BUILDING STONES. 165 



Dotomilic limestones.] 



the Mantorville dolomite (No. 20) are very fine, and not distinctly angular. In Kos. 22 and 24, are 

 occasional crystals of pyrite, and traces of organic forms. The grains also of Nos. 22 and 24, 

 are less defined, the mass appearing more like a hardened calcareous pulp. In No. 25 there is a 

 sprinkling of fine quartz particles, and the section has a yellowish, serpentinous aspect. No. 22 

 is illustrated in fig. 3, plate C. When rotated with only one Nicol in use. very distinct cleavage- 

 lines are made visible in the large central grain ( x 250). The grain itself consists of numerous 

 crystalline parts, each witli its own cleavage lines. 



The quarries at Kasota, opened in 1868, are owned by Brackenridge, 

 Stewart and Buttars, and by J. W. Babcock. The former is operated by 

 Messrs. Breen and Young. From the quarry of Brackenridge, Stewart and 

 Buttars has been taken the greater portion of the pinkish stone which is 

 characteristically known as the Kasota stone, and which was described as 

 fawn-colored by G. W. Featherstonhaugh. 



Further up the Bois Franc district, a stream comes in from the left bank called Wee-tali 

 Wakatah, or Tall island, and about five miles higher up some ledges of horizontal fawn-colored 

 limestone jut out on the right bank, very cherty and somewhat vesicular ; near the surface it takes 

 a reddish salmon-color, resembling very much some beds I had previously seen on the Wisconsin 

 and upper Mississippi. Within a few yards of these ledges and north of them, a beautiful pel- 

 lucid stream conies in, containing the purest water I had seen in the country. I could not 

 learn that any name had been given to it, and as it is in the immediate vicinity of the first 

 calcareous rock I had met with in place here, and its purity rendering it a very rare stream in a 

 country where all are turbid, I named it Abert's run, after Col. Abert, of the United States army, 

 and chief of the topographical bureau.* 



The quarry of Mr. Babcock, however, furnishes the same stone, but in 

 less abundance, the staining of the natural beds having been carried on at 

 different points with different degrees of color. Indeed the same beds, as 

 they extend north and south from Kasota are generally not so colored, but 

 rather have the usual buff color ot a magnesian limestone, similar to the 

 St. Lawrence. The greater change of color at Kasota is probably due to 

 some local conformation of the country at the time the Minnesota river 

 constantly flooded the terrace in which it is quarried, by which the rock 

 abstracted from the water there more of the coloring ingredients (probably 

 iron and perhaps some manganese) than elsewhere. A sandstone which 

 seems to be the St. Peter is stained in the same way a short distance above 

 Fort Snelling, in the Minnesota valley, giving it a rusty pink color, and at 

 the same time greater tenacity and endurance under pressure. The bed- 

 ding varies from a few inches to two and a half feet in thickness. Toward 

 the bottom of the quarry the regularity of the strata is disturbed by dish- 

 shaped contortions upward and downward. 



*Report of a geological reconnoif sauce made in 1835, from the seat of government by the way of Green bay and the Wiscon- 

 sin territory to the Cuteau des Prairies, p. 39. It has already been stated (p. 59.) that the description of Mr. Keatherstonhaugh 

 may have been applied to the outcrop at Rocky point, though Abert'fl run cannot there be identified. 



