52 GEOLOGICAL SURVEY OP WISCONSIN. 



1873, by sending a supplementary report, whicli, as above explained, 

 could not be prepared in time to be bound with the matter previously 

 reported by him. This supplementary matter is therefore herewith 

 submitted, and will be restored to its proper place in the preparation 

 of the final report, as contemplated by section five of the law author- 

 izing the survey. 



In this report will be found many details with respect to the Lower 

 Magnesian limestone, as it occurs in the northeastern part of the 

 state, showing much the same general characteristics as in the south- 

 western counties. It is interesting to note the occurrence of a con- 

 siderable fault in the strata in the town of Ellington (T. 22, R. 16 E.), 

 such dislocations being rare in Wisconsin. To this we may attribute 

 some very marked peculiarities in the hydrography of that vicinity. 

 Wherever mining has been prosecuted in search of gold, silver, 

 copper, etc., examination of the rocks gave little indication of the 

 presence of these metals; and it has very often been the business of 

 the survey to discourage the search for ores in places where they are 

 not to be found. Copper-mining at Berlin and gold-mining at Win- 

 neconne are among the projects thus discouraged. 



The quartzites of Portland, Dodge county, and some new localities 

 discovered in adjacent portions of Jefferson county, are fully de- 

 scribed. Several other outcrops of Archsean rocks are described — as 

 at Berlin, Mukwa and Keshena. 



The important subject of artesian wells is also fully discussed in 

 this report, giving many details that will be of great value in the fu- 

 ture operations of well- digging. 



It was deemed most conducive to the public interest to direct Prof. 

 Chamberlin to continue his survey from Beloit along and near tlie 

 south line of the state to Lake Michigan, and thence northward be- 

 tween his line of operations in 1873 and the shore of the lake. Though 

 much covered with drift, it was hoped that a sufiicient number of out- 

 crops of rock could be found to reveal the general geological charac- 

 ter of this district, and perhaps develop some new and interesting facts 

 in regard to this portion of the state. Funds were supplied him for 

 expenses of the field-work on the first of May, and the work com- 

 menced soon afterwards. By the last of August this party was able 

 to reach the extremity of the peninsula between Lake Michigan and 

 Green Bay, at "Death's Door," and to commence the return trip, in 

 which some points of special interest were reexamined, and many new 

 localities visited. Active duties in the field were brought to a close 

 in October. The services of Messrs. L. C. Wooster, G. D. Swezey, 

 and J. H. Chamberlin were secured during portions of the season ; 



