12 



ON THE FRESH-WATER GLACIAL DRIFT 



Local Sections and Details. 



The profiles I have made or have been able to procure, show much local variety, 

 but at the same time a general correspondence. As most of them exhibit the three 

 members above described in general terms, I present them here under a separate 

 head. One of the first characteristics, and one which demonstrates the unity of the 

 fresh water drift of the northwest, is the presence of buried timber, roots, leaves, 

 and vegetable matter. Mr. Lesquereux, who has examined many of my speci- 

 mens, is positive that none of them were deposited from salt water. There is no 

 instance of a marine shell among those of my collection. 



The timber, as will be seen, is similar throughout the formation, and thus becomes 

 of palseontological value, as well as the shells. The vegetation entombed in the 

 drift extends to aU its members. It will be seen that only the vegetation of the 

 present era in northern latitudes is represented. There must have been growing 

 contemporaneously with the drift movement, or prior to it, the same trees that now 

 flourish in northern climates. 



Among the exhumed trunks, the white cedar is most abundant ; but there are 

 also pine, spruce, willow, and other varieties not fully determined. Most of the 

 bones of the mastodon and elephant found within the limits of my observations, 

 belong to the alluvion or to the modified valley drift, but there are also cases where 

 these relics are found in the true glacial drift. I shall show, before I close, that 

 the drift period graduated into the alluvion so gently that it is difficult to draw the 

 dividinar line. 



Drift Sections. 



Artesian Well, Columbus, Ohio. 



Surface 215 feet above Lake Erie and 780 above tide. 



. 1. Soil ........ 4 feet. 



2. Sand, gravel, and boulders . . . . . .10 



3. Coarse sand . . . . . . .2 



4. Blue clay and ooulders . . . . . .4 



5. Fine quick sand . . . . . . .2 



6. Blue clay (inclosing a log) . . . . . 1*7 



7. Hardpan ........ 3 



8. Quick sand . . . . . ^ .1 foot, 



9. Hardpan to cliff limestone . . . . . . 3Y feet. 



80 " 



Coventry, Summit County, Ohio. 

 544 feet above Lake Erie, and 1109 feet above the ocean. (By Dr. Neice.) 



1. Yellow sand and clay . . . . . .22 feet. 



2. Blue clay and sand . . . . . . 12 " 



3. Gravel and small boulders . . . . . . 4 " 



4. Muck and branches of trees from which specimen No. 2, of cata- 



logue was taken . .... 4 " 



5. Gray sand . . . . . ) 



6. Coarse gravel with a great variety of pebbles > . . . 23 " 



7. Sand and gravel .... J — 



65 " 



