In the base of this bluff along the road to Quincy -- the bluff probably marks the end of the Mississippi's floodplain -- are large chambers used to store things. This entrance to this one is small compared to others farther upstream.
The bluish material in the bin is primarily zinc sulfate, a
byproduct of galvanizing steel. Another fellow with a front
end loader appeared now and then, picked up a scoop of the stuff, and
carried it into the cave. The fellow squatting and having a smoke is
the truck driver who has carried this load from Georgia. He told
me he tries to keep his distance from the stuff. If he gets too
close to it, he tends to get flu-like symptoms. He says the stuff
is used in all sorts of things, including animal feed.
When I passed the openings of other "caves," farther upstream, I was
blasted by very cold air, sometimes carrying powdery dust.
