226 F. W. SARDESON THE REDSTONE QUARTZITE 



tended, I think, to say Potsdam at New Ulm and Pipestone. In the 

 same volume in which this expression just quoted was used, Upham {6, 

 volume 2, page 157) calls the formation "Potsdam conglomerate and 

 quartzite," thus following Winchell, who says, in the preceding volume 

 (volume 1, page 537), of the quartzite of Pipestone: "probably the equiv- 

 alent of the New York Potsdam sandstone, but which Dr C. A. Wliite, 

 of the Iowa survey, has designated the Sioux quartzite . . . ." As 

 formational names, the terms New Ulm and Pipestone would be at once 

 synonymous with each other and with the name Sioux quartzite, and all 

 these three with "Potsdam," according to Winchell, and it seems improb- 

 able that he intended to introduce the former as formational names. At 

 a later date (9, page 157) Winchell says: 



"This seems to prove that the Sioux quartzite, the New Ulm quartzite, the 

 Baraboo quartzite, and the Barron County quartzites are of the same age. 



They are that which Wisconsin geologists have called Huronian, as 

 Winchell also pointed out. Whether the words New Ulm quartzite were 

 intended or not as a formational name, Winchell included under it two 

 distinct areas of rock exposure, which now appear to be of very diverse 

 age, namely, the quartzite at Eedstone, in the township of Courtland, 

 between the town of the same name and New Ulm, and the quartzite con- 

 glomerate seen near New Ulm. 



Eeference of the Eedstone quartzite to the "Huronian" or to the "Pots- 

 dam" is not definite enough, and even the term Sioux quartzite, though 

 undoubtedly applicable, is not such as to preclude the use of a term of 

 narrower definition. I propose therefore to use the formational name 

 Courtland quartzite here, with the understanding that the type locality 

 is the Eedstone near New Ulm. The name New Ulm will apply to the 

 quartzite seen opposite that city. 



Considering the Courtland quartzite, this formation at Eedstone has 

 been displaced and then profoundly eroded; so that the surface, which 

 rises in a series of exposed scarjjs and soil-covered terraces from the river 

 to the summit of the hill, is estimated to cross some 300 feet of strata in 

 150 feet elevation. The northern part of the area shows the lesser dip, 

 and the southern side of the area shows the greater dip, so that in crossing 

 it from north to south the general impression to me is that of approaching 

 a great fault from the downthrow side. 



C. W. Hall (10, page 22) finds, from an average of many observations 

 in diverse places, that "the strike of the quartzites is north 60 degrees to 

 70 degrees west, and the dip varies from 5 degrees to 27 degrees north." 



