20 PROCEEDINGS OP THE ALBANY MEETING 



I. C. Eussell, who had committed himself in favor of the chemical 

 precipitation of these deposits, with characteristic candor and generosity 

 accepted the results of Davis' work, got him to take the summer-school 

 work at Ann Arbor in 1900 and 1901, had his company in the Upper 

 Peninsula, and showed more affection than his habitually reserved, if not 

 shy, nature often permitted. Davis had a way of winning affection. 



The following letters from the files of the Michigan Geological Survey 

 illustrate his first relations with Ann Arbor and the problem of the 

 "marl" : 



{Geological Survey Letters — Michigan)'^ 



"Alma, Michigan, May 28, 1900. 

 "I made a trip Saturday to Littlefield Lake, Gilmore township, Isabella 

 County. It is a remarkable body of very fine marl, exceedingly white and fine, 

 and of great extent. The lake is said to be about seven miles around, follow- 

 ing the shoreline, and the exposed marl beach at low water would average 

 from 12 to 20 feet wide around the entire lake, and runs from 22 to 35 feet 

 deep in this entire area. Besides this exposed tract there are a number of 

 large points covered with defunct cedar swamps, one of which has 33 and 

 another about 40 acres in it, in which the average of about 20 holes gave 20% 

 feet as the depth. There are also three islands aggregating 10 acres in area 

 of solid marl, which runs about 27 feet deep — more rather than less. There 

 are several interesting features about the lake ; but the most interesting one is 

 the six daughter lakes formed by the development of marl points, which have 

 gradually reached out and cut off the parts of the lake which lay between 

 them. There are at least two of these lakelets in advanced stages of forma- 

 tion and the genesis of the older ones is very apparent. Another interesting 

 thing is the fact that the marl islands are evidently built up on sand shoals 

 about 30 feet below the surface,3 for while the bottom was more than 40 feet 

 deep otf the islands we struck sand at about 30 feet on the edges of the islands 

 and at about 27 or less in the middle. I did not have any sounding lines, so 

 could not take measurement across the lake, but it was said to be above 60 

 feet deep between the larger island and the shore and more than 80 feet in the 

 wider part. Another notable thing was the absence of any deep muck and of 

 muck-forming vegetation. Another, the very steep slope of the marl ; often the 

 dip of the banks was apparently 80 or 85 degrees, and on the island near the 

 foot of the lake the marl was washing across the submerged beach and drifting 

 by the combined wave and current action, so that it made almost a perpen- 

 dicular wall into deep water. Best of all, so far as my own work is concerned, 

 the deposit is, beyond dispute, a plant-formed marl throughout. Chara is 

 everywhere present and heavily incrusted, loaded in fact, and on the beach the 

 'sand' is broken fragments of that plant; the finer particles, where any struc- 

 ture is visible, are easily identified as the same substance. The other marl- 



2 I am obliged to mj' successor, R. C. Allen, for the use of letters from the Michigan 

 Geological Survey files. 



3 1 have seen a marl atoll that would have delighted Murray's heart. — A. C. Ij. 



