St. Peter's Sandstone. 115 



THE ST. PETER'S SANDSTONE. 

 By Joseph F. James, M. Sc., F. G. S. A., Etc. 



INTRODUCTION. 



In all geological investigations, rocks of any particular 

 formation are noticed long previous to their differentiation 

 under a distinct name. The reason is that observations are 

 made by explorers and travelers in different portions of the 

 country before the adoption of any definite system of nomen- 

 clature, and facts are recorded without a reference of the 

 rocks to any special horizon. Therefore, although the St. 

 Peter's sandstone is unknown as a formation with a distinct 

 name in the geological column prior to 1847, references were 

 made to it years previously. 



The first reference to, and description of, rocks now known 

 as the St. Peter's sandstone is given by Captain Jonathan 

 Carver, in his travels through the interior parts of North 

 America, in 1766-67-68. In this volume (p. 63) he gives an 

 account of a cave visited by him, now known by the name of 

 Carver's Cave. It is situated about thirty miles below 

 the Falls of St. Anthony, and is an excavation in the St. 

 Peter's sandstone. Carver found the stone so soft that it 

 could be cut with a knife, and the walls of the cave were 

 carved with Indian hieroglyphics. He also states that a little 

 way from the mouth of the St. Peter's River is a hill com- 

 posed entirely of white stone, the outer part of which crum- 

 bles into heaps of sand through the action of the weather.* 

 This, also, is St. Peter's sandstone. 



In 1817, Major Stephen H. Long visited the Falls of St. 

 Anthony, and in hjs book he gives an account of the forma- 

 tions observed by him in Minnesota. One of these was a 

 white or yellowish sandstone, which crumbled so easily as to 

 deserve the name of sandbank rather than that of sandstone. 



* Ibid, pp. 100, 101. 



