86 THE GEOLOGY OF MINNESOTA. 



[Woods, 1849. 



of Formation 1, more or less altered by metamorphism "where they abut upon 

 the igneous rocks." He also notes conglomerate and granite outcrops about 

 a mile in a straight line above the mouth of the Waraju. He mentions 

 granite at La Petite Roche, and at frequent other points before reaching the 

 Redwood river. He describes an interesting exposure two or three miles 

 below the mouth of this river, probably the same as that described by 

 Keating and by Beltrami. 



Mr. Shumard also gives the details of local sections on the upper Mis- 

 sissippi in Minnesota and Wisconsin, beginning with the falls of St. 

 Anthony, and on the Wisconsin and Baraboo rivers, as well as observations 

 on the sandstones, conglomerates and trap-rocks of Snake and Kettle rivers. 

 On the Snake and Kettle rivers he made collections of a peculiar green 

 mineral from the amygdaloids, which at first was soft as tallow but on 

 exposure became brittle. It was analyzed by Dr. Owen and regarded as 

 new,* but resembling phillipsite from Iceland, being really a " magnesian 

 harmotome." 



MAJOE WOODS' EXPEDITION TO PEMBINA. 



In the summer of 1849, Major S. Woods was despatched by the Secre- 

 tary ot War to the Pembina settlement for the purpose of selecting a site 

 for a military post. His reportf is not accompanied by any map, although 

 Capt. John Pope states he prepared a map of the route. He proceeded from 

 Fort Snelling to Sauk Rapids, along the east side of the Mississippi, a route 

 well known and traveled at that time every summer by large "trains" of 

 carts from the Red River settlements. Passing up the Sauk valley, on the 

 north side of the river, the expedition crossed it at the great bend, and 

 reached lake David, which is described as having a length north and south 

 and draining into a branch of Crow river, twelve miles west of the great 

 bend of the Sauk river. Seven or eight miles from lake David is lake 

 Henrie, of about the same size. Lightning lake, is about seven miles from 

 the point at which the trail crossed the branch of Crow river, so named 

 from the incident of a terrific thunder-storm in which Lieut. Nelson's life 

 was nearly lost by lightning striking his tent-pole. Fourteen miles further 



Jour. PMl. Acad. Science, (1), II. 183. 

 tHouae Ex. Doc. No. 51, 1st Sew. 31st Cong. 



