Cincinnati Society of Natural History. 



mation he afterward described under the name of St. Peter's 

 sandstone. 



The first mention of the term St. Peter's, as applied to a 

 geological formation, was made by Dr. D. D. Owen, in 1847. :: 



After referring to the formations of the Upper Mississippi, 

 it is stated that in some high situations, as near Lake St. 

 Croix, the strata are surmounted "by soft white sandstone, 

 capped with shell limestones, such as form the upper portions 

 of the hills on the Wisconsin River, near Prairie du Chien, 

 and constitute the whole of the escarpment of the St. Peter's 

 falls, as well as the bluffs on both sides of the Mississippi, 

 from thence to Carver's Cave and St. Pauls; and, therefore, 

 sometimes alluded to by us under the local name of the St. 

 Peter's formation. "f Thus, no specific description of the 

 formation is given in this, the first place of reference. That 

 this is the formation in question, however, there can be no 

 doubt, inasmuch as in the following year the strata were 

 described, and in 1852 the name St. Peter's was definitely 

 adopted. 



In the report of Dr. Owen, published in 1848,+ this forma- 

 tion is called " F. 2 c." It is superimposed on the Lower 

 Magnesian limestone, and is the rock which forms the base of 

 the bluffs at St. Peter's, and likewise the lower nineteen feet 

 of the Falls of St. Anthony, It is said to be remarkable for 

 its whiteness, and to be made up of grains of limpid and 

 colorless quartz. " It appears to be destitute of organic 

 remains; at least none have as yet come to light. In the 

 absence of these, it is difficult to say whether it ought to be 

 considered as the terminating member of F. 2, or the inferior 

 member of F. 3. Since, however, it appears to have been 

 produced by a repetition of sedimentary action, similar to 

 that which occurred just at the commencement of F. 2, I 

 have thought it best to place it, for the present, as the ter- 

 minating mass of that formation." || In the series of sections 



-Preliminary report of Progress of the Geological Survey of Wisconsin and 

 Iowa up to October nth, 1847. U. S. Land Office Report for 1847, pp, 160-173. 3 0t h 

 Cong., 1st Sess., S. Ex. Doc, No. 2. 



f Ibid, p. 169. 



|On a geological reconnoissance of the Chippewa land district of Wisconsin, 

 and the northern part of Iowa, 1848. 

 || Ibid, p. 28. 



