OCCURRENCES 297 



subangular boulders of Oneota chert are present, one of them a foot in 

 diameter. Bedding is very poorly indicated. The elevation is 1,400 feet. 



Two of the most accessible of the Wisconsin occurrences are on the 

 highway just above Tunnel Number 3, on the Chicago and Northwestern 

 Eailway, between Sparta and Norwalk (northwest i/4, southwest 14 j sec- 

 tion 18^ township 16, range 2 west), and on the hill near by, Just south 

 of the station of Summit, at the eastern portal of the tunnel (southwest 

 %, southwest 1/4, section 17, township 16, range 2 west). At these places 

 the formation consists of much weathered and broken down conglomerate 

 with a sandstone matrix, yellow and red stratified sandstone, and pow- 

 dery and botryoidal limonite. The thickness appears to be from 10 to 20 

 feet. The bedding is not well defined. A loose slab showed current 

 ripple-marks. The elevation of these localities is between 1,360 and 1,380 

 feet. 



Loose pebbles, possibly lowered by weathering, are extremely abundant 

 near Pine Hollow Church, about a mile north of Cashton (northeast i/4, 

 section 29, township 15, range 3 west). The elevation is about 1,310 feet. 

 The material rests on the Oneota dolomite and possibly in part on the 

 Saint Peter sandstone. 



Other places in the Sparta and Tomah quadrangles where pebbles or 

 rock of the Windrow formation are definitely known are listed below. In 

 the preparation of this list all doubtful occurrences of one or two pebbles 

 have not been given, since such may represent material transported by 

 human agency, either attached to mud on the wheels of vehicles or car- 

 ried as curiosities or "lucky stones." At all of these places the underlying 

 rock is the Oneota dolomite : 



Elevation, 

 Township 17, range 2 west : feet 



North 1/2, section 27 1,400 



Township 16, range 2 west : , 



East 14 post, section 12 1,440 



Soutliwest 14, uortliwest 14, section 19 1,400 



Northeast %, southwest %, section 20 1,300 



Township 16, range 3 west : 



Northwest %, section 23 1,400 



East % post, section 24 1,380 



South %, section 36 1,400 



Townsliip 15, range 3 west : 



South 14 post, section 20 1,360 



South 1^ post, section 22 1 ,360 



Township 15, range 4 west : 



North % post, section 22 1,334 



Center, section 23. . 1,360 



