46 Lake Maxinkiickee, Physical and Biological Survey 



little gravel along the east side of Long Point, and between the 

 Kettlehole and the shore. The Sugarloaf appears to be made up 

 largely of gravel. Dredging on the north and south sides of it re- 

 vealed considerable gravel ranging up to the size of hen eggs. This 

 gravel was usually not round but rough and angular. Doubtless 

 there is much gravel in the lake bed that is not apparent, it is so 

 mixed with or covered by sand or other fine material. 



Boulders: — There are not many boulders on the lake bottom. 

 There are a few on the north end and a few scattered ones on the 

 east side and south end. The more or less mythical "split-rock", 

 of which some of the older fishermen and boatmen speak, is said 

 to be somewhere in the south end of the lake, perhaps near the 

 Flatiron or the Weedpatch bars. Although we made frequent 

 search for this alleged rock, and asked many people about it, we 

 never succeeded in finding it, or, in fact, in finding but two men 

 who claim to have seen it. It must therefore remain as one of the 

 mysteries of Maxinkuckee. 



Marl: — The most interesting and important component of the 

 lake-bed is marl. The hard compact sandy bed usually extends 

 out to a depth of but a few feet — on the west side from 2 to 4 

 feet, on the east to a somewhat greater depth. Beyond this border 

 of hard bottom the marl begins. The depth to which it extends 

 varies considerably. Off Long Point it is first met in water about 

 2 feet deep. On the north and east the depth is usually greater, 

 and in some places is as much as 6 to 8 feet. From these depths 

 the marl extends inward and covers practically all the lake bed. 

 It is most evident on the bars, but is present everywhere. The 

 thickness of the marl bed varies considerably. Along the outer 

 edge it probably nowhere exceeds 6 or 8 feet in thickness. In 

 deeper water and on the bars it is probably thicker. The greatest 

 thickness determined by us was about 22 feet which was in the 

 southern part of the lake, off the Gravelpit. The color and purity 

 of the marl seem to vary in different parts of the lake. It appears 

 to be composed chiefly of calcium carbonate mixed with more or 

 less decaying vegetable matter and fine sand of aeolian origin. 

 Samples from the surface are usually quite dark; those from 

 deeper in the bed are much lighter in color. The color and purity 

 are doubtless related to the amount of decaying vegetable matter 

 present. Analyses of several examples of marl from different 

 parts of the lake were made by Dr. Wm. A. Noyes, formerly of 

 the Rose Polytechnic Institute, now of the University of Illinois, 

 with the following results: 



