OF THE NORTHWESTERN STATES. 



11 



Analyses of the Drift Clay, 



BLtTE. 







RED. 





Cleveland, Ohio. 





Bad River, 



Lake Superior. 



(Dk. Owen.) 



Insoluble in hydrochloric acid, 





Silex, . 





. 46.60 



silex, and alumina, 



17.50 



Alumina, 







. 11.50 



Carbonate of lime, . 



6.00 



Iron, 







. 10.10 



Carbonate of magnesia, . 



9.50 



Lime, 







5.40 



Sulphide of iron, 



3.50 



Magnesia, 







3.30 



Vegetable matter and loss, 



3.50 



Carbonic acid, . 





1.00 

 3.20 

 5.50 





100.00 



Water, 



' 









Loss, 



• 





0.80 



100.00 



Copper Boulders and Nuggets in the Drift. 



Pieces of native copper torn from the veins of the Lake Superior rocks, heing 

 nearly pure metal, resisted the crushing and grinding process longer than any 

 variety of stone. They entered into the mass of the drift, and were transported 

 long distances southward. Those near the mineral range are very large and not 

 much rounded by attrition. 



The copper rock weighing 3000 pounds found in red clay on the west fork of the 

 Ontonagon river, and exhibited in the yard of the war office at Washington, and 

 now a conspicuous object in the Museum of the Smithsonian Institution, is an 

 example of these boulders. One was found in 1845 opposite La Pointe on the 

 main land, weighing 800 pounds. About three miles south of the Minnesota mine, 

 on the middle fork of the Ontonagon, another was taken from the red clay that 

 weighed between 300 and 400 pounds. 



Another was discovered on the shore of the lake near Elm river, of several 

 hundred pounds weight, by Prof. Shepherd, which is now in the cabinet of Yale 

 College. Farther south they have been found on the waters of Lake Michigan, 

 and Lake Erie, their weight diminishing in proportion to the distance over which 

 they were carried. In a well at Madison Wisconsin, one was found at a depth of 

 20 feet, weight thirty pounds. I saw one of 3 or 4 pounds weight from drift 

 gravel near the mouth of the Menominee river of Green bay. In Walworth 

 county, Wisconsin, near the south line of the State, a boulder weighing forty or fifty 

 pounds was taken from the drift in a well. One of the size of a " man's fist" is 

 reported to have been found in making a railway excavation at Ada in Kent county, 

 Michigan. I have also seen notices of pieces of native copper in gravel at Eipon 

 and Kenosha, Wisconsin. On the Oconto river of Green bay a nugget of four 

 pounds was found many years since, and a much larger one on the Pensaukie river 

 near the mouth. SmaU masses are common in the drift of Lake Superior. But 

 the most southerly piece I know of is from Weymouth, Medina county, Ohio, 

 thirty miles south of Lake Erie, and now in the possession of Prof. Brainerd, of 

 Cleveland. These are true " float mineral," indicating, on a large scale and at 

 great distances, the presence of mines in the direction from which they came. 



