THE LOWER SILURIAN ROCKS. S9V 



Fig. 45 is a section across the valley of the Wisconsin from the high bluff just west of 

 RoweU s Mill, N. W. qr. Sec. 17, T. ,9, R. 6 E., Prairie du Sac, in a N. 68° E. direc- 

 tion to tlie blutfs back of Clifton, Dane county. 



Kg. 45. 



-ZytTwer ^Azayn&noTi ,^^^ 



■ ^AfacCij^ffro ' ::: '.. 



"75" riT- -^airclam (r^':'~ 



--^ ~ — —— ^ 



Section Aoboss the Vallbt of the Wisconsin, at Pbaihie du Sao. 

 Vertical scale 403 feet, 1 inch; hoi-izontal scale 1J4 miles, 1 inch. 



The veiy bold and prominent bluSf rising from the bank of the Wisconsin at tho 

 mouth of Honey creek. Sec. 21, T. 9, R. 6 E., has abeady been cited as giving a mag- 

 nificent section, and portions of tliis section have been given in some detail in the gen- 

 eral descriptions of the formation. Abbreviated, the section is as follows: 



1. Loiaer ilagmsian, in a vertical ohff facing towards Honey Creek, including. 



subdivisions as given on page 552 52 5 



2. Madison, including: slope without exposure, 15 feet; white and brown sand- 



stone for the most part non-calcareous, 16.5 feet; slope without exposure, 



7 feet; coarse, non-calcareous white and brown sandstone, 2 feet; in all 40 5 



8. Mendota, including: slope without exposure, .33 feet; brown, earthy, very com- 

 pact limestone with 34.15 per cent, of white clay, 1 foot; like the last, 

 but with 26 per cent, of clay, 2% feet; in all 36 g 



4. Potsdam, including subdivisions as given on page 534; rising abruptly fro;u 



the Wisconsin , 189 3 



Total height of bluff 318~7 



Altitude of summit . , ; . . . . 484 . . 



Fig. 46 is a section across the valley of the Wisconsin, from the bluff just described, 

 A^ milf^s in a southeasterly direction to the bluff on Sec. 1, T. 8, R. 6 E. 



South of the quartzite 



Fig. 46. 



HONET CREEK BLUFF 



,Me^<iala Jjanesirme 





—Poifiam Apanddsm- 





_^ia)l^ 



range, over all of T. 10) 

 R. 4 E., Honey Creek, 



the country is one char- 

 acterized by numerous 

 high, narrow, branching 

 ridges, which are, for 

 the most part, severed 

 into entirely separate 

 parts, showing frequent- 

 ly walls of bare rock, 

 and often rising in- 

 to the horizon of tho 

 Mendota beds, more 

 rarely into that of the Lower Magnesian. In many cases, the sides of the ridges arc 

 worn into bold and fantastic fonns of bare rock, whose very plain horizontal stratifica- 

 tion renders the effect more strildng. On the N. W. qr. of Sec. 17, T. 10, R. 5 E., a 

 narrow, precipitous spur from a higher bluff is worn entirely through, forming a natural. 



WMv ^rrtK' IV6' abvtr Uj. t^ie/iiyan 



Section across the Wisconsin Valley rnoM Uonet Obebk 

 Bluff. 



Vertical scale 400 feet to the inch; horizontal, IH miles to the inch. 



