1st Sess., 30th Cong., 1847, Vol. VII, No. 57, p. 39 
2 Ann. Report Geol. of Wis. for 1856, p. 101. 
3 Am. Jour. Science, 3d Ser., Vol. V, p. 282, and Wis. Geol. Survey, Vol 
II, p. 501. 
4 Wis. Geol. Survey, Vol. II, p. 252. 
6 Trans. Wis. Acad. Sci., Vol. IX, p. 255, et seq. 
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