528 THE GEOLOGY OF MINNESOTA. 



[Terminal moraines. Wells, 



extreme limit reached by the ice in the last glacial epoch is marked by the 

 western of these terminal moraines, which forms the summit of the Coteau 

 des Prairies. This morainic belt is intersected in southern Nobles county 

 by lake Ocheeda and Ocheyedan creek, and in southwestern Murray county 

 by Chanarambie creek. A smooth expanse of till, from ten to twenty-five 

 miles wide, intervenes between this and the eastern moraine, which has a 

 course approximately parallel with the preceding. The second moraine 

 marks the limit of the ice during a pause in its recession, the genial climate 

 before which it had retreated being changed to one of severe cold again, 

 when the ice-border, probably after some re-advance, was maintained 

 steadily at this line during a long time. 



In an earlier part of the glacial period a more extensive ice-sheet had 

 overspread all this region, and reached far to the south into Nebraska, 

 Kansas and Missouri, and its thick deposit of till continues beyond the 

 farthest boundary attained by the last ice-sheet. The depth of the drift 

 in the west part of Nobles county and farther westward, outside of these 

 moraines, and certain features of the region included by them, as the 

 remarkable chains of lakes in Martin county, prove that the greater part 

 of the drift in this state was deposited by the ice of this earlier epoch. 



Wells in Murray county. 



Sections of the drift deposits of Murray county have been observed in well-digging as follows: 



Holly. Daniel E. Way; S. W. J- of sec. 10: well, 20 feet; soil, 2 feet; yellow till, 17 feet, 

 spaded, except its last five feet which were picked; much harder blue till, 1 foot, and extending 

 lower; water filled the well six feet deep in one day, from a thin gravelly vein at the depth of 14 

 feet. 



Des Moines River. A. H. Twiss; N. E. J of sec. 10: well, 42 feet, dug 32 feet and then bored 

 10 feet; soil, 2; yellow till, all of it so hard that it had to be picked, containing many small pebbles, 

 but none larger than six inches in diameter, 39 feet; blue till, very tenaceous, but not harder than 

 the yellow till, 1 foot and more. Water rose to six feet below the surface in a half day, and stands 

 there permanently. No layer of gravel or sand was found, and the well continued dry about one 

 day after the boring was finished; then water broke into the well and rose rapidly as stated. This 

 is the greatest thickness of yellow till learned of in Murray county. 



Shetek. D. C. Greenman; sec. 20: well, 35 feet; soil, 3 feet; yellowish till, 25 feet: yellowish 

 and darker gray till, interbedded, moister and softer than above, and including sandy streaks, 

 7 feet; from this lower part of the well water rose ten feet in one day. 



D. J. Turner; sec. 26: well, 41 feet; soil, 2; yellow till, 37; harder blue till, 2 feet and reach- 

 ing lower; water rose nine feet in two hours, and thirty feet, to its permanent level, in the first 

 day, from sandy streaks in the last ten feet. 



Murray. F. H. Barrows; sec. 29: well, 18 feet; soil, 2; yellow till, spaded, 16 feet; water comes 

 from sandy streaks, mostly at 12 feet. 



At Currie and in its vicinity the wells are from 10 to 20 feet deep, in till. No wood nor shells 

 have been found in well-digging in this region; but small fragments of lignite occur frequently. 



Lime Lake. At Avoca the Lincoln hotel has a well 96 feet deep, which was soil, 2 feet; 



