244 GEOLOGY OF EASTERN WISCONSIN. 



Second Boring near river 



1. At 1 ft., fibrous, loose, dark. 



2. At 3 ft., layer of decomposed wood. 



3. At 3 ft. 6 in., clay as above. 

 Third Boring near center of marsh 



1. At 1 ft., dark, fine fibrous, soft, not well decomposed. 



2. At 3 ft. 6 in., less fibrous, reddish. 



3. At 5 ft. 9 in., clay as above. 



One of the more interesting of the smaller marshes is found in the W. hf . of sec. 30. 

 Beaver Dam (T. 11 N., R. 14 E.). There are perhaps 80 acres of available peat. It is 

 surrounded by timber and has no stream flowing through it, and was formerly a lake, as 

 shown by the shells of Sphserium, Paludina, and Helix, found in the underlying clay. At 

 8 rods from the edge, there were 4 feet of firm, dry, reddish, well decomposed peat, un- 

 derlaid by clay. Thirty rods from the edge, the following section was obtained: 



1. At 3 feet, firm peat struck; that above, soft. 



2. At 5 feet 6 inches, reddish, well decomposed peat. 



3. At 7 feet, firm, color of brown paper. 



4. At 12 feet, clay and peat mixed. 



At the centre of marsh : 



1. Upper portion as above. 



2. At 6 feet, firm, red, fairly decomposed, apparently derived from wood. 



3. At 12 feet (length of auger), bottom not reached; material muck resembling 



brown paper pulp; contained the shells mentioned above. 



In the town of Calamus (T. 11, R. 13 E.), N. W. qr. of sec. 25, and S. W. qr. of sec. 

 24, lies a marsh of 200 acres. A small stream flows through it. The following may 

 represent five borings of similar import: 



1. At 2 feet, well decomposed, firm, black. 



2. At 3 feet, well decomposed, firm, black. 



3. At 5 feet, well decomposed, firm, yellow. 



4. At 5 feet 9 inches, well decomposed, firm, color brown paper. 



5. At 7 feet, well decomposed, firm, color brown paper. 



6. Blue marly clay, containing shells. 



The peculiar brown material was found to be sandy in two of the borings. 

 In the town of Lake Mills, sees. 1 and 2, a large marsh, partially covered with tama- 

 rac, gave the following sections : 



First. Nine rods from the edge : 



1. At 4 feet, dark, well decomposed. 



2. At 7 feet 6 inches, dark, well decomposed. 



3. At 10 feet, reddish, woody, sandy. 



4. At 11 feet, sandy, blue clay. 



Second. Forty rods from the edge : 



12 feet of soft, wet, not well decomposed, dark, reddish, woody peat. 

 No evidence of sand; bottom not reached. 



Third. Nearer the edge : 



1. At 6 feet, firm, half decomposed, dark reddish, woody fiber. 



2. At 10 feet, dark, well decomposed, firm, apparently excellent. 



3. At 12 feet, sandy; bottom not reached. 



As an example of the greater depth in tamarac marshes, I may give the section ob- 



