BROWN AND REDWOOD COUNTIES. 573 



Cretaceous beds. ] 



34 North Star. The upper part of this bank, which is about 20 feet high, consists of alluvial 

 sand and gravel, a few feet thick. The section of the Cretaceous beds below, as recorded by 

 Eames, in the report of his survey as state geologist in 1866, is, first, iron ore, much broken; then, 

 marly shale, 3 feet; impure lignite, 2J feet; and dark shale to the bed of the river, 10 feet. The 

 third of these beds is a black, lignitic shale, enclosing a thickness of about four inches of quite 



clear lignite. 



A quarter of a mile south from this outcrop, a shaft was sunk to explore for coal, a year or 

 two before the date of Mr. Eames' report. lie described the section below the drift as follows: 



"1. Bands of ironstone, and crystals of selenite enclosed in shale, with a seam 



of imperfect coal 13 feet. 



2. Yellow sandstone 3 feet. 



3. Dark colored clay (siliceous), containing iron pyrites, argillaceous iron 



and sandstone alternating 64 feet.'' 



"The clay in this formation is well adapted for refractory brick and the manufacture of 



pottery ware." 



Later exploration for coal was made in 1875 and again in 1878, by shafts 40 or 50 feet deep, 

 on the north side of the river near the point where the lignite is found in the river-bank, as before 

 described. These encountered a layer of lignite, a few inches thick, at about the same level with 

 its outcrop beside the river. 



About two miles below this locality, and nearly a mile southwest from Springfield station, 

 the north bank of the Cottonwood river in the N. E. } of section 25, North Star, contains the fol- 

 lowing beds, according to Eames: 



" 1. Shaly marl 3 feet. 



2. Impure coal 2 feet. 



3. Sandstone, to bed of river, partially covered by talus 5 feet." 



This sandstone, some portions of which are richly fossiliferous, is exposed along a distance 



of four or five rods, and has been somewhat quarried. A specimen of it, showing very distinct 

 impressions of leaves, and another containing numerous easts of shells, have been presented to the 

 survey by Mr. John F. Burns. A complete leaf is shown, 5 inches long and | inch wide, lanceo- 

 late, entire, tapering into a short petiole. This has been identifk d by Dr. Leo Lesquereux as 

 Lauras Nebrascensis, Lesq. He also reports with this Salix proteaifolia, Lesq., and a new species 

 of Ficus. 



Three miles farther down the stream, its north bank in section 16, Burnstown, has a similar 

 exposure of rock, described by Eames as "buff and gray sandstone, thinly laminated, ten feet in 

 thickness, descending to the bed of the river; it contains stems and leaves of plants, but t o much 

 broken to decide either character or class." 



The next localities where outcrops of Cretaceous beds are known to occur on the Cott6n- 

 wood river, are in Sigel and Milford, about eight miles, and again about five miles, west from 

 New Ulm. Sandstone of yellowish, iron-rusty color, nearly level in stratification, partly friable, 

 but containing hard layers up to one foot in thickness, exposed along a distance of several rods and 

 rising 5 to 10 feet above the river, is reported at two points in the south bank, about sixty rods 

 apart, in the N. E. J of section 6, Sigel. Above the rock-outcrops the wooded bluffs, probably 

 consisting of till, rise about 100 feet. 



In the N. W. \ of section 3, at the south side of Milford, the north bank of the Cottonwood 

 river has a bight of 60 or 70 feet, and exhibits the following section: yellow till, about 15 feet; 

 gray sandstone, containing lignitic particles, only one foot in thickness exposed; and dark, bluish 

 clay, free from gravel or grit, but in some parts enclosing specks and small lumps of iron p} r rites, 

 which render it unfit for the manufacture of pottery, having a thickness of 25 feet clearly 

 exposed; below which the remaining 25 feet of the bluff is concealed by the talus. Prom the 

 wooded south bluff, in Sigel, a sixth of a mile farther southeast, but probably within the same 

 quarter-section, clay nearly like the foregoing has been much excavated for use by the potters at 

 New Ulm and formerly at Mankato. This clay is very fine and uniform in character, containing 

 neither grit nor pyrites. It is dug between 40 and 60 feet above the river. These beds seem to 

 have no fossils. 



About a mile farther east, near the middle of section 35, Milford, the northern bank of the 

 Cottonwood river shows very fine, nearly white, crumbling sandstone, alternating with shale, 



