GEOLOGICAL REPORT. 



Albany, December 24th, 1860V 

 To His Excellency, Alexander W. Randall : 



Sir : — In accordance with the law authorizing a Geological 

 Survey of the State of Wisconsin, I herewith submit a state- 

 ment of the condition of the work under my direction : 



I have personally continued my field explorations, with a 

 view to the determination of the general geological structure 

 of the State, and have made good progress in these investiga- 

 tions. 



Among the results of general interest, I may mention that 

 in carrying on my observations to the northwestward of the 

 westerly bend of the Wisconsin River, among the isolated 

 masses of sienitic rocks which have been regarded as of igne- 

 ous origin, I have found many of them to be essentially quartz 

 rocks of peculiar character. These rocks I find on more care- 

 ful examination in several localities, to have been originally 

 a regularly stratified sandstone, which has undergone subse- 

 quent metamorphism, so far, that on fresh fracture the rock 

 betrays no lines of lamination. When viewed as a whole, or 

 in the massive outcrops, the lines of nearly vertical jointing 

 are conspicuous ; but lines of bedding or stratification, are not 

 at once recognized. In certain localities in favorable condi- 

 tions, and particularly on Spirit Lake, we find the weathered 

 surfaces showing distinct lines of lamination ; and not only 

 the direct lines are visible, but lines of diagonal lamination at ■ 

 various angles, and the coarser and finer materials are as dis— 

 cernable as in modern sandstones. 



Not only, therefore, have we this unmistakable evidence of 

 the stratified character of these rocks, but we have the means 

 of showing that the direction of the foldings or axes (which 

 through the denudation of the more recent formations, has 

 brought these rocks to view,) lie in a nearly east and west di- 

 rection, and therefore belong to an entirely different system 

 from those which have affected the superincumbent strata. 



