The Saint Peter Sandstone. 



87 



sandstone as orig^inally deposited in an almost chemically 

 pure condition. One argument against this view lies in the 

 peculiar preservation of its fossils. Again a fair degree of 

 purity is generally found, and all the exposed portions of the 

 formation alike exhibit the conditions necessary for the theo- 

 retical origin that has been pointed out. Still it remains 

 that this formation is unique among the Mississippi valley 

 sandstones of Eopaleozoic time. 



BIBLIOGRAPHY. 



Johnathan Carver. Travels in North America, pp. 63 and 100. 



Stephen H. Long. Voyage to the Falls of St. Anthony. 



H. R. Schoolcraft. 



William Keating. Narrative of an Expedition to the Saint Pe- 

 ter's River, vol. i. 



David Dale Owen. Rep. on Geol. Explorationof Iowa, Wiscon- 

 sin, and Illinois, p. 20. and 



John Locke's Rep. in same, pp. 154-155, pi. 19, fig. 2. 



David Dale Owen. Geol. Sur. Wisconsin, Iowa, and Minnesota, 

 p. 165. 



James Hall and J. D. Whitney. Geol. of Iowa, vol. i, pt. i, pp. 

 52 and 338. ' 



James Hall. Geol. of Wisconsin, vol. i, p. 28, and 



S. D. Whitney. Geol. of Wisconsin, vol. i, p. 151. 



James Hall. 16th Am. Rep. of N. York State Museum, p. 120. 



A. H. Worthen. Geol. of Illinois, vol. i, p. 149. 



J. D. Whitney. Geol. of Illinois, vol. i, p. 164. 



H. C. Freeman. Geol, of Illinois, vol. 3, p. 279, 



N. H. Winchell. Geol. Nat. Hist. Sur. Minn., 1st Ann. Rep., pp. 38 

 and 88. 



N. H. Winchell. Geol. Nat. Hist. Sur. Minn., 2d Ann. Rep., p. 132. 



N. H. Winchell. Geol. Nat. Hist. Sur. Minn., 4th Ann. Rep., p. 41. 



M. W. Harrington. Geol. Nat. Hist. Sur. Minn., 4th Aim. Rep., 

 pp. 88 and 97. 



N. H. Wiuchell, Geol. Nat. Hist. Sur. Minn., 5th Ann. Rep., pp. 

 25 and 145. 



N. H, Winchell. Geol.Nat.Hist.Sur.Minn.,6th Ann.Rep., p. 77. 



T. C. Chamberlin. Geol. of Wisconsin, vol. 2, p. 285. 



R. D. Irving. Geol. of Wisconsin, vol. 2, p. 555. 



Moses Strong. Geol. of Wisconsin, vol. 4, p. 81. 



L. C. Wooster. Geol. of Wisconsin, vol. 4, p. 129. 



T. C. Chamberlin. Geol. of Wisconsin, vol. 4, p. 509. 



T. C. Chamberlin. Geol. of Wisconsin, vol. i, p. 145 and Atlas. 



N. H. Winchell. Geol. Nat. Hist. Sur. Minnesota, Final Rep., 

 vol. 1. 



