HISTORICAL SKETCH. 33 



1823, Keating.] 



SCHOOLCRAFT AT LITTLE FALLS AND 8AUK RAPIDS. 



In descending the Mississippi below the Pakagama, the first stratum of rock, which 

 rises through the delta of the river, occurs between the mouth of the Nokasippi and Elm rivers 

 below the influx of the Great De Corbeau. This rock, which is greenstone trap, rises conspic- 

 uously in the bed of the stream in a rocky isle seated in the rapid called I know not with what 

 propriety the BIG FALLS or Grand Chute. The precipitous and angular falls of this striking 

 object decide that the bed of the stream is at this point on the igneous, granitical and greenstone 

 series. This formation is seen at a few points above the water, until we pass some bold and 

 striking eminences of shining and highly crystalline hornblendic sienite, which rises in the eleva- 

 tion called by us Peace Rock, on the left bank near the Osaukis rapids. This rock lies directly 

 opposite to the principal encampment on the 27th of July, which was on an elevated prairie on the 

 west bank. To this point a delegation of Sioux had ascended on an embassy of peace from Fort 

 Snelling to the Chippewas, having affixed on a pole what the exploring party called a bark letter, 

 the ideas being represented symbolically by a species of picture writing or hieroglyphics. In allu- 

 sion to this embassy, this locality was called the Peace Rock. This rock is sienite. It is highly 

 crystalline, and extends several miles. Its position must be, from the best accounts, in north 

 latitude 44 30'. From this point to Rum river, a distance of seventy miles, no other point of 

 the intrusion of this formation above the prairie soil was observed. 



The rock at the falls of St. Anthony Mr. Schoolcraft regards as belong- 

 ing "to the great carboniferous and metalliferous formations, which for so 

 great a length, and in so striking a manner characterize both banks of the 

 Mississippi below St. Anthony falls." The white sandstone at the falls is 

 said to be overlain by the "metalliferous limestone." The grains of sand- 

 rock are held together by "the cohesion of aggregation," and embrace, 

 sparingly, "orbicular masses of hornblende." The overlying limestone is 

 the "same in character, which assumes at some points a siliceous, and at 

 others a magnesian character. It is manifestly the same great metalliferous 

 rock which accompanies the lead ore of Missouri and mines of Peosta or 

 Dubuque." Eeferring to Chimney and Castle rocks, in Dakota county, Mr. 

 Schoolcraft thinks they are the result of degradation and wasting away, on 

 the Huttonian theory, of all but these, probably harder, portions of the strata. 



KEATING'S NARRATIVE OP MAJOR LONG'S EXPEDITION IN 1823, TO THE SOURCE 



OF THE ST. PETER RIVER. 



Major S. H. Long, who had, in 1817, visited the falls of St. Anthony, was 

 directed by the United States Secretary of War, in 1823, to conduct a party 

 of exploration to the source of the St. Peter river, and to lake Winnipeg. 

 He was accompanied by a number of scientific gentlemen of Philadelphia, 

 including Prof. William Keating of the University of Pennsylvania, who 

 embodied the notes and manuscripts of the various members of the party, 



