The crystalline limestones of the Grenville series in the vicinity of Kingston are similar to those in other parts of eastern Ontario and in the Adirondacks. They consist of pure and dolomitic limestones. Practically all of them contain small quantities of noncarbonate minerals. Some of these are magnesian silicates which probably derive their magnesium content from the original dolomite of the limestone. Some of the noncarbonate constituents evidently were formed by additions of certain constituents from the abundant intrusives. Garnet apparently did not form commonly in the limestone because of deficiency of alumina and possibly of manganese.
Quartzites are interbedded with the limestones. Foreign material is much less abundant in them, as the quartz of the original sandstones was no doubt much more inert chemically than was the carbonate of the limestone.