WATER DEPOSITS 667 



List of Samples in Table 10 



101. Alluvium, east of Davenport, Iowa. 



102. From the bottom of the Mississippi River during a flood, Buffalo, Iowa. 



103. Recent alluvium from the Mississippi River, Rock Island, Illinois. 



104. From the bottom of the Mississippi River during a flood, Buffalo, Iowa. 



Lahe deposits. — Deposits formed in lakes are very scantily repre- 

 sented. In six beach sands from Lake Michigan it will be noted that 

 the sorting out of all but three grades has been effected in three samples, 

 and that in the other samples the quantities in the next distant grades 

 are very small. Beach material is nearty always well sorted. Some re- 

 cent lake silts have about the same composition as river silts. Another 

 lake silt is a deposit in a glacial lake and is characterized by having a 

 notable excess of medium clay and fine clay in the silt. This clay is 

 probably derived from so-called "glacial milk." In common with other 

 silts, these show a quite uniform sorting in different samples and in 

 comparison with beach sand a much less perfect sorting, for no less than 

 eight grades in each of these silts contain more than 1 per cent of the 

 whole sample. 



List of Samples in Tahle 11 



105. Sand from the beach of Lake Michigan, lyiichigan City, Indiana. 



106. Sand from the beach of Lake Michigan, Michigan City, Indiana. 



107. Sand from the beach of Lake Michigan, Michigan City, Indiana. 



108. Sand from the beach of Lake Michigan, Michigan City, Indiana. 



109. Sand from the beach of Lake Michigan, Michigan City, Indiana. 



110. Sand from the beach of Lake Michigan, Michigan City, Indiana. 



List of Samples in Table 12 



111. Deposit of clay on the bottom of Eau Claire Lake, Douglas County, Wis- 



consin. 



112. Deposit of clay in Eau Claire Lake, Douglas County, Wisconsin. 



113. "Red clay," of glacial origin, near Amminicon, Wisconsin. 



Deposits in the sea — Classification. — Through the kindness of the 

 curator of the United States National Museum, the author has secured 

 some samples of marine sediments taken by various scientific expedi- 

 tions that have been engaged in deep dredging in the Pacific as well as 

 in the Atlantic. To the collection of such dredgings have been added 

 some samples of material collected on sea beaches and some specimens of 

 mud collected from anchors on various vessels. It seems most profitable 

 to classify these marine sediments into the following divisions: 



