E. M. Kindle— Limestone Solution. 651 



Art. XL VII. — Limestone Solution on the Bottom of Lake 

 Ontario* ; by E. M. Kindle. 



The fishermen who set their nets in the deeper waters of 

 Lake Ontario very frequently bring to the surface in them, 

 slabs of limestone to which they apply the name " honeycomb 

 rock." This term of the fishermen has been suggested by the 

 extraordinary appearance of the surfaces of these specimens 

 which are deeply pitted by irregular cell-like cavities. This 

 peculiar pitted appearance is shared by every specimen of 

 limestone which has come under the writer's notice from the 

 deep waters of both Lake Ontario and Lake Huron. It is 

 clearly the result of aqueous solution in waters generally 100 

 feet or more in depth. All of the specimens seen appear to 

 indicate a much more powerful solvent action of the water at 

 the depths represented, than that which prevails at and near 

 the surface. A series of specimens secured during the last 

 field season from a depth of 150', 16 miles southwest of Presque 

 Isle, Lake Ontario, have suggested some of the factors in the 

 great effectiveness of fresh water in dissolving limestone at 

 considerable depths which it is proposed to consider in this 

 paper. 



It has been shown in an earlier paper by the authorf that 

 strong currents scour the bottom of Lake Ontario at irregular 

 intervals. It appears probable, that, while such currents are 

 in some deep-water zones depositing more material than they 

 remove, in others scour predominates over deposition. This 

 inequality results in considerable areas of limestone bottom in 

 Lake Ontario where little or no sediment has been permitted 

 by the currents to accumulate since the basin has been occupied 

 by the lake. One of these rock bottom areas lies southwest 

 of Brighton, Ontario, about 20 miles, under 150 to 200 feet of 

 water. This is an important fishing ground for Brighton 

 fishermen. 



Mr. E. J. Whittaker, my assistant, secured, during one visit 

 in a fishing boat to this area, more than a dozen slabs of the 

 "honeycomb rock" which came up entangled in the nets. 

 These vary from a few inches to nearly a foot in diameter and 

 represent remnants of detached strata of thin-bedded, non- 

 magnesian limestone. Every specimen is deeply and irregularly 

 etched. The cavities show every conceivable variety of outline 

 and shape. The individual pits will, perhaps, average three 

 fourths of an inch in depth, the walls of adjacent cells being 

 frequently broken by cavities connecting them. The deeper 



* Published with the permission of the Director of the Geological Survey 

 of Canada. * 



f This Journal (4), vol. xxxix, pp. 192-196, Feb., 1915. 



