590 GEOLOGY OF CENTRAL WISCONSIN. 



parent dip southward, or away from the quartzite. This ^anlcing sandstone is well ex- 

 posed at Dorward's Glen, on the north side of Sec. 18, where it is seen overlymg the 

 quartzite, as heretofore described and illustrated in Fig. 127, which is a section along the 

 wall of the glen. This wall shows the following succession of layei-s, the numbers of 



the layers being the same as in Fig. 27 : — 



Ft. In. 



VI. Yellowish, Sne-gramed, friable and heavily bedded sandstone 14 8 



V. Pink, fine-grained and thinly bedded sandstone 4 8 



IV. Whitish and brownish, very coarse, heavily bedded sandstone, the con- 



rtituent gi-ains much roUed translucent quartz 10 . . 



1 11. Similar to the last, but yellowish and finer grained 17 4 



II. Very coarse, like IV. 5 10 



1. Bowlder-conglomerate, almost without matrix, made up of bowlders 



mostly angidar, up to 1 foot in diameter; forms the stream bed 4 2 



Height of cliff 68 S 



lu the town of Merrimac, Sauk county, sandstone at high levels continues to flank 

 tlie quartzite. This sandstone may be seen at Parphrey'sGlen, on theN. E. qr. of Sec. 

 9:2, T. 11, R. 7 E., where 20 feet of friable, brownish, ScoWfejw-bearing, regular-beddrj 

 sa,ndstone is exposed, including thin layers of a conglomerate of red quartzite pebbles; 

 on the N. E. qr. of Sec. 28, in a high, narrow bluff, winch is partly detached from the 

 quiu-tzite; and again, lying directly against the quartzite. on the N. E. qr. of the S. E. 

 qr. of Sec. 20, T. 11, R. 7 E., where it forms a perpendicular clift' directly north of, and 

 across the valley from, the Devil's Nose. The rock at this place is medium to fine- 

 grained, friable, red-and-wliite-banded, purely silicious, and superficially viti-ified, and 

 contains throughout small pebbles of red quartzite, which are, however, aggregated 

 more numerously into two bands, the upper one 2 feet tluok, and 2-3 feet below tlie 

 smnmit, the lower one 10 feet thick and 59 feet below the summit. The whole height 

 of the vertical cliff is 210 feet, the whole thiolmess of sandstone seen, 227 feet. The top 

 of the sajidstone has an altitude of 622 feet; its base, one of 397 feot, so that the cliff 

 rises entirely across the horizon of the Lower Magnesian, as indicated by tlio occur- 

 rences of that formation in the country to the south east and west. The sections of 

 Plates XIX and XX show the structure and stratigraphioal relations of this cliff. 



TliG isolated Imob rising from the west bank of Otter creek, near tlie center of Sec. 

 15, T. 10, R. 6 E., Sumpter, shows the fallowing section: 



I. Madison sandstone in small separated exposures; upper portions very highly 

 ferruginous and firm; near the middle (1227) very fine-grained, Ughter 

 colored and sKghtly oalcai-eous; at the base white, fine-grained, much 



indm-ated or, 



II. Unexposed 20 



III. Mendota limestone; yeUow, shaly, in small quarry-opening o 



IV. Unexposed i q 



V. Grecnsand layer i 



VI. Unexposed . ■<- 



VII. Potsdam sandstone, upper layers fine, white, friable, banded with calcareous 



layers, lower portions rising in an abrupt cliff from the biUik of Otter 

 creek; heavily bedded, non-calcareous, alternating brown and white .... 140 



Height of Itnob oin 



Altitude of summit 1 1 P 



