W. J. McGee — Geology of the Mississippi Valley. 415 



many small fragments of wood, probably Eed Cedar (Junipenis 

 virginiana). Boulders were not reported in the yellow clay, but 

 were seen in it in the immediate vicinity by the writer. 



3. Artesian well at Mendota, Illinois. 



Surface soil 2 feet. 



Yellow clay, with boulders 12 ,, 



Gravel 2 or 3 inches 



Blue clay 75 „ 



Indurated and shaly blue clay 2 ,, 



Coarse reddish and yellow clay 69 „ 



Total 160 „ 



In a third well, at the same place, the layer of ancient peat 

 already mentioned was encountered. 



4. Near Cascade, Iowa. 



Clean light-yellow clay 6 feet. 



Pebbly ditto 1 „ 



Yellow clay, with boulders 13 „ 



Black sandy loam 1 ,, 



Clean blue clay 26 ,, 



Yellow sand, with boulders and pebbles 2 ,, 



Total 49 „ 



Wood was found in fragments on the surface, and in the ujrper 

 portion of the blue clay, in the black loam, and a little in the base 

 of the superincumbent yellow clay. Except for absence of member 

 number six, this is a typical section, and, besides, has the "forest 

 bed" in situ. 



Near Epworth, Iowa. 



Surface soil 



Sandy yellow clay, with boulders 



Clear blue clay, with small pebbles 



Clear, fine, white sand, laminated 



Coarse gravel, entirely free from clay 



1 feet. 



10 „ 



14 „ 



1 „ 



1 „ 



Total 



27 „ 



A sound log of Junipenis virginiana, 8 inches thick, extended 

 across the well at 20 feet from the surface, and was cut off at both 

 sides. 



6. In Dakota, Humboldt co., Iowa. 



Black soil 6 feet. 



Yellow sandy clay, with boulders and limestone pebbles 20 „ 



Clean blue clay 16 ,, 



Coarse gravel and sand, with water 1 „ 



Total 43 „ 



A stick (probably cedar) 2 feet long and 4 inches thick was found 

 30 feet beneath the surface. On reaching the water-bearing gravel, 

 the water rose 20 feet, and has ever since remained at the same level. 

 In a neighbouring well an upright trunk and branches of a tree 

 (probably Willow — Salix, sp. und.) were found below the yellow 

 clay. 



