674: 



GEOLOGY AND TOPOGRAPHY OF THE LEAD REGION. 



Fm> 6< 



mation. About a quarter of a mile east of the preceding locality, on 

 the opposite side of Grant river, some of the thin layers of the 

 Lower Magnesian are slightly folded and bent, and are underlaid 

 by other and heavier beds which are undisturbed. Their horizon 

 is a little higher than the arenaceous shales, probably near No. 

 2 or 3 of the preceding section. These flexures are probably due 

 to a slight lateral or horizontal pressure, exerted during the so- 

 lidification of the rock, which either did not extend to the under- 

 lying layers, or 

 which, by their 

 greater compactness, 

 they were able to 

 resist. The level 

 upper surface of the 

 lower beds (4), ex- 

 cludes the idea of 

 unconf or inability. 

 Fig. 6 is a section 

 taken at this locality. 

 At the Welsh Mill, 



T Kiver 



in Iowa county, a 

 short distance north 



a . T SECTION OF CURVED STRATA AT GRANT RIVER. 



or the quarter post 



. - 1 1. St. Peters sandstone. 2. Slope of hill unexposcd. 3. Curved 



of SeCS. 18 and 19, strata of limestone. 4. Heavy-bedded limestone. 5. Slope of hill 



T. 4, K. 2 E., is a 



somewhat anomalous occurrence of the Lower Magnesian, as shown 



in Fig. 7. 



FIG. 7. 



SKETCH OF LOWER MAGNESIAN LIMESTONE AT THE WELSH 

 1. Quarry. 2. Curved strata of limestone. 8. West branch of Pecatonica. 



The Lower Magnesian appears here on the south side of the stream, 

 for a distance of about a quarter of a mile. It seems to- have under- 

 gone a slight upheaval subsequent to its deposition. The stream 



