ewest, you are correct of course.
The limestone quarries of the midwest are mining the dolomite limestone and break it up into various graded sizes. The smallest pieces and powders from the crushing is what is used as Ag lime here. It is the sheer surface area exposed of the pulverized/crushed by-product that makes it more readily available to reaction as a soil amendment. Except for size, road rock and ag lime are one in the same around here.
