This is one of the more obscure images ever posted on this blog.
This was observed in a location under roof of an extensive metal building in which a great deal of farm equipment is housed.
The owner is distraught to find that the entire floor of gravel from a local quarry looks as if it has been strewn with popcorn or crispy cottage cheese or cat puke. It is not a like powdery chalky discoloration of the gravel but is so dense as to totally obscure the rock from view in most places.
I’d guess it’s a calcium salt precipitate and that maybe there is more limestone in this particular gravel source in the county, which I thought was more generally quartz-granite derived.
So help me here, geology and soil chemistry types. Not sure that anything can be done to solve this farmer’s issues with corrosion, but I’d sort of like to better know what’s going on.