674 



GEOLOaY AND TOPOGRAPHY OF THE LEAD REGION". 



Fig. 6. 



Illation. 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 horiz-on 

 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 /^J^-JZ 



lower beds (4), ex- ^.^« 



eludes the idea of 



unconformability. 



Fig. 6 is a section „__ JSSS^^Si^ 



taken at this locality. 



At the Welsh Miil, 



in Iowa county, a 



short distance north 



of the quarter post 



of Sees. 18 and 19, 



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



somewhat anomalous occurrence of the Lower Magnesian, as shown 

 in Fig. 7. 



Fia. 7. 



Section op Cubved Strata at Grant Riveb. 

 1. St. Peters sandstone. 2. Slope of liUl unexposed. 8. Curved 

 strata of limestone. 4. HeaTy-bedded li;nesftone. 5. Slope of hill 

 unexposed. 



Sketch of Lower Maonbsian LtMEeTONK at the Welsh Mocl. 

 1. Quarry. 3. 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 



